Modulating flavor and microbiota of Yunnan suancai through salt reduction with KCl and κ-Carrageenan

Fermented vegetables like Yunnan suancai are traditionally pickled with high salt, raising health concerns regarding excessive sodium intake. This study evaluated the impact of reduced-salt pickling system, partially replacing NaCl incorporating KCl with κ-carrageenan (CG) mixture (30 %, 40 %, and 50 %), on the biochemical characteristics, microbial dynamics, and flavor profiles during suancai fermentation. Result revealed significant differences in flavor profiles across treatments, driven by variations in 7 non-volatile and 46 volatile compounds. Weissella and Lactiplantibacillus dominated the microbiota. Salt primarily influenced microbiota structure in the mid-later stages of fermentation, correlating shifts in organic acids and physicochemical properties. LEfSe analysis identified 60 bacterial clades as biomarkers associated with salt levels. Specifically, Levilactobacillus brevis, Latilactobacillus sakei, Lactiplantibacillus plantarum, and Weissella cibaria contributed to desirable mild, green, and fragrant flavor. Notably, the 30 % KCl/CG replacement preserved suancai texture and acceptability. This study provided a foundation for optimizing salt reduction strategies flavor in fermented vegetables.