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FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Extraction of free aroma compounds of the apricot (Prunus armeniaca)
by different techniques
Solís-Solís 1 H. M., Calderón-Santoyo 1 M., Galindo 2 S., Rodríguez-Cervantes 1 C. H.
and Ragazzo-Sánchez 1 J. A.
1Laboratorio
de Investigación en Alimentos, Instituto Tecnológico de Tepic, Av. Tecnológico No. 2595,
Tepic, Nayarit. C.P. 63175.
ragazzo@ittepic.edu.mx
2
Laboratoire de GBSA, Université de Montpellier II, Place E. Bataillon, 34095 Montpellier. Cedex 5,
France.
ABSTRACT: Presently work eight varieties of apricot were analyzed using four different extraction
techniques; simultaneous distillation extraction (SDE), reverse phase chromatography (C18), liquidliquid
extraction (L-L) and solid phase microextraction (SPME). The aroma compound (AC) were
identified with GC-MS, finding β-ionone, phenyl acetaldehyde, linalool, β-cyclocitral, and γdecalactone.
The results were compared with ANOVA, finding a significant effect in the techniques
and on the varieties in the free aromatic fraction from apricot as well.
KEYWORDS: Prunus armeniaca, extraction, aroma components, SDE, SPME, C18
INTRODUCTION: The aroma, is one of the most significant and decisive parameters of quality in the
election of a product. However, the analysis and the establishment of standard aromatic quality are
quite complicated, because any extraction technique produces results that are similar to the original
sample (Chaintreau 2001). Simultaneous distillation extraction, reverse phase chromatography, liquidliquid
extraction and solid phase microextraction are the four techniques that were used in here,
selected by their high detection limit, precision and relative low cost.
Apricot fruits are appreciated by consumers for their flavor, sweetness and juicyness, these
characteristics are strongly related to the variety and ripening stage at harvest (Botondi et al 2003).
The aroma is an integral part of the flavor, the aroma compounds of apricot has already been studied
(Tang and Jennings, 1968; Rodríguez et al 1980; Chairote et al 1981; Guichard and Souty, 1988;
Guichard et al 1990; Takeoka et al 1990; Gómez and Ledbetter, 1997; Azondanlou et al 2003). Guillot
(2001) did a list of AC common to every varieties analyzed. Some AC in this list are hexyl acetate,
limonene, 6-methyl-5-hepten-2-one, 3,7-dimethyl-1,6-octadiene, menthone, trans-2-hexenal, linalool,
β-ionone, and Srey (2003) added hexanol, Benzaldehyde and benzyl alcohol.
SDE is a distillation system with a continuous extraction, this technique has been considered the best
isolation and recovery methods of volatile compounds (VC) of a sample when was applied
appropriately, considering their possibilities and limitations, nowadays, this is the best choice for a
high recovery for a wide range of compounds (Chaintreau, 2001).
In C18, VC are adsorbed in a stationary phase for later to be selectively eluted with organic solvents.
The solid phases used are packed silica C18 (Engel and Tressl, 1983) and the Amberlite XAD-2
resine (Williams et al 1981; Günata et al 1985; Krammer et al 1991).
L-L extraction is a direct extraction method in which the liquid sample and an organic solvent are in
contact. The principle of the extraction is based on the solubility of the VC in the used solvent, which
should be more or less dense that the water and immiscible in it.
The SPME has different advantages on the extraction techniques with solvents, such as: high
precision, low cost, short time of extraction, simplicity, high selectivity and sensibility (Sigma-Aldrich
Co 1998; Gonçalves and Alpendurada, 2002). The SPME consists of a fused-silica fibre, coated with
polymeric stationary phase introduced into a liquid or gas sample. The method involves two
processes: the partitioning of the analytes between the coating and the sample and the thermal
desorption of the analytes into gas chromatograph (Ibañéz et al 1998).
MATERIALS AND METHODS
Eight different varieties of apricot (Bergeron, Orangered, Hybride blanc, Moniqui, Double rouge,
Iranien, A4025 and Goldrich) were donated by the National Institute of the Agronomic Investigation of
Avignon, France (Institute Nationale de la Recherche Agronomique, INRA). The fruits were harvested
in a state of consumption maturity, between the months of February and July of 2002. Once in the
laboratory, were washed using distilled water, left to dry and deboned and turn into cubes (1-2 cm of
thickness). Quickly were introduced in polyethylene bags impermeable to gases (1 kg for packing),
kept frozen and stored -20 ºC.

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Preparation of apricot saturated juice. 300 g of frozen apricot were homogenized together with 150 mL
of water UP (ultra pure) and 200 g of (NH4)2SO4. The mixture was centrifuged at 10,000xg rpm during
30 min to 4 ºC, and the saturated juice (supernatant) was recovered.
Liquid-liquid extraction method (L-L).
In a cold bath, where blended 50 mL of saturated juice, with 30 mL of CH2Cl2 and 48 µg of 4-nonanol
as internal standard (IS). The mixture was agitated during 30 minutes on a gaseous nitrogen saturated
atmosphere. Later, the mixture was centrifuged at 10,000xg at 4ºC during 15 min (this extraction was
done twice). Watery phase was removed and the organic phase (CH2Cl2 + volatile compounds) was
object of microdistillation process.
Concentration using reflux (microdistillation). The microdistillation process is the final step, commonly
used in the extraction techniques with solvents here mentioned. The organic phase (CH2Cl2 + volatile
components) coming from any of the methods (L-L, SDE and C18) was concentrated, the following
way: the organic phase was dehydrated with Na2SO4 and filtrated through glass fiber, collecting the
filtrate in a flask of conical bottom of 250 mL. The sample filtrated was distilled in a Vigreux column,
heating the flask of conical bottom in a bath at 45ºC, to concentrate the volume of the sample
approximately to 0.5 mL. The extract concentrated was stored -20 ºC in a 2 mL vial, until the moment
of its analysis in GC-FID.
Clarification of the saturated juice.
210 mL of the saturated juice was defrosted in a bath of water at room temperature (15 to 20 ºC) and
treated as Boulanger (1999), liquefied using a mixture of cellulose (5 g/L), pectinase (2 g/L) PVP (0.2
g/L) at 25 ºC for 90 min, and centrifuged (30 min, 10 000xg) at 4 ºC. The clear supernatant (saturated
juice clarified) was used in the reverse phase chromatography.
Reverse phase chromatography (C18).
The C18 column (Varian®, Walnut, CA, USA) was activated passing through 25 mL of CH3OH and
later 25 mL of water UP. 50 mL of the saturated juice clarified were mixed with 48µg of 4-nonanol as
IS and filtrated through the column C18, at flow rate of 1.5mL/min, the free aroma compounds (free
fraction) were adsorbed in the solid phase of the column. Later, the column was washed with 30 mL of
water UP, to elute the polar components, the free fraction was eluted of the column with 30 mL of
CH2Cl2. Finally this fraction was conduced to the microdistillation process.
Simultaneous distillation extraction (SDE).
Preparation of the sample.
100 g of frozen Apricot were mixed with 200 mL of phosphate buffer (pH 8), 48 µg of 4-nonanol as IS
and 0.2 mL of antifoaming, during 4 min. The final pH was on a 7± 0.2 range.
Parameters in the SDE.
The flask with the sample it was assembled to the Likens-Nickerson apparatus and warmed at 100
to120 ºC range, until boiling. Simultaneously in the other section of the apparatus a small flask was
assembled, with 30 mL of CH2Cl2, this was heated to 45 ºC. The heating of the sample stayed 2 hours.
The solvent was recovered and stored at -20 ºC until their use in the micro distillation process.
Solid Phase Microextraction (SPME).
A puree was prepared with 50 g of frozen Apricot and 50 mL of water UP, in a coldbath. 5 g of this
puree was placed in a 20 mL vial and 5 mL of a saturated solution of NaCl were added. The vial was
sealed tightly and incubated at 40 ºC during one hour, later, the needle of the syringe SPME was
inserted and the fiber (Carboxen/PDMS de 65 µm, Supelco, Bellefonte, PA) was exposed in the head
space inside the vial during 20 minutes. After, the fiber SPME was retracted carefully; the needle of
the vial was taken out and immediately injected in a GC-FID exposing the fiber during 4 min in the
injector. The quantification of the concentration of volatile compounds in SPME it is determined by
means of a standard curve of 4-nonanol.
GC-FID conditions: A Varian 3300 (Walnut Creek, CA, USA) chromatograph equipped with
split/splitless injector and flame ionization detector (FID) was used for all GC analysis. A fused silica
capillary column (J&W Scientific, Folsom, CA, USA) was employed (30m x 0.25 mm i.d., film tickness,
0.25 µm). The temperature program was: increased of 40 to 200 ºC (at 3 ºC/min), then from 200 to
250 ºC (at 5 ºC/min) and maintained for 5 min. The injector temperature was maintained at 250 ºC and
the detector temperature was 300 ºC.

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
GC-MS conditions: Gas chromatograph Saturn 2200 (Walnut Creek, CA, USA) GC-SM, which is GC
Varian 3800, provided of an injector split/splitless, a fused silica capillary column DB-Wax (J&W
Scientific, Folsom, CA, USA) was used (30m x 0.25 mm i.d., film tickness, 0.25 µm), and a mass
spectrum detector series 2000 that captures electrons to identify the molecules by electronic impact.
The temperature program was: increased of 40 to 200 ºC (at 3 ºC/min), then from 200 to 248 ºC (at 5
ºC/min) and maintained for 15 min. The injector temperature was maintained at 250 ºC and the
detector temperature was 300 ºC.
RESULTS AND DISCUSSION
The concentration of volatile compounds was determined in milligrams by kilogram of pulp for all
techniques, considering the sum of the total area of all the compounds detected by GC-FID, that is , all
the free volatile compounds (VC) which include aroma compounds (AC).
The total concentration of VC (mg/kg) from varieties was compared by analysis of variance (ANOVA)
of a statistic design 8X4, the results showed a significant effect (p

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
The C18 extraction was the best technique for recovery a bigger concentration of VC, but most of the
AC was not identified, in the table 2, the AC characteristics of apricot fruit are marked in italics. The
SPME was the technique that extracted smaller quantity of VC, on the contrary this technique
extracted a major number of AC. C18 and SPME are selective methods, but C18 method is very long
that can be the reason of the low quantity of AC, contrarily SPME is a rapid method and the sample
practically was not exposed to the atmosphere.
Table 2. AC identifies in 8 apricot varieties by 4 extraction techniques.
C18 L-L SDE SPME
Methyl cyclopentane
Cis-linalool oxide
Acetic acid
Linalool oxide
Benzaldehyde
Linalool
2,6-dimethyl hexanol
α-terpineol
Epoxilinalool
Cyclohexanol
Geraniol
2,6-dimethyl-7-octen-2,6-diol
Isopropylmisystate
Ftalate
8-hydroxilinalool
5-hydroxilinalool
Pyrazine
Benzaldehyde
Linalool
1,3-dimethylcyclohexanol
Cyclohexylisotiocianate
β-ionone
γ-decalactone
Pirimidine
Pyrazine
6-methyl-5-hepten-2-one
Linalool
Furfural
Benzaldehyde
Piridine
1-3-dimethylcyclohexanol
3,7-dimethyl-1,6-octadiene
phenylacetaldehyde
Cyclohexylisotiocianate
α-terpineol
2-ethylaniline
Benzyl Alcohol
2-butyl-1-octanol
Nerol
Geranylacetone
β-ionone
γ-decalactone
Fernesylacetone
Ethyl acetate
Hexanol
Butanol
β-pinene
Heptanal
Limonene
2-hexenal
Hexylacetate
Octanol
3-hexen-1-ol
6-methyl-5-hepten-2-one
α-isofurane
Timol
Nonanal
2-ethylhexanol
Linalool
2-6-dimethylcyclohexanal
3,7-dimethyl-1,6-octadiene
α-terpineol
hexanoic acid
Geranylacetone
p-cresol
β-ionone
γ-decalactone
dietylftalate
In C18 extraction was identified benzaldehyde, linalool, cyclohexanol and geraniol of the AC
characteristics in apricot fruit while in the SPME was identified hexanol, heptanal, limonene, nonanal,
2-hexenal, hexylacetate, 6-methyl-5-hepten-2-one, linalool, 3,7-dimethyl-1,6-octadiene, α-terpineol,
geranylacetone, β-ionone and γ-decalactone. In a SDE was found VC results of the thermal treatment
as furfural.
CONCLUSIONS
The concentration of compound volatile it depends on the variety and the extraction technique used,
being bigger in the variety Orangered and for extraction in reverse phase chromatography.
The aroma of a food is not in function of the total concentration of volatile compounds, but of the
aromatic compounds characteristics of the fruit (impat compound) that are in this volatile fraction.
The solid phase micro extraction is the technique that allowed the obtaining of bigger number of
aromatic compounds, which determine the characteristic aroma of the apricot fruit.
Any extraction technique produces a clear result of analysis of the sample, but complemented each
others.
REFERENCES
Chaintreau A. 2001. Simultaneous distillation-extraction: from birth to maturity – Review. Flavr. Fragr.
J. 16, 136-148.
Botondi R. DeSantis D. Bellincontro A. Vizovitis K. and Mencarelli F. 2003. Influence of Ethylene
Inhibition by 1-Methyl- cyclopropene on Apricot Quality, Volatile Production, and Glycosidase Activity
of Low- and high-Aroma Varieties of Apricots. J. Agric. Food Chem. 51, 1189-1200.

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Tang C. and Jennings W. 1968. Lactonic Compounds of Apricots. J. Agric. Food Chem. 16, 252-254.
Rodriguez F. Seck S. and Crouzet J. 1980. Constituents Volatils de l’Abricot Variété Rouge du
Roussillon. Lebensm. Wiss. Tech. 13, 152-155.
Chariote G. Rodriguez F. and Crouzet J. 1981. Characterization of Additional Volatile Flavor
Components of Apricot. J. Food Sci. 46, 1898-1901.
Guichard M. and Souty M. 1988. Comparison of the relative quantities of aroma compounds in fresh
Apricot (Prunus armeniaca) from six different varieties. Z. Lebensm. Unsters. Forsch. 186, 301-307.
Guichard E. Schlick P and Issanchou S. 1990. Composition of Apricot Aroma: Correlations between
Sensory and Instrumental Data. J. Food Sci. 55, 735-738.
Takeoka G. Flath R. Mon T. Teranishi R. and Guentert M. 1990. Volatile Constituents of Apricot
(Prunus armeniaca L.). J. Agric. Food Chem. 38, 471-477.
Gómez E. and Ledbetter C. 1997. Development of Volatile Compounds during Fruit Maturation:
Characterization of Apricot and Plum x Apricot Hybrids. J. Sci. Food Agric. 74, 541-546.
Azodanlou R. Darbellay C. Luisier J. L. Villettaz J. C. and Amadò R. 2003. Development of a model for
Quality assessment of Tomatoes and Apricots. Lebensm. Wiss. Tech. 36, 223-233.
Guillot S. 2001. Recherche de Marqueurs de la Qualité Aromatique de l’Abricot par Mico Extraction en
Phase Solide-Cromatographie en Phase Gazeuse-Spectrometrie de Masse (SPME-GC-SM) et
Olfactometrie (SPME-CG-O). Diplome d’Etudes Aprofondies, Université de Montpellier II, France.
Srey C. 2003. Etude de la Qualité et du Potentiel Aromatique de l’Abricot. Diplome d’Etudes
Aprofondies, Université de Montpellier II, France.
Engel K. H. and Tressl R. 1983. Formation of Aroma Components from Nonvolatile Precursors in
Passion Fruit. J. Agric. Food Chem. 31, 998-1002.
Williams P. J. Straus C. R. and Wilson B. 1981. Use of C18 Reversed Phase Liquid Cromatography for
the Isolation of Monoterpene Glycosides and Nor-isoprenoid Precursors from Grape Juices and wines.
J. Cromatography. 235, 471-480.
Günata Z. Bayonove C. L. Baumes R. L. and Cordonnier R. E. 1985. The Aroma of Grepes I.
Extraction and Determination of Free and Glicosidically Bound Fractions of some Grape Aroma
Components. J. Chromatography A. 331, 83-90.
Krammer G. Winterhalter P. Schwab M. and Schereir P. 1991. Glycosidically Bound Aroma
Compounds in the Fruits of Prunus species: Apricot (P. aremeniaca, L), Peach (P. persica, L.), Yellow
Plum (P. domestica, L ssp. Syriaca). J. Agric. Food Chem. 39, 778-781.
Sigma-Aldrich Corporation. 1998. Solid Phase Microextraction, Direct, Solvent-Free Extraction of
Organic Compounds. Product Specification. www.sigma-aldrich.com. Supelco, Bellefonte, USA.
Gonçalves C. and Alpendurada A. F. 2002. Comparison of three different poly (dimethylsiloxane)divinylbencene
fibres for the analysis of pesticide multiresidues in water simples: structure and
efficiency. J. Cromatography A. 963, 19-26.
Ibañéz E. López-Sebastián S. Ramos E. Tabera J. and Reglero G. 1998. Analysis of volatile fruit
components by headspace solid-phase microextraction. Food Chemistry. 63, 281-286.
Boulanger R. 1999. Etude des Composes d’Arome Libres et Lies de Fruits Amazoniens “Bacuri,
Cupuacu, Acerola". Thése Doctorale, Université de Montpellier II. France.

FP06-2004
Food Science and Biotechnology in Developing Countries
Diet Effect upon chemical composition of Pelibuey and Polipay - Rambouillet.
Esaúl Jaramillo López (1), Gwendolyne Peraza Mercado (2) y Saraí Chávez del Hierro (3).
(1) Universidad Autónoma de Ciudad Juárez, Anillo Envolvente del Pronaf y Estocolmo s/n, C.P.
32300, A.P.1595-D, Ciudad Juárez, Chihuahua, México, Tel y Fax. 6881894.
Email: ejaramil@uacj.mx
(2) Universidad Autónoma de Ciudad Juárez, Anillo Envolvente del Pronaf y Estocolmo s/n, C.P.
32300, A.P.1595-D, Ciudad Juárez, Chihuahua, México, Tel y Fax. 6881894.
Email: gperaza@uacj.mx
(3) Universidad Autónoma de Ciudad Juárez, Anillo Envolvente del Pronaf y Estocolmo s/n, C.P.
32300, A.P.1595-D, Ciudad Juárez, Chihuahua, México, Tel y Fax. 6881894.
Email: al48917@uacj.mx
Abstract
The main objetive of the present project was to evaluate the effect of the type of gain (corn
and sorghum) upon the chemical composition of Pelibuey or Tabasco (P) and Polipay - Rambouillet
(PR) lamb meat. Longissimus dorsi samples from the right side carcass of lambs (8 from each breed)
were analysed.
Key words: Maize, sorghum, lamb, Pelibuey, Polipay - Rambouillet.
Introduction
One of the foremost activities that maintain great importance in the socioeconomic context is
the cattle; it provides manifold satisfactions to the humanity. The production of wool, skin, milk and
meat are some of the elements operated by man; mainly the meat production is the most productive
activity scattered in rural means, since it is still made in all the ecological regions of the country and in
adverse conditions that do not allow the practice of other productive activities. 1,2
The development of the country has implied in addition to the accelerated growth, and the
concentration of the population in medium and great urban centers has had a strong impact in the
demand and the habits of consumption of this type of meat, due to its attractive prices, requiring
production systems that can generate sufficient volumes of animal origin products to supply to great
cities. 2,3
The meat of this type of animals is very spread in our country and the import levels are of
334.000 heads reported for 1999, with a total production in our country of only 2%, numbers that
have stayed constant until recent years; and the increase perspective of the consumption of this type
of meat is of 5,4% for year 2000. 2
According to the ovine races, the Pelibuey is the most in the lamb zones near City Mexico,
mainly in the states of the coast of the gulf, in the Yucatan Peninsula and the states of the coast of the
Pacific; observing a fast increase of this race in the mentioned regions. The flocks are operated in
rudimentary form, without established programs of handling, genetic improvement or preventive cares
causing a low gain of weight and its consequent long period of growth, due to the lack food that
causes this cattle to grow up under excessive pasturing. 1,3,4
The cross of ovines contributes to a uniform animal obtaining as far as the production and
adaptation of the atmosphere where they are developed, besides they transmit their desirable
characteristics with greater force. 1 In the crossing and cattle production some changes like rasher
carcass greater speed of growth and a better yield when sacrificed have taken place. 5
The Rambouillet race descends from the Spanish Merino and it is in the classification of fine
wool races. From the beginning, this race was selected and developed so that it had a greater
average size than the Spanish Merino and which provided one double aptitude, being able to produce
as much wool as meat. They are great ovine, rustic and of fast growth; their skin are almost free of
wrinkles, its conformation is acceptable for meat, although nonequal to the one of the races with that
aptitude. The polipay lamb is of great interest because it develops a great productivity in the industry,
and it is characterized to have an early puberty and short gestation. 6 The main foods for cattle are
grouped in two great categories: foraging and concentrated foods. The concentrated ones include the
energetic foods, which are made up of cereals, which are from the qualitative point of view the most
important group of the energetic concentrated. 7

FP06-2004
Food Science and Biotechnology in Developing Countries
Sorghum and Maize are the most used cereals but, these reported from 1990 to 1999 the 95%
of the supply needed for cattle intake. The preference for the consumption of this cereal is based on
the levels of supplies and price as well as the quality of energy that they provide
The demand of carcass, more young and light, indicate that the lambs are the most important
product 5 since they are being fed by nursing and concentrated, presenting muscles of clear or pinkish
color with little amount of fat (smaller than 3mm of thickness in the back), due to these characteristics
the carcass are considered of high quality. The systems of classification based on the weight and age
criteria imply an economic hierarchy of the carcass since influence in other characters exist like
greasing degree, consistency of the fat, flavor and aroma. 3,5,8
Numerous animals tissues are used as food since its structure is excessively complex, 3
consisting of a colloidal tissue, that contains from 55 to 78% of moisture, from 15 to 22% of proteins, 1
to 15% lipids, 1 to 2% of glucid and 1% of mineral salts. 9
The proteins are compounds that have become at the moment the main center of attention in
the world due to their importance, 10 that depends fundamentally on the content of essential amino
acids (necesary for life) and of their biological value. 11 The consumer demands meat with less fat, 12
that is to say meat with less saturated fat, since when consuming foods with higher energetic content
and low in fat have beneficial effects. 1,13 Fats are a concentrated source of energy, they provide
something more then twice of calories by gram then proteins and carbohydrates [9 over 4 Kcal/gr]. 4
Due to the demand that exists in this type of meat, the present study focused in the evaluation
of the quality of the meat of ovines Pelibuey and Rambouillet - Polipay, two species that have great
diffusion in the national field.
Material and methods
The present work was carried out in the Food Chemistry Laboratory (V203) of the Institute of
Biomedical Sciences, with the collaboration of the Cattle Department, both of the Autonomous
University of Ciudad Juarez.
Sample obtention from Longissimus dorsi
For the accomplishment of this work 16 lambs were used: 8 Pelibuey (P) and 8 Rambouillet-
Polipay (RP), that were distributed in individual corrals, as viewed in the figures 1 and 2.
Figure 1. Lamb Pelibuey Figure 2. Lamb Polipay-Rambouillet
The lambs were weaned after sixty days after birth, with a period of adaptation of fifteen days.
The food consumed was weighed twice a day every twelve hours. The food supplied increased when
the rejection was higher then 5% of the offered portion. Portion one was composed of: rolado maize,
alfalfa hay, harinolina, ammonium sulphate and a premixture of minerals. Portion two replaced maize
by sorghum. When the lambs reached an age of six months, they were sacrificed, previously
uninformed for twelve hours. The sacrifice was by decollation, with previous sensibilizacion.
After the sacrifice, the full digestive system, lungs, heart, liver, spleen, trachea, skin, legs and
head were weighed. Once the eviceration was concluded, the carcass was weighed, later cooled off to
4ºC during twenty-four hours.
The cold carcass was divided in longitudinal form in two equal parts, in one of the parts the
most important cuts were valued like: leg, thorax, arm-shoulder, abdomen and neck. One the right

FP06-2004
Food Science and Biotechnology in Developing Countries
carcass, a was made on the back between the tenth and eleventh thoracic vertebra and the fourth and
fifth lumbar vertebra, to obtain the Longissimus dorsi, on which the chemical analyses were made on.
Sample preparation
A portion of approximately one hundred grams of Longissimus dorsi muscle was used, that
portion was ground until obtaining a homogenous sample. The meat was stored hermetically in closed
and labeled containers, freezzed at -10ºC until its analysis.
Chemical analyses
The physicochemical analyses were determined using the AOAC techniques (1995). 15 The
percentage of protein was determined by the Kjeldahl method, the moisture by means of the dry
furnace, method the fat was determined by the Soxhlet method and the ashes were determined by
incineration.
Statistical analyses
The data analysis used the statistical package SPSS version 11, using a factorial adjustment
(2x2) considering the racial group Pelibuey and Polipay - Rambouillet (P and PR respectively) and
both feeding levels applying maize and sorghum (1 and 2 respectively), Tukey method and a
correlation coefficient.
Results and Discussion
The average results obtained for the meat chemical comparing the Pelibuey race (P), and
crossed fine wool ovines Polipay-Rambouillet (PR), appear in Table 1. The effects of both types of
cereals (maize and sorghum) provided to both ovines do not present statistical difference significance
(P>0,05).
Table 1
µ±σ of the Chemical components (%) of Pelibuey (P) and Polipay-Rambouillet (PR) meat.
Chemical component Average Racial Group PRM (n=4) Racial Group PRS(n=4) Racial GroupPM(n=4) Racial GroupPS(n=3)
Proteín 15.32 ± 0.82 14.56 ± 0.01 15.04 ± 0.86 16.99 ± 0.48 14.69 ± 0.94
Fat 4.07 ± 0.90 4.57 ± 0.85 4.44 ± 0.18 3.22 ± 0.58 4.04 ± 0.98
Moisture 74.35 ± 0.79 73.70 ± 0.59 74.03 ± 0.63 74.07 ± 0.66 75.61 ± 0.29
Ashes 1.38 ± 0.24 1.33 ± 0.30 1.53 ± 0.19 1.44 ± 0.20 1.23 ± 0.27
M= Maize based diet
S= Sorghum based diet
Effect of the Race
When comparing between the races Pelibuey and Polipay-Rambouillet significant differences
(P>0,05) in the chemical components were not found. The Pelibuey race that was fed with maize
presented greater protein content in compared to ovines of that same race but fed with sorghum. The
meat of the Polipay-Rambouillet ovines fed with maize and sorghum presented the same fat content,
these percentages are similar to the ones of the Pelibuey ovines fed with sorghum; these mentioned
values are higher than the fat content of the Pelibuey race fed with maize, which registered a smaller
value without presenting significant differences (P>0,05).
Effect of the cereal
When comparing the data of the racial group Pelibuey that were fed with maize and sorghum
a noticeable difference was displayed in the percentage of protein and fat because these components
depended totally on the provided feeding.
A variance analysis was made to compare the percentage of the chemical components (protein, fat,
moisture and ashes) and their relation with the provided diet and the racial group, and its relation with
the provided diet and the racial group, as shown in graphs 1 and 2.

FP06-2004
Food Science and Biotechnology in Developing Countries
Maize
Sorghum
Pelibuey
Polipay
15.7714.88
3.89 4.26
74.7
73.88
1.38 1.39
Protein Fat Moisture Ashes
16 14.79
3.56
4.5
74.72 73.86
1.34 1.43
Protein Fat Moisture Ashes
There were no significant differences when comparing the percentage of protein, fat, moisture
and ashes with the provided cereal, which shows that maize neither the nor the sorghum affect the
components of the meat. Also there was no significance in the percentage of the chemical
components with its respective races, determining that the genetic factor did not have influence over
the obtained results.
The racial groups did not present significant differences (P>0,05) in the components like
Protein, fat, moisture and ashes, which contrast with other similar studies made by other
investigations.
The average results obtained by Lopez et al. 1 Pelibuey ovines and the crossed Rambouillet
and Suffolk had significant differences (P0.05) between the chemical components of the meat. Therefore, the meat
chemical composition of ovines fed with rolado maize, harinolina, alfalfa hay, ammonium sulphate and
premixture of minerals did not differ from the ovines fed with the same diet replacing the msaize rolado
with sorghum. Due to these results the diet can adapt to maize or sorghum depending on the
necessities of the producer, availability of the cereal and the cost.
The variation of protein and fat of the animal is due to the growth animal and the age, as well
as factors that influence directly the meat quality as race, climate, sex of the animal, form of the
sacrifice and feeding.
80
70
60
50
40
30
20
10
0
80
60
40
20
0

FP06-2004
Food Science and Biotechnology in Developing Countries
The increase in the corporal weight of the animal does not mean better quality of the meat.
Eventhough differences in the weight of the obtained cuts of a carcass exist, the yield percentage of
each cut is similar in pure ovine races and crossed ones. 1
References
1. López, P. M. G. Rubio L. M. S. Valdés S. E. M.1999.Efecto del cruzamiento, sexo y dieta en la
composición química de la carne de ovinos Pelibuey con Rambouillet y Suffolk. Vet. Méx. J (31) 11-18.
2. Villamar A. L.. Segura M. C. Barrera W. M. A. Guzmán V. H.Domínguez L. R.1999.La producción de
carnes en México y sus perspectivas 1990-1999, SAGARPA. 1-53
3. Arbiza, A. S. I. De Lucas T. J.1996. Producción de carne ovina, 1 a Edición, Ed. Editores Mexicanos
Unidos, S.A. pp. 1-166.
4. Masson, I. L..1980. Ovinos Proliferos tropicales. FAO-PNUMA, Roma Italia.pp. 24-235.
5. Gracey J. E. 1989. higiene de la carne, 8 a Edición, Ed. Interamericana Mc Graw Hill.
6. Ensminger M.E. 1976. Producción Ovina, 2 a Edición, Ed. El Ateneo. pp. 1–535.
7. Buxadè C. C. 1997. Ovino de leche, 1 a Edición, Ed. Ediciones Mundi Prensa.15-87
8. Colomer R. F. Delfa R. Sierra A. I. 1998. Método normalizado para el estudio de los caracteres
cuantitativos y cualitativos de las canales ovinas producidas en el área mediterránea, según los sistemas
de producción. p.23.
9. Cheftel J. C. Cuq J. L. Lorient D. 1989).Proteínas alimentarias. 1 a Edición, Ed. Acribia S. A.. p.p. 1-456
10. Badui D. S. 1993. Química de los alimentos, 3 a Edición, Ed. Pearson educación. p.p.12-127
11. Vollmer G., Josst G. Schenker D. Sturm W. Vreden N.1999. Elementos de bromatología descriptiva,
1 a Edición, Ed. Acribia S. A. p. 58
12. Buss D. Tyler H. Barber S. Crawley H.1987. Manual de nutrición, 1 a Edición, Ed. Acridia S. A. p. 85
13. Sunthareswaran R.1999. Lo esencial en sistema cardiovascular, 1 a Edición, Ed. Harcourt. p. 160.
14.Fennema O. R.1993. Química de los alimentos, 2 a Edición, Ed. Acribia, S. A. p.p.68-95
15. Association of Oficial Analytical Chemists. Official methods of analysis. Washington (DC): AOAC,
1995.
16. Marinova P. Banskalieva V. Alexandrov S.,Tzvetkova V. Stanchev H. 2001. Carcass composition and
meta quality of kids fed sunflower oil supplemented diet. Small Ruminant Research J (42): 219-227.
17.Scerra V. Caparra P. Fou F. Lanza M. Priolo A. 2001. Citrus pulp and wheat straw silage as an
ingredient in lamb diets: effects on growth and carcass and meta quality. Small Ruminant Research J(40):
51-56.

