evaluation of nutritional composition and sensory attributes of ...

BANGLADESH RESEARCH PUBLICATIONS JOURNALISSN: 1998-2003, Volume: 8, Issue: 2, Page: 127-133, March - April, 2013EVALUATION OF NUTRITIONAL COMPOSITION AND SENSORY ATTRIBUTES OFWEANING FOOD PREPARED FROM SWEET POTATO AND SOYBEANM.R. Haque* 1 , M. M. Hosain 2 , H. Khatun 3 , R. Alam 4 and M.O. Gani 5M.R. Haque, M. M. Hosain, H. Khatun, R. Alam and M.O. Gani (2013). Evaluation of Nutritional Composition andSensory Attributes of Weaning Food Prepared From Sweet Potato and Soybean. Bangladesh Res. Pub. J. 8(2):127-133. Retrieve from http://www.bdresearchpublications.com/admin/journal/upload/1308120/1308120.pdfAbstractWeaning foods were prepared using sweet potato flour, soybean flour, wheat flour,whole milk powder and sugar at different ratios. The prepared samples wereanalyzed for proximate composition, retinol content, minerals content and aminoacid composition, and compared with the commercial weaning food (Control).The prepared weaning food samples were found to have 13.23 to 16.76% protein,5.61 to 7.56% fat, 1.90 to 2.14%ash, 8.05to 8.16 % moisture and 65.41 to 71.2%1 totalcarbohydrate content. The retinol content, iron (Fe), and calcium (Ca) contentsdid not meet the requirement given by FAO but phosphorus (P) content satisfies theFAO specifications given for infant and babies (1-3 years groups). The sample withthe highest protein content was analyzed for amino acid content and all essentialamino acids fulfilled the requirements for infant and babies growth exceptthreonine content having chemical score of 68.68. The sensory attributes of theprepared weaning foods were evaluated and compared with commercial one.The highest score was given by commercial weaning food followed by samplecontaining 10% sweet potato flour and 25% soybean flour.Key words: Weaning food, proximate composition, amino acids.IntroductionIn Bangladesh, numerous obstacles are impeded to achieve the good health of thechildren. Among them poverty, frequent natural disasters, poor sanitation and lack ofliteracy are important. Children malnutrition and mortality rates in Bangladesh are highestin the world. It is estimated that about nine million (56%) children aged less than five yearare chronically undernourished. In Bangladesh children gain weight within the first fewmonths after birth but 48% had under weight problem due to nutritional deficiency at theirgrowth phase (Rayhan and Khan, 2006) and 56.5% of children are suffering frommalnutrition (Rahman, et al., 2009). Nutritional status of the population is an index ofpoverty of a country. Poverty, malnutrition and disease are interlinked with each other.Malnutrition in children is the consequence of a range of factors, which are often relatedto poor food quality, insufficient food intake, severe and repeated infectious diseases; orfrequently it involves some combination of three (deOnis, et al.,1993). These conditionsare, in turn, are closely linked to the overall standard of living and whether a populationcan meet its basic needs, such as access to food, housing and health care (WHO,1997).Thus, protein-energy malnutrition is a common problem among infants and children in thepoor socio-economic groups of developing countries (Gopalan and Srikantia, 1973;Darwich, 1983). Meaningfully, weaning food is intended to bridge the wide gap betweeninfant’s breast feeding and adult (Nout, 1993). The term "to wean" means simply toaccustom a baby, to food other than its mother milk .So weaning period is ultimatelydefined as the whole period during which breast milk is being replaced by other foods(Knodle, 1980). From this point of view baby food or weaning food is very important.Additionally commercial weaning foods are priced beyond the reach of the majority of* Corresponding Author: Email: fetraselhstu@gmail.com1Department of Food Engineering and Technology, Hajee Mohammad Danesh Science and Technology University (HSTU),Dinajpur-5200, Bangladesh.2Department of Food Processing and Preservation, HSTU, Dinajpur-5200, Bangladesh.3Department of Food Science and Nutrition, HSTU, Dinajpur-5200, Bangladesh.4Department of Food Technology and Rural Industries, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh.5Senior Scientific Officer, Agril. Engineering Unit, NRM Division, BARC, Farmgate, Dhaka, Bangladesh.

