Development And Nutritional Quality Of Extruded Weaning Food Based On Corn, Fermented Millet And Roasted Soybean

Nutritional status in children is most vulnerable during the weaning stages when both macro and micronutrients may be insufficient to maintain growth and development.In developing countries, starch-based foods are the major staples and have resulted in protein energy-malnutrition (PEM) of particularly infants, which has been one of the major nutritional problems worldwide. The high costs of animal proteins in most developing countries have resulted in inadequate protein intake for normal body growth and development.Combination of commonly used cereals with inexpensive plant sources like legumes can be used. Cereals are deficient in lysine but have sufficient sulphur containing amino acids which are limited in legumes whereas legumes are rich in lysine. The effects of the supplementation are highly beneficial, since nutritive value of the product is also improved.Infant foods were formulated by blending different flours composed of corn, millet and soybean, which are readily available worldwide and inexpensive, and contribute to develop valuable high-energy infant food rich in protein with high biological value.To improve the nutritional, organoleptic and physico-chemical properties of the products, raw materials were fermented and roasted while their extrusion was optimized using the orthogonal test [orthogonal array L9 (34)]. All the pre-treatments showed an improvement in the nutritional and physico-chemical properties of the products and the following extrusion parameters have been found to be the best:temperature of 80,110,140 and 170℃, rolling speed of 110 rpm, feeding speed 37g/min and moisture content of raw materials ranging between 25 and 30%. Therefore, in order to optimize the targeted nutritional quality of the blend in terms of protein, carbohydrate, fat and ash with a minimized cost, the DPSvl1.5 software was used and the formulation was done with 41% of corn,16% of millet and 43% of soybean with 10.3 RMB/kg. The expected minimum nutrients were> 15% protein,> 10% fat,> 0.5% ash and> 55% carbohydrate. Six formulations were done where F1 (corn, millet and soybean without any treatment as control), F2 (corn+ millet+ roasted soybean), F3 (corn,48h fermented millet and roasted soybean), F4 (corn,24h fermented millet and roasted soybean), F5 (corn,48h fermented millet and soybean) and F6 (corn,24h fermented millet and soybean).After extrusion, the nutritional compositions of all the six extrudates were in agreement with the expected and also fall into the requirements of FAO/WHO and China for weaning foods. There was no significant difference (P<0.05) between the protein contents of all products except Fl (22.5%) and F6 (20.68%), while for fat and ash contents there was no significant difference (P<0.05) among all the products.Physico-chemical and functional properties of extruded weaning foods such as bulk density (BD), composition of amino acids and fatty acids, water absorption index (WAI), water solubility index (WSI), swelling power (SP), pasting properties, in vitro protein digestibility (IVPD), nitrogen solubility (NS), thermal analysis, sensory evaluation and microbiological test were carried out.The results obtained showed a significant difference (P<0.05) between the BD of Fl (control: 0.9115) and F6 (0.9517 g/cm3) and in general the bulk density increased with the incorporation of fermented millet and roasted soybean. There was also a significant difference (P<0.05) between F3 with other products for both WAI and WSI 8.31 and 23.5respectively. The pasting properties revealed also a significant difference (P<0.05) between F2 and the other products in terms of pasting peak, trough, final viscosity and set back. The sensory evaluation of all products by 35 untrained members indicated that F6, F3 and F5 are the most preferred.In general, all the weaning products were nutritionally good. But considering protein digestibility, nitrogen solubility, Bulk density, WAI and the overall acceptability; F3 composed of corn,48 fermented millet and roasted soybean flour is the best compared to others.