Abstract:To explore the effect of fermentation on the digestive characteristics of soybean tissue protein products， lactic acid bacteria were employed to ferment soybean tissue protein products. The in vitro simulated digestive behavior of the fermented products was studied. According to the results of the in vitro digestion simulation， the protein hydrolysis degree， polypeptide， and amino acids contents of the fermented products were higher than those of the non-fermented ones throughout the whole digestion process. At the end of enteric phase fermentation， the degree of protein hydrolysis increased by 7.85%， while the contents of polypeptide and amino acids rose by 17.76% and 4.74%， respectively. Observing the protein degradation of the fermented products after gastrointestinal digestion， it was found that the bands around 20-35 kDa were significantly weakened and the abundance of the bands at 11-17 kDa was increased. Meanwhile， the results of size-exclusion chromatography indicated that more substances with molecular weights less than 10 000 Da were produced after gastrointestinal digestion of the fermented products. In conclusion， fermentation modified the protein structure of soybean tissue protein to some extent， enhanced gastrointestinal digestibility， and facilitated better digestion and absorption.