Correlation between the physicochemical and bacteriological qualities of pickled chili pepper (Paojiao) and its nitrite degradation study

Abstract

Nitrite produced during the processing of pickled vegetables is a primary source of nitrite intake in humans. This study monitored changes in the physicochemical quality and bacterial community structure of pickled peppers and brine during natural fermentation. We also explored the characteristics and efficacy of nitrite degradation by Lactobacillus plantarum BNCC194165 (BNCC194165) in both MRS and pickled pepper systems. The results revealed that lactic acid bacteria (LAB) and acidic substances in pickled peppers and brine were closely related to nitrite content during natural fermentation. Analysis using 16S rDNA confirmed that Firmicutes phylum and Lactobacillus genus were the dominant bacteria in pickled peppers, demonstrating strong associations with most physicochemical attributes, particularly notable for their negative correlation with nitrite content. Following inoculation, the NaCl concentration, cultivation temperature, and initial pH in the MRS medium significantly influenced the ability of BNCC194165 to degrade nitrite. Furthermore, inoculation with BNCC194165 effectively reduced nitrite levels in pickles, moderated spiciness, and shortened the fermentation period. These findings enhance our understanding of the mechanisms underlying nitrite formation and degradation in pickled foods and their intrinsic relationship with fundamental components and microorganisms, providing valuable guidance for producing safer fermented vegetables.