Effects of the addition of starches with different amylose contents on kimchi microbiota and metabolites

Starch paste, one of the ingredients used in kimchi, facilitates fermentation by acting as a nutrient source for microorganisms during the fermentation process. Changes in microbial communities and metabolites were investigated to understand the effects of starch with varying amylose contents on kimchi fermentation. Although adding starch paste changed the microbial profile of kimchi, there was no significant difference in the amylose content. In the starch paste-added kimchi, Leuconostoc, which is mainly involved in kimchi fermentation, was found to be relatively more abundant than in kimchi without starch. Furthermore, sugars such as glucose and mannitol had increased, but citric acid and tryptophan had decreased in the starch paste-supplemented kimchi. This indicates that adding starch paste can directly contribute to the taste of kimchi. Leuconostoc showed a negative correlation with many metabolites, except spermidine, suggesting that metabolite consumption was driven by Leuconostoc. Except for tryptophan metabolism, most of the metabolisms affected by the addition of starch were related to sugar metabolism. This study provides basic information for understanding the effect of starch, an essential ingredient in kimchi manufacturing, on the microorganisms and metabolites in kimchi.