title: Determination and quantification of the kokumi peptide, γ-glutamyl-valyl-glycine, in commercial soy sauces.
abstract: Recent studies have demonstrated that kokumi substances, such as glutathione, are perceived through the calcium-sensing receptor (CaSR), and screening by CaSR assay and sensory evaluation has shown that γ-glutamyl-valyl-glycine (γ-Glu-Val-Gly) is a potent kokumi peptide. In this study, the contents of γ-Glu-Val-Gly in six commercial brands of dark-coloured soy sauces, two brands of light-coloured soy sauce, and one brand of white soy sauce, were investigated by high performance liquid chromatography-tandem mass spectrometry (LC/MS/MS), followed by derivatization with 6-aminoquinoyl-N-hydroxysuccinimidyl-carbamate (AQC). The analyses indicated that γ-Glu-Val-Gly was present in all investigated soy sauces at concentrations ranging from 0.15 to 0.61mg/dl, demonstrating that it is widely distributed in soy sauces.
authors.affiliation: Institute of Food Research & Technologies, Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki-ku, Kawasaki, Kanagawa 210-8681, Japan. motonaka_kuroda@ajinomoto.com
authors.forename: Motonaka
authors.initials: M
authors.lastname: Kuroda
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Kato
authors.forename: Junko
authors.initials: J
authors.lastname: Yamazaki
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kai
authors.forename: Toshimi
authors.initials: T
authors.lastname: Mizukoshi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyano
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Eto
mesh_terms: D002853:Chromatography, Liquid; D009842:Oligopeptides / Q000032:analysis*; D045730:Soy Foods / Q000032:analysis*; D053719:Tandem Mass Spectrometry
chemical_list: D009842:Oligopeptides; C576321:glutamyl-valyl-glycine