Fermentation-driven dynamic formation of salty peptides and mechanisms of saltiness enhancement in sausage.

This study investigates the dynamic evolution of salty peptides during sausage fermentation and their potential for enhancing saltiness perception. Peptide composition shifted from early-stage peptides derived from muscle proteins to a more refined set during later fermentation stages, with pronounced changes in peptide length and abundance distributions by day 6. Enrichment of acidic residues and a structured arrangement of charged and hydrophobic amino acids formed a sequence signature of salty peptides. Molecular docking and molecular dynamics simulations revealed receptor-specific binding behaviours. DL8-2 consistently formed the most stable complexes with both TMC4 and ENaC. DR8-37 showed the greatest conformational flexibility when interacting with TMC4, whereas KR11-25 exhibited the highest flexibility in complexes with ENaC. Sensory evaluation and electronic tongue analysis confirmed the intrinsic saltiness of the peptides, with KR11-25 showing the highest perceived saltiness and the lowest salty taste threshold. Interaction studies further revealed that KR11-25 and DL8-2 exhibited synergistic effects with NaCl, with R values of 0.44 and 0.49, respectively, whereas DR8-37 showed an additive interaction with an R value of 0.56. These findings underscore the importance of peptide sequence and conformational flexibility in modulating saltiness perception, offering insights into the development of natural flavour enhancers for sodium-reduced food products.