Effects of continuous enzymolysis on the umami characteristics of Lentinula edodes and the flavor formation mechanism of umami peptides

In this study, the molecular weight distributions, electronic tongue analysis, and sensory evaluation of water extracts and continuous enzymolysis extracts of Lentinula edodes were compared and their taste-related metabolites and peptide profiles using 1H NMR and LC-MS/MS were assessed. The potential umami peptides in water extracted and continuous enzymolysis fractions were further screened, and then the binding mechanism of umami peptides to the receptor T1R1/T1R3 was evaluated by molecular docking. The results indicated that the continuous enzymolysis fraction (LFTE) of L.edodes had higher umami intensity and palatability, which might be caused by some umami-enhancing components Glu, Asp, Gln, and 5 '-AMP. The five peptides LPGVAE, LDELEK, DVELSK, LPDEAR, and TTLPDK with high umami scores were screened out. These peptides could enter the binding pocket in the T1R3 cavity through molecular docking, wherein Ala302, Asn68, Ser306, and Val277 might play major roles in the binding interactions of peptides and receptors.