Extraction, characterization, and molecular docking study of umami peptides from Antarctic krill

Abstract

The study investigated the extraction, characterization, and molecular docking of umami peptides from defatted Antarctic krill powder. Optimal conditions for enzymatic hydrolysis were hydrolysis temperature 41 °C, time 3 h, flavor protease to trypsin ratio 1:5 (2000 U/g), degree of hydrolysis 37.56%, and peptide yield 29.85%. After ultrafiltration (1 kDa), the Antarctic krill hydrolysate exhibited higher levels of bitter, umami, and sweet amino acids (27.55 g/100 g, 14.31 g/100 g, and 14.40 g/100 g, respectively) than before ultrafiltration (17.09 g/100 g, 8.05 g/100 g, and 9.03 g/100 g, respectively), indicating that ultrafiltration enhanced the flavor by concentrating umami and sweet amino acids. Overall, 179 peptides were identified via LC-MS/MS analysis, with VLALEELLAMPEN being the dominant (28.4% of the total peptides). Docking of Antarctic krill peptides with T1R1/T1R3 receptor showed hydrogen bonds and van der Waals forces as crucial interactions, deepening understanding of the taste mechanism of Antarctic krill umami peptides.