Changes in the Levels of γ-Aminobutyric Acid and Free Amino Acids during Kimchi Fermentation

The objective of this study was to examine the levels of free amino acids and identify the correlation between γ-aminobutyric acid (GABA)and L-glutamic acid contents in Kimchi during fermen tation. During 2 weeks of fermentation, the acidity of Kinchi increased, i.e., the pH level decreased from 5.24 to 4.40. The content of amino acids determined using HPLC differed significantly (p L-glutamic acid > L-glycine, except L-methionine decreased. Initially, the GABA content was found to be 72.43 μM/100 g fresh weight (fw), and it increased to 229.06 μM/100 g fw after 7 weeks. This rapid increase in the GABA content in the initial stage is considered to be due to L-glutamic acid. However, during the period of 0~7 weeks, no correlations were found between the L-glutamic acid and GABA contents.Key words: Kimchi, γ-aminobutyric acid, amino acids, correlation, L-glutamic acid