Haque et al.the population in less developed countries. These foods are mostly manufactured usinghigh technology and sold in sophisticated fancy packing (Brandtazaeg, et al., 1981).Bangladesh is a very densely populated poor country. About three- fifth portions of itspopulation are living below the poverty line. Hence, these foods are too expensive for lowincome families. It is very difficult for them to provide their children with imported weaningfood. Considering these entire problems an attempt has been taken to prepare weaningfood from available sources, and to evaluate the nutritional quality and sensory attributesof the prepared weaning food.Materials and MethodsCollection of food materials: Sweet potato, wheat flour, whole milk powder and sugarwere collected from the local market. Soybean and other relevant materials for chemicalanalysis were supplied by the department of Food Technology and Rural Industries,Bangladesh Agriculture University, Mymensingh.Preparation of sweet potato flour: Sweet potatoes were collected from the local marketand washed in clean water to remove adhering dirt, soil and stone. The washed andcleaned sweet potatoes were peeled with knife and cut into slices of about 2.0 mmthickness. The slices were then blanched at 90 C for about 4-5 min. in boiling water toinactive the enzyme system. The blanched pieces of sweet potato were dried in thecabinet drier on stainless steel trays. The drying temperature and time were 65 0 C for 8 hrs.After cooling to room temperature, the pieces were ground in hammer mill (Culatti,Model: JKA Werk, Type: DCFH, Germany) and sieved with a 60 mesh screen (Model BS410, Endeco London, England). The sweet potato flour is then packed in polythene bagsfor further use. This flour has been subsequently used in the formulation of weaning food.Preparation of soya flour: Soya flour was processed from the straw yellow or yellowishgreen varieties of soybean free from immature, field damaged and block soybeans.Using grain cleaners, the foreign materials were removed. Heavy aspiration removedloose hulls, weed seeds and other light foreign matter. The clean and fresh soybean seedswere then soaked in water [water contained 0.5% sodium bicarbonate (NaHCO3)] forovernight and applied steam for 20 min. The main purpose of using NaHCO3 was toremove the bitterness and anti-nutritional factors. The hulls were then removed and driedat 65ºC for 5 hrs. The dehulled soybean was then grinded in hammer mill (Culatti, Model:JKA Werk, Type: DCFH, Germany) and sieved with a 60 mesh screen (Model BS 410,Endeco London, England). The soya flour was packed in a high density polythene bags,sealed and stored.Formulation of weaning foods: The formulation of weaning foods is generally based on thisassumption that the child consumes an average of 100g per day. From this basis theformulation of the weaning foods are given in Table 1. Then the prepared sweet potatoflour and soybean flour were blended with wheat flour, whole milk powder and sugar. Theblends were packed in polythene bag, sealed and stored at room temperature (32-37ºC).128Ingredients (%)SampleTable 1: Formulation of weaning foodWheat flour Soya flour Sweet potato flour Sugar Milk powderA (control) * - - - - -S1 45 10 25 10 10S2 45 15 20 10 10S3 45 20 15 10 10S4 45 25 10 10 10*Commercial weaning food (Cerelac)Serving procedure: Drinking water was boiled for 5 minutes and allowed to cool. Then75ml water was added to 25 g of weaning food in a bowl and stirred until the weaningfood become smooth and soft paste.Bio-chemical analysis: All determinations were done in triplicate and the results wereexpressed as an average value of the three. The crude fat was estimated by exhaustiveextraction with petroleum ether (B.P.40 to 0°C) using a Soxhlet apparatus (AOAC, 2004).The micro Kjeldahl method was used for the determination of protein (N × 6.25). Themoisture and ash were determined by the AOAC (2004) methods while totalhttp://www.bdresearchpublications.com/journal/

