In vitro protein digestibility and biochemical characteristics of soaked, boiled and fermented soybeans

Abstract Protein digestibility of soybean obtained from the main manufacturing steps for natto, such as soaking (soaked soybeans ‘S’), boiling (boiled ‘B’), and fermentation (fermented ‘F’), was examined in this study. Biochemical indices processed each step those digested fractions by simulated vitro gastrointestinal digestion were also evaluated. The result showed a significant ( P < 0.05) increase protein B (48.71 ± 0.04%) F (50.21 0.45%) compared to that S (20.58 0.25%), accompanying accumulation small sub-fractions essential amino acids. Besides, antioxidant activity all increased around two fourfold at end digestion. consistently increasing trend when stage progressed maximum values overall final stage. Soybeans higher indispensable acids well potential bioactivities than step. results demonstrated improved nutritional protein, bioavailability certain bioactivities.