FSB1-2004
Food Science and Biotechnology in Developing Countries
PROCESS OF A SUGAR FREE NOPAL MARMALADE AND ITS EFFECTS IN
PEOPLE WITH IMPAIRED GLUCOSE TOLERANCE.
Vargas Contreras Sandra (1), García Torres Iver (2), Sánchez-Díaz Lima Dulce Ma. (3), Soriano
Santos Jorge (4), Arellano Meneses Alma Gpe. (5), Ruiz Guzmán Gloria (6).
(1) Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biotecnología y Departamento
de Ciencias de la Salud. sanvc9@msn.com
(2) Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biotecnología y Departamento
de Ciencias de la Salud. ia_ivergt@yahoo.com
(3)Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biotecnología.
dusa@xanum.uam.mx
(4) Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Biotecnología
jss@xanum.uam.mx
(5) Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Ciencias de la Salud
agam@xanum.uam.mx
(6) Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Ciencias de la Salud
rugg@xanum.uam.mx
ABSTRACT
A cacti marmalade, low in calories, with similar characteristics to comercial marmalade and that could
also be consumed by people with impaired glucose tolerance was elaborated. It was given to people
with normal and impaired glucose tolerance and its effect on glucemia was evaluated. The results
showed that the consumption of the marmalade diminished glucemia in a statistically siginificant way.
KEYWORDS: marmalade, cactus, impaired glucose tolerance, sucralose.
INTRODUCCION
Diabetes mellitus is a public health problem of priority in Mexico due to its growing tendency and its
relation with others diseases, such as obesity and cardiovascular ones. 1 .
People with impaired glucose tolerance must be careful with their food consumption, avoiding the
excessive use of glucose in their diet 7 . Nevertheless, a necessity to consume sweet foods, such as
desserts exists. At the present time, thanks to the biotechnology, there are some alternatives in which
the glucose of these foods is replaced for free sweeteners to satisfy these need 2 . On the other hand, it
has been proposed that some foods can help to diminish the glucose 3 .
The cactus is one of these foods besides it has other important characteristics like it is one of the
Mexican natural resources of greater abundance, is economic and some studies had shown that it has
important nutritional properties and a high amount of fiber 3 . These studies have verified that it has
curatives and preventive properties that include the decrease of sugar levels in the blood 4,5 .
In this work it was decided to elaborate a marmalade with cactus base and glucose free in order to
evaluate its effect on people with alterations in the tolerance to the glucose.
METODOLOGY
The material used for the elaboration of the marmalade was: cladodio cactus (Opuntia ficus),
obtained from the Central de Abasto in Mexico City. The cacti was taken to the laboratory where it was
washed, unsplinted and grinded to obtain the pulp. The cacti is one of the most difficult vegetables to
process, due to the high quantity of fiber it contains and the mucilaginous substance that presents that
gives viscosity and certain hardness.
The physical and chemical parameters of the pulp were determined, being pH is 3.7, the °Bx 7. It was
then proceeded to modify the parameters that were necessary to fulfill the norms of codex
alimentarius for marmalade. In this case only the pH was modified, using citric acid to get a final value
of 3.2. Afterwards this procedure helped us to eliminate the mucilaginous substances that the cacti
has.
It is good to mention that because this marmalade was destined to people that have some type of
intolerance to glucose, the selected sweetener was the sucralose (from commercial brand Splenda),
since:

FSB1-2004
Food Science and Biotechnology in Developing Countries
• In diabetic people it is not recognized by the organism like the carbohydrates, therefore it does
not affect the normal insulin secretion.
• Is approximately 600 times sweeter than sugar, absorbed in smaller amounts and it’s excreted
quicker.
• Is not toxic, nor carcinogenic or caloric.
• It has an excellent chemical stability of pH, temperature, process and storage.
• Is soluble and it disperses common solvents, it prevents tooth decay 6
Four formulations were made in order to determine which was the most suitable as far as its sensorial
characteristics; the composition of each formula is shown below:
FORMULATION % OF INGREDENTS PARAMETERS
I 45 % pulp; 54 % powder sucralosa ; 1 % comercial pectina pH = 3.5; °Bx = 7
II 45 % pulp; 54 % liquid sucralosa; 1 % comercial pectina pH = 3.2; °Bx = 7
III 49 % pulp; 49.5 % powder sucralosa; 1.5 % comercial pectina pH = 2.8; °Bx = 7
IV 49 % pulp; 49.5 % liquid sucralosa; 1.5 % comercial pectina pH = 3.5; °Bx = 7
Twenty volunteers evaluated the obtained marmalades; they described their flavor, color, texture and
consistency and reached the conclusion that the most accepted formulation was formulation II. From
these results, it started the procedure to elaborate and to vacuum-packed the marmalade for all the
experiment. A bromatologic analysis was made. According to this analysis the marmalade has the
following nutriments:
NUTRIMENTS %
Dampness 91
Carbohydrates 3.22
Fat 0.32
Protein 1.37
Ashes 0.84
Fiber 3.25
Universe:
The amount of fiber and carbohydrates give to this marmalade the
characteristics that were looked for in accordance to the use that was going to
be given.
The evaluation of the marmalade with respect to the effect on glucemia was
carried out in people with diverse tolerance to glucose, in agreement with the
following scheme:
Working adults and students of the Universidad Autónoma Metropolitana - Iztapalapa and its
relatives, as well as any person interested in participating in the study.
Procedure of collect:
• Those who freely and voluntarily wanted to participate, that presented certain intolerance to
glucose, as well as people without alteration, were selected randomly. All those whom
participated signed a letter of consent and they were given written and oral indications before
the test was applied.
• Each individual was programmed on a certain date and time to make the somatometric
measurements (weight and height), as well as a fasting capillary blood sample. Based on
these measurements the body masss index (BMI) was calculated.
Initial measurement of glucose in the blood:
• The amount of glucose from the obtained samples were determined by an electrochemical
analysis with a glucose measurer (PRECISION QID) and also they were classified according
to the criteria of the Latin American Association of Diabetes in:
Normal
Glucose levels
< 100 mg / dL
With impaired fasting glucose 100-115 mg/ dL
Diabetics > 115 mg / dL

Determination of the effect of the cactus marmalade:
FSB1-2004
Food Science and Biotechnology in Developing Countries
• The marmalade was administrated to diabetic, normal and glucose intolerant people in the
amount of 30 g per day, which is about a tablespoon and for the people that wanted a
personalized diet was designed.
• Subsequently measurements on the blood glucose and somatometric measurements were
made every week.
RESULTS
The studied population was conformed of 54 individuals from whom 14.8 % deserted the study, the
85.2 % remaining continued with the study; only the first 4 glucose measurements were considered, in
order to have representative sample size for this work. Of the 46 studied subjects 32 were women and
14 men.
Men
The population was divided in three groups according to their glucose tolerance: without alteration,
with impaired fasting glucose and diabetic. Graphic 2 shows the percentage of people that were
included in each group.
Diabetic
30.4%
30.4%
45.7%
69.6%
23.9%
altered
Woman
without
alteration
Graphic 1.
Distribution of the populación
studied by sex
One of the following treatments was proposed to each one of the previous groups:
• Without treatment (T0)
• Consumption of cactus marmalade (T1)
• Consumption of cactus marmalade and diet (T2)
Graphic 2.
Percent of peoples included in
each group
The diet given to the individuals on group T2 was variable in accordance to the type of nutrition of
each person and was calculated from the ideal weight of each individual.
Graphic 3 shows the percentage of individuals that were put under each treatment. It is important to
state that these percentages are variable due to the decision of each individual on whether to take or
not the treatment and which treatment they chose.
WITH IMPAIRED GLUCOSE TOLERANCE
Marmalade
and Diet T2
Marmalade (T1)
27.3%
27.3%
NORMAL
45.5%
Graphic 3.
Percent for treatments of each one
groups studied.
Marmalade
and Diet (T2)
Without
treatment
T0
35.7%
DIABETICS
28.6%
Marmalade
(T1)
35.7%
Without
treatment
(T0)
marmalade and
Diet (T2)
Without
treatment
(T0)
23.8%
14.3%
61.9%
Marmalade
(T1)

FSB1-2004
Food Science and Biotechnology in Developing Countries
Sanguineous glucose measurements were made on fasting every 7 days during 2 months. It is good
to mention that for the analysis the only values that were taken into consideration were the initial and
final values; nevertheless weekly samples were taken in order to have a control of the diet and the
consumption of the marmalade by the individuals that opted for these treatments. In order to
determine if a difference between the initial and final values exist a paired t student test was made for
the glucose (G) and the BMI with a significance level of P

Graphic 3 presents the initial and
final values of glucose, but now of
the group of diabetic people with
their respective treatments, in this
case it is possible to see that
significant differences between
the groups do not exist, it is to say
that the marmalade and the diet
did not caused any effect on the
glucemia since there’s not a
statistical difference between
them. The individuals that were
included in this group did know
that they were diabetic and in
most cases they already had
taken a pharmacological
treatment and so their glucemia
could be the reflex of these
treatments rather than the
marmalade. In this case the
marmalade effect is not clear and
it doesn’t seem to increase the effect of the medicaments
CONCLUSION
220
205
190
175
160
145
130
115
100
85
FSB1-2004
Food Science and Biotechnology in Developing Countries
GRAPHIC 3. Initial and final glucemia in
diabetic subjects
This cactus marmalade can decrease the glucose levels in altered peoples but not in diabetic people.
This marmalade will can be an alternative for decreasing the glucose levels in peoples with glucemia
alteration, to satisfy the sweet necessity, improvement the glucose levels and to delaying the diabetic
mellitus appearance. Exist a complicated for work with diabetics patients owing to the control in not
the 100 percent, generally the peoples is influenced for the environment in the found, and this
peoples not follow to prescribe of adequate manner. Is important to continue with is study of the nopal
marmalade effects on the glucose levels in a sample major of patients, to validate the results and
determinate the product beneficial in subjects which present glucose tolerance alteration.
REFERENCES
1. González-Villalpando C, Martínez DS, Arredondo PB, et al. 1996. Factores de riesgo
cardiovascular en la Ciudad de México. Estudio en población abierta urbana. Rev. Med.
IMSS. 34:461-6.
2. American Diabetes Association. 2000. Screening for type 2 Diabetes. Diabetes Care Vol. 23.
suplement 1.
3. Carmena R. 2000. Diabetes y riesgo cardiovascular. Diabetes Care. Suplemento de la edición
en español. Julio:22.
4. Chandalia M, et al. 1974. Dietary Fiber and disease. Ed. Jama: 1068-1074
5. Vázquez CI, Jiménez A. 1999. Servicio de aparato digestivo. Hospital Universitario de la
Princesa. Prescripción de Fármacos, 5(4).
6. Food and Drug Administration (FDA), 1998. Food additives permitted for direct addition to
food for human consumption; sucralose, 63(64), rules and regulations: 16417-16433.
7. Rojas HE. 1991. La dieta del diabético. En: Revista Clínica Española. 188(5):221-222.
Tratamiento dietético en la diabetes mellitus artículo escrito por Teresa Motilla Valeriano y
Carmen Martín Salinas.
T0
T1
T2

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Turning Waste into Profit:
Vegetable Residues as a Valuable Processing Stream
Guenther Laufenberg
Department of Food Technology, University Bonn, Roemerstr.164, 53117 Bonn, Germany
g.laufenberg@uni-bonn.de
Abstract:
Waste can contain many reusable substances of high value. Based on a holistic concept of food
production a need statement is visualized for the vegetable industry; recording occurrence, quantity
and utilization of the residual products. The synchronization of all material streams in food processing
enables the industry to produce new products with own net product value. Hence value is added to the
residues and a reduction of investment and raw material costs is achieved.
Keywords:
Upgrading, sustainability concept, bioadsorbents, food flavors, multifunctional food ingredients
A thing is right when it tends to preserve the integrity, stability and beauty of the biotic community.
It is wrong when it tends to do otherwise.
(Aldo Leopold)
Food and Agricultural industry produce large amounts of solid and liquid organic residues, most of
which is currently disposed or used on a low technological and economical level. The scale of the
problem is illustrated by looking at the total amounts of waste materials produced by different
countries. Table 1 is a list of waste quantities mentioned in the literature.
Table 1: Waste quantities in different countries (selection)
Country/state Quantity and waste type
Germany (1997) [1]
Belgium (1992) [3]
380,000 t/a organic waste only from potato, vegetable and fruit processing
1,954,000 t/a spent malt and hobs (breweries)
1,800,000 t/a grape pomace (viniculture)
3,000,000 t/a crude fiber residues (sugar production)
Spain (1997) [4] >250,000 t/a olive pomace
100,000 t of wet apple pomace (≅ 25,000 t dry apple pomace) remain if 400,000
t of apples are processed into apple juice [2]
105,000 t/a biowaste (vegetable, garden and fruit waste)
280,000 t/a estimations due to legislation of separate household collection
EEC (1996) [5] 14,000,000 t/a sugar beet pulp (dry matter!)
Thailand (1993) [6]
palm oil production
386,930 t/a empty fruit bunches
165,830 t/a palm press fiber
110,550 t/a palm kernel shells
1,000,000 t/a cassava pulp (1994, [7])

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Country/state Quantity and waste type
Portugal (1994) [8] 14,000 t/a tomato pomace
Jordan (1999) [9] 36,000 t/a olive pomace
Malaysia (1996) [10]
palm oil production
2,520,000 t/a palm mesocarp fiber
1,440,000 t/a oil palm shells
4,140,000 t/a empty fruit bunches
Australia (1995) [11] 400,000 t/a pineapple peel
USA
300,000 t/a grape pomace in California only (1994) [12]
9,525 t/a cranberry pomace (1998) [13]
200,000 t/a almond shells (1997) [14]
3,300,000 t/a orange peel in Florida (1994) [15]
In the last decade the interest in the alternative use of waste streams beyond disposal or fertilization
has increased drastically. Further to rising disposal costs the economic interest has appeared as well.
All of these raw materials contain considerable amounts of valuable substances like sugars, oils, fibers
or polyphenols. Yet, they are either wasted or used at low technological and economical levels, e.g. in
animal feeding or fiberboard production [16][17].
During the last years it has been of interest to develop new processes to use these valuable
substances contained in the residual matter. These raw material streams can now be reintegrated into
the chain of food production, in contrast to ordinary food manufacturing which excludes these material
streams from the production process. Laufenberg et al. [18][19] have designed a sustainability concept
which aims to convert the raw material stream into a new product and/or ingredient.
Raw
material
Prime
processing
Pre
processing
Residual
matter
Food
Ingredient
Intermediate
product
Adaptation
processing
Figure 1 The holistic approach to food processing - the synchronization hexagon [18][19]
Treating residual matter in a three-step process and employing pre-, prime-, and adaptation
processing adds value to the waste as well benefit ecology. This holistic approach to food processing
is presented schematically in Figure 1 , the strategy of the sustainability concept in Figure 2. Starting

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
with residual matter from the fruit and vegetable industry, the use of technical standard equipment for
upgraded processing is an important factor.
olive oil
processing
olive oil
food processing
fodder/fertilizer
biological
treatment
single strain
fermentation
key flavor
pure flavor for cosmetics
or pharmacy
upgraded processing
residual matter
pre-processing I
chemical
treatment
intermediate product
adaptation processing
complex flavor
physical
treatment
example olive cake
olive cake
(possibly extracted)
hygienization, drying
raw material stable olive cake
pre-processing II
prime processing
mixed culture
fermentation
food products with
natural ingredients
pre-processing II
bt: fermentation or enzymatic
catalysis to metabolize or degrade
certain components
ct: acid /alkaline hydrolysis,
oxidation
pt: pressure, temperature or
ultrasound treatment
pretreated olive cake substrate
prime bioconversion:
fermentation with selected
microorganisms, single strain or
mixed culture
a.: key component flavor
e.g. γ-decalactone
b: natural food ingredient
peach flavor
Figure 2 The sustainability concept converting the product stream olive press cake into flavor [20]
The recycling strategy, applied in the outlined example to olive press cake as one of the major oil
press cakes in Europe, is designed in a modular manner (Figure 2). In this case pre-processing is the
main focus due to the fact that olive press cake contains reasonable amounts of polyphenols inhibiting
the growth of flavor producing microorganisms. The actual bioconversion of fatty acids into flavors is
attained in the prime processing module, converting the fraction into flavor components. According to

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
the key components needed, e.g. γ-decalactone or the complex peach flavor aroma, such substances
are produced in the prime processing module.
The sustainability concept offers excellent possibilities to be used for the production of value-added
products by biotechnological processes [21] [22]. Biotechnological processes include the production of
chemical substances like organic acids, sugars, alcohol or aroma compounds as well as different
enzymes and proteins.
Another promising possibility for the utilization of organic residues in the frame of green productivity is
the development of multifunctional food ingredients (MFI). In the mentioned context MFI have to be
understood as natural ingredients taking over food additive functions during processing and /or add a
further benefit to the final product.
Several research groups have been working on the development of multifunctional ingredients from
vegetable residues and its application in different food products. The crude fiber content combined
with at least one other property enables them to fulfill several functions in food as exhibited in Table 2.
Table 2: Food properties and quality influenced by multifunctional food ingredients [23]
Operating areas of multifunctional food ingredients due to food properties and quality
(1) Nutritional and healthy quality
(2) Food product structure
e.g. vitamin content, dietary fiber content
e.g. porosity, network structure
(3) Sensorial properties
(4) Physical properties
e.g. texture/ structure, mouth feel, freshness
e.g. density, viscosity
(5) Processing properties
e.g. water binding ability, emulsifying properties
The high crude fiber content of the vegetable pomace, see Table 3, suggests its utilization as a crude
fiber “bread improver”. One reason for the low dietary fiber uptake is the non-acceptance of whole
meal products in large parts of the population. An enrichment of different products with crude fiber
compounds can thus raise the dietary fiber uptake, if the food products are not strongly modified. The
macromolecular structure of the fiber must not be changed during the transformation of the residue
into a food compound, and the fiber material has to be of food grade.
Table 3: Content and composition of dietary fiber of some residues [23][24][25][26]
Residues
Fiber
Pectin Lignin Cellulose
Total Insoluble Soluble
Apple pomace 62.5 48.3 14.2 15.69 18.2 -
Barley pomace 65.3 62.1 3.2 - - -
Carrot pomace 29.6 18.9 10.7 22-25 - -
Cocoa pod
bean shells
husks/
[27]
36.3 - - 6 - 13.7
Corn cobs -
- b
43 - 17 [28] 32
Kiwi pomace 25.8 18.7 7.1 7.25 3.2 -
Lemon peel 50.9 28.2 22.7 25.23 5.5 -
Lemon pulp 45.8 26.0 19.8 12.02 2.9 -
Olive cake 69.4 65.7 3.7/ 15.5 [9] b 4.10 37.2/ 35.4 [9] 18.4 [9]
Pea pots 90.1 84.7 5.4 - - -
Peach pomace [29] 54.5 35.4 19.1 - - -
Pear pomace 43.9 36.3 7.6 7.05 5.2 -

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Residues
Fiber
Pectin Lignin Cellulose
Total Insoluble Soluble
Potato peel [30] 73 6.2 b
16 13.8 16
Potato pulp 15.8 9.4 6.4 ~15 [31] - -
Soy bean shells 64.6 56.9 7.7 - - -
Sugar beet pulp 75.3 50.1 25.2/ 22.1 [32] 30 [33] / 26 [34] 1.85 [32] / 4.56 [34] 23/ 27.2 [32]
White wine pomace 58.6 56.3 2.3 3.9 [25] / 5.5 [35] 41.2 [25] / 53.6 [35] -
Results expressed as percentage of original dry matter, - no data available, b= as hemicellulose
To view vegetable waste recovery processes as potential goldmines is typically overly optimistic, as
the costs of extraction and purification of the components generally reduce the profit margins available
to levels that are barely economic, as already described.
For this reason the third example is focused on the creation of ‘bioadsorbents’ to be used in waste
water treatment with improved functionality, using their natural content of adsorptive components or
enhancing their adsorption rate by combination of favored raw materials.
Adsorption happens on the interface; therefore an important criterion for the effectiveness of
adsorbents is its surface area. Several methods are available to reach as large as possible surface
area like fine grinding, chemical or biochemical modification, or creating a specific structure. Hence
there is a relation between the natural properties of vegetable material and the requirements for high
quality adsorbents which could be matched during adaptation processing, as visualized in Figure 3.
decent
moderate
moderate
adsorption rate
surface area
chemical stability
possible
regeneration easy
Residual matter low, easy disposal life cycle
long
Adsorbens
good macropores : micropores 50:50
low
chemical inertness high
acceptable pore size distribution decent
very cheap
prize
low
bulk ware
handling
easy
Figure 3 Natural properties of vegetable waste (average) and expected product profile for carbons at
waste water treatment
Effective adsorption is feasible without physical or chemical activation. Several vegetable residues
have been used as bioadsorbents for waste water treatment so far. The raw material has only been
cut, dried, and ground before the experiments; important influencing parameters arise. We did series
of experiments with different residues, checking their ability to adsorb waste water components.
Toluene representing a substance of oecotoxic relevance has been tested in aqueous solution. The
adsorbing conditions were determined while changing the influencing process parameters. As
bioadsorbents we have used olive press cake, dried and ground to different particle sizes.
high
high
good

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
This clean production concept shows a good utilization potential for solid vegetable waste. It could
achieve a reduction of investment and raw material costs and can contribute to a waste-minimized
food production. Especially the development of bioadsorbents is a promising area to add value to
vegetable residues. They will appear as a cheap and environmentally safe alternative to commercial
ion-exchange resins.
References:
[1] Henn, T. (1998). Untersuchungen zur Entwicklung und Bewertung funktioneller Lebensmittelzutaten aus
Reststoffen am Beispiel von Möhrentrestern und ihrer Anwendung in Getränken (Thesis Bonn/D 1998).
Cuvillier Verlag Göttingen.
[2] Henn, T.; Kunz, B. (1996) Zum Wegwerfen zu schade. ZFL 47 (1/2) 21-23.
[3] Lucas, J. et al. (1997) Fermentative utilization of fruit and vegetable pomace (biowaste) for the production
of novel types of products - results of an air project. Proceedings of the eleventh forum for applied
biotechnology, Gent, Belgium, 25-26 September 1997, Part II. Mededelingen -Faculteit-Landbouwkundigeen-Toegepaste-Biologische-Wetenschappen,-Universiteit-Gent.
1997, 62 4b, 1865-1867.
[4] Clemente, A.; Sanchez-Vioque, R.; Vioque, J.; Bautista, J.; Millan, F. (1997). Chemical composition of
extracted dried olive pomaces containing two and three phases. Food-biotechnology 11(3), 273-291.
[5] Dronnet, V.M.; Axelos, M.A.V.; Renard, C.M.; Thibault, J.F. (1998) Improvement of the binding capacity of
metal cations by sugar-beet pulp. 1. Impact of cross-linking treatments on composition, hydration and
binding properties. Carbohydrate polymers 35, 29-37.
[6] Prasertsan, S.; Prasertsan, P. (1996) Biomass residues from palm oil mills in Thailand: an overview on
quantity and potential usage, Biomass and Bioenergy 11 (5) 387-395.
[7] Sriroth, K. et al. (2000) Processing of cassava waste for improved biomass utilization. Bioresource
Technology 71, 63-69.
[8] Carvalheiro, F.; Roseiro, J.C.; Collaco, M.T.A. (1994) Biological conversion of tomato pomace by pure and
mixed fungal cultures. Process biochemistry. 29 (7), 601-605.
[9] Haddadin, M.S.; Abdulrahim, S.M.; Al-Kawaldeh, G.Y.; Robinson, R.K. (1999) Solid state fermentation of
waste pomace from olive processing. Journal of Chemical Technology and Biotechnology 74, 613-618.
[10] Hussein, M. Z., Tarmizi, R. S. H., Zainal, Z., Ibrahim, R. (1996). Preparation and characterization of active
carbons from oil palm shells. Carbon, 34 (11), 1447-1454.
[11] Tran, C.T.; Mitchell, D.A. (1995) Pineapple waste - a novel substrate for citric acid production by solid-state
fermentation. Biotechnology-Letters. 17 (10) 1107-1110.
[12] Nakata, Bill (1994) Recycling by-products on California vineyards. Biocycle 4, 61.
[13] Zheng, Z.; Shetty, K.(1998) Cranberry processing waste for solid state fungal inoculant production. Process
biochemistry 33 (3), 323-329.
[14] Toles, C.A. et al. (2000) Acid-activated carbons from almond shells: physical, chemical and adsorptive
properties and estimated cost of production. Bioresource Technology 71, 87-92.
[15] Manthey, J.A.; Grohmann, K. (1996) Concentrations of Hesperidin and other orange peel flavonoids in
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[16] Idarraga, G. et al. (1999) Pulp and Paper from Blue Agave waste from Tequila production. Journal of
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[17] Iniguez-Covarrubias, G; Lange, S.E.; Rowell, R.M. (2001) Utilization of byproducts from the tequila
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[18] Laufenberg, G.; Kunz, B.; Nystroem, M. (2002) Transformation of vegetable waste into value added
products: a) the upgrading concept b) practical implementations. Biores. Technol. 87, no. 2 167-198.
[19] Laufenberg, G. (2001) Adding value to vegetable waste- Synergy of new utilisation routes and latest
processing technology. Eurocaft2001, European conference on Advanced Technology for Safe and High
quality Foods, 5.-7.12.01 Berlin (D).
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FSB1 – 2004
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Lebensmittelindustrie - Chancen für die Kartoffelstärkeindustrie. New concepts for the utilisation of residual
products from food industry- Prospects for the potato starch industry. Starch-Stärke 48, 315-321.
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fiber content of pear and kiwi pomaces. Journal of Agriculture and Food chemistry 43 (3), 662-666.
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fibre materials: A physicochemical approach. Food Chemistry 54 (1) 23–31.
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spices journal 8 (3), 78-80.
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from sugar beet pulp and potato pulp: influence of extrinsic parameters on their gelling properties. Food
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Zuckerrübenfaserstoffen auf die Qualität von Cookie-Keksen. Zuckerindustrie 124 No. 7, 542-544.
[33] Purchase, B. (1995) Products from sugarcane. International sugar journal 97 No. 1154, 70-71.
[34] Broughton, N.W.; Dalton, C.C.; Jones, G.C.; Williams, E.L. (1995) Adding value to sugar beet pulp.
International Sugar journal 97, No.1154, 57-60 + 93-95.
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of Food Science 60 (4), 818-820.

