A novel and efficient technique for peptides preparation coupled with enzyme membrane reactor from Lentinus edodes tails and identification of umami peptides by virtual screening

This study aimed to establish an efficient method for preparing umami peptides from Lentinus edodes tails (LET) and select the appropriate pore size of the enzymatic membrane reactor (EMR). The protein conversion rate (PCD) of enzymatic hydrolysis from the protein of LET by EMR equipped with a 30k ultrafiltration membrane was significantly increased from 23.53 ± 0.24 % (without EMR) to 62.30 ± 0.39 %. The enzymatic hydrolysate of 30 kDa (30k-EMR) also showed the highest proportion of peptide fractions (<1 kDa) (62.13 ± 4.91 %), the highest proportion of umami amino acids (26.78 ± 0.13 %), and the highest umami intensity, among the three membrane pore sizes 30 kDa, 10 kDa, and 5 kDa. Five umami peptides (FGDGAP, SGGSPGADRVVF, RLDAPGHRDF, FSYGDVGPR, NFADY) were selected by six virtual screening tools, and binding energy (< -8.5 kcal/mol) from 30 k-EMR, and the umami thresholds were 0.023 – 0.375 mmol/L. Molecular docking revealed that the amino acid residues Glu889, Glu946, Gly891 were crucial in the binding of the umami peptide to the T1R1/ T1R3. Therefore, this study provides a theoretical basis for the development of condiments from LET. • The membrane pore size of EMR had a significant effect on the peptide yield; • EMR with large pore size produced more small molecular weight peptides (<1 kDa); • The umami threshold of SGGSPGADRVVF was 0.023 mM, which showed strong umami activity. • Glu889, Glu946, Gly891 of T1R1 played a key role in the umami peptides docking.