Nutritional Composition and Sensory Attributescarbohydrate was obtained by difference (100 – (% moisture + % crude protein + % crudefat + % ash). Retinol content was also determined by AOAC (2004).Mineral content: Mineral content such as Calcium (Ca), Phosphorus (P), Iron (Fe) wereestimated by atomic absorption spectrophotometer using Perkin-Elmer 290 instrument asper the methods described by AOAC (2004).Amino acid content: After determining the proximate composition, the sample havingmaximum protein content was then used for amino acid analysis. The analysis was donefollowing the method described by the Association of Official Analytical Chemists (AOAC,2004).Sensory evaluation: Weaning foods were tested by a panel of 15 judges as described byRuston, et al. (1996). The panelists were selected from the nursing mothers. The judgeswere briefed about the procedure for judgment and marking the product within thenumerical value of 1-9 in ascending order of some quality parameters like color, flavor,taste and overall acceptability.Statistical analysis: The data were subjected to analysis of variance (ANOVA) whereapplicable and a difference was considered to be significant at p ≤ 0.05. Means wereseparated using Duncan’s multiple comparison tests through SPSS software (version16.0)ResultsProximate composition of prepared weaning foods and commercial weaning food(control sample): The moisture content of the prepared samples and commercialweaning food sample are shown in Table 2.The lowest value for moisture content wasfound in S1 (8.05%) whereas the moisture content were determined in S2 (8.10%), S3 (8.16%)and S4 (8.13%).However, the moisture content in S1 was much higher than the controlsample-A (commercial weaning food- Cerelac).The most acceptable result was found in S4 (16.76%) for protein content while theminimum value of protein was observed to be 13.23% in S1 (Table 2). The result of thesample (S4) indicated that it was better than commercial weaning food (14.2%) as well asother prepared foods.The fat content in S4 (7.56%) was higher than the fat content of S1, S2 and S3, respectively(Table 2). However, the fat content in S4 was slightly lower than commercial weaning foodsample (9.0%).The maximum ash content was calculated to be 2.14% in S4 followed by S1, S2 and S3,respectively (Table 2). In contrast, fat content in S4 was lower than the sample A (2.4%) buthigher than the other prepared samples.The total carbohydrate content of 71.21% was found in S1 (Table 2) which is comparableto the commercial weaning food (71.90%). Nevertheless, the total carbohydrate contentof other prepared sample was estimated 69.24%, 66.93% and 65.41% for S2, S3 and S4,respectively.Table 2. Proximate composition of prepared weaning foods and commercial weaningfood with RDA* and PAG** requirementsComponents(percentages are on dryweight basis)SamplesA S1 S2 S3 S4RDA * byFAOPAG **Moisture (%) 2.5 8.05 8.10 8.16 8.13 ≤ 5.0 ≤ 5.0Protein (%) 14.2 13.23 14.59 15.68 16.76 ≥16.0 ≥20.0Fat (%) 9.0 5.61 6.16 7.13 7.56 ≥12.0 ≤10.0Ash (%) 2.4 1.90 1.91 2.10 2.14 ≤5.0 ≤5.0Total carbohydrate(by difference)(%)71.90 71.21 69.24 66.93 65.41 ≥60.0 -*Recommended dietary allowance (RDA) for infants and babies of 1-3 years by FAO**Protein advisory groups (PAG) requirements for weaning food formulation (WHO/FAO/UNICEF,1972)[A = Commercial weaning food- Cerelac (control); S1 = (45% wheat + 25% sweet potato+ 10%soybean + 10% milk +10% sugar); S2=(45% wheat + 20% sweet potato+ 15% soybean + 10% milk+10% sugar); S3 =(45% wheat + 15% sweet potato+ 20% soybean + 10% milk +10% sugar) and S4=(45% wheat + 10% sweet potato+ 25% soybean + 10% milk +10% sugar)].129http://www.bdresearchpublications.com/journal/

