The effect of salt concentration on the bacterial composition and some physicochemical properties of pickled cabbage

Sauerkraut is known as the fermented product of the Brassica type of vegetable that is widely consumed in countries such as China. The purpose of this study was to prepare piclet cabbage in different salt concentrations and study the effect of salt concentration on some physicochemical properties, as well as to determine the effect of different salt ratios on bacterial composition using metagenomic analysis. During the fermentation process, total acidity, pH value, color analysis and salt concentration were performed during the production of piclet cabbage, and metagenomic analysis was carried out on the last day of the fermentation process. All microbial analysis results showed that Proteobacteria, and Firmicutes phyla were found to be significant at the phylum level in sauerkraut prepared at different salt concentrations. Metagenomic analysis revealed that it dominates the Proteobacteria phylum (49.64%) in sauerkraut, which contains a small amount of salt, and that Firmicutes phylum (66.232% ) increased with the increase in salt content in the piclet cabbage. At the genus level, Yersiniaceae, Leuconostoc, Lactiplantibacillus, Weissella, and Levilactobacillus genera were found at different concentrations and affected by salt concentration. Microbiological analysis showed that with an increase in salt concentration, the number of genera Yersiniaceae, Lactiplantibacillus decreased, by that time the number of genera Weissella, and Levilactobacillus increased. With an increasing salt concentration to 5%, the number of genera Leuconostoc provided positive results, while an increasing salt to 8% had an adverse effect on the growth of the microorganisms in this genus. Salt concentration had a significant effect on the fermentation of piclet cabbage, and the highest value in terms of pH' decrease and acid accumulation was found in sauerkraut containing 2% and 5% salt. In terms of sensory quality, piclet cabbage containing 5% salt was found to be the best.