Exploring flavor perception through metabolite profiling and sensory approaches during starter kimchi fermentation

Starter cultures can enhance sensory properties during the starter kimchi fermentation. However, while many studies have primarily focused on physicochemical properties, the impact of starters on flavor perception remains unclear. The aim of this study was to assess the impact of starter culture inoculation, specifically Companilactobacillus allii WiKim39 and Lactococcus lactis WiKim0124, on aroma and flavor perception through a comparison of metabolite profiling and electronic tongue and nose data. Notably, 19 and 11 compounds were identified using UHPLC-Q-Orbitrap-MS and HPLC, respectively. Principal component analysis revealed that variations in fermentation metabolites and sensory properties were significantly categorized based on the particular starter culture employed during the ripening process. Moreover, the correlation analysis between the 19 key fermentative metabolites and e-tongue measurements in each starter kimchi revealed significant differences in sourness (AHS), bitterness (SCS), and comprehensive taste (CPS and PKS) sensors. The e-nose system identified four major volatile compounds contributing to the sweetness and off-flavor-related aroma profile of the starter kimchi. These findings highlight the significant impact that starter culture has on taste and flavor development, serving as a valuable guide in predicting sensory properties during starter kimchi fermentation.