Haque et al.Retinol and Mineral content of prepared weaning foods and commercial weaning food(control sample): The control sample was found higher in retinol content (270 μg/100g)than prepared weaning foods (Table 3). In addition, from prepared samples the higherretinol content was found in S1 (45 μg/100g) than the sample S2 (30 μg/100g), S3 (20μg/100g) and S4 (15 μg/100g), respectively.The amount of Iron (Fe), Phosphorus (P) and Calcium (Ca) were varied from 1.18-1.86, 140.2-188.4 and 55.3-77.2 mg/100g, respectively for the prepared weaning foodsamples (Table 3). The maximum value for Iron, Phosphorus and Calcium content for theprepared samples were found in S3 (1.86 mg/100g), S4 (188.4 mg/100g) and S4 (77.2mg/100g), respectively. In contrast, the estimated mineral contents of the preparedsamples was lower than the control sample-A.Table 3. Vitamin and mineral contents of prepared weaning food and commercialweaning food with recommended dietary allowance (RDA) for infant and babies(1-3 yr)Vitamin andSamplesmineral A (control) S1 S2 S3 S4RDA 1Retinol (μg/100g) 270 45 30 20 15 400.0Iron (mg/100g) 7.5 1.2 1.64 1.86 1.18 ≥6.0Phosphorus280 160.1 140.2 170.3 188.4 ≥180.0(mg/100g)Calcium (mg/100g) 380.0 55.3 58.6 63.6 77.2 ≥360.0 1 Recommended dietary allowance (RDA) for infants and babies (1-3 years) byFAO,[A = Commercial weaning food- Cerelac (control); S1 = (45% wheat + 25% sweet potato+10% soybean + 10% milk +10% sugar); S2=(45% wheat + 20% sweet potato+ 15% soybean +10% milk +10% sugar); S3 =(45% wheat + 15% sweet potato+ 20% soybean + 10% milk +10%sugar) and S4 =(45% wheat + 10% sweet potato+ 25% soybean + 10% milk +10% sugar)].Amino acid analysis: The sample (S4) containing higher percent protein (16.76%) wasanalyzed for amino acid composition. The amino acid analysis (Table 4) showed that theisoleucine content was found as 42.11 mg/g whereas leucine and lysine were estimatedat 80.25 and 57.34 mg/g; Methionine and cystine were found to be 30 mg/g whilephenylalanine and tyrosine was 80.5 mg/g; Histidine is essential for infant growth and thecontent was 20.38 mg/g and Tryptophan and valine were found to be 10.53 and 47.25mg/g, respectively. However, it was observed that the sample (S4) fulfils the requirementfor all amino acid requirements for infant growth except threonine content (30.22 mg/g).Thus, the result also indicated that threonine was the first limiting amino acid withchemical score of 68.68 (Table 4).Table 4. Amino acid composition and chemical scores of a weaning food sample (S4)RecommendedPrepared weaning foodEssential Amino acidsrequirements for Infants * Amino acid(EAA)Chemical score(mg/gm protein) (mg/gm protein)Isoleucine 35 42.11 120.31Leucine 80 80.25 100.31Lysine 52 57.34 110.26Methionine and29 30 103.44cystinePhenylalanine and63 80.5 127.7tyrosineThreonine 44 30.22 68.68Tryptophan 8.5 10.53 123.88Valine 47 47.25 100.53Histidine b 14 20.38 145.57 FAO/WHO reference pattern (1998), for infants only bSensory evaluation of weaning food: The mean scores of different sensory parameters aregiven in Table 5. It is seen that a statistical significant variation was observed among130http://www.bdresearchpublications.com/journal/

Nutritional Composition and Sensory Attributesdifferent samples regarding color, flavor, taste and overall acceptability (as per DMRT at5% significant level). The results shown in Table 5 , indicates that in term of colorpreference the highest score was observed in sample A (8.1) and the next rated in S4 (7.5).The variability of color was not found between S1 and S2 which were statistically identical(P

