Effects of two-step fermentation on protein enhancement and nutritional composition of rice (oryza sativa l.) and wheat (triticum aestivum l.) using lactobacillus bulgaricus and saccharomyces cerevisiae

Abstract

The effects of two-step fermentation on the protein content and nutritional composition of rice and wheat and their formulated blends (1:1, 1:3, and 3:1) have been studied in vivo. The rice and wheat substrate and their formulated blends were subjected to two treatments; (i) fermentation with mono-cultures of S. cerevisiae and L. bulgaricus and (ii) two-step fermentation for up to 10 days at 25 °C. After 10 days of fermentation, the protein content increased in all substrate. Fermentation with S. cerevisiae only and L. bulgaricus only increased the protein content varying from 22.56 % - 77.50 %, whereas, two-step fermentation increased the protein content varying from 43.48 % - 86.67 %. Therefore, two-step fermentation produced a synergistic effect in increasing the protein content in all substrate. The ash content increased in all substrates while carbohydrate content reduced. These findings show that employing a solid-state fermentation technique using S. cerevisiae and L. bulgaricus either as mono-culture or in two-step fermentation, could effectively enhance the protein contents and the nutritional composition of rice and wheat and their formulated blends for possible use as weaning and supplementary food for infants, adults and the aged. Results obtained in this study are being reported for the first time for rice and wheat and their amendments in a solid-state fermentation using S. cerevisiae and L. bulgaricus singly or in reverse order to improve nutritional status of grains and cereals in Ghana.