Increased production of GABA in non-alcoholic Makgeolli by optimization of lactic acid fermentation using Lactobacillus plantarum

Lactic acid fermentation of non-alcoholic Makgeolli a traditional Korean rice wine was optimized for increased production of γ-aminobutyric acid (GABA). The Makgeolli was concentrated by vacuum evaporation at 85℃ for 30 min to yield non-alcoholic Makgeolli and sterilize the indigenous microorganisms. As a result, yeast and lactic acid bacteria were not observed in the non-alcoholic Makgeolli. The non-alcoholic Makgeolli had an unpleasant odor in the absence of glucose in lactic acid fermentation. Therefore, the non-alcoholic Makgeolli was mixed with 3% mono sodium-L-glutamate (MSG) and 1% glucose followed by fermentation with Lactobacillus plantarum EJ2014 at 30℃ for 7 days in stationary culture. During this period, the pH increased from 5.1 to 5.5 and acidity decreased from 0.41% to 0.2%. The viable cell count increased to 3.0×108 CFU/mL by the end of the 7 day period. The production was determined using TLC; results showed that Most of the MSG was bio-converted on within 5 days. of lactic acid fermentation. HPLC analysis confirmed GABA production 1.59%. In conclusion, non-alcoholic Makgeolli with 1% glucose and 3% MSG could produce functional rice ingredients including GABA and probiotics as well as wholesome rice products through lactic acid fermentation.