Haque et al.and babies, which will increase the energy density as well as act as a transport vehicle forfat soluble vitamins. These vitamins are necessary for optimum growth in an infant(FAO/WHO, 1998). Fats also contribute essential fatty acids to diet and these acids areimportant for optimum health (Meyer, 1987).The ash content of prepared foods meets both the RDA 1 and PAG 2 requirements. Thisresult is supported by Ismail, et al., (2000). Ash content of prepared samples also increasedwith increasing soybean flour (10-25%) in the formulation. The total carbohydrate contentof prepared samples fulfills the RDA 1 requirement for infant and babies. The outcomes ofthis experimental work agree with other author’s (Sadana, et al., 2008; Ahmed, 2005). Thecarbohydrate content decreased gradually with decreasing amount of sweet potatoflour (25-10%) due to the fact that sweet potato is the rich source of carbohydrates. Sweetpotato is a starchy staple food that is high in carbohydrate content since decrease itsamount in the formulation may decrease its content. This kind of changing was observedby Espinola, et al., (1997).The results (Table 3) indicate that retinol content of the prepared samples does not meetthe RDA 1 requirement. The prepared samples were observed to be low in retinol content.Perhaps, it is due to losses of vitamins during processing and its poor bioavailability. Thebioavailability of vitamin may be increased or decreased since it is reactive and generallypresent in varying amounts in food systems (Potter and Hotchkiss, 1995). The resultsobtained (Table 3) for mineral content does not meet the requirements of RDA 1 given byFAO except phosphorus content in S4. The obtained result for mineral content agrees withvarious author’s findings (Sadana, et al., 2008; Onweluzo and Nwabugwu, 2009; Idowu, etal., 1992). The prepared samples were observed to be low in mineral contents comparedto the commercial weaning food and recommended dietary allowance (RDA 1 ). This maybe due to presence of high anti-nutritional factors and poor bioavailability of minerals inplant based foodstuffs. According to Mariam, (2005), the bioavailability of minerals insoybean based diet was observed poor due to anti-nutritional factors.The sample was found to be low in threonine content compared to recommended level(Table 4). It is possibly due to lower amount of milk powder (10%) mixed with the samples.Moreover, it was mentioned that when the diets composed of cereals, legumes andmixed with some animal protein source (17-25.5%) to be sufficient in amino acids to meetthe recommended nutrients intake (RNI) for infants and babies (FAO/WHO,1998).ConclusionIn Bangladesh, the weaning foods are imported to overcome the problem of malnutritionof infants and babies during weaning periods. But these foods are too expensive for lowincome peoples/families. So it is important to prepare weaning food from locally availableraw materials because commercial weaning food is gradually getting out of the reach forthese families. Developing a technology to prepare weaning from low cost materials hasdrawn lots of attention now in the country. From this research work, it may be concludedthat weaning food can be prepared using sweet potato flour and soybean flour, to meetthe macro nutritional needs of infants and babies. However, certain aspects like thedigestibility and bio-availability of macronutrients as well as micronutrients in the preparedweaning food needs further study to know whether the prepared food needs furthermodification with or without fortification.Acknowledgements: We are grateful to all staff member in the Department of FoodTechnology and Rural Industries, Bangladesh Agriculture University, Mymensingh providingall necessary facilities for conducting this research work.ReferencesAdenuga, W., (2010): Nutritioanl and sensory profiles of sweet potato based infantweaning food fortified with cowpea and peanut. J. Food Tech., 8(5):223-228.Ahmed, M., (2005): Effect of processing treatment on acceptability of soybean basedweaning food. M. S. thesis, Bangladesh Agricultural University, Mymensingh.AOAC, (2004): Official method of analysis, 14 th edition, Washington, DC: Association ofOfficial Analytical Chemistry.Brandtazaeg, B., Mallechi, N.G., Savanberg, U., Desikachar, H.S., and Mellander, O.,(1981): Dietary bulk as limiting factor for nutrient intake in pre-school children. J.Trop. Sci., 27:184-249.132http://www.bdresearchpublications.com/journal/

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