Development of Nutritionally Balanced Sorghum-based Weaning Food

In this study different sorghum-based weaning foods were formulated by blending sorghum (Sorghum bicolor L.) with various combinations and quantities of loocally available legumes and oil seeds and processed by a twin-roller drum dryer. The raw materials included: partially defatted sesame (Sesanum indicum indicum) flour (oil content 13) and groundnut (Arachis hypogaea) flour (oil content 15)dehulled pigeon pea (Cajanus cajan) flourCowpea (Vigna unguiculata) flour and Chickpea (Cicer arietinum) flour. The effect of fermentation and the addition of malt on the nutritive value and functional properties of the weaning blends were also investigated using fermented sorghum flour and malted sorghum flour. All prepared raw materials used were analyzed for moisture, protein and fat according to AOAC (1986). The calculated amino acid score was used to screen the most promising baby food blends. The most limiting essential amino acids in most food diets (lysine, treptophan and sulphur containing amino acids) were considered in calculating the score of the suggested blends. The proportion of sorghum, legumes and oil seeds for the weaning food formulation were based on FAO/WHO/UNU (1985) recommendation for children. The different weaning blends were evaluated with respect to their: proximate compositionsensory evaluation (appearance, taste (sweetness), flavor (odour and taste), consistency (mouth feel) and overall acceptance)functional properties (water absorption capacity, bulk density, wettability and sinkability and dispersability)viscosityprotein quality (amino acids and PER)starch contentin vitro starch digestibility. The weaning blends were stored at room temperature and at 8 deg C (fridge) for ten monthsand in vitro protein-digestibility. The keeping qualllity in terms of acceptability, total microbial loads, peroxide vallue, and total aflatoxin were evalluated at zero time and at the end of the storage period. The results of the protein content of the blends (16.8-19.2) were found to be in line with the Codex recommendations. The results also showed that carbohydrates of all the blends was higher than that of the commercial and higher than the minimum standard level of 58specified by Codex. In this study the crude fibre of the weaning blends was below the maximum value (5) specified by many authorities. Energy values of the blends ranged from 400 to 418 kcal/100gram, which was in line with many recommendations for children under five. Macro - and micro-elements content of the blends were all within the recommended weaning food standard levels prescribed by FAO (1991). As for the functional properties, the results indicated that all the blends reconstituted well and formed soft paste consistency when stirred with hot and cold water. The water holding capacity, wettability and sinkability and bulk density all fell in line with the corresponding measured vallues of the commercial weaning food. The results of the mean scores for sensory attrributes showed that untreated sorghum/pigeon pea/sesame, untreated sorghum/pigeon pea/groundnut blens (B3 and B4) were better accepted than the other two untreated sorghum/cowpea/sesame, untreated sorghum/cowpea/groundnut blends(B1 and B2). Both fermented sorghum/cowpea/groundnut (B5), and fermented sorghum/pigeon pea/groundnut (B7) weaning blends had significantly (p0.05) better overall acceptability than the two malted sorghum/pigeon pea/groundnut (B6) and malted sorghum/cowpea groundnt (B8) blends. The viscosity of the two blends containing amylase rich flour, malted sorghum/pigeon pea/groundnut (B6) and malted sorghum/cowpea/groundnut (B8). was significantly lower (p0.05) than that of all other blends at all comparable slurry concentration followed by th commercial brand and then the two fermented sorghum blends (fermented sorghum/cowpea/groundnut (B5) and fermented sorghum/cowpea/groundnut (B7). The starch content was significantly lower (p0.05) in both malted sorghum blends (B6 and B8) and fermented sorghum blends (B5 and B7) than untreated sorghum blend, while the starch digestibility was significantly higher in malted blends. Both fermented blends recorded a significantly higher (p0.05) in vitro-protein digestibility throughout the storage periods as compared to all others. The results also showed that neither the storage temperature nor the storage time had significant effect on in vitro-digestibility. The results revealed that the sulphur-containing amino acids were found to be the liimiting amino acids in all the blends. On the other hand, there was a considerable improvement in lysine contents in all blends. Both fermented sorghum/cow pea blend and fermented sorghum/pigeon pea blend showed significantly higher (p0.05) lysine score (84and 85, respectively) as compared to all other blends. The fermented blends showed significantly higher (p0.05) PER (1.9 and 1.8) compared to other blends. Results of the keeping quallity showed that all the weaning blends showed no sign of spoilage in terms of off-flavour, or caking at the end of the storage periodtotal count ranged between 2.3x102 -7.6x104, peroxide values were within the safe limits set by the codex, and that most the blends were free from aflatoxin, except for some traces of aflatoxin detected in sorghum/cowpea/sesame blend (Blend2) and sorghum/pigeon pea/sesame blend (Blend 4). However, the vallues detected were below the permissible safe llimits set by the Codex.