Quantitative Analysis of g Glutamyl valyl glycine in Fish Sauces Fermented with Koji by LC/MS/MS
Quantitative analysis of a kokumi peptide, g glutamyl valyl glycine (g 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 g Glu Val Gly was detected in all four sauces. The g 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 g Glu Val Gly may be widely present in fish sauces fermented with koji.