Quality improvement of soybean meal by yeast fermentation based on the degradation of anti‐nutritional factors and accumulation of beneficial metabolites

Abstract

BackgroundSoybean meal (SBM) is the main protein source for animal diet, but its anti‐nutritional factors affect the animal growth and immunity. Yeast culture based on soybean meal (SBM‐YC) by simultaneous yeast fermentation and protease enzymolysis can effectively reduce anti‐nutritional factors and accumulate beneficial metabolites.ResultsThe crude protein and acid‐soluble protein content of SBM‐YC reached 542.5 g•kg‐1 and 117.2 g•kg‐1, respectively, and the essential amino acid content was increased by 17.9%. Raffinose and stachyose were decreased over 95.0%, and the contents of organic acid such as acetic acid, butyric acid, citric acid, lactic acid, succinic acid, and propionic acid produced by fermentation reached 6.1, 3.8, 3.6, 2.5, 1.2 and 0.4 g•kg‐1, respectively. As the biomarker of yeast culture, nucleosides and their precursors reached 1.7 g•kg‐1, especially inosine content increased from 0 to 0.3 g•kg‐1. In terms of antioxidant capacity evaluation, the total antioxidant capacity, ABTS free radical activity, metal chelating ability and DPPH scavenging ability were increased by 50.3%, 46.1%, 43.9%, and 20.6%, respectively.ConclusionThis study established a diversified evaluation index, which could lay a foundation for the production and quality control of SBM‐YC in the future.This article is protected by copyright. All rights reserved.