Decoding salty peptides from pea protein: Isolation, characterization, and structure-activity relationship

Pea protein, characterized by high nutritional value and a rich amino acid profile, constitutes a promising source for the development of salty peptides. In this study, hydrolysates of pea protein were fractionated by ultrafiltration and gel permeation chromatography, and peptides were identified using LC-MS/MS. Ten peptides were selected based on docking energy, frequency of occurrence of saltiness-related amino acid sequences, and hydrophobic amino acid content. Sensory evaluation analysis further showed that FDDKVR exhibited the highest saltiness intensity (4.25) and RSDPQNPF increased the saltiness of a 3 mg/mL NaCl solution by 136%. Molecular docking analyses indicated that hydrogen bonding was the primary interaction between salty peptides and TMC4 receptor, primarily involving arginine and alanine residues. 3D-QSAR model was established to elucidate the structure-activity relationship of peptides. Molecular dynamics simulations further elucidate the hydrogen bond interactions. These findings provide insights into the development of salt-reducing formulations and the application of pea protein.