Simultaneous Microbial Fermentation and Enzymolysis: A Biotechnology Strategy to Improve the Nutritional and Functional Quality of Soybean Meal

Soybean meal is a co-product of soybean oil extraction, and is the main protein source as its high protein content, well-balanced amino acid profile, and abundant supplies. However, the presence of anti-nutritional factors (ANFs) in the soybean meal affects the growth performance, reduces the apparent digestibility and utilization of nutrients, and induces intestinal disorder. This review aims to discuss the ANFs that limit the application of soybean meal, and compare their elimination methods. Then, the biotechnology strategy based on anti-nutritional factor degradation and beneficial metabolites accumulation are recommended. Moreover, the combination of conventional indicators and untargeted metabolomics technology to establish the quality evaluation system of fermented soybean meal with the perspective of postbiotics have been proposed. This review provides the first quantitative summary of anti-nutritional factors in the soybean meal, and compares the emergent biotechnology strategies for the elimination of ANFs in the soybean meal with existing practical methods, which could promote the efficient use of fermented soybean meal in the animal farming industry.