Effects of glutinous rice paste and fish sauce on kimchi fermentation

To investigate the effects of glutinous rice paste (GRP) and fish sauce (FS) on kimchi's the fermentation characteristics, kimchi, kimchi with GRP, and kimchi with FS were prepared and the bacterial communities, metabolites, and volatile compounds were analyzed over 30 days of fermentation. Leuconostoc was most dominant, and Lactobacillus was next in all kimchi, and Lactobacillus was slightly more abundant in kimchi with GRP or FS. Bacterial abundances were clearly lower in kimchi with FS than other two kimchi. Compared to the other two kimchi, glucose (only initial period) and lactic acid, acetic acid, and ethanol concentrations were higher in kimchi with GRP, whereas mannitol (30 days) and amino acid concentrations were higher in kimchi with FS. The metabolite profiles of kimchi and kimchi with GRP were relatively similar, but slightly different from that of kimchi with FS. Volatile compounds were slightly higher in kimchi with GRP or FS compared to kimchi and their profiles in the three kimchi were a little different at the initial period (5 days), but they became relatively similar during the late periods (20–30 days). This enhanced understanding of GRF's or FS′ effects on kimchi's fermentation will contribute to the production of high-quality kimchi.