Identification and mechanism exploration of novel umami peptides from oysters with an integrated pipeline

Umami peptides, as critical contributors to food flavor, necessitate precise methodologies to identify novel sequences and clarify their mechanisms for advancing the understanding of umami perception. This study aimed to develop an integrated pipeline for investigating umami peptides from oysters. A portfolio of 327 short peptides (2-5 amino acids) was identified from oyster hydrolysates using UPLC-Q-Orbitrap-MS/MS. Twelve potential umami peptides were further selected via virtual screening, and their interactions with the recombinant T1R1-Venus flytrap domain protein were validated using fluorescence spectroscopy. Among them, DVVHP exhibited the highest binding affinity, with a binding constant of 5061.74 M^-1, 324.26-fold stronger than monosodium glutamate. Molecular docking and isothermal titration calorimetry revealed that the binding was dominated by hydrophobic interactions, supplemented by hydrogen bonds and electrostatic forces. This pipeline provides a systematic framework for efficient umami peptide identification in aquatic products, illuminating their interaction mechanisms with umami receptor to facilitate novel flavor enhancer development.