FSB1- 2004
Food Science and Biotechnology in Developing Countries
THE ALBUMINS AND GLOBULINS RECOVERED FROM SLAUGHTERHOUSE FOR ENRICHMENT
OF BEEF PATTIES
(1) Macedo S.L. ; (2) Pérez Gavilán E.J.P,
(1) (2) Instituto de Investigaciones Biomédicas UNAM.
Circuito escolar S/N Ciudad Universitaria, México D.F .
(1) luis@ correo.biomedicas.unam.mx , (2)pgavilan@servidor.unam.
ABSTRACT
The plasma is heated at 95°C and the precipitate product (albumins & globulins) which is composed of
protein (dry base) ≥ 90%, moisture 82.86% +/-1.32, ash ≤1, total count 2000 cfu/g, coliforms ≤10 cfu/g,
fungus ≤ 5 cfu/g. This product was used as a substitution of meat, in meat patties at level of 0, 10, 20%.
The of cooked patties showed a lost of weight when the level of substitution was increased (P >0.01).
during storage: The ammoniac content of was less than 20mg/100g (20 days at 3°C), the evolution of
microbial count at 3°C was less that in the 0% sample. In the sensory analysis, the acceptability for
appearance, texture and flavor was the one with 10% of substitution the most acceptable (P>0.05)
KEYWORDS: Albumins, globulins, plasma, patty, slaughterhouse.
INTRODUCTION
The first step in the industrialization of the animals is the slaughter, in first instance meat, organs, skins
and blood are obtained The blood that can be gathered in this process is around 3% of the live weight of
the animal (Ockerman, H. W. and Hansen, C. L. 1994 ) and the rest is retained in the muscles. By this
data it is possible to recollect 200 million liters per year in Mexico. This contains 20% of solids of which
96% is hemoglobin, albumin, globulin and fibrinogen, the remaining 4% contains minor compounds
(Cheftel, J. C. 1989.) ,that means that 40,000 ton of proteins can be recover. The blood with
anticoagulant can be divided by centrifugation in globular package with 32% of total solids and plasma
with 9%. The globular package is mainly hemoglobin with useful functional properties in the formulation
of foods (Nakamura, R., et at the 1984) from the nutritional point of view it have deficiencies in leucin and
metionin. Internationally this package is dried by aspersion and used in the animal feeding. The plasma
contains 60% of albumin 35% of globulin and 5% fibrinogen, with similar functional properties to the egg
albumin (Howell, N. K. and Lawrie, R. A. 1984. Howell, N. K. and Lawrie, R. A. 1985., O'Riordan, et to
the one. 1989). from the nutritional point of view for humans doesn't have limiting amino acids, they are
high in lysine (12% ) and has a protein efficiency ratio (PER) above that casein, (Young et al 1973).
Internationally the plasma is concentrated and dried off by aspersion. In Mexico these products don't
take place due that is uneconomical for high investment costs and operation. In the country 175
slaughterhouses ( federal inspection type) exist (SAGARPA, 2000) in 11 of them (Cuautitlan, Los arcos,
Tlalnepantla, Cerro Gordo, Temamatla, Ecatepec, Naucalpan, Muñora, La paz, Nezahualcoyotl and
Atizapan) were ask about the destination of blood. The result of the blood has 3 destinations drainage,
morcilla and blood flour. The main one coagulated with pressed heat and dried off in the sun in patios,
others with different type of drying we can obtained products of variable quality and of very doubtful
bacteriological content especially in salmonellas. The objective of this work was investigate the recovery
from proteins of the plasma using its gelatin properties and use this proteins with ground meat in the
production of beef patties.
METHODS AND MATERIALS
Blood recollection For all the experiments, the pig blood was gathered from the slaughterhouse
(TIF 179 of Cuautitlán Izcalli). It was received in recipients of a gallon of capacity that contained 100 ml
25%of sodium citrate solution to avoid the clotting. After 1 h they were stored at 4 ºC. Recovery of the
plasmatic proteins was carried out as follow: the blood was centrifuged 3000 r.p.m. during 10 min. to
separate the globules from the plasma. The plasma was warmed slowly up to 92 ºC with constant
agitation let it stay during 10 min. and then decanted. Two liters of top water was added by each liter of
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FSB1- 2004
Food Science and Biotechnology in Developing Countries
coagulated plasma, and agitated for 3 min, decanted again this operation was reported. The washed
coagulated plasma was placed on a gauze and it was pressed manually to eliminate the excess of water.
The plasma was placed inside a plastic bag, closed and stored in refrigeration at 4 ºC Effect of the time,
among the bleed of the animal and the refrigeration of the blood, and the time of refrigeration of the blood
before the separation and clotting (TRASC) in the yield and microbial contained of coagulated plasma. By
means of a factorial design 2x4x2 were studied: the time among the bleed of the animal and the
refrigeration of the blood (1 or 4 h, approximately at 37ºC) the (TRASC) (18, 42, 66 and 90 h) the
temperature of the laundry water (20 or 80ºC). Determination during storage (TRASC) the pH, total solids
for evaporation at 100ºC during 4 h and the total count of aerobic mesophilic . The yield was defined as
the quantity of solids recovered in coagulated and washed plasma by each 100g of solids of plasma
without coagulating ..During the storage at 4ºC, was determined the total count of aerobic mesophilic at
the 7 and 14 days. Effect of the addition of acetic acid and atmosphere of CO2 in the of shelf life of
coagulated plasma. Prepared samples of 100g of coagulated and washed plasma, with 48 and 67 h of
storage at 4ºC before cotting were added 0 and 0.5% of glacial acetic acid before their storage, it was also
made happen or not, a current of CO2 (4 Kg/cm2 for 2 min) in the bags containing the coagulated plasma,
the samples were stored at 4ºC. The determinations were carried out at the same times and under the
same conditions that in the previous experiment. Use of plasma proteins (PP) in Ground meat (GM) for
preparation of beef patties. Commercial ground meat was used, plasma proteins were obtained from the
recovery plant of FIRASA Company and pig fat (G) from the same company. Determination of pH,
protein, ether extract , ash, humidity and total count aerobic mesophilic were done by conventional
methods. For the shelf life, the samples were: GM, PP+10% of G, GM+10%(PP+10% G) they were
maintain in refrigeration (3°C) and freezing (-13°C). For the sensorial analysis 96 hamburgers, for each
treatment were prepared. .The formula for each treatment were: GM100%, GM90%+10%(PP+10%G) and
GM 80%+20%(PP+10%G). To all the samples was added 0.2% of salt. Cooked samples were offer to 64
panelist and requested they ordered the three samples offered for their preference by the attributes
appearance, odor, texture and flavor.
RESULTS AND DISCUSSION
Effect of the time, among the bleed of the animal and the refrigeration of the blood, and the time of
refrigeration of the blood before the separation and clotting (TRASC) in the yield and microbial contained
of coagulated plasma.
In the Table 1 the results of the effect of time between the bleed of the animal and the refrigeration are
presented and the time of storage of the blood (TRASC), in the obtaining of the coagulated plasma; as it is
observed a high significance it exists on the pH, of the time among the bleed of the animal and the
refrigeration of the blood, and of the time of refrigeration of the blood before the separation and clotting
(TRASC), since the values of pH of the blood maintained at 37ºC during 4 h are consistently bigger than
those only maintained 1 h, and in what concerns at the time of storage (TRASC) as this happens there is
a pH increase until the 66 h, this is accountable from the point of view that this situation is usually
presented when the substrate of the microorganisms is only protein, (like in the case of the blood), since
so that these can use it as source of carbon it should exist a proteolysis and a production of ammonia like
consequence of the liberation of the group amino of the amino acids and they use this way as source of
carbon the sour carboxylic acids, however, between the 66 and 90 h this effect no longer present
significant difference.
In what concerns to the humidity of the coagulated plasma, the time among the bleed of the
animal and the refrigeration of the blood had a significant effect where the humidity of the obtained
coagulated plasma maintained 4 h at 37ºC is higher to the obtained of plasma refrigerated 1h after
bleed. The time of storage (TRASC) it also affects in significant form the water contain of the coagulated
plasma having a tendency to obtain minor contain of water when the time increase ; this means that the
functional property of capacity of retention of water of the plasma is better maintain when the blood is at
37ºC and with short time of storage.
From our results it is deduced that they recover of proteins is between 70 and 80% of the
proteins contained in the plasma and that the time of storage of the plasma before coagulating (TRASC)
has a negative effect in the yield, because during the storage there is microbial growth and therefore
proteolysis, what affects the gelification properties, this agrees with Howell and Lawre (1985), which study
the effect from the tripsin addition to the plasma and they observe a very important reduction of the
2

FSB1- 2004
Food Science and Biotechnology in Developing Countries
gelification properties.
In the quality microorganism of the plasma before coagulating, it is clear a significant effect of the
time of storage (TRASC) increasing of log from 3.48 UFC in 18 h to log of 5.00 UFC at 90 h, however,
using a source of plasma with different contained microorganism, this is not reflected since in the
conservation, that is why significant effects of the time of storage don't exist (TRASC) neither at the 7
neither at 14 days; if our results are compared in absolute form with those of Surkiewicz, et to the (1975)
who analyzed hamburgers prepared in establishments with Federal Inspection finding that 76% of the
obtained samples contained 1X106 total counts of aerobic, we see that the coagulated plasma and
maintained 7 days, is in the range of the usual contamination of ground meat for hamburgers.. The only
two significant effects of the temperature of the top water were presented in the humidity and the weight
of the coagulated plasma being higher at 80ºC than at 20ºC. Effect of the addition of acetic acid and
atmosphere of CO2 in the life of plasma coagulated .The results indicate (Table 2) that the effect of the
addition of acetic acid in the concentration of aerobic mesophilic at 7 and 14 days of storage at 4ºC it is
significant (p>0.05), however the effect of the CO2 is not significant, although the antibacterial property of
the CO2 has generally been used to lengthen the shelf life of meats in refrigeration developing the
technique call packed in modified atmosphere (Gill and Harrison, 1989. Gill et to the, 1990). It is important
to mention that the N° of microorganism at the 7 and 14 days are smaller in all the treatments, with regard
to previous experiments even in the control samples the speculative explanation that will be necessary to
clarify in later experiments, is that when having stored the samples that contained CO2 together with the
samples that didn't control it minimized the effect since it is probable that there has been permeability of
this gas.
The samples with acetic acid and atmosphere of CO2 were continued until the 3 and 6 months of
storage at 4ºC, not being any growth neither of aerobic mesophilic neither of anaerobes. The conservative
power of the acetic acid is very well-known (Russell et to the, 1982), and in our results this conservation
capacity is shown since in dramatic form while the coagulated plasma maintained without preservative
during 14 days at 4ºC has count of aerobic mesophilic in around 1x108 when one adds acetic acid and
CO2 don't exist aerobic neither anaerobic, a possible explanation to this fact you could base in that the
procedure to obtain coagulated plasma recovers the proteins exclusively, being the glucose and the
minerals wash during the procedure and the acetic acid in anaerobic conditions cannot be used ,since by
the microorganisms like source of carbon to metabolize it they would need of the oxygen presence.
Recently Dickens et al t (1994 and 1994b) used the acetic acid to diminish the enterobacteria count in the
conservation of chicken channels, the concentration used by Dickens was 0.6% near concentration to
which we use in this work.
Use of the proteins of plasma (PP) in meat milled for hamburgers The results of the analysis carried out to
GM and PP were: Humidity 71.53% and 82.86%, protein19.22% and 17.14%, fat 9.37% and 0.0%, ash
0.97% and 0.5%, pH 5.6.y 4.8 ,mesophilic aerobic 450,000 and 44,000 respectively. .It was observe that
the evolution in the content of microorganisms in the samples maintained at -13°C is high when the
samples contain GM while the sample that doesn't control it maintains without growth until for but of 100
days in a similar way the samples maintained 4°C .concerns to the content of ammonia nitrogen the
samples that GM contains they surpass that allowed by the Mexican official norm in 12 days while, In the
other hand those that didn't contain GM stayed inside norm for but of 40 days to both storage
temperatures.
The results of the analyses sensorial carried out indicate that the better acceptability corresponds to the
sample that contains 10% of (PP +10% of G) in all the attributes however is only significant (p> 0.01) in
odor in vs. control ,in the case of the sample that contains 20% significant detrimental effects are
presented (p> 0.01) in appearance and flavor vs. the other two samples.
CONCLUSIONS
1.-Se conclude that the procedure of recovery of the proteins of the blood by means of the use of the heat
is possible and the proteins useful for preparing beef patties.
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Food Science and Biotechnology in Developing Countries
REFERENCES
Cheftel, J. C. 1989. Proteínas alimentarías. Ed. Acriba, S. A. Zaragoza, España. 221-32.
Dickens, J. A. and Whittemore, A. D. 1994. The effect of acetic acid and air injection on appearance,
moisture pick-up, microbiological quality and Salmonella incidence on processed poultry carcasses.
Poultry Science. 73:582-86.
Dickens, J. A. Lyon, B. G., Whittemore, A. D. and Lyon, C. E. 1994. The effect of an acetic acid dip on
carcass appearance, microbiological quality, and cooked breast meat texture and flavor. Poultry Science
73:576-81.
Gill, C. O. and Harrison, J. C. L. 1989. The storage life of chilled pork packaged under carbon dioxide.
Meat Sci. 26:313-24.
Gill, C. O., Harrison, J. C. L. and Penny, N. 1990. The storage life of chicken carcasses packaged under
carbon dioxide. Int. J. Food Microbiol. 11:151-57.
Howell, N. K. y Lawrie R. A. 1984. Functional aspects of blood plasma proteins. II. Gelling properties. J.
Food Tech. 19: 289-95.
Howell, N. K. and Lawrie, R. A. 1985. Functional aspects of blood plasma proteins IV. Elucidation of the
mechanism of gelation of plasma and egg albumen proteins. J. Food Tech. 20:489-504.
Mao R., Tang J., Swanson B G, Texture properties of high and low acyl mixed gellan gels, Carbohydrate
Polymers (41) 2000 331-338.
Nakamura, R., Hayakawa, S. Yasuda, K. and Sato, Y. 1984. Emulsifying properties of bovine blood
globin: A comparison with some proteins and their improvement. J. Food Sci. 49:102-
Norma Oficial Mexicana NOM-034-SSA1-1993, Bienes y servicios. Productos de la carne. Carne molida
moldeada. Envasada. Especificaciones sanitarias.
O'Riordan, D. Mulvihill D. M. Morrissey P. A. and Kinsella J. E. 1989. Study of the molecular forces
involved in the gelation of plasma proteins at alkaline pH. J. Food Sci. 54:5 1202-05.
Ockerman, H. W. y Hansen, C. L. 1994. Industrialización de subproductos de origen animal. Ed. Acribia,
S.A. Zaragoza, España. 239-63.
Pons M. and Fiszman S.M. 1996. Instrumental Texture Profile Analysis with particular reference to gelled
sistems597-621, journal of texture estudies (27) 1996. 597-624.
Russell, A. D., Hugo, W. D. and Ayliffe, G. A. J. 1982. Principles and practice of disinfection, preservation
and sterilization. Blackwell Scientific Publications. Osney Mead Oxford, London. 314-16
SAGARPA 2000 Secretaria de agricultura, ganaderia, desarrollo rural,pesca y alimentacion. Direccion
general de salud animal.Directorio de Plantas tipo inspeccion federal en operacion.
Surkiewicz, B. F., Harris, M. E., Elliot, R. P., Macaluso, J. F. and Strand, M. M. 1975.
Bacteriological survey of raw beef patties produced at establishments under Federal Inspection. Appl.
Microbiol. 29:3 331-34.
Young, C. R., Lewis,R. W., Landmann, W. A. and Dill, C. W. 1973. Nutritive value of globin and plasma
protein fractions from bovine blood. Nutr. Rep. Intl. 8:211.
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Food Science and Biotechnology in Developing Countries
TABLE 1
EFECT OF THE TIME AMONG THE BLEED OF THE ANIMAL AND THE REFRIGERATION OF THE BLOOD, AND TIME OF REFRIGERATION OF THE
BLOOD BEFORE OF THE SEPARATION AND CLOTTING, IN THE YIEL AND CONTAINED MICROORGANISM OF COAGULATED PLASMA
Logarithm of
aeróbic
mesophilic of
stored
coagulated 14
days at 4ºC
Logarithm of
aeróbic
mesophilic of
stored
coagulated
plasma 7 days
at 4ºC
Logarithm of
aeróbic
mesophilic of
plasma without
coagulating
yield 1
(%)
g of coagulated
plasma / 100 ml
of plasma
without
coagulating
Humidity
coagulated
plasma
(%)
Humidity of
plasma
without
coagulating
(%)
pH of
plasma
without
coagulating
Temperature
of the laundry
water
(ºC)
Time of
refrigeration of
the blood before
the separation
and clotting
(h)
Time among
bleed of the
animal and
refrigeration of
the blood
(h)
5.49 8.69
3.48 a
78.26 a
44.8 a
83.79 a
ND
6.90 a
>4.00 9.05
3.48 a
80.11 a
49.2 a
84.89 a
ND
6.90 a
5.30 9.24
ND
4
18 20
4
18 80
1 18 20
4.90 a
78.26 a
40.8 a
82.20 a
6.77 a
4.70 8.66
4.90 a
75.81 a
41.0 a
82.84 a
ND
6.77 a
1 18 80
7.48 9.03
3.48 a
83.69 b
36.3 b
78.26 bc
90.57
6.97 a
4 42 20
5.78 9.11
3.48 a
82.95 b
40.7 b
80.78 bc
90.57
6.97 a
4 42 80
6.85 8.88
4.60 a
81.23 b
31.6 b
75.99 bc
90.66
6.72 a
1 42 20
7.00 8.79
4.60 a
80.12 b
35.0 b
78.62 bc
90.66
6.72 a
1 42 80
7.08 9.49
4.95 ab
72.10 c
32.3 c
78.84 b
90.52
7.23 b
4 66 20
5.48 8.59
4.95 ab
71.85 c
31.2 c
78.17 b
90.52
7.23 b
4 66 80
7.00 9.23
4.70 ab
69.20 c
26.9 c
76.00 b
90.67
7.17 b
1 66 20
7.00 9.28
4.70 ab
68.13 c
26.2 c
75.74 b
90.67
7.17 b
1 66 80
6.30 8.66
5.48 b
73.52 c
30.6 d
78.52 c
91.06
7.17 b
4 90 20
>7.00 >7.00
5.48 b
76.26 c
37.4 d
81.77 c
91.06
7.17 b
4 90 80
6.00 8.41
5.00 b
68.58 c
29.8 d
78.92 c
90.84
7.12 b
1 90 20
>7.00 >7.00
5.00 b
70.27 c
31.4 d
79.50 c
90.84
7.12 b
1 90 80
Variation source Significance
Time among bled and refrigeration
0.0007 - 0.0023 0.0002 0.0005 0.1148 0.8264 0.9390
Time of storage (TRASC)
0.0000 - 0.0000 0.0000 0.0000 0.0292 0.2489 0.8545
Temperature of the laundry water 1.0000 - 0.0257 0.0236 0.9052 1.0000 0.8760 0.6199
a, b, c, d = Value means that don´t have common superscript they are significantly different to the 0.05 regarding the time of storage of the blood. All the counts of m.o. they are reported
by gram of plasma.
1 Defined as the quality of solids recovered in the coagulated plasma divided by the quantity of the plasma without coagulating for 100.
5

FSB1- 2004
Food Science and Biotechnology in Developing Countries
TABLE 2
EFFECT OF THE ADDITION OF ACETIC ACID AND ATMOSPHERE OF CO2 IN THE SHELF LIFE OF COAGULATED PLASMA
logarithm of
aeróbic
mesophilic of
stored
coagulated
plasma 7 days
14 day at 4ºC
logarithm of
aeróbic
mesophilic of
stored
coagulated
plasma 7 days
at 4ºC
Initial
logarithm of
aeróbic
mesophilic
of
coagulated
plasma
pH of plasma
coagulated
stored 14 days
at 4ºC
pH of plasma
coagulated
stored 7 days
at 4ºC
Initial pH of
coagulated
plasma
Atmosphere
of CO2
Concentration
glacial acetic
acid (%)
Time of
refrigeration of
the blood before
the separation
and clotting
(h)
48
0.0 no ND ND 7.40 ND 3.30 3.00
48
0.5 no ND ND 5.74 ND 2.00 0.00
48 0.0 si ND ND 7.46 ND 3.00 3.30
48 0.5 si ND ND 5.84 ND 0.00 0.00
67 0.0 no 8.54 7.20 7.48 2.60 3.00 2.60
67 0.5 no 4.98 6.18 5.89 2.30 2.00 2.00
67 0.0 si 8.54 7.49 7.55 2.60 2.48 2.60
67 0.5 si 4.98 6.18 6.14 2.30 1.70 1.00
Variation source Significance
Time of storage (TRASC) - - 0.0403 - 0.6717 0.4588
Concentration of acetic acid - - 0.0000 - 0.0328 0.0202
Atmosphere of CO2 - - 0.0816 - 0.1756 0.7766
ND = Not certain
All the counts of m.o. they are reported by gram of plasma.
Additionally, to the 3 and 6 months of storage at 5°C, it was determined aerobes mesophilic.
6

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Food Science and Biotechnology in Developing Countries
Studies on starch digestibility in Phaseolus coccineous L. bean
Luis Arturo Bello Pérez, Perla Osorio Díaz, Edith Agama Acevedo y Francisco García Suárez
Centro de Desarrollo de Productos Bióticos del IPN. Km 8.5 carr. Yautepec-Jojutla, Colonia San
Isidro, Apartado Postal 24, 62731 Yautepec, Morelos, México. e-mail: labellop@ipn.mx Tel.: + 52 735
3942020; Fax: +5273941896
Abstract
“Ayocote” beans (Phaseolus coccineous) were cooked and studied regarding their chemical
composition and in vitro starch digestibility. Protein and ash contents were 19.15 and 1.39 %,
respectively, lipid content was relatively high (3.31 %). Available starch (AS) values decreased with
storage at 4 o C, changing from 37.93 (freshly cooked “control” seeds) to 32.18 % (seeds stored for 96
h). RS ranged between 2.24 %, and 3.49 % for the control and 96 h-stored samples. Retrograded
resistant starch (RRS) had similar behavior, as its values increased with the storage time.
Keywords: Starch; resistant starch; digestibility; Phaseolus coccineous; beans; legumes.
Introduction
Beans are a rich and inexpensive source of proteins (20-25 %) and carbohydrates (50-60 %) for a
large part of the world’s population, mainly in developing count ries 1 . México is accepted as center of
origin of beans, since 47 of the 52 species classified in the Phaseolus genus were identified in Mexico;
besides, Mexico possesses the wild type of the 5 cultivated species of this genus, i.e. P. vulgaris, P.
acutifolius, P. lunatus, P. coccineous and P. polyanthus 2 . Although carbohydrates are the major
component of legumes, relatively little work has been carried out on this fraction 3 . Besides, being a
major plant metabolite, starch is also the dominating carbohydrate in the human diet 4, 5 . Starch was
considered an available carbohydrate that was completely digested and absorbed in the small
intestine. However, it is now known that there exists a starch fraction that is resistant to enzyme
digestion, passing through the small intestine and reaching the large bowel where it may be fermented
by the colonic microflora. This fraction is called resistant starch (RS) and is defined as the sum of
starch and the products of starch degradation not absorbed in the small intestine of healthy
individuals 6 . The types of RS identified in foods are: physically entrapped starch within whole or partly
milled grains or seeds (RS1), native (ungelatinized) granules of B-type starches (RS2), and
1

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
retrograded starch (RS3) 7 . Most studies on starch digestibility in beans in México 8, 9, 10,11 , Venezuela 12,
13 , Spain 14 , and Pakistan 15 , were carried out in common beans (Phaseolus vulgaris L.). However, to
the best of our knowledge, no research has been conducted on starch digestibility of “ayocote” beans
(Phaseolus coccineous), a specie widely consumed in central and southern Mexico. The objective was
to evaluate the in vitro starch bioavailability of cooked “ayocote”, looking also at the influence of cold-
storage on their available and resistant starch content and in vitro rate of starch digestion.
Materials and Methods
Sample preparation
“Ayocote” bean seeds were purchased from local market in Yautepec, Morelos, México. The beans
were cooked using a Mattson cooker, and cooking time was determined 16 . The sample, cooked seeds
plus cooking water, were cooled down at room temperature and stored during 24, 48, 72 and 96 h at 4
°C, simulating cooking and store conditions applied in Mexican households.
Chemical analysis
Moisture content was determined by gravimetric heating (130 ± 2°C for 2 h) using 2-3 g of sample.
Ash, protein (N x 5.85) and fat were analyzed according to AACC methods 08-01, 46-13, and 30-25,
respectively 17 .
Digestibility tests
Available starch (AS) content was assessed following the multienzymatic protocol of Holm et al. 18 ,
using Termamyl® (Novo A/S, Copenhagen) and amyloglucosidase (102857 Roche Diagnostics,
Indianapolis, IN, USA). The method proposed by Goñi, et al. 19 was employed to estimate the amount
of indigestible starch (comprising part of RS1 plus RS2 and RS3 fractions). Retrograded resistant
starch (RS3) content was measured as starch remnants in dietary fiber residues, according to the so
called Lund method as modified by Saura-Calixto et al. 20 . In all these enzymatic tests, a portion of
cooked beans was weighed into a test tube or a beaker, and homogenized with the corresponding
solution (depending on the assay) under controlled conditions: first step (speed level 2, 1 min) and
second step (speed level 2.5, 1 min), using a Polytron PT 1200 homogenizer (Kinematica AG,
Switzerland).
Statistics
2

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Results were expressed by mean values ± standard error of the three separate determinations.
Comparison of means was performed by one-way analysis of variance (ANOVA) followed by Tukey’s
multiple comparison tests using the SPSS statistical program (v. 2.03, Chicago, IL).
Results and Discussion
Chemical composition
Moisture content in the raw flour of “ayocote” bean was of 9.33 ± 0.13 %, a value that is slightly higher
than those det ermined in other legume species. Protein content in the here-studied species was of
19.15 ± 0.40 %, a value that is in the range reported 10 in common black beans (between 18.87 and
24.20 %), and was slightly lower than those reported by Reyes-Moreno and Paredes-López 16 , who
found protein values between 20.3 and 29.0%. The lipid content in the “ayocote” sample was of 3.31 ±
0.06 %, which is higher than data recorded previously in seeds from other Phaseolus species, ranging
between 0.90 and 2.80 % 10, 21 . This value may be of importance in the formation of amylose-lipid
complexes, which may reduce the starch digestibility 4 . In relation to ash content, “ayocote” had a value
of 1.39 ± 0.04 %, being lower than those reported in an Indian Phaseolus vulgaris cultivar 21 and four
other black bean cultivars (Phaseolus vulgaris L.) from México (between 3.62 and 5.15 %) 10 . Total
starch (TS) in “ayocote” bean was 42.1 %. This is higher than those reported in Phaseolus vulgaris
cultivars; Tovar and Melito 12 reported TS contents in two raw bean varieties of 39.3 and 39.9 %; a
similar value was recorded in raw white beans 14 . However, Bravo et al. 21 reported TS value of 34.9 for
Haricot beans, and Vargas-Torres et al. 10 between 33.56 and 36.69 % for four cultivars of black
beans.
Available starch (AS)
AS was determined at different cold-storage times (Table 1), the level decreased from 37.93% in
freshly cooked “ayocote” seeds to 32.18 % in the sample stored for 96 h. These values represented
90 and 76 % of TS, respectively, differences that may be due to the presence of resistant starch (RS).
A previous study on cooked black beans from different cultivars, reported AS contents in cooked
control samples (without storage) ranging between 32.1 and 21.7 %; these values decreased with the
storage time, reaching levels between 21.8 and 13.5 % 11 . Nonetheless, it is important to mention that
3

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
some beans show lower AS contents and higher retrogradation tendencies than others; in the case of
“ayocote” bean, the decrease of AS values in the stored samples appears relatively low.
Resistant starch (RS)
The RS values increased with the storage time (Table 1). Levels ranged between 2.24 %, for the
control sample, and 3.49 % for the 96 h-stored preparation, representing a 56 % increase in RS
content with the storage. Ample variation in RS content values has been previously observed for
freshly cooked common beans (Phaseolus vulgaris). Indeed, most cultivars exhibited greater levels
than those recorded here for “ayocote” seeds 11, 12, 21 . Furthermore, RS in “ayocote” beans exhibited
only a moderate rise after cold-storage. Thus, this legume seems to have a modest proclivity to
develop retrograded resistant starch fractions upon cooling, which is contrast with the generally
recognized behavior for starch in pulses 11, 12, 22, 23, .
Table 1. Available starch (AS), resistant starch (RS) and retrograded resistant starch (RRS) content of
cooked “ayocote” bean*,**
Storage time (h) AS RS RRS
0 37.93 a ± 1.30 2.24 a ± 0.15 1.49 a ± 0.12
24 35.29 b ± 0.73 2.79 b ± 0.08 1.72 b ± 0.16
48 34.58 b,c ± 0.94 2.88 b,c ± 0.17 1.89 b ± 0.21
72 32.93 d ± 1.04 3.08 d ± 012 1.95 b ± 0.18
96 32.18 d,e ± 0.89 3.49 e ± 0.09 2.53 c ± 0.22
* Values are mean of three replicates ± standard error, dry matter basis.
** Means inside each column with a different letter are significantly different (α=0.05)
Retrograded resistant starch (RRS)
The value of RRS (Table 1) in the control sample was of 1.49 %. It increased with the storage time,
reaching 2.53 % after 96 h. The RRS contents at 24, 48 and 72 h were not different (a=0.05), but at 96
h the value increased significantly; perhaps, only after this time starch retrogradation becomes
quantitatively important in this system, as it was suggested for the recrystallization process in corn
starch gels 24 . Some black bean cultivars 11 presented RRS contents that increased within the 0-72h
4

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
storage period, becoming constant thereafter. Again, present data suggest that “ayocote” bean had a
lower retrogradation rate than common beans and other pulses.
Conclusions
“Ayocote” bean had lower protein and ash contents and higher lipid and total starch levels than other
Phaseolus seeds. Available starch in this bean is higher than in other species’ seeds, but it tends to
decrease upon cold-storage. Both total resistant and retrograded resistant starch contents increased
with storage time, as a consequence of starch retrogradation. Storage time, in addition to the botanical
species/variety, may influence digestibility of starch pulses; suggesting that some species might be
preferred for specific dietetic uses.
Acknowledgements
We appreciate the economic support from CGPI-IPN, IPICS, LANFOOD, CONACYT-México and
COFAA-IPN.
REFERENCES
1. Rehman Z. Salariya A.M. Zafar S.I. 2001. Effect of processing on available carbohydrate
content and tsrach digestibility of kidney beans (Phaseolus vulgaris L.). Food Chem. 73: 351-
355.
2. Sousa-Sánchez M. Delgado-Salinas A. 1993. Mexican leguminoseae: Phytogeographic
endemism and origins. In: Biological diversity in México: origins and distribution.
Ramamoorthy TP, Bye R, Lot A, Fa J. New York: Oxford University Press. pp. 459-511.
3. Bravo L. Siddhuraju P. Saura-Calixto F. 1998. Effect of various processing methods on the in
vitro starch digestibility and resistant starch content of indian pulses. J. Agric. Food Chem. 46:
4667-4674.
4. Björck I.M. Granfeldt Y. Liljeberg H. Tovar J. Asp N.G. 1994. Food properties affecting the
digestion and absorption of carbohydrates. Am. J. Clin. Nutr. 59: 699S-705S.
5. Skrabanja V. Liljeberg H.G.M. Hedley C.L. Kreft I. Björck I.M.E. 1999. Influence of genotype
and processing on the in vitro rate of starch hydrolysis and resistant starch formation in peas
(Pisum sativum L.). J. Agric. Food Chem. 47: 2033-2039.
6. Asp N-G. 1992. Resistant starch. Proceedings from the second plenary meeting of EURESTA.
Eur. J. Clin. Nutr. 46: SI.
7. Englyst H.N Kingman S.M. Cummings J.H. 1992. Classification and measurement of
nutritionally important starch fractions. Eur. J. Clin. Nutr. 46: S33-S50.
5

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Food Science and Biotechnology in Developing Countries
8. Osorio-Díaz P. Bello-Pérez L.A. Agama-Acevedo E. Vargas-Torres A. Tovar J. Paredes-
López O. 2002. In vitro digestibility and resistant starch content of some industrialized
commercial beans (Phaseolus vulgaris L.). Food Chem. 78: 333-337.
9. Osorio-Díaz P. Bello-Pérez L.A. Sáyago-Ayerdi S.G. Reyes -Benítez M.P. Tovar J. Paredes-
López O. 2003. Effect of processing and storage time on in vitro digestibility and resistant
starch content of two bean (Phaseolus vulgaris L.). J. Sci Food Agric. 83: 1283-1288.
10. Vargas-Torres A. Osorio-Díaz P. Tovar J. Paredes-López O. Ruales J. Bello-Pérez L.A.
2004a. Chemical composition, starch bioavailability and indigestible fraction of common beans
(Phaseolus vulgaris L). Starch/Starkë 56: 74-78.
11. Vargas-Torres A. Osorio-Díaz P. Islas-Hernández J.J. Tovar J. Paredes-López O. Bello-Pérez
L.A. 2004b. Starch digestibility of five cooked black beans (Phaseolus vulgaris L.) varieties. J.
Food Comp. Anal. (In press)
12. Tovar J. Melito C. 1996. Steam-cooking and dry heating produce resistant starch in legumes.
J. Agric. Food Chem. 44: 2642-2645.
13. Velasco Z.I. Rascón A. Tovar J. 1997. Enzymic availability of starch in cooked black beans
(Phaseolus vulgaris L) and cowpeas (Vigna spp.). J. Agric. Food Chem. 45: 1548-1551.
14. García-Alonso A. Goñi I. Saura-Calixto F. 1998. Resistant starch formation and potential
glycemic index of raw and cooked legumes (lentils, chickpeas and beans). Z. Lebensm Unter
Forsch 206: 284-287.
15. Rehman Z. Salariya A.M. Zafar S.I. 2001. Effect of processing on available carbohydrate
content and tsrach digestibility of kidney beans (Phaseolus vulgaris L.). Food Chem. 73: 351-
355.
16. Reyes-Moreno C. Paredes-López O. 1993. Hard-to-cook phenomenon in common beans- A
review. Crit. Rev. Food Sci. Nutr. 33: 227-286.
17. AACC. 2000. Approved methods. (10th ed). St. Paul, MN: American Association of Cereal
Chemists.
18. Holm J. Björck I. Drews A. Asp N-G. 1986. A rapid method for the analysis of starch.
Starch/Stärke 38: 224-229.
19. Goñi I. Garcia-Diaz L. Mañas E. Saura-Calixto F. 1996. Analysis of resistant starch: a method
for foods and food products. Food Chem. 56: 445-449.
20. Saura-Calixto F. Goñi I. Bravo L. Mañas E. 1993. Resistant starch in foods: modified method
for dietary fiber residues. J. Food Sci. 58: 642-643.
21. Bravo L. Siddhuraju P. Saura-Calixto F. 1999. Composition of underexploited indian pulses.
Comparison with common legumes. Food Chem. 64: 185-192.
22. Rosin M.P. Lajolo M.F. Menezes W.E. 2002. Measurement and characterization of dietary
starches. J. Food Comp. Anal. 15: 367-377.
23. Tovar J. Melito C. Herrera E. Rascón A. Pérez E. 2002. Resistant starch formation does not
parallel syneresis tendency in different starch gels. Food Chem. 76: 455-459.
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24. Farhat I.A. Blanshard J.M.V. Mitchell J.R. 2000. The retrogradation of waxy maize starch
extrudates: Effects of storage temperature and water content. Biopolymers 53: 411-422.
7

