Utilization of flour from germinated maize to enhance nutrient density of soy-enriched maize complementary flours

Abstract

Low nutrient density of cereal based complementary porridges resulting from high viscosity is one of the major causes of protein energy malnutrition in children aged 6-24 months in Tanzania. A number of studies have been done, which have shown that germination of cereals leads to reduction in porridge viscosity and facilitates increased energy and nutrient density, but the actual quantity of flour from germinated maize used to obtain drinkable porridges with appropriate nutrients for children is not clear. Therefore, this study aimed at assessing the utilization of flour from germinated maize for the development of nutrient dense complementary flours for children aged 6-24 months. Specifically, the study assessed the variation in amylase activity in two maize varieties (yellow and white) during germination, determined the effect of varying proportions of flour from germinated maize yellow variety on the viscosity, energy- nutrient density and in vitro digestibility of protein of the soy-enriched maize complementary flour. The study also evaluated the effect of different proportions of flour from germinated maize on the sensory acceptability of complementary porridges. Amylase activity, proximate composition and in vitro protein digestibility were analyzed using standard methods and viscosity was measured using viscometer. The yellow and white maize varieties had average amylase activities of 15.81 CU/g and 14.98 CU/g respectively. Varying proportions of flour from germinated maize (5%, 10%, 15%, and 20%) were added in soy-enriched yellow maize porridge, which significantly (P<0.05) decreased the viscosity of the porridge by 65.2, 68.3, 73.5 and 74.8% for 5, 10, 10, 20% respectively. Increasing proportions of flour from germinated maize did not significantly increase the in vitro protein digestibility of the porridge. The proximate composition of the porridges was not significantly affected by varying proportions of flour from germinated maize. Based on the study, germinated maize has shown to be an important technique for reducing the viscosity values of complementary porridges and improve the energy and nutrient density.