Effects of garlic on kimchi metabolites exerted through selective growth control of Lactobacillus and Leuconostoc

Garlic generally inhibits the growth of microorganisms; however, the mechanism underlying its selective impact on the growth of various kimchi microorganisms is unknown. We investigated the effects of garlic on the microbial community and metabolites in kimchi during fermentation. Difference in color and white colony-forming yeast were found only in kimchi without garlic on the 100th day of fermentation. The microbial community in kimchi without garlic showed a relatively high proportion of Lactobacillus, but a low proportion of Leuconostoc. The levels of homoserine were correlated with the initial quantities of garlic added. Meanwhile, the levels of 11 metabolites, including putrescine and GABA, differed between the groups as the fermentation period progressed. Metabolic differences were confirmed by applying Lactobacillus and Leuconostoc to a kimchi model system. These results show that the garlic addition can produce different metabolites by controlling the ratio of Lactobacillus and Leuconostoc in kimchi.