Isolation and identification of the umami peptides from Trachinotus ovatus hydrolysate by consecutive chromatography and Nano-HPLC-MS/MS

The aim of this study was to isolate and purify umami peptides from Trachinotus ovatus, the meat was hydrolyzed with 4000 U/g of papain and 1200 U/g flavourzyme at 50 °C with pH 6.5 for 3.5 h. The hydrolysates were further separated by consecutive ultrafiltration, gel filtration chromatography (GFC) and reversed-phase high-performance liquid chromatography (RP-HPLC) in combination with sensory evaluations and electronic tongue. Five peptides were identified by Nano-HPLC-MS/MS having amino acid sequences of APAP, ASEFFR, AEASALR, LGDVLVR, WDDMEK with threshold values in the ranges of 0.034–0.306 mmol/L. Molecular docking of the identified peptides with the umami receptor T1R1/T1R3 inferred that the amino acid residues of Asp192 and Glu301 in T1R3 might play an important role in umami release of umami peptides and the hydrogen bond and electrostatic interactions were the most important interaction forces between ligand and receptor. • Multienzyme synergistic hydrolysis was an effective way for pleasant flavor hydrolysates. • Five novel umami and umami-enhancing peptides were identified from the Trachinotus ovatus. • Asp192 and Glu301 in T1R3 may play an important role in the umami release of umami peptides.