Reduction in Biogenic Amine Content in (Napa Cabbage) Kimchi by Biogenic Amine-Degrading Lactic Acid Bacteria.

This study was performed to mine biogenic amine (BA)-degrading lactic acid bacteria (LAB) from kimchi and to investigate the effects of the LAB strains on BA reduction in kimchi fermentation. Among 1448 LAB strains isolated from various kimchi varieties, five strains capable of considerably degrading histamine and/or tyramine were selected through in vitro tests and identified as PK08, PK05, YM20, KD15, and YM21. The selected strains were used to ferment five groups of kimchi, respectively. The LB group inoculated with PK08 showed the highest reduction in tyramine content, 66.65% and 81.89%, compared to the control group and the positive control group, respectively. Other BA content was also considerably reduced, by 3.76-89.26% (five BAs) and 7.87-23.27% (four BAs), compared to the two control groups, respectively. The other inoculated groups showed similar or less BA reduction than the LB group. Meanwhile, a multicopper oxidase gene was detected in PK08 when pursuing the BA degradation mechanism. Consequently, PK08 could be applied to kimchi fermentation as a starter or protective culture to improve the BA-related safety of kimchi where prolific tyramine-producing LAB strains are present.