Exploring correlation between microbial communities and flavor profiles during fermentation of rape moss based on metagenomics and metabolomics

Fermented rape moss (FRM), one of pickled vegetable with salt cured in a short period fermentation (7 days), is broadly popular among consumers for crispness and mellowness. This study aimed to elucidate the variation of physicochemical indicators, flavor profiles, as well as bacterial communities during rape moss fermentation and the relationship between them. The results showed that flavor characteristics were dominantly accumulated in the late stage (day 6-day 7) of FRM. Moreover, the volatile compounds (VCs) of FRM were mainly ketones, esters and aldehydes, and 12 key VCs were detected, including 1 ester, 4 ketones, 2 terpenes, 1 aldehyde, 1 nitrile, 1 sulfur, 2 isothiocyanates. Additionally, Pseudomonas , Weissella , Leuconostoc , Latilactobacillus , Ligilactobacillus occupied relatively high abundance in the entire FRM fermentation. Furthermore, Spearman correlation analysis revealed that Latilactobacillus was positively correlated with 15 flavor profiles (5 FAAs, 2 OAs and 8 VCs). These findings may provide scientific references for the rational utilization of rape moss and the meticulous development of FRM.