Structural characteristics of saltiness-enhancing enzymatic hydrolyzed red bean protein and its molecular docking...

The demand to reduce excessive dietary sodium intake has made the application of saltiness-enhancing peptides a promising strategy. This study investigated red bean protein hydrolysates (RBPH) as saltiness enhancers and established a rapid screening strategy using molecular docking with the salt taste receptor TMC4. Comprehensive structural characterization revealed that alkaline protease hydrolysis remodels red bean protein by disrupting its native structure, enhancing peptide flexibility, and exposing functional groups. The alkaline protease hydrolysate of red bean protein exhibited significant saltiness enhancement with minimal bitterness. Molecular docking identified peptide QDEPF as a high-affinity TMC4 binder through a "charge complementarity-hydrophobic embedding" interaction, and LC-MS/MS analysis validated its presence in RBPH-A. This study elucidated the structure-function relationship underlying RBPH-mediated saltiness enhancement, addressing the research gap in utilizing RBPH as a source of taste-modulating peptides, and provides a strategic framework for developing plant-based saltiness-enhancing agents to support the formulation of low-sodium foods.