Porcine bone-derived umami-enhancing peptides: Identification and mechanistic insights via dual-ligand docking,...

This study evaluated eight porcine bone-derived peptides for their umami-enhancing effects and clarified underlying molecular and neurophysiological mechanisms. Sensory dose-response tests and sigmoidal curve analysis showed GVNAMLRK/PGRGCPGN additively, GPGCKAGL/GPTAANRM synergistically, intensified monosodium glutamate (MSG) umami. Response surface analysis identified optimal peptide-MSG pairs whose umami remained stable across 4-55 °C and pH 5.5-8.0 (except for GPGCKAGL-MSG), but exhibited sodium chloride concentration-dependent enhancement. Molecular docking and dynamics simulations revealed that peptides-primarily via hydrophilic residues-formed additional interactions (predominantly hydrogen bonds) with taste receptor type 1 member 1/taste receptor type 1 member 3 (T1R1/T1R3) hydrophilic residues, yielding tighter, more stable ternary complexes that strengthened dual-ligand binding to T1R1/T1R3 and amplified umami perception. Scalp-electroencephalogram showed that supplementing MSG with any peptide significantly increased δ, θ, α or β power in multiple cortical regions, with peptide-specific spatial-frequency signatures. This work expands the umami-enhancing peptide catalog, clarifies their multi-level mechanisms and provides guidance for future food applications.