Effects of seasoning matrices on umami peptides: molecular insights into mechanisms of umami perception.

This study investigated how pH, salt, and sugar regulate the conformation and umami perception of LEADLVH using response surface optimization, sensory evaluation, spectroscopic analyses, and molecular dynamics simulations. Seasoning matrices enhanced umami perception by modulating peptide conformation, with the optimal combination of pH 7.01, 0.58% salt, and 0.40% sugar increasing umami intensity by 62.45%. Under these conditions, β-sheet content decreased from 45.45% to 36.12%, while α-helix and random coil contents increased from 17.61% and 13.58% to 23.05% and 17.75%, respectively, indicating a more extended and flexible conformation. This structural rearrangement was driven by pH-induced deprotonation, salt-mediated electrostatic shielding, and sugar-induced disruption of hydrogen-bond networks, thereby strengthening peptide-receptor interactions and improving binding free energy from -53.07 to -83.32 kcal/mol. In the ternary seasoning matrix (PSSu; pH 7.01, 0.58% salt, 0.40% sugar), Ser122, Asp144, Asp254, Tyr172, and Ser100 were the major favorable energetic contributors.