Biosensor guided effective degradation of anti-nutritional factors via selected soybean fermentation process

Abstract

Soybean meal (SM) is an important protein source for animal feed, and the β-conglycinin included is a significant allergen that can cause severe allergic reactions such as diarrhea in piglets and other animals. Fermentation can remove anti-nutritional factors and allergenic proteins, however, it is very difficult to find the fermentation endpoint, because the current protein detection methods are difficult to be applied for the rapid detection. In this study, AuNPs-aptamer sensor was used to evaluate the degradation of β-conglycinin during SM fermentation, and found a synergistic effect between alkaline protease and Lactobacillus plantarum DY6 with the optimum process parameters below: solid–liquid ratio 2, L. plantarum DY6 5%, alkaline protease 500 U/g, molasses 3%, 37 °C for 72 h. The fermented SM reached the 80.75% degradation and the final products possessed with a 1.87-fold increase in total free amino acids. This research validates the feasibility of using aptamer sensor to assess the anti-nutritional factors, and provides data for further large-scale production.