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Food Science and Biotechnology in Developing Countries
RESISTANT STARCH CONTENT OF CORN TORTILLAS WITH TC-1 HYDROCOLLOID
Rendón-Villalobos, Rodolfo 1 ; Bello-Pérez, Luis Arturo 1 ; Agama-Acevedo, Edith 1 ;
and Islas-Hernández, José Juan 1 .
1 Centro de Desarrollo de Productos Bióticos del IPN.
Km 8.5 carr. Yautepec-Jojutla, colonia San Isidro,
apartado postal 24, 62731 Yautepec, Morelos, México .Fax: +5273941896
Summary
Tortillas were prepared using TC-1, stored for 96 hours and their total, available starch (AS) and
resistant starch (RS) were evaluated. AS decreased with the storage time and tortillas with TC-1 had
lower values than control sample. Control tortilla had RS content that increased with storage time, but
in general, tortillas with TC-1 hydrocolloid presented a slight increased after 96 h. approximately 50 %
of RS is due to retrogradation phenomenon.
Keywords: Nixtamalization, hydrocolloids, tortillas, resistant starch, starch bioavailability
INTRODUCTION
The nixtamalization of maize is an ancient process developed by the Aztecs and still utilized in the
production of high quality tortillas and other maize related food products (i.e., pozole). The aztecs
grind the maize grains after an alkali (i.e., lime) and heating treatment in a process known as
“nixtamalización”. Still today, Latin American countries manufacture maize food product after
nixtamalization; these products are represent an important source of calories, proteins, dietary fiber
and calcium 1 . Nowadays, table corn tortillas, as part of the ethnic food trend, are highly popular in
developed countries (e.g., United States) and are consumed as break during the main meal 2 .
Nevertheless, masa production at the industrial level does not quite follow the traditional
nixtamalization conditions, resulting in tortillas which texture and stability during storage are of lower
quality went compared with the traditional-made tortilla. Carbohydrates represent the main fraction of
cereal grains, accounting for up to 50-70 % of the dry matter; of these, starch and non-starch
polysaccharides (dietary fiber) are the major constituents. When tortillas are cook starch gelatinization
is carried out, the gelatinized starch gels are thermodynamically unstable structures and, on cooling,
reassociation of the starch molecules may occur. The ability of starch chains to form ordered
structures in pastes, gels and baked foods during storage, a process often described by the term

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
“retrogradation”, greatly influences the texture and shelf-life of these products 3 . The tortillas have a
problem, because after preparation staling ocurrs increasing rigidity which affects palatability. On the
other hand, starch retrogradation increases enzymatic resistance to starch digestion due to the
formation of resistant starch wich is associate with low glycaemic and insulinemic responses and is
very important for prevention of some diseases as colonrectal cancer, low blood cholesterol, decresed
of coronary infart. Hydrocolloids are normally added to bakery products to improve shelf life by
retaining more moisture and retarding staling 4 ; however, adding hydrocolloids to bakery products to
reduce staling also affects processing and product qualities 5 . It has been reported that adding
hydrocolloids in tortillas enhance the flexibility and strenght, reduce stickiness during process and
packing, increase postbake moisture levels, slow the staling process, and extend shelf life 6,7,8 ;
however, interactions between starch and hydrocolloids may ocurrs in tortillas containing these
additives which might decrease starch digestibility. Good quality corn tortillas are soft and can be
rolled into “taco” from without damage. The textural characteristics of tortillas are related to the binding
forms and the amount of water contained. The fresh masa is highly susceptible to lose moisture which
makes its texture hard and therefore difficult to shape into round flat form 7 . A dehydrated corn masa
produce hard and breakable tortillas. Thus, retention of water in masa and tortilla is important since
excessive water loss makes an unacceptable product. The nixtamalization process produces changes
that improve the nutritional quality of tortillas. Many studies have been conducted on nutritional
aspects of nixtamalized maize in relation with protein, minerals and lipids, but very few studies have
been carried out on the digestibility of its carbohydrate constituents 9,10 , and there are not studies on
starch digestibility in tortillas mixed with hydrocolloid and the mechanims involved in these perceived
phenomenon. The objective of the present study was to evaluate the influence of the commercial
hydrocolloid TC-1 on the resistant starch content in tortilla.
MATERIALS AND METHODS
Sample preparation: The traditional method to produce nixtamal, masa and tortillas was used.
Sample lots of 5 kg maize (commercial white dent maize grown in the state of Guerrero, México) were
cooked in 15 L of lime solution. Lime is added at 1 % (grain weight basis). Maize was cooked for 1 h at
boiling temperature, steeped in the same cooking vessel for 16 h, and then the cooking solution
(called nejayote) was discarded. The cooked-steeped maize (called nixtamal) was washed three or

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Food Science and Biotechnology in Developing Countries
four times with tap water to remove excess of lime and lost pericarp tissue. Nixtamal was ground into a
masa using a commercial stone grinder. Masa was mixture with commercial hydrocolloid TC-1 (Gum
Technology Corporation, Tucson, AZ), pressure-molded and extruded into thin circles to make tortillas
1 mm of thick. Tortillas were baked into a gas –fired domestic oven (Hotpoint, 6B4411LO, Leisser S.A.
de C.V., San Luis Potosí, México) for 1 min on each side at ≈250 °C.. After cooling, tortillas were
packed into poly-ethylene bags (20 X 30 cm, Plásticos de México, S.A. de C.V., México) and stored
for 24, 48, 72 and 96 hours at 4°C; after witch the samples were freeze-dried in liquid nitrogen. Stored
tortilla samples were reheated in the gas oven for 30 sec on each side at ≈250 °C, cooled to 30 °C,
then freeze-dried in liquid nitrogen. The variation was introduced to replicate the consumer preparation
of this product. All samples were stored at room temperature in sealed plastic containers.
In vitro digestibility tests: Potentially available starch content was assessed following the enzymic-
colorimetric method of Holm et al. 11 using Termamyl® (Novo A/S, Copenhagen) and amyloglucosidase
(Boehringer, Mannheim). Resistant starch was measured by two different protocols: 1) Retrograded
resistant starch (RRS or RS3) content was measured as starch remnants in dietary fiber residues,
according to the so called "Lund method" as modified by Saura-Calixto et al. 12 , 2) The method
proposed by Goñi et al. 13 was employed to estimate the total amount of indigestible starch (comprising
RS2, RS3 and part of RS1 fractions).
Experimental design and statistical analysis: Data were analyzed using one-way Analysis of
Variance (ANOVA) procedures. Where analysis showed significant differences (p

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Generally, available starch (AS) content decreased with storage length, (72.03 – 64.44 %). This might
be related to the development of retrograded indigestible fractions on cold storage. AS content was
lower than TS level in all samples, although the smallest differences was detected for control sample.
According Rendón-Villalobos et al. 10 and Agama-Acevedo et al. 15 , cold storage of tortillas affected AS
values, showing a time related decreased. Such observations do not differ much from here reported
data.
Table 1. Total starch (TS), available starch (AS) and resistant starch (RS) content in tortillas
with hydrocolloid TC-1.
Storage
(hr)
Sample TS (%) AS (%) RS (%)
0 Control 75.89 ± 0.35 71.89 ± 0.20 2.68 ± 0.02
Tortilla with TC-1 75.45 ± 0.34 72.0 ± 0.30 2.82 ± 0.03
24 Control 75.66 ± 0.12 68.02 ± 0.30 3.68 ± 0.01
Tortilla with TC-1 75.85 ± 0.32 70.61 ± 0.20 3.15 ± 0.05
48 Control 75.80 ± 0.09 65.29 ± 0.30 3.93 ± 0.02
Tortilla with TC-1 75.38 ± 0.10 68.73 ± 0.20 3.54 ± 0.03
72 Control 75.48 ± 0.05 62.16 ± 0.30 4.20 ± 0.03
Tortilla with TC-1 75.85 ± 0.10 65.89 ± 0.30 3.92 ± 0.03
96 Control 75.44 ± 0.13 60.90 ± 0.25 4.25 ± 0.05
Tortilla with TC-1 75.87 ± 0.11 64.44 ± 0.30 3.95 ± 0.03
Mean value ± standard deviation (n = 12), dry matter basis.
The total resistant starch values in tortilla samples showed minimal variations (2.82 – 3.95%), however
when storage time increase, RS content increased as well. Tortillas whit TC-1 exhibited lower RS
values that those determined in laboratory-made tortillas (3.12 – 3.87 %) 10 ; maize botanical type and
nixtamalization conditions may play an important role in this behavior. Such a raise in RS during cold
storage is consistent with recorded AS decrease after 72 hours (Table 1).

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Food Science and Biotechnology in Developing Countries
CONCLUSIONS
The results obtained for RS content in tortillas with hydrocolloids are important in the nutritional point
of view, due to those tortillas can extend the shelf life but also appreciable RS contents are obtained in
these periods.
This type of studies can help to design process for tortilla production with hydrocolloids that presented
specific starch digestibility.
ACKNOWLEDGEMENTS
The authors wish to acknowledge the economic support from CGPI-IPN and COSNET.
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nixtamal, masa and tortilla. Cereal Chemistry. 79, 340-344.

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Starch/Stärke. 38, 224-229.
[12] Saura-Calixto, F., Goñi, I., Bravo, L., and Mañas, E. 1993. Resistant starch in foods: Modified
method for dietary fiber residues. Journal of Food Science. 58, 642-645.
[13] Goñi, I., García-Díaz, L., Mañas, E., and Saura-Calixto, F. 1996. Analysis of resistant starch: A
method for foods and food products. Food Chemistry. 56, 445-449.
[14] SPSS. 1996. SPSS para Windows. Programación y Análisis Estadístico. Mc-Graw Hill, México.
[15] Agama-Acevedo, E., Rendón-Villalobos, R., Tovar, J., Paredes-López, O., Islas-Hernández, J. J.,
and Bello-Pérez, L. A. 2004. In vitro starch digestibility changes during storage of Maite flour
tortillas. Nahrung/Food. 48(1): 38-42.

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
In vitro starch bioavailability in tortillas prepared with gums
Rendón-Villalobos, Rodolfo 1 ; Bello-Pérez, Luis Arturo 1 ;Agama-Acevedo, Edith 1 ;
and Islas-Hernández, José Juan 1 .
1 Centro de Desarrollo de Productos Bióticos del IPN.
Km 8.5 carr. Yautepec-Jojutla, colonia San Isidro,
apartado postal 24, 62731 Yautepec, Morelos, México.Fax: +5273941896
Summary
The objective was to evaluate the influence of the type of gums and storage on the in vitro digestibility
of starch in tortilla. Commercial gums TC-1, TC-20 and WHIP, were added to nixtamalized masa, and
mixed to obtain tortillas that were baked and stored at 4 o C for up to 14 days and then
analyzed.Tortillas with gums did not shown change in Resistant Starch values with storage time,
except tortillas with TC-1 gum that presented a slight increased after 7 storage days.
Keywords: Nixtamalization, hydrocolloids, tortillas, resistant starch, starch bioavailability
Introduction
The nixtamalization of maize is an ancient process developed by the Mesoamerican civilizations and
is still utilized in the production of “tortillas”. The maize grains are cooked with alkali (i.e. lime) and
steeped, in a process known as nixtamalization. After grinding and washing the “nixtamal” (i.e.,
alkaline-cooked maize grains) a soft dough, known as “masa”, is obtained. The masa is a mélange
constituted by starch polymers, mixed with partially gelatinized starch granules, intact starch granules,
pieces of endosperm, and lipids. All these components develop a complex heterogeneous network in
a continuous water phase 1 . Masa is used in the production of tortillas, which are the principal staple
food in the Mexican diet, representing the main source of carbohydrates and calcium 2 . The
nixtamalization process produces changes that improve the nutritional quality of tortillas. Many studies
have been conducted on nutritional aspects of nixtamalized maize, but very few studies have been
carried out on the bioavailability of its carbohydrate constituents 3 . Carbohydrates represent the main
fraction of cereal grains, accounting for up to 50-70 % of the dry matter; of these, starch and nonstarch
polysaccharides (dietary fiber) are the major constituents. When tortillas are cooked, starch
gelatinization is carried out, the gelatinized starch gels are thermodynamically unstable structures and,
on cooling, reassociation of the starch molecules may occur. The ability of starch chains to form
ordered structures in pastes, gels and baked foods during storage, a process often described by the
term “retrogradation”, greatly influences the texture and shelf-life of these products 4 . The tortillas have
a problem, because after preparation staling ocurrs increasing rigidity which affects palatability. On the
other hand, starch retrogradation increases enzymatic resistance to starch digestion due to the
formation of resistant starch wich is associated with low glycaemic and insulinemic responses and is
very important for prevention of some diseases as colon cancer colonrectal, low blood cholesterol,
decres of coronary infart. It has been reported that adding hydrocolloids in tortillas retards
1

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
retrogradation; however, interactions between starch and hydrocolloids may ocurrs in tortillas
containing these additives which might decrease starch digestibility. Good quality corn tortillas are soft
and can be rolled into “taco” form without damage. The textural characteristics of tortillas are related to
the binding forms and the amount of water contained. The fresh masa is highly susceptible to lose
moisture which makes its texture hard and therefore difficult to shape into round flat form 5 . A
dehydrated corn masa produce hard and breakable tortillas. Thus, retention of water in masa and
tortilla is important since excessive water loss makes an unacceptable product. The objective of the
present study was to evaluate the influence of the type of commercial hydrocolloid and storage on the
in vitro digestibility of starch in tortilla.
Materials and methods
Sample preparation: The traditional method to produce nixtamal, masa and tortillas was used.
Nixtamal was ground into a “masa” using a commercial stone grinder. Masa was mixtured with
commercial hydrocolloids TC-20, TC-1 (Gum Technology Corporation, Tucson, AZ) and WHIP
(Colloides Naturels International, Rouen, France) mold by pressure and extruded into thin circles to
obtain “tortillas” of 1 mm of thickness. Tortillas were baked in a home gas fired oven for 1 min per side,
at an approximate temperature of 250 °C. After cooling, tortillas were packed into poly-ethylene bags
(20 X 30 cm) and stored for 2, 4, 7 and 14 days at 4 °C, a sample inmediately baked and cooled was
analyzed (0 storage time). After each time the samples were frozen in liquid nitrogen and freeze dried.
In the case of stored tortillas, the samples were reheated in a home gas fired oven during 30 s each
side, at an approximate temperature of 250 °C, cooled down to 30 °C, frozen in liquid nitrogen and
freeze dried; such a variation was introduced in order to replicate the same conditions used when this
product is eaten. All samples were stored at room temperature in sealed plastic containers.
In vitro digestibility tests: Potentially available starch content was assessed following the
multienzymatic protocol of Holm et al. 6 , using Termamyl® and amyloglucosidase. Resistant starch
was measured by two different protocols: 1) Retrograded resistant starch (RRS or RS3) content was
measured as starch remnants in dietary fiber residues, according to the so called "Lund method" as
modified by Saura-Calixto et al. 7 , 2) The method proposed by Goñi et al. 8 was employed to estimate
the total amount of indigestible starch (comprising RS2, RS3 and part of RS1 fractions). The in vitro
rate of hydrolysis was measured using hog pancreatic amylase, according to Holm et al. 9 ; each assay
was run with 500 mg available starch.
Statistical analysis: A randomized complete design with three replications was used to analyze
changes during tortilla storage. Data were analyzed using one-way Analysis of Variance (ANOVA)
procedures. Where analysis showed significant differences (p

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
The values for available starch (AS) are presented in Table 1. For all analyzed samples, AS
decreased when storage time increased, this pattern is due to the retrogradation phenomenon as was
reported in tortillas elaborated with masa prepared in the laboratory 3 . When AD of tortillas without
storage (0 h) and stored for 14 days were compared, tortillas control, tortillas with WHIP and TC-1
presented the same difference, indicating that these gums did not affect the AS content in tortillas.
However, the lowest difference between these two values of AS was shown in tortillas with TC-20,
demonstrating that this gum decrease in higher proportion starch reorganization and AS is not altered
significantly. This pattern can be related with the gum formulation, because TC-20 is a mixture of
modified food starch, guar, xanthan and monodiglycerides, that the last components can be
responsible of decrease starch retrogradation, as it was reported in bread 10,11 . AS values of 72.92 %
and 70.97 % were reported in tortillas without storage and with 72 h of storage, respectively 3 , values
that were higher to those found in this study. Similar values (between 64.52 and 76.04 %) were
determined in tortillas stored until 72 h 12 .
Table 1. Available starch (AS), resistant starch (RS) and retrograded resistant starch (RRS) in corn
tortillas with hydrocolloids.
Sample/Storage
(days)
AS (%)
TC
0
70.03 ± 1.24 a
7 68.38 ± 0.56 a,b
14
66.91 ± 0.72 b
T_WG
0
7
14
T_TC-1
0
7
14
T_TC-20
0
7
14
67.42 ± 0.81 a,b
64.17 ± 0.93 c
62.55 ± 0.60 c
68.00 ± 0.67 a,b
66.44 ± 0.70 b,c
64.77 ± 0.89 c
65. 69 ± 0.57 c
64.22 ± 0.61 c
63.20 ± 067 c
RS (%) 1
RRS (%) 2
2.74 ± 0.07 a
1.66 ± 0.08 a
5.04 ± 0.11 b 2.83 ± 0.05 b
5.23 ± 0.06 b
3.05 ± 0.11 b
2.49 ± 0.05 a
3.55 ± 0.63 a,c
3.08 ± 0.11 a,c
3.01 ± 0.05 a
3.18 ± 0.07 c
3.38 ± 0.06 c
3.01 ± 0.11 a,c
3.33 ± 0.05 c
3.27 ± 0.07 c
1.71 ± 0.08 a
1.23 ± 0.13 c
1.54 ± 0.15 a,c
1.69 ± 0.09 a
1.71 ± 0.16 a
1.76 ± 0.13 a
1.46 ± 0.09 a,c
1.37 ± 0.18 a,c
1.48 ± 0.11 a,c
TC = control corn tortilla; T_WG = corn tortilla with hydrocolloid WHIP gum; T_TC1 = corn tortilla with hydrocolloid TC-1;
T_TC20 = corn tortilla with hydrocolloid TC-20.
1 8
Using method of Goñi et al .
2 7
Using method of Saura-Calixto et al .
Mean values of eighteen replicates ± standar error, dry matter basis. Values followed by the same letter in the same column are
not significantly different (p > 0.05).
Resistant starch
Total resistant starch (RS) values in control tortillas increased approximately 50 % after 7 storage
days (Table 1). However, tortillas added with gums did not shown appreciable differences with storage
time, only tortillas with TC-1 gum had RS values that changed after 7 storage days. In all cases
tortillas added with hydrocolloids presented low retrogradation tendency, because these gums impede
3

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
interactions between starch chains solubilized during gelatinization. In laboratory-made tortillas without
storage was determined a RS content of 3.12 %, and when this sample was stored for 3 days, RS
value increased at 3.87 % 3 , this last RS content is comparable with that obtained in tortillas added with
gums and stored for 7 days. These results indicate that hydrocolloids can retard retrogradation
phenomenon in tortillas until 100 %. Other studies reported in tortillas prepared with nixtamalized
maize flour, showed RS values for samples stored for 72 h between 2.52 and 3.29 % 12 , and for
tortillas prepared with masa obtained using the traditional nixtamalization process stored for 72 h, RS
values ranged 2.70 and 4.18 % 12 .
Retrograded resistant starch in tortillas studied was lower than total RS, this indicate that there are
others resistant fractions (principally RS1 or RS4) that contribute to total RS. Perhaps some portions
of the hydrocolloids at high temperatures interact with starch diminished starch susceptibility, because
in other studies of tortillas without hydrocolloids, the difference between RS and RRS is lower than
that showed in this study 3,12 . More studies are necessary in this sense. Wet thermal treatment followed
by cooling and storage produces retrograded resistant starch (RRS), as reported for corn flour 13 and in
various starch gels 14,15 . The formation of retrograded starch requires dehydration of the gelatinized
sample 14,16 , a phenomenon that is likely to take place when tortillas are baked, at approximately 250
ºC, and cooled. However, as hydrocolloids interaction with water molecules, impede water elimination
during the baking and storage steps of tortillas.
Rate of enzymatic starch hydrolysis
When the behavior of tortillas were compared at the different storage times, control (Figure 1a) and
tortillas with TC-20 hydrocolloid (Figure 1b) did not show statistical differences (p

a)
c)
FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Hydrolysis(%)
Hydrolysis(%)
80
60
40
20
TC_0
TC_7
TC_14
0
0 20 40 60 80 100
Time (min)
80
60
40
20
0
TC1_0
TC1_7
TC1_1
4
0 20 40 60 80 100
Time (min)
b)
d)
Hydrolysis(%)
Hydrolysis(%)
80
60
40
20
0
90
60
30
TC20_0
TC20_7
TC20_14
0 20 40 60 80 100
Time (min)
WG_0
WG_7
WG_14
0
0 20 40 60 80 100
Time (min)
Figure 1. In vitro starch hydrolysis of corn tortilla without hydrocolloids = TC (a); corn tortilla with
hydrocolloids TC-20 = T_TC20 (b); corn tortilla with hydrocolloids TC-1= T_TC1 (c); corn
tortilla with hydrocolloids WG = WG (d).
5

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
References
[1] Gomez, M.H., Rooney, L.W., and Waniska, R.D. Cereal Foods World 1987, 32, 372-377.
[2] Campus-Baypoli, O.N., Rosas-Burgos, E.C., Torres-Chávez, P.I., Ramírez-Wong, B., Serna-
Saldívar. S.O. Starch/Stärke 1999, 51, 173-177.
[3] Rendón-Villalobos, J. R., Bello-Pérez. L. A., Osorio-Díaz. P., Tovar J,. Parédez-López, O. Cereal
Chem. 2002, 79, 340-344.
[4] Biliaderis, C.G. Can. J. Physiol. Pharmacol. 1991, 69, 60-78.
[5] Arámbula, V. G., Mauricio, S. R. A., Figueroa, C. J. D., González-Hernández, J., and Ondorica, F.
C. A. Journal of Food Science 1999, 64, 120-124.
[6] Holm, J., Björck, I., Drews, A., Asp, N.G. Starch/Stärke 1986, 38, 224-229.
[7] Saura-Calixto, F., Goñi, I., Bravo, L., Mañas, E. J. Food Sci. 1993, 58, 642-645.
[8] Goñi, I., Garcia-Diaz, L., Mañas, E., Saura-Calixto, F. Food Chem. 1996, 56, 445-449.
[9] Holm, J., Björck, I., Asp, N.G., Sjoberg, L.B., Lundquist, I. J. Cereal Sci. 1985, 3, 193-200.
[10] Russell,P.L. J. Cereal Science 1983, 1, 297-303.
[11] Krog, N., Olesen, S. K., Toernaes, H., and Joensson, T. Cereal Foods World 1989, 34, 281-285.
[12] Agama-Acevedo, E., Rendón-Villalobos, R.,Tovar, J., Paredes-López, O., Islas-Hernández, J. J.,
and Bello-Pérez, L. A. Nahrung/Food 2004, 48, 31-40.
[13] García-Alonso, A., Goñi, I., Jiménez-Escrig, A., Martín-Carrón, N., Bravo, L., Saura-Calixto, F.
Food Chem. 1999, 66, 181-187.
[14] Fredriksson, H., Björck, I., Andersson, R., Liljeberg, H., Silverio, J., Eliasson, A.-C., Aman, P.
Carbohydr. Polym. 2000, 43, 81-87.
[15] Tovar, J., Melito, C., Herrera, E., Rascón, A. and Pérez, E. Food Chemistry 2002, 76, 455-459.
[16] Björck, I.M., Granfeldt, Y., Liljerberg, H., Tovar, J., Asp, N.G. Am. J. Clin. Nutr. 1994, 59, 699S-
705S.
6

FP16-2004 Food Science and Biotechnology in Developing Countries.
DOUGH RHEOLOGY FOR ADDING ASCORBIC ACID AND α-AMYLASE.
Gómez-Ortiz Salomón 1 *, Cifuentes-Díaz de León Armando 1 *, Esquivel-Pensabén J. Manuel 2 .
CIIDIR-IPN, Unidad Dgo. 1 , ITD 2 . Becario de COFAA*. Sigma S/N 20 de Noviembre II Durango
Dgo. C.P.34220 Méx. Salgo5@hotmail.com, armando552@hotmail.com,
mpensaben@yahoo.com.
Index words: alveograms, additives, flour wheat.
SUMMARY
It was analyzed the effect that had the adding of ascorbic acid, the α-amylase
and the time in the dough rheology coming from a half strong wheat flour.
Four concentrations of ascorbic acid were used (0, 25, 50 and 75 mg/kg flour),
four of α-amylase (0, 160, 320 and 480 mg/kg flour) and four resting times (0,
10, 20 and 30 days).
Latin square was selected like experimental design. With base in the results of
the tests and with p≤0.05; it found that the ascorbic acid presented significant
effect in the value of the force (W) and tenacity (P) increasing these and
diminishing the extensibility (L). The best answer for baking biscuit was ascorbic
acid concentration 0 mg for kg flour and 480 mg of α-amylase for kg flour. It is
not recommended to use ascorbic acid in flours with W>250 x 10 -4 Julies, and
L

The Latin Square was selected like experimental design. It was developed in
one stage; in there, were controlled: moisture of the flour, temperature of room,
relative humidity, kneading temperature, time of having kneaded, fermented and
alveograms.
FP16-2004 Food Science and Biotechnology in Developing Countries.
Variables like force, tenacity, extensibility and the relationship P/L were
evaluated. The total of treatments was 16 with 3 repetitions and a total of 48
samples. The results were analyzed by ANOVA and Test of Tukey.
RESULTS
Square 1. Physical chemical analysis of the flour.
Determination (%) H1
Moisture 11.50 ± 0.01
Ash* 0.60 ± 0.01
Ethereal extract* 1.60 ± 0.02
Protein (F=5.7)* 14.59 ± 0.02
Raw fiber* 0.03 ± 0.01
Gluten* 13.5 ± 0.02
*D.b.
With base in the data of ash (Square 1), it can say that it is a flour of high
extraction, 75%, that influences in the quality of the same one. Considering the
quantity of protein can be inferred that it is good to elaborate bread, however, it
should considered other factors. To the flour used in this work it was added a
mixture of ascorbic acid and α-amylase in different concentrations, with the
purpose to evaluate the effect in the dough rheology Fig. 1 – 9.
Force (W x 10 -4 Joule)
300
290
280
270
260
250
0 20 40 60 80
Ascorbic Ac.(mg kg -1 flour)
Fig. 1. Effect of the Ascorbic Ac.in
the force of dough.
Tenacity P (mm)
138
136
134
132
130
128
126
124
122
120
118
0 20 40 60 80
Ascorbic Ac. (mg kg -1 flour)
Fig. 2. Effect of the Ascorbic Ac in
the tenacity of the dough.
Extensibility L (mm)
66
64
62
60
58
56
54
0 20 40 60 80
Ascorbic Ac.(mg kg -1 flour)
Fig. 3. Effect of the Ascorbic Ac in
the

FP16-2004 Food Science and Biotechnology in Developing Countries.
Force (W x 10 -4 Julies)
Force (W x 10 -4 Joule)
290
285
280
275
270
265
0 100 200 300 400 500 600
α amylase (mg kg -1 flour)
Fig. 4. Effect of the α-amylase in the
force
of dough.
290
285
280
275
270
265
260
0 5 10 15 20 25 30 35
Time (day)
Fig. 7. Effect of the time in the force of
dough.
Tenacity P(mm)
Tenacity P (mm)
150
145
140
135
130
125
120
115
0 100 200 300 400 500 600
α amylase (mg kg -1 flour)
Fig. 5. Effect of the α-amylase in the
tenacity of the dough
140
135
130
125
120
115
0 5 10 15 20 25 30 35
Time (day)
Fig. 8. Effect of the time in the tenacity
of
the dough.
Extensibility L (mm)
Extensibility L (mm)
64
62
60
58
56
extensibility of the dough.
54
0 100 200 300 400 500 600
α amylase ( mg kg -1 flour)
Fig. 6. Effect of the α-amylase in the
extensibility of the dough
62
60
58
56
54
52
0 5 10 15 20 25 30 35
Time (day)
Fig. 9. Effect of the time in the
extensibility of the dough.
CONCLUSIONS
1. From statistical analysis of the data and with p≤0.05 it can conclude that
the ascorbic acid, the α-amylase and the time influence significantly in
the rheological properties of dough.
2. The increment of the force and tenacity are due to that the ascorbic acid
when reacting with the catalysts presents in flour, becomes in
dehidroascorbic acid, acting this as oxidizer, allowing the formation of
disulphuro connections, which reinforce the gluten.
3. The addition of ascorbic acid to dough with W>250 and of low
extensibility, became it more tenacious.

4. The α-amylase has effects contrary to those of the ascorbic acid, they
diminish the values of W, P and extensibility is increased. It contributes
to improve the quality of dough.
5. When flour has P/L>1.5, it is not necessary to add reducers agents,
since it would became them more tenacious.
6. With base in the rheological characteristics of this flour, the best answer
was obtained to concentrations of 0 mg ascorbic acid /kg of flour and 480
mg of α-amylase/kg of flour, for that is recommended not to use ascorbic
acid in flours
FP16-2004 Food Science and Biotechnology in Developing Countries.
7. With W>250 x 10 -4 Julies and L

Food Science and Biotechnology in Developing Countries
Process viscosity study on heterogeneous foods
L. Medina Torres 1 *, E. Brito de la Fuente 2 , J.A. Gallegos Infante 3
1,2 Departamento de Alimentos y Biotecnología, Facultad de Química
Universidad Nacional Autónoma de México., 04510 México, D.F.
3 Instituo Tecnológico de Durango
Departamento de Ingenieria Química y Bioquímica
Felipe Pescador 1930 Ote., Durango, Dgo. 34080., México
Tel./Fax (5)56-22-53-08. email: luismt@servidor.unam.mx
ABSTRACT
The rheological properties are of great importance in food fluids as
mermelades, salad dressing, soups, sauces and creams [Baudi, 1996]. The
knowledge of rheological properties are very important in the industrial
optimization as pumping, mixing, cooling, drying and others. The usual
viscometers are not good for this systems cause the heterogeneous nature of the
dispersion. With the objective of a best determination of the fluid properties it has
been used the rheometry with mixing principles for heterogeneous systems.
Key words: Non-Newtonian, process viscosity, heterogeneous foods, mixing
principles.

