Taste mechanism of umami peptides from Chinese traditional fermented fish (Chouguiyu) based on molecular docking using umami receptor T1R1/T1R3.

Umami peptides formed during fermentation of Chouguiyu contribute to its unique taste. In this study, the umami taste of peptide extract from Chouguiyu was improved after fermentation, as determined by sensory evaluation. After umami peptide identification using peptidomics, molecular docking with T1R1/T1R3 was used to evaluate the likely taste mechanism. There were 400 umami peptides identified in Chouguiyu, most of which were significantly enhanced after fermentation. These peptides were hydrolyzed from 77 precursor proteins, mainly including myosin, troponin, and titin, at multiple locations. The umami structures in the six core umami peptides with the lowest binding energy were easy to connect with Ser, Glu, His, Gln, Arg and Lys residues in T1R3 through hydrogen bond and salt bridge. The hydrogen bond, hydrophilcity, aromatic interaction, and solvent accessible surface were the main interaction surface forces. This study provides important information of the unique taste formation in Chouguiyu based on umami peptides.