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 degrees 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.

Automated summary

This study aimed to isolate and purify umami peptides from Trachinotus ovatus, and identified five peptides with specific amino acid sequences. Molecular docking experiments revealed that Asp192 and Glu301 in T1R3 may play a crucial role in the release of umami peptides, with hydrogen bond and electrostatic interactions being the key forces between the ligand and receptor.