A Novel Umami Peptide Selector (UPS) for Identifying Key Peptides from Maillard-Reacted Chicken Hydrolyzates: From Taste Evaluation to Antioxidant Properties

The Maillard reaction (MR) enhances the flavor of chicken enzymatic hydrolyzates, yet pinpointing key umami peptides remains challenging due to complex matrices. Sensory evaluation showed increased umami intensity despite decreased equivalent umami concentration (EUC: 0.29–0.41 g/100 g dry weight), suggesting that peptides may contribute substantially to the observed umami perception beyond the contribution captured by EUC. We developed a novel Umami Peptide Selector (UPS) integrating quantitative peptidomics with predicted taste thresholds to identify potent peptides. Guided by UPS, five key peptides (e.g., DVGDWRKN (DN8)) with low recognition thresholds were synthesized and confirmed to exhibit robust antioxidant activity. Molecular docking and density functional theory (DFT) suggested structure–activity relationships: acidic residues may contribute to T1R1/T1R3 receptor binding, while electron-rich residues (e.g., Trp) drove radical scavenging. This work provides a potentially applicable framework for screening high-value umami peptides with dual functionality, demonstrating the feasibility of rational design for flavor and bioactive enhancement in food systems.