Biochemical Studies on Kokumi γ-Glutamyl Peptifdes

As described in Chap. 1 , kokumi substances are defined as taste-related substances that modify flavor characteristics, such as complexity, mouthfulness, and lastingness (continuity), when added to basic taste solutions or food, but are tasteless themselves at the dose tested. Among the kokumi substances reported to date, γ-glutamyl peptides have been examined in detail. This chapter introduces studies on γ-glutamyl peptides. γ-Glu-Leu, γ-Glu-Val, and γ-Glu-β-Ala in edible beans (Phaseolus vulgaris L.) and γ-Glu-Tyr and γ-Glu-Phe in soybean seeds were identified as kokumi peptides. γ-Glu-Glu, γ-Glu-Gly, γ-Glu-Gln, γ-Glu-Met, γ-Glu-Leu, γ-Glu-Val, and γ-Glu-His in cheese, γ-Glu-Glu, γ-Glu-Gly, γ-Glu-Gln, γ-Glu-Met, γ-Glu-Leu, γ-Glu-Val, and γ-Glu-Val-Gly in soy sauce, and γ-Glu-Val-Gly in some fermented fish seasonings were indicated to act as kokumi peptides.