Objectives: This study investigated the effect on microbial ecology, fermentation characteristics and anti-obesity of Platycodon grandiflorum (PG) fermentation with salt.
Methods: PG was fermented for four weeks with 2.5% salt and the characteristics of fermented PG were performed by measuring pH, total sugar content, viable bacteria number and microbial profiling. Also, we measured total polyphenol, flavonoid and the percent of inhibition of lipase activity and lipid accumulation.
Results: Salt added to PG for fermentation had an effect on pH, total sugar, total and the number of lactic acid bacteria. Total sugar and pH were reduced and number of total and lactic acid bacteria were increased after fermentation. The majority of bacteria for fermentation were Lactobacillus plantarum, Leuconostoc psedomesenteroides and Lactococcus lactis subspecies lactis regardless of salt addition. However, microbial compositions were altered by added salt and additional bacteria including Weissella koreensis, W. viridescens, Lactobacillus sakei and Lactobacillus cuvatus were found in fermented PG with salt. Total flavonoid was increased in fermented PG and lipid accumulation on HepG2 cells treated with fermented PG was reduced regardless of salt addition. Moreover, fermented PG without salt suppressed lipase activity.
Conclusions: Addition of salt for PG fermentation had influence on fermentation characteristics including pH and sugar content as well as number of bacteria and microbial composition. In addition, fermented PG showed anti-obesity effect by increasing flavonoid content and inhibition of lipase activity and lipid accumulation.