Food Science and Biotechnology in Developing Countries
Process viscosity study on heterogeneous foods
L. Medina Torres 1 *, E. Brito de la Fuente 2 , J.A. Gallegos Infante 3
1,2 Departamento de Alimentos y Biotecnología, Facultad de Química
Universidad Nacional Autónoma de México., 04510 México, D.F.
3 Instituo Tecnológico de Durango
Departamento de Ingenieria Química y Bioquímica
Felipe Pescador 1930 Ote., Durango, Dgo. 34080., México
Tel./Fax (5)56-22-53-08. email: luismt@servidor.unam.mx
INTRODUCTION
On the food industry there are an important group of food systems that it are
constituid by a dispersant phase, in this phase there are a lot of relative soluble
components and a disperse phase with particles with distinct physics properties.
The rheological properties are of great importance in food fluids as mermelades,
salad dressing, soups, sauces and creams [Baudi, 1996]. The knowledge of
rheological properties are very important in the industrial optimization as
pumping, mixing, cooling, drying and others. The usual viscometers are not good
for this systems cause the heterogeneous nature of the dispersion. With the
objective of a best determination of the fluid properties it has been used the
rheometry with mixing principles for heterogeneous systems. [Brito et al., 1998].
Rheological measurements.
EXPERIMENTAL METHODOLOGY
It were working three different simples of heterogeneous foods: Salad
dressing, orange mermelada and peach yogurt, at 25°C. The rheological
measurements were making in a rotational rheometer (Haake, CV20N, RV20)
with temperature control. It was used a system with helicoidal geometry adapted
to rheometer.
On the Figure 1 is shown the system used. The Viscosity data were obtained
following the method. [Brito et al., 1998].
The process viscosity was determinated with the next algoritm:
η
e
=
mK
p
( n)
K
p
N
n −1
RESULTS AND DISCUSSION
(1)

Food Science and Biotechnology in Developing Countries
The process viscosity data are presented on the Table 1. Its observed that the
presence of particles not interfere with the torque signal.
On the Figure 2 its observed that in the food systems measured with the
hellicoidal system shown a best approximated functional response in comparison
to the usual geometries as plate and cone, couette, parallel plates, data difficult to
obtain in these systems. Each one of systems used in this work show a Non-
Newtonian behavior type pseudoplastic, with (n) determination in the experimental
window of the fluids.
The particulate presence not limited the measurement of viscosities. It can be
to any that for this system its possible characterizing the material function respect
the viscous component (i.e. process viscosity) using the mixing principles with best
result in comparison to traditional measurement systems.
H= 0.04m
w= 0.004m
D= 0.029m
d= 0.0248m
Figure 1. System of mixing rheometry
h= 0.0315m
b= 0.004m

Viscosity [Pa.s]
10
Yoghurt
η e = 2.113N -0.854
Food Science and Biotechnology in Developing Countries
1
0.1 1.0 10.0
N, [r.p.s]
Mermelada
η e = 5.397N -0.552
Aderezo
η e = 2.417N -0.59
Figura 2. Curves of process viscosity in heterogeneous
foods
REFERENCES
Fluid Rheological parameters
Salada
dressing
n
Fluid
Index
Kp(n)
Consistency
index
m (Pa s n )
0.410 29.71 13.22
Orange
marmalade 0.448 32.79 26.75
peach
yogurth
0.146 18.03 17.37
Table 1. Values of fluid index (n) and consistency index (k)
of the heterogeneous fluids used in this work.

Food Science and Biotechnology in Developing Countries
1. Baudi, D. S. (1996). Química de los Alimentos. Universidad. México, D.F.
2. Brito- De La Fuente, E.; Nava, A., López, L. M.; Medina, L.; Ascanio, G. and
Tanguy, P. A.,1998. Process Viscometry of Complex Fluids and Suspensions
with Helical Ribbon Agitators. The Canadian Journal of Chemical Engineering;
76: 689.

FSBI – 2004
Food Science and Biotechnology in Developing Countries
Bleaching of Amaranth Oil (A. hypochondriacus)
Ariza-Ortega J.A. (1) , López-Valdez F. (2) , Montalvo-Paquini C. (3) , Arellano-Huacuja A. (4) , and Luna-
Suárez S. (5) .
(1) CICATA-IPN Puebla. Acatlán 63, La Paz. Puebla, Pue. México 72160.
E-mail: ariza_ortega@yahoo.com.mx
(2) CICATA-IPN Puebla. Acatlán 63, La Paz. Puebla, Pue. México 72160.
E-mail: flopez2072@yahoo.com
(3) CICATA-IPN Puebla. Acatlán 63, La Paz. Puebla, Pue. México 72160.
E-mail: cpaquini@yahoo.com
(4) CICATA-IPN Puebla. Acatlán 63, La Paz. Puebla, Pue. México 72160.
E-mail: amy@puebla.megared.net.mx
(5) CICATA-IPN Puebla. Acatlán 63, La Paz. Puebla, Pue. México 72160.
E-mail: silvials2004@yahoo.com.mx
Tel.: 52 (222) 230 - 4459. Tel/Fax: 249 - 8540.
Abstract
The bleaching was made by two methods, using 2 clays: actisil (A), optimum (O) and activated
charcoal (AC). Method 1: The oil was mixed with 10 % A + O and 0.5 % (w/v) AC at 20º increasing
each 10º up to 120° C. Method 2: The oil was mixed with 2 % A + O and 0.2 % (w/v) AC at 20°, 70º,
100º, 110º and 120º C. The best result in the method 1 was 1.01 units of photometric color (PC) at
120º C. The best result in the method 2 was 3.25 units PC at 70º C and 3.1 units PC at 20º C.
Key words: Oil, bleaching, clays and photometric color.
Introduction
The obtained oils from different sources (mainly seeds) are called crude oils (1). The oil has undesired
compounds that make it undesired to use. To resolve this problem, the oil is refined (2 y 3). Andersen
(1965) proposed the following methods: sedimentation, centrifugation, filtration, degumming,
neutralization, bleaching and deodorization. The bleaching is a method used to diminish pigments
(carotenoid, flavonoides and others) that provide a colour nonwished in crudes oils. The most common
methods for bleaching are; chemical action, hidrogenation, neutralization, heat and adsorption. The
purpose of this work was bleaching the neutralized oil from amaranth seed of A. hypochondriacus with
the adsorption method.
Materials and Methods
Amaranth oil
Neutralized amaranth oil from Hidalgo (Mexico) was used.
Bleaching
Two methods were used: 1) the oil was mixed with clays: 10 % (w/v) each one of actisil (A) + optimum
(O) and 0.5 % (w/v) activated charcoal (AC). Both treatments were working at 20º C increasing 10º up
to 120° C and were stirred for 10, 20 and 30 minutes, each one. Then, were filtered. 2) The oil was
mixed with clays: 2 % (w/v) (each one) of A + O and 0.2 % (w/v) AC. Both treatments were working at
20º, 70º, 100º, 110º and 120° C each one. Then, were stirred for 10, 20 and 30 minutes and filtered.
To diminish the photometric color (PC) in oil, were carry out three steps mixing clays and activated
charcoal each one of anterior treatments. The PC was measured in a Spectronic Genesis 2
spectrophotometer, using the method proposed by Allen (1982).

FSBI – 2004
Food Science and Biotechnology in Developing Countries
Characteristics of the clays and the activated charcoal
Clays: actisil 220 FF (pH: 2.5, retained in 230 mesh, particle size: 23) and optimum 320 FF (pH: 2.5,
retained in 230 mesh, particle size: 25, obtained from Sûd Chemie). Activated charcoal (pH: 6.0 - 8.5,
90 % size particle, minimum passes 200 mesh, obtained from Polifos).
Statistical analysis
The experimental data were analyzed statistically by analysis of variance, for statistical significance
(α= 0.05) using LSD test. (Statistical Analysis System, SAS).
Results and Discussion
Bleaching
The results for bleaching with method 1 are shown in figure 1.
PHOTOMETRIC COLOR
30
25
20
15
10
5
0
Control 20º C 30º C 40º C
50º C 60º C 70º C 80º C
90º C 100º C 110º C 120º C
TREATMENTS
Figure 1.Treatments at different temperatures with mixtures of clays and AC at 20 minutes.
The treatments at different temperatures (20º to 70º C) did not have significant effect (α=0.05). In
comparison, the treatments at 100º to 120º C decreased the PC. In other hand, the agitation time (10
and 20 minutes) had significant effect (α=0.05) on PC, meanwhile 20 and 30 minutes did not had
(results not presented). The temperature and acidity of clays are factors that help to the adsorption of
the complexes of proteins, lipids and carotenoids, because there are high concentration of ions
aluminum in the clays, and the activated charcoal adsorbs also odor and flavor from oil (1 y 4). The
best treatment was at 120º C resulting 1.01 units PC (figure 1). Badui (1998) reported 2.86 PC units to
corn oil. We obtained 1.01 PC units to amaranth oil, but the yield obtained for us was less than 50 %,
because the three steps to bleach with the clays diminished it for adsorption of the amaranth oil.
The results of the oil yields obtained are shown in the figure 2.

FSBI – 2004
Food Science and Biotechnology in Developing Countries
YIELD
60%
50%
40%
30%
20%
10%
0%
TREATMENTS
Figure 2. Yields of the method 1
20º C
30º C
40º C
50º C
60º C
70º C
80º C
90º C
100º C
110º C
120º C
In the treatments at 20º to 90º C the percentage of oil was less than 50 % and in the 100º to 120º C
treatments were less than 40 %. In figure 3 is shown the color obtained from treatment one.
(a) (b) (c) (d)
Figure 4. Bleaching the amaranth oil a) Control, (b) First step, c) Second step,
and d) Third step.
The results of the method 2 are shown in the figure 4.
PHOTOMETRIC COLOR
30
25
20
15
10
5
0
TREATMENTS
Control
20º C
70º C
100º C
110º C
120º C
Figure 4.Treatments with 2 % clays and 0.2 % AC, at 20 minutes

FSBI – 2004
Food Science and Biotechnology in Developing Countries
The treatments at 100º and 120º C did not have significant effect (α=0.05), they did not had good
results on PC. In comparison, the treatments at 20º, 70º and 110º C were good. In other hand, the
agitation time (10 and 20 minutes) had significant effect (α=0.05) on PC, meanwhile 20 and 30
minutes did not had (results not presented).The best results were 3.25 units PC at 70º and 3.1 units
PC at 20º C. Both presented an acceptable PC and the yield was 80 %.
Lyon and Becker (1987) bleached neutralized oil from amaranth seed (A. cruentus) using adsorption
method. They found that the best method for bleaching was the mixture of clays 2 % (Filtrol–105 FAC)
and activited charcoal 0.2 % (Norit–A) at 110° C, and recovered 94.3 % of bleached oil (7). We
obtained 80 % oil bleached (A. hypochondriacus) smaller than recovered by Lyon and Becker.
The advantage for bleaching as this work, is that it can do it using 20º C with the mixed clay and
activated charcoal, since it would diminish the cost of bleaching method, it does not require energy to
heat the mixture, and an acceptable PC is obtained in the amaranth oil (figure 3).
Conclusions
The best result of the method 1 was 1.01 units PC at 120º C obtaining 50 % yield. The best results of
method 2 were 3.25 units PC at 70º C and 3.1 units PC at 20º C obtaining 80 %yield. We recommend
to employ the method 2 at 20º C because it would diminish the cost of treatment, and the oil obtained
presented characteristic edible oil color.
Acknowledgments
We thank the programs PIFI, PIBP and COFAA for financial support for the realization of this work.
References
1. Cabrera A.A. Melchón G.A. Sosa J.A. 1991. Preparación de material didáctico como apoyo en la
enseñanza superior en la materia de Química de Alimentos. Vol. II. Tesis de licenciatura. Depto.
Ciencias Químicas, Universidad Autónoma de Puebla. pp: 200-276.
2. Cheftel J.C. 1986. Introducción de la Bioquímica y tecnología de los Alimentos. C.E.C.S.A. pp: 7-9,
16-24.
3. Ho C.C. Chow C.M. 2000.The effect of the refining process on the interfacial properties of palm oil.
JAOCS. 77(2): 191-199.
4. Andersen A.J. 1965. Refinación de Aceites y Grasas Comestibles. 2ª ed. C.E.C.S.A. pp: 17-95,
130-197, 216-241, 284-301.
5. Allen R.R. Formo M.W. Krishnamurthy R.G. Mcdermott G.N. Norris A.F. Sonntag O.V. 1982.
Bailley´s Industrial oil and fat products. Vol. 2. 4ª ed. Reverté. pp: 269-313.
6. Badui J.S. 1998. Química de los Alimentos. Alambra. pp: 185-202.
7. Lyon C.K.. Becker R. 1987. Extraction and Refining of oil from Amaranth Seed. JAOCS. 64(2): 233-
236.

FSBI – 2004
Food Science and Biotechnology in Developing Countries
Degumming and Neutralization of the Amaranth Oil (A. hypochondriacus).
Ariza-Ortega J.A. (1) , López-Valdez F. (2) , Montalvo-Paquini C. (3) , Arellano-Huacuja A. (4) , and Luna-
Suárez S. (5) .
(1) CICATA-IPN Puebla. Acatlán 63, La Paz. Puebla, Pue. México 72160.
E-mail: ariza_ortega@yahoo.com.mx
(2) CICATA-IPN Puebla. Acatlán 63, La Paz. Puebla, Pue. México 72160.
E-mail: flopez2072@yahoo.com
(3) CICATA-IPN Puebla. Acatlán 63, La Paz. Puebla, Pue. México 72160.
E-mail: cpaquini@yahoo.com
(4) CICATA-IPN Puebla. Acatlán 63, La Paz. Puebla, Pue. México 72160.
E-mail: amy@puebla.megared.net.mx
(5) CICATA-IPN Puebla. Acatlán 63, La Paz. Puebla, Pue. México 72160.
E-mail: silvials2004@yahoo.com.mx
Tel.: 52 (222) 230 - 4459. Tel/Fax: 249 - 8540.
Abstract
Two methods were made to degumming: the (A) H2SO4 (0.5 %) and (B) method by hydration. Oil
degummed was neutralized by three methods: (C) 4 eq L -1 NaOH, (D) 10 eq L -1 NaOH and (E) 7 eq L -1
Na2CO3 + 10 eq L -1 NaOH. The initial acid value (AV) of the crude oil was 35.02 % of oleic acid. The
best method to degumming was the (B) with 24.17 % AV and 3.82 % of remainders, the yield was 97
% of oil and the best method to neutralization was (E), the AV decreased to 0.43 %.
Key words: Oil, degumming, neutralization and acid value.
Introduction
The amaranth belongs to the family Amaranthaceae of the genus Amaranthus, there are sixty genus
and around eight hundred species (1). The amaranth contains nutritious of good quality that benefits
the health for its protein, fiber, tocopherols, oil and squalene (2 y 3). The consumers in general ignore
these functional and therapeutic properties. The annual production of amaranth in Mexico is very
important, about 4 227 tons per year (4).
The amaranth oil is an unused by-product. The oil is discharged to the environment because
contained undesired compounds. To obtain ideal characteristics it must be treated by refining methods
(5 y 6). Andersen (1965) proposed the follow methods for refining: sedimentation, centrifugation,
filtration, degumming, neutralization, bleaching and deodorization. The degumming is used to
eliminate proteins and gums; they are nutrients for the microorganism growth that degraded the oil.
This method uses the follow treatments: acid, heat, hydration and others (6, 7 y 8).
The neutralization diminishes free fatty acids in oil, since these indicate deterioration in fatty acids.
The common treatment is employing NaOH. But, there are many others such as: Na2CO3, lime,
destilation, and others (7 y 8).
Lyon and Becker (1987) refined oil from amaranth seed (A. cruentus). Crude oil amaranth was
degummed for the hydration method at 50º C with 1 % (v/v) water, and yield was 96 %. The initial AV
of the crude oil was 2.37 % of oleic acid, and was neutralized employing 16º Bé NaOH at 14.4 % (v/v),
the AV decreased to 0.03 % obtaining 89.4 % of neutralized oil. The purpose of this work was
degumming and neutralizing the oil from amaranth seed (A. hypochondriacus) with 35.02 % AV as
oleic acid.
Materials and Methods
The materials used were reagent degree.
Amaranth oil
The oil used was crude oil amaranth, from Hidalgo (Mexico).

FSBI – 2004
Food Science and Biotechnology in Developing Countries
Determination of Acid Value (AV)
The acid value was made as Lees´s method (9).
Pretreatment
The amaranth oil was centrifuged at 1500 rpm for 15 minutes at 20º C, was filtered using whatman
paper (number 1). All the filtrations were carried out at reduced pressure.
Degumming
Was carried out by two methods: A) Using H2SO4 at 60º Bé (7) at 0.5 % (w/v), at 20º and 30º C, was
stirred for 10 and 20 minutes, water was added at 97º C and 2 % (v/v), was filtered. B) Using the
hydration method (2): 2 % (v/v) water was added to the oil at 50º C. Stirred for 20 minutes and filtered.
In each treatment the AV was measured and precipitation residues were quantified.
Neutralization
Three methods were applied: C) the degummed oil at 60º C was mixed with 4 eq L -1 NaOH at 10 %
(v/v). 10 % (v/v) water was added at 20º and 30º C. Was stirred for 10 and 20 minutes. Was then
centrifuged at 1500 rpm (centrifugal Hermle Z 323 K) for 15 minutes at 20º C. D) Using 40 % (v/v) of
10 eq L -1 NaOH at 60º C. Was added 10 % (v/v) water at 20º and 30º C. Was stirred for 10 and 20
minutes and centrifuged at 1500 rpm (15 minutes, 20º C). E) Using 35 % (v/v) of 7 eq L -1 Na2CO3. The
solution was heated at 45º C and it was added to the degummed oil. The temperature was increased
up to 75º C, was added 50 % (v/v) hot water and was drained. After that, was added 10 % (v/v) of
solution 10 eq L -1 NaOH plus 10 % NaCl (w/v). Then, was added 50 % (v/v) hot water, it was
centrifuged at 1500 rpm for 2 minutes at 20º C and was drained. In each treatment the volume of
neutralized oil was measured and was determined the AV.
Statistical analysis
The experimental data were analyzed statistically by analysis of variance, for statistical significance
(α= 0.05) using LSD test. (Statistical Analysis System, SAS)
Results and Discussion
Degumming
The results for degumming method of the amaranth oil are shown in table 1.
Table 1. Results from degumming amaranth oil
Treatment AV (% oleic acid) Residues (g)
A 46 ± 0.636 1.70 ± 0.007
B 30.94 ± 0.028 3.42 ± 0.042
Control 35.02 -
The method A resulted in AV 46 % (initial 35.02) and residuals was 1.70 % (Table 1).This method
originated alterations, it gave a strong brown color, due to the presence of proteins and pigments that
were carbonized by the acid.
Method B had a significant effect at α=0.05 on AV, it was 30.94% and 3.42 % of residues at 10
minutes of stirring. The yield was 97 % of degummed oil. The residues can be separated easily. Lyon
and Becker (1987) used the hydration method obtaining 96 % of degummed oil (A. cruentus). The
yield is similar to the obtained by us.
Neutralization
The results for neutralization method of amaranth oil are shown in table 2.

FSBI – 2004
Food Science and Biotechnology in Developing Countries
Table 2. Results neutralization the amaranth oil
Treatment AV (% oleic acid) Yield (%)
C 24.11 ± 0.007 90
D 12.03 ± 0.034 30
E 0.43 ± 0.021 87
Control 30.94 -
With C treatment, the obtained AV was 24.11% and yield 90 %. Matissek et al. (1992) reported that
an AV for refined oils should be less than one, expressed as % oleic acid. Not obtained with this
method (Table 2).
With D treatment was obtained an AV of 12.03 % and 30 % yield, with this method the AV not was
less than one, was affected the yield and was formed a soap excess. The temperature, the time of
stirring and the concentration of NaOH (4 eq L -1 and 10 eq L -1 ) did not have a significant effect
(α=0.05) on reduction of free fatty acids.
The degummed amaranth oil presented 30.94 % initial AV and the method E diminished it to 0.43 %
(81 times), and we obtained 87% of neutralized oil (Table 2). Lyon and Becker (1987) neutralized the
amaranth oil with 16º Be NaOH at 14.4 % (v/v) with an initial AV 2.37 % and diminished to 0.03 % (79
times), and their yield was 89.4 % of oil. If is compared the initial and final AV obtained by method E
versus Lyon and Becker’s results then, we find that AV decrease 81 times (by method E) and 79 times
(by Lyon and Becker). In addition, the yields were similar: 87 % and 89.4 %. Both oils, classified as
refined oils because the values are below than one (10). It is noticeable that, the species of amaranth
employed were different: A. cruentus by Lyon and Becker, and A. hypochondriacus in this work.
Conclusions
The crude oil amaranth presented a high AV (35.02 %), indicative of fatty acids alteration and
consequently it is necessary to refine.
The best method to degumming was the hydration, because it improved the quality of the oil
decreasing the AV and the content of residuals. The method not requires a special equipment to carry
out the treatment than required by acid treatment. The yields are considerable (97 %). In other part,
the residuals obtained can be separated easily from oil.
The best result to neutralization was Na2CO3+NaOH because it diminished the free fatty acids, and
yield was 87 %.
4 eq L -1 and 10 eq L -1 NaOH solutions were not appropriate for amaranth oil because they did not
neutralize all free fatty acids. In other hand, the yield was affected by 10 eq L -1 NaOH solution.
Acknowledgments
We thank the programs PIFI, PIBP and COFAA for financial support for the realization of this work.
References
1. Romero G.F.M. Sánchez. T.J.S. Velásquez G.O. 1986. Proyecto para la aplicación de harina de
amaranto con harina de trigo en la industria de la Panificación. Tesis de licenciatura. Depto. Ciencias
Químicas, Universidad Autónoma de Puebla. pp: 110-114.
2. Lyon C.K. Becker R. 1987. Extraction and Refining of oil from Amaranth Seed. JAOCS. 64(2): 233-
236.
3. Marcone F.M. 2000. First report of the characterization of the threatened plant species Amaranthus
pumilus (Seabeach Amaranth). J. Agric. Food Chem. 48(2): 378–382.

FSBI – 2004
Food Science and Biotechnology in Developing Countries
4. SAGARPA 2000. Anuario Estadístico de Producción Agrícola de los Estados Unidos Mexicanos.
Por Cultivo. pp: 94-95.
5. Cheftel J.C. 1986. Introducción de la Bioquímica y tecnología de los Alimentos, C.E.C.S.A., pp: 7-9,
16-24.
6. Ho C.C. Chow C.M. 2000.The effect of the refining process on the interfacial properties of palm oil.
JAOCS. 77(2): 191-199.
7. Andersen A.J. 1965. Refinación de Aceites y Grasas Comestibles. 2ª ed. C.E.C.S.A. pp: 17-95,
130-197, 216-241, 284-301.
8. Cabrera A.A. Melchón G.A. Sosa J.A. 1991. Preparación de material didáctico como apoyo en la
enseñanza superior en la materia de Química de Alimentos. Vol. II. Tesis de licenciatura. Depto.
Ciencias Químicas, Universidad Autónoma de Puebla. pp: 200-276.
9. Lees R. 2000. Análisis de los Alimentos (Métodos Analíticos y de Control de Calidad), 2ª ed.
Acribia. pp: 69-70.
10. Matissek R. Schnepel M.F. Sterner G. 1992. Análisis de los Alimentos, Fundamentos, Métodos y
Técnicas. 2ª ed. Acribia. pp: 297-302.

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
EVALUATION OF SOME CHEMICAL AGENTS TO INHIBIT THE ENZYMATIC BROWNING IN
HAWTHORN (Crataegus mexicana)
Abstract.
Pluma-Alvarado V. (1) , López-Valdez F. (2) and Luna-Suárez S. (3)
(1) CICATA-IPN PUEBLA, Acatlán 63 La Paz, Puebla, Pue. México 72160.
vianp_a@yahoo.com.mx
(2) CICATA-IPN PUEBLA, Acatlán 63 La Paz, Puebla, Pue. México 72160.
flopezva@ipn.mx, flopez2072@yahoo.com
(3) CICATA-IPN PUEBLA, Acatlán 63 La Paz, Puebla, Pue. México 72160.
sluna@ipn.mx, silvials2004@yahoo.com.mx
Tel.: 52 (222) 230 - 4459, Tel/Fax: 249 - 8540.
We evaluated the effect of some chemical agents to inhibit the enzymatic browning in hawthorn, as
inhibitors were used solutions: salt, sugar, citric acid, ascorbic acid and its combinations. The
peroxidase and catalase activities were evaluated, in addition to color change in the exposition to air
for 24h. The peroxidase´s best treatments were salt-sugar-citric and salt-sugar-ascorbic-citric; to
inhibit catalase, salt-sugar-ascorbic acid. The worst treatment for enzymes was salt but not for
exposition to air.
Key words: Enzymatic browning, hawthorn, peroxidase and catalase.
Introducción.
Appearance, flavor, texture and nutritional value are attributes considered by consumers when making
food choices. Appearance which is significantly impacted by color is one of the first attributes used by
consumers in evaluating food quality. Color may be influenced by naturally occurring pigments such
as chlorophylls, carotenoids and anthocyanins in food, or by pigments resulting from both enzymatic
and non-enzymatic reactions. Enzymatic browning is one of the most important color reactions that
affect fruits and vegetables. It is catalysed by enzymes like polyphenol oxidase (1,2 benzenediol;
oxygen oxidoreductase, EC1.10.3.1) catalase and peroxidase.
Enzymatic browning does not occur in intact plant cells since phenolic compounds in cell vacuoles are
separated from the enzymes which are present in the cytoplasm. Once tissue is damaged by slicing,
cutting or pulping, the formation of brown pigments occurs. Both the organoleptic and biochemical
characteristics of fruits and vegetables are altered by pigment formation. The rate of enzymatic
browning in fruit and vegetables is governed by the active enzymes content of the tissues, the
phenolic content of the tissue, pH, temperature and oxygen availability within the tissue (1).
Enzymatic browning is one of the most studied reactions in fruits and vegetables. Many researches
have been done this field, and many agents have been tested to prevent this reaction. The more used
are the antioxidants. Although, in hawthorn (Crataegus mexicana) there are low studies. Hawthorn is
an autochthon fruit from Mexico, this fruit is susceptible to enzymatic browning in oxygen contact or
mechanical damage as many fruits.
The objective of this work was to evaluate some chemical agents to inhibit the enzymatic browning in
hawthorn (Crataegus mexicana).
Material and methods
Fresh hawthorn was supplied by a Puebla producer. The fruit was cleaned by water and submerged in
0.02% sodium hypochlorite solution to disinfection.

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
We used two varieties of fresh sliced fruit: grafted and creole.
As inhibitors were used solutions: salt (9%), sugar (14%), citric acid (0.5% and 1%), ascorbic acid
(0.5% and 1%) and its combinations. The fruit was submerged in the solutions by 50 min. The
peroxidase and catalase activities were evaluated by the method proposed in (2 and 3), in addition to
color change in the exposition to air for 24 and 48 h.
The positive control was fruit submerged in distilled water.
The negative control was sterilized fruit.
Statistical analysis
The experimental data were analyzed statistically by analysis of variance, for statistical significance
(α= 0.050) using LSD test (Statistical Analysis System, SAS).
Results and discussion
Table 1 shows the results from color change at 24 hours in exposition to air, peroxidase and catalase
tests.
Table 1. Color change, peroxidase and catalase probe.
PEROXIDASE CATALASE
Color change at 24 hr in
exposition to air
AGENT CREOLE GRAFTED CREOLE GRAFTED CREOLE GRAFTED
Salt 9% + + + + - -
Sugar 14% + + + + + +
Salt-sugar - + + + - -
Salt-sugar- ascorbic - - + - - -
Salt-sugar- citric - - + + - -
Sugar - citric + + + + + +
Sugar - ascorbic + - - + + +
Salt- ascorbic + + + + - -
Salt - cítric - - + + - -
Salt-sugar-citric 0.5%-ascorbic
0.5%
- - + + - -
Salt/sugar-citric 1%-ascorbic acid
1%
- + + + - -
Ascorbic acid 1% + - - + + +
Citric acid + + + + + +
Positive control + + + + + +
Negative control - - - - - -
There was significant difference between the 2 fruit types. The creole´s enzymes were more resistant.
To inhibit the peroxidase, the best treatments were salt-sugar-citric acid and salt-sugar-ascorbic-citric
acid; to inhibit catalase was salt-sugar-ascorbic acid.
The worst treatment to inhibit these enzymes was salt, although in color change in exposition to air, it
was the best one. In the figure 1, it is shown some of the treatments applied.
The peroxidase is more sensitive to these chemical agents, and the catalase may be not so involve in
the enzymatic reaction, because of the results presented in the table.
The peroxidase and catalase are not the only enzymes that are involved in this reaction, because in
some treatments, the exposition to air did not change the color of the hawthorn and the tests of these
enzymes were negative.

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Conclusions
Figure 1. Some treatments applied to hawthorn, at 24 h to air exposition.
Salt, Salt-sugar-ascorbic, Salt-sugar-citric, Salt-ascorbic, Salt-citric, Salt-sugar-citric 0.5%-ascorbic
0.5% and Salt-sugar-citric 1%-ascorbic 1% treatments presented good results to avoid the color
change ought to the exposition to oxygen and mechanical damage, enzymatic browning.
The combination of these antioxidants with salt had good effect in the inhibition of the enzymatic
browning; combination of sugar with ascorbic and citric acids dif not inhibited the reaction. The acids
alone did not inhibit this reaction.
The enzymes tested are not the only involved in the enzymatic browning of hawthorn. It is necessary
to test the polyphenol oxidase too.
The variety of hawthorn have effect, is more inhibited the creole than the grafted, may be ought to the
porosity and the chemical composition.
References
1. Anese M. Nicoli M.C. Dall’aglio G. Lerici C. 1995. Effect of high pressure treatments on peroxidase
and polyphenoloxidase activities. J. Food Biochem. 18: 285-293.
2. Braverman J.B.S. 1976. Introducción a la Bioquímica de Alimentos. Ed. Manual Moderno pp. 283-
291.
3. Estudio de la actividad de la peroxidasa, pectinesterasa y polifenoloxidasa en extracto enzimático
de sandía (Citrullus vulgaris Schard). Comunicaciones Científicas y Tecnológicas. Laboratorio de
Tecnología Industrial III - Laboratorio de Química Analítica Instrumental. Facultad de Agroindustrias
- UNNE. Argentina.
4. Avallone C.M. Cravzov A.L. Montenegro S.B. Pellizzari, E.E. 2000. Estudio de la actividad de
polifenoloxidasa y peroxidasas en Carica papaya L. mínimamente procesada. Comunicaciones
Científicas y Tecnológicas. Lab. de Tecnología Industrial III y Lab. de química Analítica
Instrumental - Facultad de Agroindustrias - UNNE. Argentina.
5. Desrosier N.W. 1963. Conservación de Alimentos. Segunda edición. CECSA. pp. 361.

