Quantitative analysis of a kokumi peptide, γ-glutamyl-valyl-glycine (γ-Glu-Val-Gly) in fish sauces fermented with koji (grain steamed and fermented with Aspergillus oryzae) was performed using high performance liquid chromatography / tandem mass spectrometry (LC/MS/MS) after the derivatization with 6-aminoquinolyl-N-hydroxy-succinimidyl-carbamate (AQC). Four brands of commercial fish sauce fermented with koji were analyzed, and γ-Glu-Val-Gly was detected in all four sauces. The γ-Glu-Val-Gly content was below the limit of quantification in one of the four sauces, while the content of this peptide ranged from 1.7 mg/L to 5.7 mg/L in the other three sauces. These results indicate that γ-Glu-Val-Gly may be widely present in fish sauces fermented with koji.
2016 The Society for Chromatographic Sciences