An innovative germination-driven LAB fermentation strategy for allergenicity reduction in soymilk gels through spatiotemporal protease-mediated epitope disruption

Abstract

This study innovatively integrated seed germination (1–3 days) with LAB fermentation to establish a structure–immunomodulation nexus in fermented soymilk gels. Germination degraded hydrophobic proteins, forming soft gels with substantially reduced hardness and improved water-holding capacity, alongside refined porous networks. Structural loosening enabled LAB proteases to access core allergenic domains, cleaving β-barrel (e.g., Gly m 5.03, residues 134–164) and α-helix clusters (e.g., Gly m 5.02, residues 118–124). This synergistic proteolysis reduced IgE-binding and antigenicity by over 40% compared to the FSM gel. Peptidomics revealed a continuous degradation process: surface epitopes (e.g., Gly m TI, residues 92–101) were predominantly degraded during days 1–2, whereas interior IgE-binding regions (e.g., Gly m Bd 30K, residues 202–209) became increasingly cleaved by day 3. The germination–fermentation cascade synergistically reconfigured protein matrices via hierarchical proteolysis, linking the porous gel architecture with immunoreactivity suppression. This dual bioprocessing strategy bridges texture engineering and allergen inactivation, offering a structure-guided approach for developing hypoallergenic plant-based foods.