Dynamic formation of umami peptides in traditional fermented sausage and their roles in umami perception and saltiness enhancement

This study investigated the dynamic formation of umami peptides during traditional fermented sausage fermentation and evaluated their contributions to umami and saltiness enhancement. Fermentation selectively enriched peptides of 5–11 amino acid residues in a stage- and precursor-dependent manner, especially those derived from troponin T, skeletal alpha-actin, and related muscle proteins, and these peptides were characterized by acidic residue enrichment, negative charge, and overall hydrophilicity, indicating favorable structural attributes for umami perception. Molecular docking indicated that all target peptides displayed favourable binding towards T1R1/T1R3 and TMC4. Sensory evaluation combined with psychophysical S-curve and R-value analysis revealed that DC10-8 possessed the lowest umami threshold (0.42 mmol/L) and the most potent synergistic effect (R = 0.45). In peptide–NaCl systems, all three peptides enhanced perceived saltiness, while DL8-2 exhibited the most stable synergy. These findings provide a molecular basis for flavour enhancement and sodium reduction in fermented meat products.