Decoding of Salty/Saltiness-Enhancing Peptides Derived from Goose Hemoglobin and the Interaction Mechanism with TMC4 Receptor

Amid the growing concern for health-oriented food choices, salt reduction has received widespread attention, particularly in the exploitation of salt alternatives. Peptides with a saltiness-enhancing effect may provide an alternative method for salt reduction. The objective of this study was to isolate and extract novel peptides with salt-reducing effects by fermenting goose blood using a Lactobacillus plantarum strain. Five potential target peptides were screened by a virtual database prediction and molecular docking. Sensory evaluation and E-tongue analysis showed that five peptides (NEALQRM, GDAVKNLD, HAYNLRVD, PEMHAAFDK, and AEEKQLITGL) were identified as target peptides. Particularly, the results of E-tongue showed that GDAVKNLD can increase the saltiness intensity (2.87 ± 0.02) in the complex system. The sensory evaluation results also indicated an increase in saltiness intensity (46.67 ± 4.67 mmol/L NaCl) after adding GDAVKNLD. The results of molecular dynamics simulation indicated that five peptides have good ability to bind tightly to TMC4 receptor, thereby stimulating it to exert an active effect. And these peptides interacted with the TMC4 receptor via hydrogen bonding, hydrophobic interactions, and electrostatic interactions. This research lays a theoretical foundation for discovering novel salty/saltiness-enhancing peptides and provides meaningful contributions to efforts in salt reduction.