Effects of germination on the digestibility of instant soybean powders based on an in vitro digestion model of the aged static gastrointestinal tract.

Germination and heat processing can improve the digestibility of soybean protein, so for the elderly and people with gastrointestinal dysfunction, instant soybean powder is an ideal source for protein intake. In this study, the changes in protein and anti-nutritional factors in the instant germinating soybean powders were investigated systematically, and the aged gastrointestinal digestion model analyzed the digestive characteristics of instant germinating soybean powders. The results showed that during processing, particle size, disulfide bond, and β-sheets decreased, free sulfhydryl and α-helix increased. The change resulted in the decrease of proteolysis degree and particle size of gastrointestinal digestive products, and the increase of surface hydrophobic index. At the same time, anti-nutritional factors decreased by about 30 % to 60 %. The above reasons are combined with the protein digestibility of S 5.88 % higher than Y. This study proved that instant soybean powder is more conducive to the digestion and absorption of the elderly.