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
6. Pérez L. González-Martínez C. Chafer M. Chiralt A. Cambios de color en Pera (var. Blanquilla)
mínimamente procesada. Departamento de Tecnología de Alimentos, Universidad Politécnica de
Valencia. Camino de Vera s/n, 46022 Valencia, España
7. Ponting J.D. Joslyn. M.A. 1948. Ascorbic acid oxidation and browning in apple tissue extracts. Arch.
Biochem. Biophys. 19: 49.

Water and calcium absorption during corn nixtamalization
Herrera-Rivera, R.H., Alvarado-Garcia, M..A., Monroy-Rivera J.A.
(jamonroy@itver.edu.mx)UNIDA-Instituto Tecnologico de Veracruz, Mexico.
Corn is the base staple food of Mexican diet. Nixtamalization is a limetemperature
process used in corn transformation to rend it into a functional
product. In this work, the water and calcium absorption by the grain were
studied. Six nixtamalization temperatures (25, 35, 45, 70, 80 and 90°C)
and three lime concentration (1, 2 and 3%) were evaluated using a
complete factorial statistical design. The results showed that water
absorption was produced during the first 10 hours of soaking which was
mainly influenced by temperature but not by the lime concentration as
well as the calcium absorption into the corn. Nevertheless, the diffusion
coefficient calculated through the Fick mass transfer equation was
independent of lime concentration and temperature.
KEY WORDS: Corn nixtamalization, water absorption, calcium absorption, Fick,
diffusivity.
INTRODUCTION
Corn nixtamalization is a process used to produce tortillas, toasted ships and nixtamalized
corn flour. These products are the base of a variety of Mexican food products. The
nixtamalization process is an alkaline cooking process followed by soaking. During this
process, many physical-chemical, rheological and structural changes take place, which are
very important in the final texture characteristics of the tortilla. Mexican culinary culture
has been progressively increased in the last years. Nowdays, the industrial production of
corn dough (masa) and tortilla does not use the traditional conditions of nixtamalization,
reducing texture and stability characteristics of tortilla (2). During Nixtamalization, corn
starch is gelatinized and then just after the end of thermal treatment effect, starts the
retrogradation (3). These phenomena have a great influence on the mechanical properties
of the tortilla. The final calcium content of the tortilla changes the textural smoothness
during storage (4). The cross linkage between starch and calcium is controlled by the lime
concentration and cooking and stepping times. For consumers, the tortilla is a very
important calcium source. Biological studies have shown that practically all this calcium is
available (1).
Calcium ion absorption during nixtamalization is developed in a progressive way from the
outer surface towards inside layers. In non damaged grains, this diffusion takes several
hours (5). Studies on thermal diffusivity of tortilla have shown that there is a maximal
value of this property in a short range of the tortilla calcium content (6). The calcium
absorption is then an important variable to control during nixtamalization process. In this
work, the water and calcium absorption by the corn grain was determined and the Fick
mass transfer equation was used to estimate the mass diffusion coefficients.

MATERIALS AND METHODS.
A complete factorial design 6X3 (6 temperatures and 3 lime concentrations) with one
replication and three analyses per sample were performed to obtain the experimental data.
Sample preparation. 3 L of water, 500 g of corn and the lime were put in a temperature
controlled cylindrical container. The water and lime experimental concentrations were set
to be in excess such that regardless of calcium absorbed by the grain, the calcium
concentration in solution was the same. Samples were taken until the equilibrium
concentration was reached. The sample was rinsed with unionized distilled water and the
water excess was eliminated.
Water content. The gravimetric method was used to determine water content. Samples
were dried in a vacuum oven at 70 mm Hg and 60°C for 24 h.
Calcium content. This analysis was performed by Atomic Absorption Spectroscopy of
Flame Ionization at 422.7 nm with a 10 mA calcium lamp and a slit of 0.7 nm in dried
samples.
RESULTS AND DISCUSSION.
Water and calcium absorption kinetics. Water absorption at the three lime
concentrations was not significantly different. The 1% lime concentration results are
showed in figure 1 at the studied temperatures. This behavior was expected and confirms
the fact that water and calcium absorption was not limited by lime concentration. The lime
solubility in water is 1.25 mg/L, and then all the concentrations used in this experiment
were oversaturated. This figure shows that at 25, 35, 45 and 70°C, the equilibrium was
reached in 10 h of processing, higher temperatures favored water absorption and the
equilibrium was reached sooner (6-8 h). At these temperatures figure 1 shows an increase
in the final water content of the samples. The equilibrium wasn’t really obtained at these
temperatures because the samples presented gelatinization and the starch was able to
absorb more water in its structure.
HBS (g water/g d.s.)
1.6
1.2
0.8
0.4
0
%H 25°C
%H 35°C
%H 45°C
%H 70°C
%H 80°C
%H 90°C
0 2 4 6 8 10 12 14
Time (h)
Figure 1. Water kinetic absorption during
nixtamalization at several temperatures. 1% of
Ca(OH)2

Calcium absorption is shown in figure 2. At low temperatures, there is a well defined
tendency to increase as a function of temperature. However, this pattern is lost at 70, 80
and 90°C. At these temperatures the equilibrium was reached up to 0.3% of calcium
content after 6-8 h of nixtamalization. After this concentration, the starch was gelatinized
and the grain structure was collapsed (fig. 1). The calcium is deposited within the external
structure (pericarp).
% Ca (g Ca/100 d.s.)
0.5
0.4
0.3
0.2
0.1
0
25°C I
35°C I
45°C I
70°C
80°C I
90°C I
0 2 4 6 8 10 12
Time (h)
Figure 2. Calcium kinetic absorption during
nixtamalization at several temperatures. 1% of
Ca(OH)2
Water and calcium diffusivity.
These parameters were estimated by the Fick law:
dC 2
dt
= D ⋅∇
The following assumptions were considered:
a) The grain is an infinite slab, then the diffusivity is unidirectional,
b) The diffusivity is not a constant.
By using the next boundary conditions,
t=0 C=Co x=L
t>0 C=C 0< x< L
The analytical solution is expressed as a Fourier series
∑ ∞
2
C − Ce
8 1 ⎡ π ( 2n
−1)
=
exp⎢−
2
2
2
C0
− Ce
π n=
1 ( 2n
−1)
⎣ 4L
Where Ce is the equilibrium concentration, Co is the initial concentration, C is the
concentration at t>0, D is the diffusivity and L is the middle grain thickness.
C
2
Dt ⎤
⎥
⎦

The equilibrium water and calcium concentrations obtained in this study permitted to
C − Ce
allowed the equation (3) because if p 0.
7 the solution of the Fick equation is
C0
− Ce
reduced to
C − C
C
0
e
− C
e
2
8 ⎡ π Dt ⎤
= exp⎢−
2
2 ⎥
π ⎣ 4L
⎦
This equation was linearized and the diffusivity was calculated as the slope obtained by
linear regression.
The D values are shown in Figure 3. The order of magnitude of values is that reported for
food diffusion coefficients. Both D values, for water and calcium, follow the same pattern.
It seems that the diffusivity increases as a function of temperature. Calcium is minimally
soluble in water but results suggest that water and calcium diffuse together into the corn
grain. However, if the diffusivity values are compared against water or calcium content,
(Figure 4), no temperature effect is observed. At low temperatures (25, 35 and 45°C), the
diffusion is independent of temperature, but at 70, 80 and 90°C this is not valid for water
content lower than 0.5 g of water/g dried solid (Figure 5).
D (m2/s)
2.5E-10
2E-10
1.5E-10
1E-10
5E-11
0
Dwa (m/s)
Dca (m/s)
0 20 40 60 80 100
Temperature (ºC)
Figure 3. Water and calcium diffusivities in corn
nixtamalization at 1%. Of lime content

D (m2/s)
1.00E-09
9.00E-10
8.00E-10
7.00E-10
6.00E-10
5.00E-10
4.00E-10
3.00E-10
2.00E-10
1.00E-10
D 25ºC
D 35ºC
D 45ºC
0.00E+00
0 0.1 0.2 0.3 0.4
HBS (g water/g d. s.)
0.5 0.6
Figure 4. Water diffusivities into corn grain
in alkaline solutions at 1% Ca(OH)2 and
25,35 and 45C
D (m2/s)
1.20E-09
1.00E-09
8.00E-10
6.00E-10
4.00E-10
2.00E-10
D 70ºC
D 80ºC
D 90ºC
0.00E+00
0 0.5 1 1.5 2
HBS (g water/g d. s.)
Figure 5 . Water diffusivities into corn grain
in alkaline solutions at 1 % Ca(OH) 2 and
25,35 and 45C

CONCLUSIONS
The water and calcium kinetics can be described by the second Fick law and the applied
considerations are corrects in this case. The water and the calcium diffuse together into the
grain and the diffusion coefficient is not strictly temperature dependent. At low
temperatures, the diffusion is temperature independent. It seems necessary to complement
this study with s study of the degree of gelatinization during nixtatinization.
BIBLIOGRAFÍA
1. Urizar H. A. and Bressani R., 1997, Efecto de la nixtamalización del maíz sobre el
contenido de ácido fítico, calcio y Hierro. Archivos Latinoamericanos de Nutrición,
Vol. 47, No.3.
2. Bello P., L. A., Osorio D., P., Agama A., E., Núñez S., C., and Paredes L., O., 2002.
Propiedades químicas, fisicoquímicas y reológicas de masas y harinas de maíz
nixtamalizado. Agrociencia. Vol. 36: 319-328.
3. Goméz, M. H., Waniska, R. D., and Rooney, L. W. 1991. Starch characterization of
nixtamalizad corn flour. Cereal chem. 68: 578-582.
4. Del Valle, F. R., Santana, and V, Clason, D.,1999. Study of the posible formation of
calcium cross-links in lime treated (nixtamalizad) corn. Journal of food procesing
presevation. 23:307-315.
5. Zazueta, C., Ramos, G., Fernández M., J. L., Rodríguez, M. E., Acevedo H., G., and
Pless, R., 2002. A radioisotopic study of theentry of calcium ion into the maiz kernel
during nixtamalization. Cereal chemestry. 79(4): 500-503.
6. Alvarado G., J.J., Zelaya, A. O., Sánchez Sinencio, M., Yánez Limón, M., Vargas, H.,
Figueroa, J.D.C., Martínez B., f., Martínez, J.L., and González H., J., 1995,
Photoacustic monitoring of processing conditions in coged tortillas: measurement of
thermal diffusivity. Journal of food science, 60,3: 438-444

Tejate Drying Study
Mendoza-Santiago H. 1 , Cortés-Noh M. M. 1 , Monroy-Rivera J. A. 2 *
1 Instituto Tecnológico de Oaxaca (amos_31@itoaxaca.edu.mx), 2 UNIDA, Instituto Tecnológico de
Veracruz (jamonroy@itver.edu.mx)
The Tejate is a prehispanic beverage made from corn (Zea mays),
cocoa (Theobroma cocoa), mamee sapote seeds (Calocarpum
mammosum), Rosita de Cacao (Quararibea funebris), corozo,
water and lime. This beverage is consumed mainly in the Central
Valley of Oaxaca, Mexico. The purpose of this study was to dry the
tejate, so as to make it more stable by reducing its water activity
(Aw). Consumer testing was used to find out the most liked
formulation for the tejate. Drying was done in a hot air dryer at 60,
70 and 80°C with different layer thicknesses (0.25, 0.5 and 0.75
cm). Isotherms were performed at 15, 25 and 35°C. Results
showed that the best tejate formulation was obtained when corozo
was not used. The best drying conditions were set at 70°C and 0.5
cm layer thickness. Moisture and Aw were correlated by both the
Henderson expression (r 2 =0.94-0.98) and Chung-Pfost expression
(r 2 =0.93-0.98).
KEY WORDS: Tejate, drying, sorption isotherms.
INTRODUCTION.
Tejate is a traditional beverage of the
central valley of Oaxaca, in Mexico. It
is prepared from corn (Zea mays),
cocoa (Theobroma cocoa), mamee
sapote seeds (Calocarpum
mammosum), Rosita de Cacao
(Quararibea funebris), corozo, water
and lime. People like this brew,
because it has a very special taste
and it is also a highly energetic
beverage. People drink it during hard
farming activities when they spend
most of the time outside, being
exposed directly to the sun. The
ingredients are mixed and grounded
in a stone mill. The product obtained
is a paste. This paste is dissolved in
water during the beverage
preparation. The water is slowly
added with hand agitation until the
desired consistency is achieved. A
foam layer must be formed on the
surface of the liquid (Cortes, 1999).
This way of Tejate preparation is not
very hygienic. Fecal contamination
has been found in samples of tejate
beverage (Jimenez Santiago et al.,
2004). The dough and the drink are
unstable, they have a high Aw value
and microorganisms and enzymatic
and physical-chemical deteriorative
reactions take place. The purpose of
this study was to dry the tejate so as

to make it more stable through
reducing its water activity (Aw).
Materials and Methods
Raw materials. Corn (Zea mays),
cocoa (Theobroma cocoa), mamee
sapote seeds (Calocarpum
mammosum), Rosita de Cacao
(Quararibea funebris), corozo, and
lime were bought in the local market
of Oaxaca. These products were well
inspected to avoid insects and
microbial damage.
Tejate preparation. 1kg of white
corn, 100g of cocoa, 20g of Rosita de
cacao, 20g of mamme sapote seeds,
3L of water and 250g of lime were
used for tejate preparation (Cortes,
1999). The corn was cooked with lime
for 2h. Then, it was washed and
mixed with the other ingredients
previously roasted. The mixture was
grounded until an homogeneous
dough was obtained.
Tejate drying. The tejate was dried
in a cabinet drier at 60, 70 and 80 °C
in different layer thicknesses (0.25,
0.5 and 0.75 cm) and 1-1.5 m/s of air
velocity. During drying, samples were
taken to obtain the drying kinetics.
The dried product was grounded and
sieved to obtain particle sizes smaller
than 500 mm (Mendoza, 2004).
Sorption Isotherms. The gravimetric
method, with sulfuric acid solutions,
was used to obtain the sorption
isotherm at 15, 25 and 35°C. The
samples were put in glass containers
with the solutions of known Aw. The
containers were closed and vacuum
was made into the containers to avoid
variations in the inside relative
humidity. The samples remained in
the glasses until equilibrium was
reached. Equations of Chung-Pfost
⎡ C
⎤
(1967): Aw = exp ⎢−
1 exp(
− C2H
) ⎥⎦
⎣ RT
and Henderson (1952):.
C
ln(
1−
Aw ) = −C
TH 2
1
Were used, where Aw is water
activity, T is temperature (K), M is
water content (g H2O/g dm), R is
constant of gases and C1, C2 are
constants.
Water Content. Water content of
samples taken during drying and
sorption isotherms were determined
by the AOAC recommended method
(1991).
Results and Discussion
Preliminary drying experiments
showed that dried tejate was very
unstable. Besides, it developed a
rancid flavor attributed to corozo,
which is rich in polyunsaturated fatty
acids. Drying temperatures catalyzed
oxidation reactions provoking the off
flavors. Instead of using antioxidants
to avoid this problem, corozo was
eliminated from the original
formulation. The new formulation was
tasted by 100 tejate producers and
consumers. No difference was found
between the original and new
formulations.
Drying Kinetics. Kinetics of tejate
drying are shown in Figure 1 at the
three tested temperatures. The effect
of layer thickness is clearly notorious
and it was increased with
temperature. At 60 C, this effect is
more important between 0.25 and
0.50 cm than 0.50 and 0.75 cm
thickness. Nevertheless, when the
temperature increases the
thicknesses effect is less important.

The tejate dough is mainly constituted
by starch. During processing, this
starch is partially gelatinized and
water is caught into its structure. This
effect is seen at 0.75 cm thickness
(Figure 1C).
Water content (X/Xo)
Water content (X/Xo)
Water content (X/Xo)
1
0.8
0.6
0.4
0.2
60 C 0.25 cm
60 C 0.50 cm
60 C 0.75 cm
0
0 50 100 150 200 250 300 350
Time (min)
1
0.8
0.6
0.4
0.2
a
70 C 0.25 cm
70 C 0.50 cm
70 C 0.75 cm
0
0 50 100 150 200
Time (min)
250 300 350 400
1
0.8
0.6
0.4
0.2
b
80 C 0.25 cm
80 C 0.50 cm
80 C 0.75 cm
0
0 50 100 150 200
Time (min)
250 300 350 400
c
Figure 1 Thickness effect in Tejate drying
kinetics at 60, 70 and 80 C
Water content (X/Xo)
Water content (X/Xo)
Water content (X/Xo)
1
0.8
0.6
0.4
0.2
60 C 0.25 cm
70 C 0.25 cm
80 C 0.25 cm
0
0 20 40 60 80 100
Time (min)
120 140 160 180 200
1
0.8
0.6
0.4
0.2
a
0
0 50 100 150 200 250 300 350
1
0.8
0.6
0.4
0.2
Time (min)
b
60 C 0.50 cm
70 C 0.50 cm
80 C 0.50 cm
60 C 0.75 cm
70 C 0.75 cm
80 C 0.75 cm
0
0 50 100 150 200
Time (min)
250 300 350 400
c
Figure 1 Temperature effect in Tejate drying
kinetics at 60, 70 and 80 C
When drying rate is high, the water
transports solids to the surface and a
barrier is formed due to water
evaporation (Figure 2C). This
phenomenon diminishes the
temperature effect in drying. A
compromise between drying time and

product quality needs to be taken into
account during food processing.
Sorption isotherms. Figure 3 shows
the sorption isotherms at 15, 25 and
35C. The figure indicates that there is
a great influence of temperature on
the isotherm sorption. Data are
exponentially distributed as shown in
other high starch products (Chen,
2002).
Water content (g H2O/g d.m)
0.8
0.6
0.4
0.2
15°C
25°C
35°C
0
0.2 0.4 0.6
Aw
0.8 1
Figure 3 Sorption isotherm of Tejate at 15,
25 and 35 C
The Chung-Pfost equation was
linerized to calculate the constant
values
ln
⎛
( − ln Aw ) = ⎜ln
+ ( − b)
M ⎟
⎝ T ⎠
a
where: a=C1/R and b=C2
and also Henderson equation
[ − ln(
1−
A ) ] = ln aT b ln M
ln w +
a=C1 and b=C2.
Table 1 shows the constant values
and the correlation coefficient (r 2 ) for
Chung-Pfost and Henderson models.
The accuracy of models at the
studied temperatures is the same for
both equations. They represent
⎞
isotherm behavior but they were more
accurate at low temperatures than at
high temperatures. Chung-Pfost and
Henderson models have been used
to predict sorption isotherms for
cereals or starchy products (Sun
D.W., 1998, Silakul and Jindal, 2002,
Chen, 2002). Both equations have
been modified to increase their
accuracy. Chung-Pfost equation has
been recommended to use in rice
products and mushroom (Durakova
and Mendkov, 2004, Shivhare et al.,
2004). Figure 4 fits both equations
and experimental results at 15 C.
There is a region between 0.7 and
0.95 of Aw where the isotherm was
not well described by the models.
Table 1. Values of constants and r 2 of
Chung-Pfost and Henderson equations for
Tejate.
Chung-Pfost
a= 668.84
b= 8.5224
Henderson
a= 0.0243
b= 1.1473
r 2
15C 25C 35C
0.9841
0.9851
Water content (g water/g d.m.)
0.6
0.5
0.4
0.3
0.2
0.1
Experimental
Chung-Pfost
Henderson
0.9650
0.9718
0
0 0.2 0.4 0.6 0.8 1
0.9343
0.9469
Aw
Figure 4. Experimental and predicted
absorption isotherms by Chung-Pfost and
Henderson models at 15C

CONCLUSION
A tejate formulation was developed.
The best operational and sensory
drying conditions were 70C and 0.05
cm thickness under the conditions
used in this study. Adsortion
isotherms showed an important
temperature effect to take in account
during storage of dried tejate. The
models evaluated described the
sorption isotherm behavior of tejate
powder.
REFERENCES
Chen C.(2002). Sorption isotherms of
sweet potato slices. Biosystems
Engineering. 83(1), 85-95.
Cheng D.S., Pfost H.B. 1967.
Adsortion and desorption of water
vapor by Cereal grains and their
products. Transactions of ASAE,
10(4), 552-555.
Cortez-Noh , M. M; 1999. Estudio
Nutricional y Bebidas a base de
Vegetales en la Alimentación, Tesis
Inst. Tec. Veracruz. México.
Durakova A.G., Menkov, N.D, 2004.
Moisture sorption characteristics.
Nahrung/Food, 48(2), 137-140.
Henderson S.M. 1952. A basic
concept of equilibrium moisture.
Agricultural Engineering, 33(1), 29-
32.
Silakul T.,and Jindal V.K. 2002.
Equilibrium moisture content
isotherms of mungbean. International
Journal of food properties, 5(1), 25-
35.
Shuvhare U.S., Arora S., Ahamed J.,
Raghavan G.S.V. 2004. Moisture
adsorption isotherms for mushroom.
Lebensmittel-Wissenschsft und
Technologie. 37(1), 133-137.
Sun D-W. 1999. Comparison and
selection of EMC/ERH isotherm
equations for rice. Journal of Stored
Products Research, 35, 249-264.

Studies on double emulsion (W/O/W) of iron aminoacid chelate.
Rubén Jiménez Alvarado, Gerardo Valerio Alfaro, José Alberto Monroy Rivera*
jamonroy@itver.edu.mx. UNIDA, Instituto Tecnológico de Veracruz
Double emulsions are meta-stable dispersions of water/oil/water type (W/O/W) or
oil/water/oil type (O/W/O). They are widely used in pharmaceutical applications. In
this work, the preparation conditions of a double emulsion W/O/W-type containing
water soluble iron aminoacid chelate were studied. The primary emulsion was
obtained at 25 000 rpm after 30 min of agitation. Three span 80 concentrations
were tested as W/O emulsifying agent (2, 17 and 32%). The secondary emulsion
was prepared at 600 rpm during 15 min. The hydroxipropilcellulose (5%) and
Sodium Lauryl Sulfate –SLS- (0.1, 1 and 10 the Critical Micelle Concentration,
CMC) were the emulsifiers for the secondary emulsion O/W. The double emulsion
was steady when span 80 concentration in the primary emulsion was 17% and the
SLS concentration in secondary emulsion was 10 CMC. The inner droplets mean
diameter was in the 0.25-0.47 µm range and the diameter of the external droplet
were between 15 and 30 µm. The water concentration was 90% in the W/O
primary emulsion and 10% in the secondary emulsion.
KEY WORDS. Double emulsion, iron aminoacid chelate, span 80, Sodium Lauryl
Sulfate
INTRODUCTION
Emulsions contain two immiscible
fluids like water and oil. The oil in
water dispersions are called direct
emulsions. The double emulsions can
be of type W/O/W or O/W/O 3,5,6,7 .
This structure of double compartment
has created great interest toward
multiple systems since his first
description in 1925 12 . At this time,
they were considered as a depot of
encapsulated substances that could
be released under different
conditions 8 . A more important number
of applications is encountered in
human pharmaceutics 2,11,12 . The
W/O/W emulsions have been tested
as a potential carrier of several
hydrophilic drugs (vaccines, vitamins,
enzymes, hormones) progressively
released 1 . Considering the
importance of iron in the biosynthesis
of vital molecules (hemoglobin,
miohemoglobin, metabolic enzymes,
etc.), there is a tendency to fortify
foods with iron, in some cases in
mixture with microelements and
vitamins. Iron is better absorbed as
chelate iron than the sulfate form 9 .
Besides, the biglicined iron has a high
potential as a food fortifier because
its absorption isn’t diminished by
precipitation, or by its linkage with
other molecules, like phytates.
However, biglicined iron increases
the oxidation of unsaturated fatty
acids more strongly than other
fortifiers and it has an unpleasant
flavour. The stability of the biglicined
iron is other disadvantage; it is easily
oxidized to its ferric form. These

problems can be controlled by double
emulsion encapsulation 4,10,13 . The
aim of this work was to prepare a
W/O/W double emulsion containing
biglicined iron in its internal acuose
phase.
MATERIALS AND METHODS
The double emulsion was prepared at
20°C in two steps 11,14 .
Primary emulsion: 9 ml of biglicined
iron solution were slowly added to a
mixture of 1 ml of mineral oil and
sorbitan monooleate (SPAN 80 at 2,
17 and 32%) in a Polyscience
homogenizer at 25000 rpm during 30
min.
Secondary emulsion: The primary
emulsion was dispersed in deionized
water using a magnetic stirrer at 600
rpm. Hydroxipropil cellulose was
added as thickener. Sodium Lauril
Sulfate (SLS) was evaluated as
emulsifying agent at 0.1, 1 and 10 of
the Critic Micelle Concentration
(CMC=8 E-03 Mol/l).
The primary and secondary
emulsions were analyzed using 100X
immersion lens in an optical
microscopic (National) equipped with
digital camera and software for data
analysis.
RESULTS AND DISCUSSION
The inverse emulsion (W/O) obtained
(fig. 1) was a cuasimonodisperse
emulsion of biglicined iron with
diameter drops of 0.25-0.47 mm.
Figure 2 shows the double emulsion
structure obtained with 2% of SPAN
80 in the primary emulsion. The
emulsion W/O was highly
a)
b)
c)
Fig. 1. Primary W/O Emulsion obtained with:
a) 2%; b) 17%; c) 32% Span80
viscous and it was very difficult to
disperse. A cluster of the primary
emulsion surrounded by water is
appreciated in this figure. The
aggregate was bigger at lower

concentrations of SLS. When the SLS
concentration increases the
hydrophilic emulsifying compete
against the lypofilic emulsifying agent
breaking the viscous structure of the
primary emulsion.
a)
b)
c)
Fig. 2. Doubles Emulsions obtained with 2%
Span80 and: a) 0.1CMC de SLS; b) CMC de
SLS; c) 10CMC de SLS as emulsifying
agents
The double emulsion prepared at
17% of SPAN 80 in oleic phase is
shown in figure 3 at the three SLS
concentrations
a)
a)
b)
c)
Fig. 3. Doubles Emulsions obtained with 17%
Span80 and: a) 0.1CMC de SLS; b) CMC de
SLS; c) 10CMC de SLS as emulsifying
agents

The primary emulsion was still
viscous. However when the SLS
concentration increases (10 CMC), it
was possible to obtain a double
emulsion structure with biglicined iron
in the acuose internal phase. The
inner drop diameter was 0.25-0.47
mm and the outer drop diameter was
15-30 mm.
Figure 4 presents the double
emulsions prepared with 32% of
SPAN 80. The dispersion of the
primary emulsion is better, but there
were some clusters. The high
concentration of emulsifying agent
span 80, was too much and increases
the viscosity, stopping the
desegregation of the primary
emulsion.
CONCLUSSION
According to this study, it is possible
to prepare double emulsions W/O/W
containing 90% of biglicined iron
solution in the primary emulsion by
using a span 80 concentration of 17%
as oleic emulsifying agent, SLS at 10
CMC (8E-2M) and 5% of hydropropil
cellulose.
BIBLIOGRAPHY
1. Alexey Kabalnov (1996)
Macroemulsion Stability: The Oriented
Wedge Theory Revisited. Langmuir
1996, 12, 276-292.
2. Dhanorkar et al., (2001) Formation
and Stability Studies of multiple (w/o/w)
Emulsions Prepared with Newly
Synthesized Rosin-Based Polymeric
Surfactants. Drug Development and
Industrial Pharmacy, 27(6), 591–598.
a)
b)
c)
Fig. 4. Doubles Emulsions obtained with 32%
Span80 and: a) 0.1CMC de SLS; b) CMC de
SLS; c) 10CMC de SLS as emulsifying
agents

3. Ficheux M. F. Et al. (1998). Some
Stability Criteria for Double Emulsions.
Langmuir 14, pages 2702-2706.
4. Fukuzawa, K.; Fujii, T. (1992)
Peroxide dependent and independent
lipid peroxidation: site-specific
mechanisms of initiation by chelated iron
and inhibition by R-tocopherol. Lipids
1992, 27, pages 227-233.
5. Goubault C. Et al. (2002) Shear
Rupturing of Complex Fluids: Application
to the Preparation of Quasi-
Monodisperse Water-in oil-in-Water
Double Emulsions. Langmuir 17, pages
5184-5188.
6. J. Giermanska-Kahn et al., (2002) A
New Method To Prepare Monodisperse
Pickering Emulsions, Langmuir 2002, 18,
2515-2518.
7. Jim Jiao, David G. Rhodes, and Diane
J. Burgess (2002) Multiple Emulsion
Stability: Pressure Balance and
Interfacial Film Strength. Journal of
Colloid and Interface Science 250, 444–
450.
8. K. Pays, J. et al, (2001) Coalescence
in Surfactant-Stabilized Double
Emulsions. Langmuir 2001, 17, 7758-
7769.
9. Lindsay H Allen. Properties of Iron
Aminoacid Chelates as Iron Fortificants
for Maize. Department of Nutrition,
University of California Davis, California.
10. Lixiong Wen and Kyriakos D.
Papadopoulos, (2000) Effects of
Surfactants on Water Transport in
W1/O/W2 Emulsions. Langmuir 2000,
16, 7612-7617.
11. Matsumoto S., Kita Y., Yonezawa D.,
(1976) An Attempt at preparing Water-in-
Oil-in-Water Multiple-Phase Emulsions.
Journal of colloid and interface science
1976, 52 (2), 353-359.
12. Mc Clements D. J. 2000. Food
Emulsions, Principles, Practice, and
Techniques. CRC Press.
13. S. P. Uchil et al., (2002) Texture and
Stability of Emulsions: Role of Oscillatory
Structural Forces. J. Dispersion Science
and Technology, 23(1–3), 187–198.
14. Zhao and J. L. Goveas, (2001) Size
Selection in Viscoelastic Emulsions
under Shear. Langmuir 2001, 17, 3788-
3791.

