Initial storage of kimchi at room temperature alters its microbial and metabolite profiles

Abstract

In Korea, the mixed kimchi ingredients are usually left at room temperature (20 °C) for one or two days for the growth of microorganisms and then stored at refrigerated conditions (2–6 °C) for fermentation. The initial storage duration at room temperature before storing kimchi at low temperatures are key variables affecting kimchi quality, but no research has been conducted on this issue. Therefore, we sought to investigate the extent of the effects of initial room temperature (20 °C) storage on kimchi quality by studying the changes in microbial community and metabolite profiles during kimchi fermentation. According to the results of multivariate statistical analysis score plots, the microbial community and metabolite profiles of kimchi stored at room temperature for one and two days mimicked those of kimchi stored at 4 °C for 80.8 and 90.1 days and 31.3 and 50.3 days, respectively. The levels of succinic acid, propylene glycol, and alanine on 100 days of fermentation were much higher in kimchi stored at room temperature than in control. These results could be used in kimchi industry to control the fermentation speed or to make customized kimchi by controlling the formation of early microbial communities.