Effect of Fermentation on Physicochemical and Antinutritional Factors of Complementary Foods from Millet, Sorghum, Pumpkin and Amaranth Seed Flours
In this study, effect of natural fermentation using different fermentation time (0-36 h) on physicochemical and functional properties as well as antinutritional factors on complementary foods formulated from pumpkin seeds, amaranth, finger millet and sorghum grains was investigated. High protein content above WHO/FAO recommended levels for weaning foods was observed in sorghum-pumpkin (SP) (24.5%), millet-pumpkin (MP) (23.6%), Sorghumamaranth-pumpkin (SAP) (22.8%) and millet-amaranth-pumpkin (MAP) (17.6%), which varied with fermentation time ranging from 0 - 36 h. Results on protein digestibility, showed that MAP had the highest value of 92.8% followed by MP (92.3%), SP (86.9%), SAP (78.7%), (SA) (88.2%) and (MA) (79.0%); while fermented SP for 36 h registered the highest starch digestibility of 77.7%, followed by SAP (74.8%), SA (74.6%), MAP (70.1%) and MA (69.3%). Total polyphenols, tannins and phytates decreased after fermentation. Functional properties such as Water Absorption Index (WAI), Water Solubility Index (WSI), Oil Absorption Capacity (OAC), Bulk Density (BD) and Least Gelation Concentration (LGC) were within the acceptable ranges for complementary foods with WSI showing an increase after fermentation while WAI and OAC decreased and LGC observed at 20% flour concentration after fermentation. These results showed that pumpkin seed, amaranth, finger millet and sorghum flours, in their blended form have potential to formulate a complementary food with high protein content and reduced antinutritional factors. In this way, utilization of cereals not commonly used for complementary foods, pseudo cereals and oil seeds in infant foods can be enhanced to address nutritional
related cases especially in developing countries.