Evaluation of microbial, physicochemical and sensorial characteristics of fresh
and dried tejate
Jiménez Santiago Mayra 1 , Cortés Noh María M 1 , Brena Robles Edith 1 , Monroy Rivera José A. 2 *
1 Instituto Tecnológico de Oaxaca (amos_31@itoaxaca.edu.mx), 2 UNIDA, Instituto Tecnológico de
Veracruz (jamonroy@itver.edu.mx)
The Tejate is a traditional beverage from Oaxaca, Mexico. It is prepared from corn
(Zea mays), cocoa (Theobroma cocoa), mamee sapote seeds (Calocarpum
mammosum), Rosita de Cacao (Quararibea funebris), water and lime. This study
was performed in two steps; in the first one, samples of fresh tejate were collected
in local markets of Oaxaca Central Valley in order to measure water content and
microbial flora. In the second part, tejate was prepared in laboratory and dried in a
hot air dryer at 70C for 4 hours. The air velocity and the product thickness were
1.25 m/s and 0.5 cm respectively. The water content of fresh and dried products
were 1.6 and 0.6 g of H2O/g of dry mater respectively. The water activity of dry
tejate was 0.45. Microbial counts were higher in the fresh tejate than in the dried
(a=0.5). Protein, fat, non digestible fiber, pH as well as the sensory attributes
were not different between fresh and dried tejate.
Key words. Tejate, sensory evaluation, drying, microbial counts, sorption
isotherm.
INTRODUCTION
The Tejate is a traditional beverage from Oaxaca, Mexico. It is drunk as an energetic
and refreshing brew. Tejate is prepared from corn (Zea mays), cocoa (theobroma
cocoa), mamee sapote seeds (calocarpum mammosum), Rosita de Cacao
(Quararibea funebris), water and lime. The ingredients are mixed and grounded in a
stone mill. The product obtained is like a paste. This paste is solved in water during
the beverage preparation. The water is slowly added with hand agitation until the
desired consistency. A foam layer must be formed on the surface of the liquid
(Cortes, 1999). This way of Tejate preparation is not very hygienic since the brew is
microbiologically unstable. In this work a new way of tejate production was evaluated
in order to obtain a healthy and stable product, easy to prepare and with identical
sensory characteristics to the original.
MATERIALS AND METHODS
15 samples of fresh tejate were obtained in the markets of Oaxaca city, Etla,
Tacolula, Ocotlan, Santa Maria “El tule”, and San Andres Huayapan in the Oaxaca
state, Mexico. The samples were put in sterilized bags, and transported to the
laboratory for their analysis.
Microbial analysis. The methods approved the Mexican Standars were used:
Coliforms (NOM-112-SSA1-1994), Aerobic mesophyles (NOM-092-SSA1-1994),
yeast and fungi (NOM-114-SSA1-1994) and salmonella (NOM-112-SSA1-1994).

Physical-chemical analysis: Moisture content, ash, fat, non digestible fibre and pH
were determined by AOAC methods (1991). Brut Protein by MicroKjieldal method,
and True protein by Bradford method, minerals by Plasma emission spectrometry
(Thermo Jarrel Ash) and density by picnometry. Water activity and sorption isotherm
were performed using Aqualab serie 3,
Tejate drying. The tejate was dried in a cabinet drier at 70C and 1-1.5 m/s of air
velocity for 4 h. The thickness of the tejate layer was 0.5 cm. The dried product was
grounded and sieved to obtain particle size smaller than 500 mm (Mendoza, 2004).
Tejate preparation. 1 kg of white corn, 100 g of cocoa, 20 g of Rosita de cacao, 20 g
of mamme sapote seeds, 3 L of water and 250 g of lime were used for tejate
preparation (Cortes, 1999). The corn was cooked with lime during 2 h, then it was
washed and mixed with the other ingredients previously roasted. The mixture was
grounded until an homogeneous dough was obtained.
Sensory test. Optimal concentration of dried tejate, sucrose and water were
determined and a consumer preference test was performed to compare fresh and
dried tejate.
RESULTS AND DISCUSION
1.- Microbiologic analysis. Results of the sampling in the Oaxaca Central Valleys
markets show that 9 samples had for E. coli (table 1). The E. coli presence is mainly
due to fecal contamination and it is a risk indicator of the presence of other
pathogens. In some cases, the water used for the preparation of tejate drink was
contaminated; salmonella was present in 4 samples. There is a lack of sanitary
control in the markets of Oaxaca City, 8 of the 9 samples were contaminated with E.
coli. The dried tejate samples were negative for the entire microbiological tests
performed (table 2).
2.- Chemical composition. As shown in table 3, the tejate is a drink basically
energetic, with few quantities of protein and fat. It contains 10 minerals (table 4). A
serving of tejate contributes, 60% phosphorous, 75% magnesium and, 16% zinc of
children RDA.
3.- Physical characteristics. Results on the physical characteristics are the same
for both, fresh and dried tejate. Density was 1.046 g/cm 3 and 1.057 g/cm 3 , pH 7.43
and 7.47, for fresh and dried drink tejate respectively. It is slightly alkaline due to the
lime added for corn cooking. The solubility of tejate powder was 14 g/100 ml.
4.- Drying and sorption behavior. Figure 1 shows the drying kinetics of tejate paste
at 70C. Its high starch content partially gelatinized, had extended the time of tejate
drying; 2 h after drying started, only 50% of water had been eliminated. The
composition presented the same effect in the desorption isotherm (fig. 2).

Table 1. Microbiological results of tejate samples of the Oaxaca Central Valley markets
Sample Coliforms
NMP / g
aerobic
Mesofiles
UFC/g
Yeast and
fungi
UFC/g
E. coli
Salmonella
En 25 g
1 > 11 000 70 x 10 4 75 x 10 5 + +
2 > 11 000 160 x 10 3 45 x 10 4 + -
3 11 000 110 x 10 3 140 x 10 3 + -
4 > 11 000 140 x 10 5 120 x 10 5 + -
5 2900 100 x 10 4 70 x 10 4 + +
6 530 240 x 10 4 180 x 10 4 + -
7 280 110 x 10 5 90 x 10 5 + +
8 > 11 000 90 x 10 5 40 x 10 5 + +
9 > 11 000 50 x 10 4 45 x 10 3 - -
10 750 70 x 10 3 60 x 10 3 - -
11 440 78 x 10 5 30 x 10 5 - -
12 11 000 90 x 10 5 100 x 10 5 - -
13 >11 000 50 x 10 5 40 x 10 5 - -
14 930 45 x 10 3 30 x 10 3 - -
15 > 11 000 90 x 10 3 50 x 10 3 + -
1.Etla; 2. Benito Juárez market, Oaxaca ; 3. Benito Juárez market, Oaxaca; 4. Central de abastos market,
Oaxaca; 5.Central de abastos market, Oaxaca; 6. Paz Migueles market, Oaxaca; 7. 20 de Noviembre market,
Oaxaca; 8. Reforma, Oaxaca; 9. Tlacolula; 10. Ocotlán; 11. Sta. María “El tule”; 12. Merced market, Oaxaca; 13.
San Andrés Huayapam; 14. San Andrés Huayapam; 15. Regional market Las Flores, Oaxaca.
Table 2. Chemical composition of fresh and dried tejate (% dry mater)
COMPOUND FRESH TEJATE DRIED TEJATE
Water Content 57.0 5.0
Fat 1.075 2.37
Ash 0.70 1.56
Protein 3.34 7.39
Non digestible Fiber 0.34 0.75
Carbohydrates 37.52 82.90

Table 3. Mineral content of tejate (ppm)
MINERAL FRESH TEJATE DRIED TEJATE
g of H 2O/g of dry mater
Ca 248 573
Cu 1 3
Fe 13 23
P 1086 2848
Mg 450 1176
Mn 3 7
K 2113 5012
Na 78 95
Zn 11 24
V 0.9 2.2
1.4
1.2
1
0.8
0.6
0.4
0.2
0
0 30 60 90 120 150 180 210 240 270 300
Time (min)
Figure 1. Tejate drying kinetic at 70 °C

BIBLIOGRAPHY
g of H 2O/g of dry mater
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0 0.1 0.2 0.3 0.4 0.5
Aw
0.6 0.7 0.8 0.9 1
Figure 2. Sorption Isotherm of tejate at 24 °C
Bradford, M.M. 1976. A Rapid and Sensitive Method for the Quantitation of
Microgram Qualities of Protein Utilizing the Principle of Protein Dye Binding.
Analytical Biochem ,72, 248-254.
Bussey, D. M. 2000. Basic Food Microbiology. CRS, Press, New York.
Copeland, R.A. 1994. Methods for protein analysis. Ed Chapman and Hall, New
York.
Cortés, N.M.1999. Composición química de alimentos y bebidas preparados a base
de vegetales del Valle de Tlacolula, Oaxaca. Tesis. Instituto Tecnológico de
Veracruz, Ver, México.
Mahan K, Escott-Stomp S. 1996. Nutrición y Dietoterapia de Krauze. Mc Graw-Hill
Interamericana, México, D.F.
Mendoza, S.I. 2004. Estudio de secado del tejate. Tesis. Instituto Tecnológico de
Oaxaca, Oaxaca, Mex.
Official Methods of Analysis (AOAC). 1990. Fifteenth edition, Arlington, Virginia.
Stone, H., Sidel, J.L. 1985. Sensory Evaluation Practices. Ed. Academic Press INC,
Orlando Florida.
http://www.salud.gob.mx/nom147ssa16.html
http://www.salud.gob.mx/unidades/cdi/nom/186ssa12.html

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
“DEVELOPMENT AND FORMULATION OF AN EGG-MILK BASED POWDER BEVERAGE FOR
CHILDREN”
Bailón Soto Claudia Edith, 1 ; Herrera González, Silvia Marina, 2 ; Ibarra Alvarado Marcela, 3 .
(1) doribay hotmail.com.mx
I.- ABSTRACT
We used an experimental design to examine ingredient interactions in a beverage made of
albumen, egg yolk and milk and their effects on functional properties and nutritional requirements.
Sensory Evaluation Type I with a Hedonic Scale of 9 points combined with intensity was made.
Composition and microbiological assays were necessary. For statistical analysis, a Variance
Analysis as well as Response Surface Analysis were used. The approval of finished dried product
with level 1 of stabilizers, 0.6g albumen/ml of milk and 0.4g yolk/ml of milk was good.
Key words: egg, milk, beverage, protein, microencapsulation.
II.- INTRODUCTION
Infant malnutrition is a public health problem that includes social and economic phenomena and is
now becoming one of the main causes of morbidity and mortality of children through out the world
(2).
The need for easy to prepare nutritive food suplements, has made manufacturing food products
with milk and soy proteins possible, obtaining good results (3).
Nonetheless, nowadays in Mexico, there are no available products that combine milk and eggs as
a dried powder beverage in order to enhance a better development in children from one year old
and up.
In this part of the country it is a very common practice to give a preschool child a chocolate milk
shake with raw eggs, or instead of milk, an orange juice with eggs. As far as public health is
concerned, this manner of preparing shakes is inadequate because of the high prevalence of
alergenic agents besides antiphysiological and antinutritional elements in raw eggs (4).
Children malnutrition can arise when an improper and inadequate diet is given for a long period of
time. One of the aims of this new beverage is to take advantage of the high protein values of egg.
Besides, alergenic elements decrease tremendously in processed eggs (5) and it becomes safer for
human consumption, more attractive for children and easier to prepare. Moreover, an egg´s added
value can be reached and a waste of products avoided, specially in the hottest season of the year
when egg´s shelf life is enormously reduced.
For all these reasons, the main aim of this work was to prepare a protein beverage made of
albumen, egg yolk and milk for children as a food complement . We intended to create a nutritive,
safe and atractive alternative for the consumer.
1

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
III.-MATERIALS AND METHODS
Materials
Eggs were selected according to their freshness; skim milk, vanilla extract, cocoa and purified water
were obtained in the local market; corn starch, maltodextrine, carboximetilcelulose, soy lecithin,
kappa carragenine and guar gum were used.
Equipment employed consisted in a spray drier of tubular type, Apex, capacity 10 L, and
peristaltic bomb for feeding.
Analytical methods
Three experimental designs for the formulation of the beverage were used. First, for defining the
appropiate relation between albumen and yolk in the first design. Corn starch and maltodextrine
were used as stabilizers and the dehydratation conditions as well as the volumetric flux of
entrance were fixed. In the second design the relation albumen-egg yolk was redefined, kappa
carragenine and adex (maltodextrine with 30 DE) were used as a stabilizers. Finally, the third
experimental design aim was to improve the formulation. For this purpose, different blends of
maltodextrine, carboximetilcelulose, kappa carragenine, soy lecithin and guar gum were employed.
With each experimental design, a Sensory evaluation was carried out. This consisted in a Sensory
Evaluation Type I with a Hedonic Scale of 9 points combined with intensity in which the degree of
acceptance of finished product was tested (1).
The evaluated atributes were chosen according to the formulation of the egg-milk based powder
beverage. The main qualities observed, as a reference, were taken from the NOM (Norma Oficial
Mexicana) for lactant products and children powder products.
The sensory panel was integrated for 8 family mothers with ages ranging of 24 to 42 years old.
STATISTICAL ANALYSIS
It consisted in a Multivariate Analysis of Variance (Manova) with p

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
IV.- RESULTS AND DISCUSSION
In the first experimental design a temperature of 130°C was fixed; however, after a three month
storage most samples developed bad odors and rancidity when the seal was broken. Due to this
problem, process temperature conditions considered optimum were then fixed at 140°C with a
feeding speed of 14ml/min.
Results from the first experimental design showed that the best product acceptance was reached
with the blend of 0.8g of egg albumen and 0.2g of egg yolk per ml of milk. In adition to the use of
food hidrocolloids, the selection of a blend made of kappa carragenine and adex had a good result
because it was possible to obtain a stable emulsion (14).
Acording to the bibliography, combinations of food hidrocolloids have a limit of 0.03% in foods (14),
so that, in the beverage, the adex proportion must be higher than carragenine´s or very similar.
As it can be observed, the following graphic shows that the highest degree of acceptance is
reached with a blend containing the highest levels of carragenine and adex. According to the code
employed, the relationship between food hidrocolloids must be equivalent in quantities using
superior limits.
Also, the graphic shows that it is necessary to use as much albumen as yolk in order to obtain
better results.
z = 4.143+7.361*x-3.377*y-3.78*x*x+3.604*x*y-0.326*y*y
Fig. 4.1. 3D Response Surface of the degree of acceptance for the flavor of the egg-milk
5.217
5.485
5.753
6.020
6.288
6.556
6.823
7.091
7.359
7.626
7.894
8.162
8.429
8.697
8.965
9.232
based powder beverage according to the interaction albumen-egg yolk.
3

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
In the third experimental design the formulation was improved and a new hidrocolloid selection was
made.
The solubility, odor and flavor of this new beverage was improved. Figure 6.5 of solubility shows
that the use of stabilizers 1 and 2 is more factible when using middle levels of albumen, egg yolk
and stabilizer 1. Consequently, in order to obtain a good solubility is necessary to employ albumen,
0.6g/ml of milk; egg yolk, 0.4g/ml of milk. The best stabilizer complex is integrated for
maltodextrine, soy lecithine and kappa carragenine. The degree of acceptance with a value of
6.775 taken as good was reached with this blend.
v=-10.994*x-4.327*y-2.536*z+50.42*x*y+41.253*x*z+24.586*y*z
2
2
ESTABILZ
1
1 21 2
2
CLARA YEMA
1
1
5.178
5.355
5.533
5.71
5.888
6.065
6.243
6.42
6.598
6.775
Fig.4.2. Ternary Graphic of interaction among egg and stabilizers 1 and 2 for the solubility of
ANALYSIS OF COMPONENTS
the egg-milk based powder beverage.
The following table shows the results obtained from the analysis of components of the egg-milk
based powder beverage:
Table 1. Results of the analysis of the beverage components
Protein content 34.04%
Lipid content 27.4%
Ash content 3.36%
Moisture content 3.83%
4

Such results satisfactory covered the requirements stablished by the NOM for spray dried products
for children from 1 year old and up.
FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Microbiological assays.
The results obtained from the different microbiological assays may be seen in the next table:
Table 2. Beverage Microbiological Assay Results
ACCOUNT OF: RESULTS
Aerobic Mesophilic Plate UFC/g Negative
Total Coliforms (NMP/g) Negative
Staphylococcus aureus Negative
Salmonella spp in 25 g Absence
Mold and yeasts 50 UFC/g
Microbiological assays were necessary to evaluate the product safety, specially when it is done
for covering essential requirements for children development (NOM-131-SSA1 1995). Aerobic
Mesophilic Plate count was negative, the stablished limits by the NOM –159-SSA1-1996
estipulates that the maximum permited number is 2500 UFC/g of aerobic mesophilics.
Coliforms count for the NMP Method also resulted negative indicating that contamination post-
thermal treatment was absence. It was good because the NOM –131 –SSA1-1995 marks that the
maximum number accepted for Coliforms is 20NMP/g for dehydrated foods.
The count of Staphylococcus aureus alsoresulted negative. In this case may be observed that the
management of the beverage was adequate.
The NOM –131-SSA1-1995 stablishes that Salmonella count most be reported as absence in 25 g
of the examinated food. Consequently, the egg-milk based powder beverage was inside the
specifications of the regulation because Salmonella count resulted negative.
V.- CONCLUSIONS
About process conditions for drying, the safest and most adequate temperature at 140°C
was fixed.
Presence of kappa carragenine in the formulation permited to obtain a pleasant texture as well
as a good general acceptance.
The blends among food hidrocolloids resulted apropiated for the beverage purpose. Solubility
was the first characteristic improved. Using maltodextrine, soy lecthin and kappa carragenine the
flavor had a better acceptance.
5

FSB1 – 2004
Food Science and Biotechnology in Developing Countries
Statistically, the best blend with a good general acceptance was: Level 1 of stabilizer, 0.6 g of
albumen/ml of milk and 0.4 g of egg yolk/ml of milk.
VI.- REFERENCES
(1) O´Mahony Michael. 2000. Food Sensory Science. University of California. L.A. USA.
Stadelman, W.J. 1977. Egg Science and Technology. 2 nd ed. The AVI Publishing Co. Inc.
Westport Connecticut.
(2) Behrman, R.B., Vaughan, V.C. 1989. Nelson. Tratado de Pediatría. 13ª ed. Tomo I.
Interamericana-MC Graw Hill. Pp. 118-161.
(3) PLM, Diccionario de Especialidades Farmacéuticas, 2000, México.
(4) Zubirán, Salvador; Arroyo, Pedro; Ávila, Héctor. 1990. La Nutrición y la Salud de las Madres y
los Niños Mexicanos. Tomo II. Secretaría de Salud. Fondo de Cultura Económica. México. Pp
251-272.
(5) Martin, M., Pascual, C. Dir. Huesped Sierra Monroe, J. L. 1997. Temas de Pediatría.
Asociación Mexicana de Pediatría A.C. Alergia e Inmunología. 1era ed. español. MC Graw Hill
Interamericana. México. Pp. 93-118.
(6) NOM- 159-SSA1-1996. Bienes y servicios. Huevo, sus productos y derivados.
(7) NOM- 131-SSA1-1995. Bienes y servicios. Alimentos para lactantes y niños de corta edad.
(8) NOM- 086-SSA1-1994. Bienes y servicios. Alimentos y bebidas no alcohólicas con
modificaciones en su composición. Especificaciones nutrimentales.
(9) Kirk, R.S., Sawyer, R., Egan, H. 1999. Composición y Análisis de Alimentos de Pearson. 2ª ed
español. Compañía Editorial Continental.
(10) Frazier, W.C., Westhoff, D.C. 1993. Microbiología de los Alimentos. 4ª ed. español. Acribia.
Zaragoza, España. Pp. 341-357 y 547-564.
(11) Banwart, G.J. 1989. Basic Food Microbiology. 2 nd ed. Avi Book. Van Nostrand Reynold USA.
Pp. 198-320 and 506-540.
(12) Manual of BBL Products and Laboratory Procedures. 1988. Cat. No. 52000. 6 th ed. Pp.177.
(13) American Public Health Association. 1976. Compendium of Methods for the Microbiological
Examination of Foods. ED. Marvin L. Speck. USA.
(14) Glicksman, Martin. 1983. Food Hidrocolloids. Vol II. CRC. Press Inc. Boca Ratón Florida USA.
pp. 63-115.
6

FSB1-2004
Food Science and Biotechnology in Developing Countries
PECTIN EXTRACTION FROM Passiflora edulis (MARACUYA): PREPARATION
METHODS AND PARTIAL CHARACTERIZATION
E.P. Segura Ceniceros, J. I. Montalvo Arredondo, J.C. Contreras Esquivel, C.I Vargas Domínguez, J.L.
Angulo Sánchez*, A. Ilyina
Universidad Autonoma de Coahuila, Facultad de Ciencias Químicas, Blvd. V. Carranza e Ing.J. Cardenas
V., C.P. 25280, Saltillo, Coahuila, Mexico, Fax: 844-415-95-34,
E-mail: pathysegura@yahoo.com ; anna_ilina@hotmail.com
* Centro de Investigación en Química Aplicada
Key words: Pectin, polysaccharide, maracuya
Abstract: The optimum conditions for extraction of soluble pectin from the flavedo,
albedo and the complete rind of maracuya were studied. The time of steam treatment
and the citric acid concentration were the variable factors in pectin extraction from
residual fiber. The optimization of conditions helped to increase the quantity of extracted
pectin to 23%. The Molecular weights of the biopolymer and etherification grade (51%,
HM) were determined.
Introduction: The rind of maracuya (Passiflora edulis) represents an important
byproduct of maracuya juice industry. The fact that 65-70 % of the total weight of the
fruit turns out as waste creates ecological problems 1 . The rind is used in Brazil as an
additive to cattle feedstock, since it is rich in amino acids, proteins and carbohydrates.
Pectin is cell wall polysaccharides which have a structural role in plants. They are
predominantly linear polymers based on a 1, 4-linked alpha-D-galacturonic backbone,
interrupted randomly by 1, 2-linked L-rhamnose. Accurate determination of molecular
weights is difficult, partly because of the extreme heterogeneity of commercial pectin
samples, and partly because of the tendency of pectin molecules in solution to
aggregate. The pectin molecular weights can be expressed either as a weight average
or a number average value. Owens et al. using viscometer and osmometry, carefully
and systematically studied molecular weights and molecular weight distribution of pectin.
They reported molecular weights varying from 20,000 to 300,000, depending on the
preparation procedure 2 . There exist two major sources for pectin: citrus peel (mostly,
lemon and lime) and apple peels. Apple pectin has a slightly darker brown color
compared to citrus pectin which is light in color, almost white; the two pectin types do
not show major differences in their properties 3, 4 .
The chemical structure of the pectin is very complex and depends on the source,
location and method of extraction. The pectin is widely used in the food industry,
pharmaceuticals and cosmetics for production of compounds like viscosity stabilizers,
jellifying and emulsifying agents 4 .
The process of extraction of the pectin consists of thermal and acidic treatment solid
byproducts generated by the principal juice industries of citric fruits (rinds) and apple
(bagasse). This physicochemical process is economically acceptable; nevertheless, it
possesses some disadvantages since the soluble pectin is depolymerized significantly
during this process. Also, the vegetable material softens during the extraction and
impedes the post-filtration processes, resulting in corrosion of the equipment by the
1

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acids used and high levels of contamination 5
The present work focuses on the extraction and characterization of pectin of maracuya
(Passiflora edulis) fruits, under different conditions of extraction with citric acid and
comparing the characteristics of the pectin of maracuya with that of citrus fruits reported
in the literature.
Methodology: A total of 12 kg of maracuya fruits was divided into 6 lots of 2 kg. Each
lot was weighed and decorticated manually first flavedo and then albedo, separating the
juice and the seeds of albedo carefully 5 . The albedo (white and spongy part) and the
flavedo were weighed carefully avoiding any loss of material; the juice was separated
from the seeds and later weighed separately. The mean, standard deviation and
corresponding per cent were calculated taking two kilos of fruit as 100 %.
The extraction of pectin was performed using the different fractions of the fruit in a 100 g
sample of albedo, flavedo and rind of raw maracuya. The sample was cooked under
steam for 15 minutes under different ratios of water (w/v) (1:1, 1:2, 1:3 and 1:4) and the
number of washes (1 and 2). This was followed by the precipitation of pectin with
ethanol at 1:2 ratios. Once precipitation was completed, filtration and drying was done
with solvent exchange (ethanol / acetone). The obtained fiber was dried in an oven
saving the sample for other treatments. After the selection of the best conditions of
extraction based on the yield of pectin, the effect of variations in the time of heating 10,
15, 20 and 25 minutes was studies with 1:3 water to sample ratio and with two washes.
The extraction of insoluble pectin was performed with 20 mg of albedo fiber, using citric
acid at 0, 0.5 and 1 % concentration under different period of heating 5, 10, 20, 40 and
60 minutes, with a wash ratio of 1:2 and two washes. pectin was precipitated with
ethanol as described earlier. The weight of the extracted pectin was measured to obtain
the yield as per cent.
The characterization of the pectin obtained of the different treatments was performed
depending on the content of galacturonic acid by colorimetric analysis with mhdf 4 as a
parameter of purity of the pectin. Molecular weight was determined by viscometer using
Oswald's Viscometer at 30 o C 6,
Results: From the quantity of residues generated during the extraction of juice from
Maracuya is presented in Table 1. It can be seen that out of the total mass, 79.2 per
cent was constituted by flavedo, seed and albedo for 20.8% juice extraction. This large
amount of waste from the food industry can be used (albedo and flavedo) as a source of
pectin and environmental problems due to the accumulation of these wastes can be
eliminated.
2

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Food Science and Biotechnology in Developing Countries
Table 1 Analysis of the different fractions from the fruit maracuya.
Sample Average of weight
(g) in 2 kg of fruit
% of Yield
Flavedo 273.5 13.5 ± 1.15
Albedo 839.3 41.5 ± 1.42
Seed 489.7 24.2 ± 0.25
Juice 421.9 20.8 ± 1.16
Total 2024.4 g 100 %
It was observed that the amount of pectin extracted in different fractions of the fruit
increased treated by steam during 15 minutes increased as the ratio of water increased,
the best being 1:3 in which the best pectin yield was obtained.
mg pectin/g fruit
160
140
120
100
80
60
40
20
0
01:01 01:02 01:03 01:04
Relations from washing
mg pectin/g albedo
mg pectin/g flabedo
mg pectin/g rind
Fig 1. Extraction of pectin with different relations from washing in water
3

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Food Science and Biotechnology in Developing Countries
The results of the study on varying the cooking time is presented in Fig 2. A cooking
time of 20 min was found to be the best with pectin yields of 475.5, 87, 174 mg/g from
albedo, flavedo and complete rind respectively.
mg pectin / g fruit
500
450
400
350
300
250
200
150
100
50
0
10 15 20 25
Times of cooking
mg pectin/galbedo
mg pectin/g flabedo
mg pectin/g rind
Fig. 2 Extraction of pectin proving different times from cooking
4

mg pectin/g fruit
500
450
400
350
300
250
200
150
100
50
0
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Food Science and Biotechnology in Developing Countries
0 10 20 30 40 50 60 70
Time of cooking
Fig. 3 Yield of pectin in mg extracted with citric acid.
0% citric aid
0.5 % citric acid
1 % citric acid
The fiber obtained after extracting the soluble pectin, was also rich in pectin which could
be extracted by treatment with citric acid. The results of the study on the optimization of
citric acid concentrations and the treatment times are presented in figure 3; the best
yield of 441 mg pectin was obtained at 0.5% citric acid with a cooking time of 60 min.
Table 2 depicts the characterization of different pectin obtained in this study. Similar
amounts of pectin were obtained after aqueous extraction in flabedo, albedo and
rind completes while the best solubilization of 23 % was achieved with citric acid
extraction in albedo. This different pectin had more than 50% galacturonic acid
indicating their purity and high molecular weights. The highest degree of methylation
was determinate for the pectin obtained with citric acid extraction. Acid-soluble pectin
with a high DM has been reported from citrus 6 .
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Food Science and Biotechnology in Developing Countries
Table 2. Molecular weight of the different pectin
Sample Molecular weight Yield of pectin (%) % Moisture
Pectin of albedo 89 000 D 0.28 87.5 ± 1
Pectin of flavedo
Pectin of rind
completes
Pectin of albedo
(extraction in citric
acid)
Conclusion:
52 000 D 0.14 72.8 ± 3.5
110 000 D 0.29 85.4 ± 0.32
107 000 D 23 86.5 ± 0.52
1. The best conditions of extraction of the soluble pectin in the fruit of maracuya
were 20 minutes of cooking time with a washing ratio (w/v) 1:3; highest yields
were obtained with rind.
2. The insoluble pectin yield from fibers could be increased by using citric acid at 0,5
% concentration with 40 minutes cooking time.
3. The pectin obtained with the different treatments displayed characteristics similar
to those of citric pectin, were of high molecular weight and high methoxyl pectin.
References:
1. Ruggiero, C. Colheita. In: RUGGIERO, C. 1987. Maracujá. Ribeirão Preto: Legis
Summa, p.167-72.
2. Segura Ceniceros E.P., Ilyina A., Contreras Esquivel J.C., 2003. Entrapment Of
Enzymes In Natural Polymer Extracted From Residue Of Food Industry:
Preparation Methods, Partial Characterization And Possible Application. Moscow
University Chemistry Bulletin, Vol.44 (1) p. 84.
3. Betty Matsuhiro, Maria Jose Rubio. 2001. Chemical Modification of lemon pectin.
Boletin de la Sociedad Chilena de Química. V 46 (4) p. 1-9
4. Thakur, BR, Singh, RK, Handa, AK. 1997. Chemistry and uses of pectin. A
review. Crit. Rev. Food Sci. Nutr.· 37(1), 47-73.
5. J.C Contreras-Esquivel. 1997 Revisión: Extracción microbiológica y enzimática
de pectina. 47(3) 208-216.
6. M.A. Ceniceros-Reyes, E. Zúñiga-Violante. 2001 Preparación de fibra de pectina
a partir de residuos de jícama y maracuyá. Memorias del XIII Encuentro Nacional
de la AMIDIQ: 21-23.
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MICROENCAPSULATION OF BARLEY GREEN JUICE BY SPRAY DRYING
González-Maldonado, M. B. 1 ; García-Gutiérrez, C. 1* ; Ochoa-Martínez, L.A. 2 y Medrano-Roldán, H. 2
1 CIIDIR-COFAA-IPN Unidad Durango. Sigma s/n Fracc. 20 de Nov. II. C.P. 34220. Durango, Dgo.
México. E-mail: garciacipriano@hotmail.com
2 INSTITUTO TECNOLÓGICO DE DURANGO. Av. Felipe Pescador No. 1830 Ote. C.P. 34080. Durango,
Dgo. México.
ABSTRACT
The barley green (BG) Hordeum vulgare L. is a plant with a high nutritive value. Spray drying (SD) has
been used as a technique to encapsulate food materials, keeping its nutritional properties. The objective
of this work was to evaluate the SD operation conditions to obtain microencapsulate BG powder.
Parameters such as moisture content, color, proteins, sugars, minerals and, rehydration properties were
determined. Juice from BG was obtained and maltodextrin was added as microencapsulating agent. The
SD operation conditions were: inlet air temperature: 120,140, and 160 0 C; maltodextrin concentration: 1, 3
and 5%, feed rate: 9, 11, and 13 ml/min; outlet air temperature ranged from 70 to 80 0 C. L*, a* and b*
parameters in BG powder had significant differences with respect to juice. Due to inlet air temperatures
statistical differences (p≤0.5, F=395.98), while the maltodextrin concentration and feed rate did not have
statistical differences with respect to microencapsulate nutritive properties (p≥0.05). Statistical differences
were found between treatments with respect to rehydratation properties, moisture content and
temperature, so these were the most influencing parameters.
KEY WORDS: Microencapsulation, Spray drying and Barley green.
INTRODUCTION
The green barley Hordeum vulgare L. as a plant has a high nutritive value, it contains essential amino
acids, proteins, fat acids, vitamins and minerals, are a very important chlorophyll source, contain
approximately 20 enzymes, in addition it has a high alcaline power (Hagiwara, 1985). A way to conserve
these nutrients is by means of the microencapsulation by spray drying (SD), which is a technique that has
been applied to preserve numerous foods (Dziezak, 1988). Within the parameters most important to
control during the SD are: The inlet and outlet drying air temperature, the feeding flow and the time of
residence and the preparation of the raw material (Ramirez, et al. 2003). In the nutritional industry
different encapsulating agents are used, such as: inorganic carbohydrates, esters, rubbers, lipids, proteins
and materials within carbohydrates and maltodextrins are important for the preparation of juice that has
been dried by SD, since they are colourless, odourless and of the low viscosity to high concentrations, in
addition allow the dust formation of free flow without masking the original flavor (Ré, 1998).
Microencapsulations from a great number of fruits and vegetables have been elaborated. A product dried
by aspersion is the juice of maracuyá which was obtained to a inlet air temperature of 155 0 C, 350ml/h and
12% w/v of maltodextrin, the dust presented/displayed good solubility and low content of humidity
(Ramirez et al. 2003). McNamee et al. 2001, used the of maltodextrin/starch mixture (DE 5,5-38)
obtaining an efficient microencapsulation in flavor terms (swetnees) and solubility. Another commercial
dust product is the juice of the leaves of barley green (Barleygreen ® ), cultivated organically and mixed with
small amounts of brown rice and pulverized marine seaweed, that containaining macro-nutrients, proteins
(12.7%), carbohydrates (71.0%) and fat (3.0%) (Hagiwara, 1985). On the other hand, Valenzuela, et al.
(1995) elaborated a dust from the vegetable juice (tomato, cucumber, carriot, lettuce, beet, spinach, celery
and parsley) using SD which presented a humidity of 1,4%, to a inlet temperature of 145 0 C and outlet
temperature of 108 0 C, the juice feeding was of 16,7 ml/min, with these conditions the dust easily was
reconstituted, obtaining a juice with similar characteristics to the original juice.
Candelas and Alanís (2003) evaluated the effects of SD operation condictions from the tomato juice as far
as the humidity, the changes in licopeno concentration in dust and measured the color parameters of the
rehidratated juice, finding an average of 3,172% of humidity and a value of a * (redder) of 8,737 to a

