Evaluation of Quality and Microbial Communities in Fermented Chinese Mustard Greens from Guangdong Province, China

Abstract

Fermented Chinese mustard greens are popular fermented vegetable foods in Guangdong Province, China. In this study, the quality characteristics and microbial composition of fermented Chinese mustard greens from different regions, including Shantou (ST), Meizhou (MZ), Yunfu (YF), and Guangzhou (GZ), were evaluated. The colour and texture of fermented Chinese mustard greens were significantly different from those of ST, MZ, YF, and GZ. L* values were 48.62, 42.30, 32.43, and 34.02 in the stem parts of ST, MZ, YF, and GZ, respectively. The chewiness value was greater in GZ (131.26 N) than in MZ (53.25 N), YF (39.99 N), and GZ (24.22 N) zones. The microbial community structure determined by high-throughput sequencing (HTS) demonstrated that Firmicutes, Proteobacteria, and Campilobacterota were the predominant phyla. Lactobacillus was the most predominant microorganism in the MZ and GZ samples and accounted for a greater proportion of the microorganisms in the ST and YF samples. In addition to Lactobacillus, the relative abundances of Cobetia and Weissella were greater in the ST group, while those of Halomonas and Pediococcus were greater in the YF group. There was a significant correlation between the microbial composition and quality indices (colour and texture) among the samples from the four regions. The quality of the fermented Chinese mustard greens in MZ and GZ was significantly different from that of other samples in ST and YF. The Lactobacillus genus (Lactobacillus plantarum and Lactobacillus selangorensis) in MZ and GZ contributed to changes in colour (b*, C*, L*, a*) and texture (firmness and chewiness). This study provided a comprehensive correlation between quality and microbial composition of fermented Chinese mustard greens from different regions in Guangdong Province. The evaluation and correlation between quality and microbiota are helpful for guiding future improvements in fermentation processes and manufacturing high-quality fermented Chinese mustard greens.