Saltiness enhancing peptides isolated from enzymolysis extract of Lentinula edodes and their taste enhancing action mechanisms

The purpose of this study was to identify saltiness-enhancing peptides from continuous enzymolysis extract of Lentinula edodes by gel filtration chromatography (GFC), LC-MS/MS, virtual screening, molecular docking, molecular dynamics simulation, electronic tongue analysis, and sensory evaluation. The results showed that the molecular weight of peptides in GFC P2 fraction was between 647 and 2110 Da, and heptapeptides-decapeptides were the most important. Four potential saltiness peptides, ADHDLPF, DIQPEER, DEPLIVW, and LPDEPSR were screened by BIOPEP-UWM and further verified by sensory evaluation. Molecular docking and molecular dynamics simulations indicated that four peptides could interact with TMC4 receptors, Arg583, Arg294, Ala584 and Glu161 of TMC4 pocket1 and Arg437, Gln527, Arg580 and Lys412 of TMC4 pocket2 may play a key role in saltiness binding. In addition, the electronic tongue results showed that saltiness peptides had a synergistic effect on improving the saltiness of NaCl solutions and could replace at least 25%-50% of NaCl. The results showed that the saltiness-enhancing peptides of L.edodes could be obtained by enzymolysis, which laid a foundation for developing salt-reducing condiment from L.edodes.