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Food Science and Biotechnology in Developing Countries
temperature of air inlet of 180 0 C and 100% of maltodextrin DE 110. In dust products the humidity content
is important since to smaller humidity the time of shelf life is greater, which reduces costs and facilitates
the transportation. IAbout this, is desirable that a dust food has a smaller humidity content of 10%.
Hogan, et al. (2001) obtained an microencapsulation from oil of soy protecting it with sodium caseinate as
encapsulating agent, presenting a humidity rank of the 1,5-4%, these same authors found a humidity of 1-
3% in emulsions that contained soy oil emulsiona and flour proteins concentrated as encapsulating agent.
It has been observed that in dusts with high content in fats and oils the time of the re-dispersion of
emulsions with oil of soy using gum arabic as encapsulating agent the time was of 0,5 to 24h. The
particles must have a size between 1-2 µm so that they are quickly rehidratated in water (McNamee et al.
1998). The nutritional dust products elaborated from fruits and vegetables with good nutritious properties
and of rehidratation are of interest in the nutritional industry, reason why the objective of the present work
was to establish the effect of SD conditions from the juice of barley for the obtaining of a
microencapsulation dust and for determining its nutritional and of rehidratation properties.
MATERIALS AND METHODS
The barley juice was obtaining from an organic culture, in Durango, Mexico, the plant was harvested a
height of 40cm (SEP, 1984).
The juice of barley was caracterizate for the proximal chemical composition following the next techniques:
Humidity: It was determined using Ohaus balance a humidity, model MB200.·
Measures of color L *, a * and b *: they were determined by means of a colorimeter Hunter Lab
MiniScan, model Ms-4,500 L. 2, Formato ¼ P65/100.·
Soluble solids: They were determined using of a refractometer Bausch & Lomb, A60 model.·
Ashes: It was carried out by method 938,08 (AOAC, 1990).·
Proteins: The Microkjdahl technique was used, using factor 5,83 for barley grains, oats and rye, for the
protein nitrogen conversion.·
Total sugars: The Fenol Sulfuric method was used, Dubois modified by Vicencio, (1984). The curved
type was prepared with saccharose (0-100µg/ml).·
Minerals (Na, K, Mg, Ca and Fe): The technique indicated in the NMX-AA-51-1981 Norm the
espectrofotometric Method of Atomic Absorption (Perkin Elmer, 1984) and Methods Standard, (1995) was
used.·
pH: 520A was moderate with a potentiometer ORION model.
Drying by Aspersion
The necessary juice for the drying process was obtained from the expression of barley leaves which the
root was eliminated to them, later were washed with a chlorine solution of 1% and water. An extractor
was used semi-industrialist Supermatic with capacity for 7kg. The juice obtained was add with
maltodextrin DE 10 as encapsulating agent to concentrations of 1, 3 and 5% b.h. The dehydration of the
juice was carried out in a dryer by aspersion Apex Mark, of scale plants pilot with rotatory spray (Apex
Construction, LTD). An experimental design of blocks at random with factorial adjustment (3) 3 with three
replications was used. The independent treatments and variables were: inlet temperature (120, 140 and
160 0 C), flow of feeding (9, 11 and 13ml/min) and maltodextrin concentration (1, 3 and 5% b.h). The outlet
temperature were 70-80 0 C and the air pressure was of 4 Kps/cm 2 . The dependent variables evaluated
were: humidity, insolubility and dispersability index and time of humidification. The data were analyzed in
program STATISTICA (1991), by means of an analysis MANOVA and a test of Tukey.
Barley powder characterization
The microencapsulate powder was characterized following the next determinations: humidity content,
color, proteins, sugars, minerals (Ca, Mg, Na, K, Fe), according to the described techniques previously. In
addition the powder rehydratation properties were determined, as they are: humidification time, insolubility
and dispersability index. These determinations were made according to the indicated techniques in the
manual of the British Standar Methods (1988).
RESULTS AND DISCUSSIONS
Characterization of the juice of barley

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Food Science and Biotechnology in Developing Countries
In Table 1, show fisico-chemstry the obtained of the characterization results of the fresh juice of barley.
*Means three replicates.
Tabla 1. Fisico-chemestry composition and parameters of color of barley juice.
FISICOCHEMESTRY VALUE *
ANALYSIS
Humidity 80.22 %
Color L* 33.54
a* - 3.00
b* 32.33
Soluble solids 8.3 0 Brix
Ashes 0.83%
Proteins 13.04 %
Total sugars 4.91 %
Minerals Ca 0.0088%
Mg 0.0018%
Na 0.0315%
K 0.045%
Fe No representative
pH 6.1
Characterization of the barley powder
The conditions of drying and their relation with the humidity parameters, color, proteins, sugars, minerals
(Ca, Mg, Na, K and Fe), as well as with the rehidratation properties (time of humidification, insolubility and
dispersability index) are indicated next:
Humidity
The Figure 1, show the relation that exists between the humidity of powder products and the conditions of
drying (% of maltodextrin and inlet temperature to the dryer). To a temperature of drying of 160 0 C the
powders presented a greater humidity content (8,4 to 9,69%), to a temperature of drying of 140 0 C the
humidity was smaller (3,68 to 5,46%) and to 120 0 C the humidity was in a rank from 5,53 to 7,68%, these
variations were was due to the different conditions of operation in the SD (temperature, flow of feeding
and maltodextrin content). The smaller humidity was 3,68%, to the following conditions of drying: inlet
temperature of 140 0 C, flow of feeding of 11 ml/min and a maltodextrin content of 1% and the greater
humidity was 9,69% to a inlet air temperature of 160 0 C, 13 ml/min of flow of feeding and 5% of
maltodextrin. The inlet air temperature to obtain powder products from juice of barley with low humidity
contents (average 4,43%) was to 140 0 C, which demonstrated that the temperature of inlet air went
influence considerably in the obtained humidity results, this value is similar to the values of humidity found
by Ramirez et al. (2002) (3,2 %); Valenzuela, et al. (1995) (1.4%) and Candelas and Alanís (2003)
(3.172%), for the microencapsulations powder elaboration from juice of maracuyá, different vegetables
and tomato, respectively. The results previous indicates that our powder had a smaller humidity to 10%,
which is desirable in industrialized powders.
Color
The highest value of the chromatic component a* was 7.05, which corresponds to a powder with a
compared dark green color with the fresh juice of barley, to a inlet air temperature of 160 0 C, flow of
feeding of 13 ml/min and 3% of maltodextrin, as well with a greater humidity content (9.61%), reason why
us observed that to a greater humidity content the powders presented a darker green color (average a* = -
5,21), in comparison with the samples with smaller humidity content (average a* = -2,52), to 140 0 C, where

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Food Science and Biotechnology in Developing Countries
they obtained dusts with a green color similar to the one of the fresh juice of barley (a* = -3,00). For this
reason to a inlet air temperature of 140 0 C to the dryer powder with parameters of color were obtained
similar to the fresh juice, due to their chlorophyll content.
Whistler and Daniel (1985) consider that these changes had to non-enzymatic reactions of darkening, the
factors that take part in the speed of darkening were the content of humidity, temperature, pH and barley
composition.
Proteins
The barley juice presented a protein content of the 13,04%, value similar to the found by Hagiwara (1985)
in the commercial product Barleygreen ® , which contains 12,7% of proteins, whereas the powder barley
had a maximum value of 19,72% proteins, is amount was better than the protein content of the juice and
of Barleygreen ® , this possibly must to that the dehydrated barley is concentrated more in nutrients than
when it is juice.
Sugars
The sugar microencapsulation content was of 10,28% and in the juice was of 4,91%, which indicates that
this one nutrient is concentrated more in the microencapsulation due to the water liberation in the drying
process.
Minerals (K, Ca, Mg, Na and Fe)
The mineral that appeared in greater proportion was the potassium (3.53%-6.28%) with an average of
4,62% with respect to the average of other minerals (Ca 0,46%, Mg 0,71%, Na 0,76% and Fe 45,74 mg/l).
In the fresh juice the amount of this mineral was of 0,045%, smaller value to the reported for powders.
The iron was the element that was in smaller amount (Table 2). The previous amounts of minerals were
smaller to the found by Alais and Linden (1990) that reported a value of potassium of 100-500 mg/100g in
diverse vegetables, on the other hand Martinez (1999) found a value in inferior sodium to 30mg/100g. By
the previous thing, we can say that the microencapsulation powder of barley presented important amounts
of minerals, which turns out satisfactory to use it possible power drink.
g p y
Figure 1. Effect of inlet temperature and maltodextrin concentration with respect to the humidity.
0.794
1.088
1.382
1.676
1.971
2.265
2.559
2.853
3.147
3.441
3.735
4.029
4.324
4.618
4.912
5.206

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Food Science and Biotechnology in Developing Countries
Tabla 2. Means value of powders minerals in the microencapsulate powder in comparation with the fresh
barley juice.
SPRAY
CONDITIONS T,
A y M*
K (%) Ca (%) Mg (%) Na (%) Fe (mg/l)
120, 9, 5 3.88 0.38 0.73 0.69 36.55
120, 13, 3 4.10 0.48 0.69 1.05 29.65
120, 13, 5 3.53 0.36 0.68 0.45 40.00
140, 11, 1 6.00 0.52 0.78 0.74 57.24
140, 11, 5 3.84 0.40 0.70 0.99 15.86
140, 13, 1 5.17 0.65 0.72 1.19 67.59
160, 11, 1 4.75 0.53 0.72 0.32 50.34
160, 13, 1 6.28 0.43 0.74 0.98 77.93
160, 13, 5 4.10 0.45 0.70 0.38 36.55
FRESH JUICE 0.045 0.0088 0.0018 0.0315 **
T = Temperature ( 0 C), A = Feed of flow (ml/min), M = maltodextrin (%).
*Drying conditions of random samples.
Properties of rehidratación of the powders
Time of humidification
The necessary time for that the powders dispersed in water after the drying was 0,21 to 2.15h; this
variations had to the properties of the dispersion mainly, the powders with a high humidity content (8.4-
9.69%), took more time in rehidratation itself completely, also the powders with greater content of
maltodextrin (5%), presented greater undissolved powder particles (10-15 µm) and they became damp
more slowly. These results were good if we compared them with those of Mc Nemme et al. (1998) where
the time of dispersion was greater, in emulsions using gum arabic as encapsulating agent, with 0,5 to 24h
so large a particle minor and variation of humidification (1-2 µm).
Insolubility index
Insolubility index indicates the volume in mililiters of sediment (insoluble remainder) that is obtained when
a solid product is reconstituted with water, the barley powders were reconstituted according to its original
water content on the basis of contained total solids in the juice. The powders with a content of greater
humidity (8.4-9.69%) found to a temperature of drying of 160 0 C, presented greater water insoluble particle
index at the time of the rehidratation (7,49-7,8 ml/l), also these treatments took greater time in becoming
damp (1.63-2.15h), since the particles agglutinated with greater facility avoiding their fast rehidratation in
water. The powders with low humidity contents (3.68-5.46%) presented/displayed minors insoluble particle
indices (5.04-6.14ml/l), also the samples with higher concentrations of maltodextrin (5%) presented
greater insolubility index. Nevertheless, the speed of the feeding (ml/min) did not present significant
influence in this parameter.
Dispersability
The samples with greater humidity content (8.4-9.69%) processed with the greater inlet air temperature to
the dryer (160 0 C) presented minor percentage of dispersion and their insoluble particle index were greater
(7.49-7.8ml/l), thus the particles agglutinated with greater facility and was more difficult the rehidratation of
powders with these characteristics. To smaller temperature (140 0 C) and minor humidity (4.43%) the
powders had percentage of greater dispersability (68.29%), which is good at the time of reconstituting a
powder and obtaining a juice with characteristics similar to the fresh juice of barley. The humidity
presented significant differences, with respect to the variables of operation of the SD (F = 395,98, p <
0,05); to greater humidity content, existed greater time of humidification of powders when were
rehidratation them (F= 209,71, p

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Food Science and Biotechnology in Developing Countries
CONCLUSIONS
To a inlet air temperature of 140 0 C and an average of humidity of 4,43% the powders particles had
percentage of dispersability of 68,29%, which was goodat the time of reconstituting a powder and
obtaining a juice with characteristics similar to the fresh juice of barley. Also, to these conditions the
insoluble particle index were smaller (5,21 ml/l) and also the time of humidification (0,36 h), which
provides properties of acceptable reconstruction for the powder. There are statistical differences between
humidification time, dispersability and insolubility index, where the humidity of powders and the
temperature were the variables that influenced in the powders obtaining with good nutritious values of
content of proteins, sugars and minerals.
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Deshidratado por Aspersión. Tecnología de Alimentos. México. 30(6): 34-40.
Vicencio de la R. M. G. 1984. Estudio del comportamiento del cultivo de tejidos de Solanum eleagnifolium
y de la producción de una proteasa, saponinas y sapogeninas a partir del cultivo. Tesis de
licenciatura. Instituto Politécnico Nacional. 31 p.
Whistler, R. L. and Daniel, J. L. 1988. Carbohydrates. In Food Chemistry. Second Ed., Fennema, O. W.
(Ed). Marcel Dekker, Inc., New York. 96-105.

FSB1-2004
Food Sience and Food Biotechnology in Developing Countries
RHEOLOGY OF MODIFIED STARCHES FOR ESTABLISHING CONTROL
PARAMETERS IN THE FOOD INDUSTRY.
Luis E. Chacón-Garza and Arturo Rodríguez-Vidal
Universidad Autónoma de Coahuila, School of Chemistry V. Carranza and J. Cardenas-
Valdez Phone: +52 844 4 16 92 13 Fax: + 52 844 4 39 05 11, POBox: 935 Zip: 25 000,
Saltillo, Coahuila, México E-mail: ervey_2680811@hotmail.com
ABSTRACT
______________________________________________________________________
At the present time the use of preservatives to improve the physical, chemical,
nutrition and sensorial properties is very disseminated in the foods. One of the most
used preservatives is the starch which helps to improve the food texture. Starch is used
especially for their properties of moisture managment and especially for its water
retention capacity. Chemical properties of comercial corn modified starches and
starches of corn, wheat and potato obtained in this study were evaluated. The corn
starch in natural state and commercial corn modified starch B990 presented the highest
water retention capacity (129.60 % and 143.73 % respectively).
______________________________________________________________________
Keywords: Modified starch, corn, wheat, potato, water retention capacity.
INTRODUCTION:
Actually the use of food additives to improve physical, chemical, sensorial and nutrition
properties of foods is more and more disseminated in the world (Badui, 1999;
Bioaplicaciones, 2003). One of the most used additives is the starch, which helps to
improve the food texture ; starch is utilized in the manufacture of ice cream, yogurt,
preserved foods, sauces, processed meat food (ham, sausages, salami) and others
(Bioaplicaciones, 2003). Its use is based on starch properties of moisture magnament,
especially in its water retention capacity (WRC) (Shoemaker, 1987).Starch is found in
cereals and potatoes and is easily extracted and very inexpensive; the starch most
commonly used is from corn. However the starch in it´s natural state present problems
in products of acid type and where high or low temperature are used, these
inconvenients can be avoided modifying chemical and physical starch properties using
simple treatments (Bioaplicaciones, 2003; Muller, 1973; Shoemaker, 1987). To know
how these modifications can improve food processing it´s important to perform
rheological studies. This kind of studies helps in the raw material and final product
evaluation. In addition, it may help in food processing, machine design and in the
aceptation of the products by consumers (Bioaplicaciones, 2003; Shoemaker, 1987).
The objetive of the present study was to evaluate three commercial corn modified
starches and compare them with corn, wheat and potato starch obtained in this study.

FSB1-2004
Food Sience and Food Biotechnology in Developing Countries
MATERIALS AND METHODS
Starch was extracted from three natural sources (corn, wheat and potato) and it´s
physico-chemical properties were determinated and compared with three commercial
samples of corn modified starch. The variables evaluated were moisture content, ash,
and acid content using the AOAC methods (1994), damaged starch determination using
the colorimetric method of equivalents units of Farrand (Williams, 1969) and starch
water retention capacity (Yamazaki, 1953).
RESULTS AND DISCUSSION
Starch from three differents natural sources: corn, wheat and potato was obtained. After
that it´s physical and chemical properties were evaluated. The moisture content was
very low in the corn and wheat starches (1.78 and 3.69 % respectively) while in the
potato starch was high (15.34 %), this was due mainly to extraction method because the
potato starch sample was dried in a oven for 3 days while corn and wheat starch were
dried for 4 days. The table 1 shows the Water Retention Capacity of the starch samples.
Corn starch had a big WRC (129.60 percent) of it dry weigth this may probabily for a
less moisture content and damage starch in comparision to other starch samples. Potato
starch had the highest amount of damaged starch with 28.8 %. All corn, wheat and
potato starches had a big amount of ash (0.3, 0.15 and 0.27 % respectively).
Table 1. Chemical composition of starches in 3 diferents natural sources.
Starch % Moisture % Solids % Ash % WRC Acid (g % FEU
sample
ac.lactic)
Corn 1.78 98.21 0.30 129.60 2.21 5.19
Potato 15.34 84.66 0.27 79.12 0.07 28.80
Wheat 3.64 96.36 0.15 76.51 0.95 29.46
The table 2 shown the chemical composition of three commercial corn modified starches
which are used for meat processing. It was observed that these commercial starches
had higher moisture than the starches obtaind in our lab. The acid and other content
were lower in the comercial starches than the starches obtained in our lab. WRC
increased in the order 97.22 in the B900, 120.76 in the B950 and 143.73 in the B990. In
comercial starches WRC was different among samples; this may be due to the grade of
structure modification. In conclusion, it was observed that corn starches with and
without modifications were better than potato and wheat starches.
Table 2. Chemical composition in corn modified starch presents in the market
Starch % Moisture % Solids % Ash % WRC Acid (g FEU
sample
ac.lactic)
B900 10.24 89.76 0.170 97.22 4.2 x10 -4
23.77
B950 11.06 88.94 0.055 120.76 3.3 x10 -4 B990 11.17 88.83 0.122 143.73 3.0 x10
29.67
-4 27.58

FSB1-2004
Food Sience and Food Biotechnology in Developing Countries
REFERENCES.
1. Almidones Modificados (Online) Find in
http://www.bioaplicaciones.galeon.com.Der.html (Verify 8 abr 2003)
2. Almidones Modificados PURE-GEL B900 y PURE-SET B950 (Online) Find in
http://www.orgpeisa.com.mx/prod/index.html (Verify 10 sep 2003)
3. AOAC 1994. Official Methods of Analysis. 14 th ed. Association of Official
Analytical Chemists Washington
4. Badui, D.S. 1999. Química de los Alimentos. Alambra Universidad México D.F.
pag. 89-98
5. Kirk, R.S., R. Sawyer y A. Egan. 1999. Composición y Análisis de los Alimentos
de Pearson. 2ª ed. CECSA México D.F. 777 pag.
6. Muller, H. G. 1973. Introducción a la Reología de los Alimentos 1ª ed en
español. Acribia Zaragoza España 174 pag.
7. Pomeranz, Y. and C.G. Melona. 1987. Food Analysis Theory and Practice 2 nd ed.
AVI New York USA pag. 483-485
8. Shoemaker, C.F., J.I. Lewis and M.S. Tamura. 1987. Instrumental far Rheological
Measurements of Food. Food Technology. march: 80-84
9. Williams, P.C. and K.S. Fenol. 1969. Calorimetric determination of damaged
starch in flour. Cereal Chem. 46:56
10. Yamazaki, W.T. 1953. An Alkaline water retention capacity test for the evaluation
of cookie baking potentialities of soft winter wheat flours. Cereal Chem. 30:242

Food Science and Biotechnology in Developing Countries
Process viscosity study on heterogeneous foods
L. Medina Torres 1 *, E. Brito de la Fuente 2 , J.A. Gallegos Infante 3
1,2 Departamento de Alimentos y Biotecnología, Facultad de Química
Universidad Nacional Autónoma de México., 04510 México, D.F.
3 Instituo Tecnológico de Durango
Departamento de Ingenieria Química y Bioquímica
Felipe Pescador 1930 Ote., Durango, Dgo. 34080., México
Tel./Fax (5)56-22-53-08. email: luismt@servidor.unam.mx
ABSTRACT
The rheological properties are of great importance in food fluids as
mermelades, salad dressing, soups, sauces and creams [Baudi, 1996]. The
knowledge of rheological properties are very important in the industrial
optimization as pumping, mixing, cooling, drying and others. The usual
viscometers are not good for this systems cause the heterogeneous nature of the
dispersion. With the objective of a best determination of the fluid properties it has
been used the rheometry with mixing principles for heterogeneous systems.
Key words: Non-Newtonian, process viscosity, heterogeneous foods, mixing
principles.

Food Science and Biotechnology in Developing Countries
Process viscosity study on heterogeneous foods
L. Medina Torres 1 *, E. Brito de la Fuente 2 , J.A. Gallegos Infante 3
1,2 Departamento de Alimentos y Biotecnología, Facultad de Química
Universidad Nacional Autónoma de México., 04510 México, D.F.
3 Instituo Tecnológico de Durango
Departamento de Ingenieria Química y Bioquímica
Felipe Pescador 1930 Ote., Durango, Dgo. 34080., México
Tel./Fax (5)56-22-53-08. email: luismt@servidor.unam.mx
INTRODUCTION
On the food industry there are an important group of food systems that it are
constituid by a dispersant phase, in this phase there are a lot of relative soluble
components and a disperse phase with particles with distinct physics properties.
The rheological properties are of great importance in food fluids as mermelades,
salad dressing, soups, sauces and creams [Baudi, 1996]. The knowledge of
rheological properties are very important in the industrial optimization as
pumping, mixing, cooling, drying and others. The usual viscometers are not good
for this systems cause the heterogeneous nature of the dispersion. With the
objective of a best determination of the fluid properties it has been used the
rheometry with mixing principles for heterogeneous systems. [Brito et al., 1998].
Rheological measurements.
EXPERIMENTAL METHODOLOGY
It were working three different simples of heterogeneous foods: Salad
dressing, orange mermelada and peach yogurt, at 25°C. The rheological
measurements were making in a rotational rheometer (Haake, CV20N, RV20)
with temperature control. It was used a system with helicoidal geometry adapted
to rheometer.
On the Figure 1 is shown the system used. The Viscosity data were obtained
following the method. [Brito et al., 1998].
The process viscosity was determinated with the next algoritm:
η
e
=
mK
p
( n)
K
p
N
n −1
RESULTS AND DISCUSSION
(1)

Food Science and Biotechnology in Developing Countries
The process viscosity data are presented on the Table 1. Its observed that the
presence of particles not interfere with the torque signal.
On the Figure 2 its observed that in the food systems measured with the
hellicoidal system shown a best approximated functional response in comparison
to the usual geometries as plate and cone, couette, parallel plates, data difficult to
obtain in these systems. Each one of systems used in this work show a Non-
Newtonian behavior type pseudoplastic, with (n) determination in the experimental
window of the fluids.
The particulate presence not limited the measurement of viscosities. It can be
to any that for this system its possible characterizing the material function respect
the viscous component (i.e. process viscosity) using the mixing principles with best
result in comparison to traditional measurement systems.
H= 0.04m
w= 0.004m
D= 0.029m
d= 0.0248m
Figure 1. System of mixing rheometry
h= 0.0315m
b= 0.004m

Viscosity [Pa.s]
10
Yoghurt
η e = 2.113N -0.854
Food Science and Biotechnology in Developing Countries
1
0.1 1.0 10.0
N, [r.p.s]
Mermelada
η e = 5.397N -0.552
Aderezo
η e = 2.417N -0.59
Figura 2. Curves of process viscosity in heterogeneous
foods
REFERENCES
Fluid Rheological parameters
Salada
dressing
n
Fluid
Index
Kp(n)
Consistency
index
m (Pa s n )
0.410 29.71 13.22
Orange
marmalade 0.448 32.79 26.75
peach
yogurth
0.146 18.03 17.37
Table 1. Values of fluid index (n) and consistency index (k)
of the heterogeneous fluids used in this work.

Food Science and Biotechnology in Developing Countries
1. Baudi, D. S. (1996). Química de los Alimentos. Universidad. México, D.F.
2. Brito- De La Fuente, E.; Nava, A., López, L. M.; Medina, L.; Ascanio, G. and
Tanguy, P. A.,1998. Process Viscometry of Complex Fluids and Suspensions
with Helical Ribbon Agitators. The Canadian Journal of Chemical Engineering;
76: 689.

FRUIT JUICES WITH SABILA (Aloe Vera L)
N.J. MARTÍNEZ-RAMÓN, M.L. REYES -VEGA, J.C. Contreras -Esquivel
Food Research Department, Faculty of Chemical Sciences, Universidad Autonoma de
Coahuila. 25080 Saltillo, Coahuila, México
INTRODUCCTION
Sabila (Aloe vera L) has been used as emmenagogue, febrifuge in pleurisy and phthisis and
a remedy for gastrointestinal disorders, constipation, burns and against insect bites, amog
other uses. Its leaves contain a number of anthracene and chromone derivatives, sucha as
aloeemodin, aloesin, barbaloin, and other active principles. Actually, the tendency to use
vegetables with such active principles, as additives in foods is increasing. The addition of
sabila to fruit juices is an alternative to improve the nutraceutical value of these beverages.
This work comprehended the study of the variables that affect the process to prepare fruit
juices with sabila.
Fruit juices (orange, lemon, pinapple, tamarind and jamaica) were prepared from fresh
fruits. Sabila was added as a juice extract and as small cubes. Product development
included studies related with the concentration of sabila, the addition of sabila juice or
cubes, pretreatment of the cubes with calcium chloride, stability of the pulp and cubes in
the juice, addition of CMC and evaluation by HACCP.
METODOLOGY
Flow Diagram
1. Sabila was washed and cut in cubes, 1 cm.
2. Sabila cubes were pretreated with calcium chloride before their incorporation to the
juices.
3. Fruit juices with CMC (Carboxymethyl cellulose) were stirred during 90 minutes.
4. Potassium sorbate and sodium benzoate was added to the fruit juices to preserve
their microbiology quality.
5. Sabila cubes were added to the fruit juices and mixed to homogenize.
6. Pasteurization was carried out.
Analysis
a. Integrity of sabila cubes.
It was performed by means of a visual analysis.

. Texture attributes of sabila cubes before and after their incorporation to fruit
juice.
The texture attributes were determined using a Texture Analizer TA.TX2? (Texture
Technologies Corp., Scarsdale). Sabila cubes placed into a cylinder, before and after
their incorporation to the fruit juices, were compressed with a probe, 1cm dia., 50%
and the crosshead speed was 2 mm.s -1 . There were used twenty-five samples.
c. Sensory analysis.
The sensory quality of sabila cubes was evaluated by visual examination and finger
touching using an intensity scale method. Samples for sensory evaluation were
obtained from fruit juices previously prepared. A panel of twenty people was trained.
The sabila was cut into cubic samples (? 1 cm 3 ) and placed on a plastic glass with a
random number.
d. Suspension stability of sabila cubes incorporated to fruit juices (with and
without CMC).
It was evaluated with fruit juices with and without CMC. The samples were stored in
graduated cylinders at room temperature by 24 hours. It was expressed as percentage
of sediment material.
RESULTS AND DISCUSION
a. Integrity of sabila cubes.
A pretreatment of the cubes with calcium chloride provided major fimness.
b. Texture attributes of sabila cubes before and after their incorporation to fruit
juice.
The correlation between the addition of sabila cubes before and after the addition of
CMC to the fruit juices didn´t show a significant difference (p? 0.05) between
treatments. But it was observed that the sabila cubes added before the CMC to the fruit
juices produced a viscous mixture.
c. Sensory analysis.
Our results showed that the sabila cubes with pretreatment were prefer by consumers.

d. Suspension stability of sabila cubes incorporated to fruit juices (with and
without CMC).
Our results showed that the addition of CMC improved the suspension stability of
sabila cubes and interacted with the pulp and water of the fruit juices. This is showed in
figure.
ml
80
70
60
50
40
30
20
10
0
CONCLUSION
Stability of the pulp and cubes in the juice
1 2
Samples
water
cubes
Data showed that the best conditions for this process were the addition of sabila cubes
previously treated with calcium chloride solution, CMC as stabilizer of the multiphase
system and a moderately heat treatment. The self life of the product, at room
temperature, was larger than three months. Consumers liked most the juices with
sabila cubes.
pulp