Effect of Lactobacillus plantarum enriched with organic/inorganic selenium on the quality and microbial communities of fermented pickles

• Probiotic enriched in different selenium sources and fermented selenium-enriched pickle were prepared. • The pH; antioxidant activities; the inhibition of advanced glycation end-products (AGEs); flavor components, and the contents of organic acids, free amino acids (FAAs), amino acid nitrogen (AAN), and nitrite were determined. • The composition of microorganisms and the main differences in the microorganism composition among different groups were identified. • The correlation between microorganisms, environmental factors and flavor substances was analyzed. Lactobacillus enriched with organic/inorganic selenium and pickles fermented with the Lactobacillus plantarum R were prepared. The results showed that selenium-enriched Lactobacillus plantarum R enhanced the antioxidant capacity, inhibition rate of advanced glycation end-products (AGEs), nitrite degradation, and the organic acid production of fermented pickles, while Lactobacillus plantarum R enriched with inorganic selenium (R-Se-IN) showed the best performance. Twenty-three aroma-active substances and seven characteristic compounds were detected in the R-Se-IN group. Moreover, the bacterial community result revealed that Lactococcus , Lactobacillus , and Leuconostoc were predominant in the R-Se-IN group, while the other groups contained Enterobacter , Halomonas , and Klebsiella . Furthermore, the correlations between environmental factors, differential flavor substances, and microbial communities were explored based on multivariate statistical analysis. These results indicate that the addition of Lactobacillus plantarum R enriched with organic/inorganic selenium influenced the environmental factors, differential flavor substances, and microbial communities of the fermented pickles.