Bio-modified soybean meal as a new protein source for food

Abstract

Soybean meal has long been considered as a plant protein source particularly for animal feedstuff. Nowadays, there is a promising prospect of this material for food processing. However, its protein utilization has drawbacks, such as poor protein solubility and anti-nutritional factors called phytic acid. The phytic acid could be reduced by the addition of phytase, whereas nutrient content enhanced by microbial fermentation. In this study, we analyzed the bio-modified of soybean meal (SBM) through fermentation by phytase producing Lactobacillus plantarum A1-E to evaluate its effect on nutritional quality and anti-nutrient factor called phytic acid and aflatoxin. The study was designated into two treatments consisted of unfermented soybean meal (USBM) and fermented soybean meal (FSBM) by L. plantarum A1-E. Parameters observed were microbial population, phytic acid content, aflatoxin content, and nutrient composition (moisture, ash, crude protein, crude fiber, and lipid). Data were analyzed using analysis of variance (ANOVA) and a T-test to compare treatment means. FSBM by L. plantarum A1-E increased population (6.8x107 CFU/ml) during 72 h incubation (P<0.05) than 0 h (2.1x106 CFU/ml). FSBM reduced phytic acid content (34.13%) and aflatoxin (6.12%) compared to control (USBM). Fermentation during 72 h had on average more crude protein (1.33-fold), crude fiber (2.09-fold), ash (1.13-fold), and less crude lipid (0.71-fold) than SBM. Thus, it can be concluded that FSBM by phytase producing L. plantarum A1-E could be applied for degradation phytic acid during food processing and represents an improvement in nutritional quality thereby becomes potential raw material as a new protein source for food.