K Nn mK - Amecamex.org.mx

FSB1-2004
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