Effects of microbial community succession on flavor compounds and physicochemical properties during CS sufu fermentation

CS sufu is a fermented food composed of mixed chickpeas and soybeans. To explore the effects of the microbial community on the physicochemical and flavor properties of this product, microbial succession and metabolite changes during the fermentation stage of CS sufu production were detected using high-throughput sequencing and HS-SPME-GC-MS. The results showed that bacterial diversity was higher than that of fungi in CS sufu, and core communities included Enterococcus, Enterobacter and Rhizopus. Moreover, enriched species in different fermentation stages were significantly different. Seventeen free amino acids (FAAs) were detected at the post-fermentation stage. Sweet amino acids (TSAAs) and umami amino acids (TUAAs) mainly contributed to the taste of CS sufu. A total of 106 flavor compounds were identified at the different post-fermentation stages of CS sufu production, and esters, including ethyl caproate, ethyl octanoate, and isoamyl phenylacetate, accounted for the highest proportion. Furthermore, metabolic profile and microorganism analyses showed a significant correlation between the microbial profile and dominant flavor compounds. Lactococcus and Enterococcus were positively correlated with flavor compounds. This study provided information for the analysis of CS sufu at different fermentation periods in terms of microbial diversity and metabolites, and this information is important for understanding the properties of sufu made with mixed soybeans.