Investigation on the Screening and Taste Mechanisms of Umami Peptides in Natural and Hydrolyzed Jinhua Ham

This study aimed to identify novel umami peptides from both natural and enzymatically hydrolyzed peptides from Jinhua ham, and to characterize their properties. Following LC-MS identification, known flavor sequences were annotated using a curated flavor-peptide database containing 2617 known flavor peptides, and potential novel umami peptides were screened through an integrated approach combining multiple machine learning models and LibDock molecular docking. From over 2000 identified peptides, this integrated virtual screening pipeline precisely yielded 10 candidate umami peptides, which were confirmed to possess distinct umami characteristics by sensory evaluation and electronic tongue analysis. These peptides had umami intensities ranging from 2.87 ± 1.38 to 3.90 ± 1.56 and significantly lower taste thresholds (0.1109-0.2634 mg/mL) than that of monosodium glutamate (MSG, 0.3 mg/mL). Subsequent CDOCKER analysis demonstrated significantly stronger binding affinity and stability of these peptides to the T1R1/T1R3 receptor compared with MSG, with -CDOCKER ENERGY values of 78.45-94.95 and -CDOCKER INTERACTION ENERGY values of 56.67-86.71, both significantly higher than those of MSG (22.27 and 46.58, respectively). Hydrogen bonds were identified as the dominant binding force, accounting for over 66% of total interactions, and HIS145 and ARG247 were confirmed as the key residues maintaining the stability of the peptide-receptor complex. Overall, these findings provide mechanistic insight into the umami properties of Jinhua ham peptides and support their potential application in food processing.