Distribution of a kokumi peptide, γ-Glu-Val-Gly, in various fermented foods andthe possibility of its contribution to the sensory quality of fermented foods

A potent kokumi peptide, γ-glutamyl-valyl-glycine (γ-Glu-Val-Gly), was identified and quantified in various fermented foods using high performance liquid chromatography-tandem mass spectrometry (LC/MS/MS). This peptide was present in fermented seasoning such as fish sauces, soy sauces, and fermented shrimp pastes. Among the brewed alcoholic beverages, γ-Glu-Val-Gly was detected in beer. In addition, the content of γ-Glu-Val-Gly positively correlated with the quality grade of dark-colored soy sauce (correlation coefficient ρ=0.810, p<0.05). These results suggest that γ-Glu-Val-Gly is widely distributed in fermented foods and that the content of this peptide can be an indicator of sensory quality of fermented foods.