Germination-tunable structural remodeling of LAB-fermented soymilk gels: Unraveling gastrointestinal digestive fate and bioactive peptide release.

This study explores how germination duration affects the structure and gastrointestinal digestion of LAB-fermented soymilk gels. Soybeans germinated for 0-3 days were fermented, with their rheology, microstructure, intermolecular interactions, and in vitro digestion analyzed. Germination weakened gel viscoelasticity, increased pore size, and shifted the dominant forces from hydrogen bonds to hydrophobic interactions. This is likely due to the higher endogenous proteases and 7S/11S ratio. Germination-derived gels (especially 2-3 days) disintegrated faster in the stomach, released more soluble protein in the intestine, and produced more peptides. Peptidomic analysis revealed that 2-day germination (fermented soft gel, FSG) yielded the most bioactive peptides via targeted subunit degradation, while 3-day germination (fermented ultrasoft gel, FUG) caused over-hydrolysis, leading to loss of specific bioactive motifs. These findings demonstrate that controlled germination time (2-day) optimizes LAB-fermented gel structure to improve digestive efficiency and bioactive peptide release, providing a novel strategy for designing plant-based dairy.