Fermented vegetables are increasingly being recognized as an important dietary component, particularly of plant-based diets, to achieve a sustainable healthy gut because of their microbial diversity and antioxidant properties. However, the functional relevance of fermented vegetables varies based on the raw ingredients used and nutrient supplementation. Therefore, in the present study, we investigated the microbial diversity and antioxidant activity of three formulas of fermented vegetables (standard, supplemented with Lacticaseibacillus rhamnosus GG, and supplemented with polyphenol vitexin) at days 0 and 15. The bacterial community profiles were determined through 16S rRNA sequencing analysis, and antioxidant activity was analyzed using 2,2-diphenyl-1-picrylhydrazyl and by measuring the oxygen radical absorbance capacity, the ferric reducing ability of plasma, and the total phenolic content. The results confirm microbial diversity in the taxonomic composition of the different formulas of fermented vegetables, with different bacteria predominating, particularly lactic acid bacteria including the genera Weissella, Pedicocccus, Leuconostoc, and Lactobacillus. Spearman’s correlation analysis showed significant differences in the specific bacteria present in the different formulas of fermented vegetables that conferred antioxidant capacity. Our findings show that supplementation with L. rhamnosus GG and polyphenol vitexin may effectively enhance the functional relevance of foods by promoting cellular protection against oxidative stress.

Research in metagenomics and metaproteomics can reveal how microbiological interactions in fermented foods contribute to their health benefits. This study examined three types of fermented vegetables: a standard formulation, a probiotic formulation with Lacticaseibacillus rhamnosus GG, and a polyphenol formulation with vitexin from Mung bean seed coat. Measurements were taken at day 0 (after 36 h of fermentation at room temperature) and after 15 days. We applied 16S rRNA sequencing to evaluate microbial diversity and utilized LC-MS/MS to investigate the proteomic profiles of specific genera (Lactobacillus and Weissella) and species (Lacticaseibacillus rhamnosus and Levilactobacillus brevis) of lactic acid bacteria (LAB). All of these taxa demonstrated significant relative abundance between 0 and 15 days of fermentation in our metagenomic analysis. Our findings from principal component analysis and clustering analysis categorically distinguished protein expression patterns at various stages of fermentation. By comparing samples from day 0 to day 15, we identified proteins associated with DNA replication and repair mechanisms, including transcription elongation factor GreA, tRNA pseudouridine synthase B, and helicases. We also observed their roles in protein synthesis, which encompasses oxidoreductases and aspartokinase. Furthermore, we identified strong correlations of specific proteins across the three formulations with antioxidant markers. In conclusion, the results of this study decisively enhance our understanding of the role of the proteins related to specific LAB in fermented foods, highlighting their potential to improve texture, flavor, nutritional quality, and health benefits.

(1) Background: This study aimed to investigate the bacterial microbiomes in the ingredients and final PBM products during a storage period of 28 days at 2–4 °C for food safety and quality. (2) Methods: DNA from raw ingredients (i.e., defatted soy flour, potato starch, wheat gluten, mung bean protein, and duckweed) and three PBM formulations were extracted and sequenced using 16S rRNA gene sequencing. (3) Results: Alpha diversity (Simpson and Shannon) was high in the raw ingredients (p ≤ 0.05). Beta diversity showed dissimilarities between the samples. Firmicutes and Proteobacteria were the core microflora in these ingredients. The heat-stable microbes in PBM (e.g., Nostocaceae in SF and Cyanobacteriale in MB and DW) survived after extrusion. After the ingredients were stored at room temperature, the bacterial communities shifted, with Paucibacter being the majority population in raw ingredients and PBM in the 2nd batch. The predictions of Potential_Pathogens related to the abundance of Aeromonadaceae and Enterobacteriaceae need to be monitored during storage. (4) Conclusions: Our results showed that the bacterial community in PBM containing 30% MB and 3% DW did not drastically change during 28 days of storage at cold temperatures. Uncovering bacterial microbiomes in the ingredients should be emphasized for quality and safety, as ingredients influence the microbiome in the final products.

The growing global population has highlighted the need to replace animal-based meat with plant-based meat (PBM) as a protein source. Using lactic acid bacteria (LAB) offers a promising and sustainable approach to prolong PBM shelf life and maintain quality comparable to non-food additives. This study investigated the potential of LAB to improve the qualities of PBM products. Three LAB strains, Lactiplantibacillus plantarum (LM), Lactiplantibacillus pentosus (LS), and Pediococcus acidilactici (PA) were selected from vegetable sources, and their effects on PBM shelf life were monitored for 21 days at 4 °C. Results showed that PBM samples treated with both Lactiplantibacillus spp. maintained consistent color properties throughout the cold storage period. Textural analysis revealed that the control samples exhibited the lowest hardness, springiness, gumminess, and chewiness, while LS-treated samples showed the highest values. Both Lactiplantibacillus spp. treated samples had pH values at less than 5, with no statistically significant differences. Volatile organic compounds were not impacted by LAB. LM-treated PBM exhibited higher amino acid content compared to LS and non-LAB-treated samples. Our findings showed that L. plantarum improved the texture and prolonged the shelf life of PBM products at 4 °C for 21 days. Results indicated that L. plantarum could be used as an alternative sustainable green biological preservative agent, serving as a clean label product.