# Influence of autochthonous Lactiplantibacillus plantarum strains on microbial safety and bioactive compounds in a fermented quinoa-based beverage as a non-dairy alternative

## TL;DR

This study explores how different Lactiplantibacillus plantarum strains affect the safety and nutrient content of a fermented quinoa drink.

## Contribution

The study reveals strain-specific effects of L. plantarum on microbial safety and bioactive compounds in plant-based fermented beverages.

## Key findings

- L. plantarum strains 3, 9, and 10 inhibited Enterobacteriaceae and increased glycosylated flavonoids and saponins.
- Strain 10 decreased saponin levels, while strain 5 increased aglycone abundance.
- Native microbiota significantly influenced fermentation outcomes despite inoculation.

## Abstract

Plant-based alternatives are considered microbiologically safe; however, recent studies have raised concerns about hygienic quality. Additionally, the relationship between microbiological safety and polyphenolic content in fermented products remains unexplored. This study assessed the potential of four autochthonous Lactiplantibacillus plantarum strains (3, 5, 9, and 10) to impact microbial composition and modulate polyphenol and saponin levels in a quinoa-based beverage. The results identified Lactiplantibacillus plantarum strains 3, 9, and 10 as effective in inhibiting Enterobacteriaceae (p = 0.001), and increasing concentrations of glycosylated flavonoids, 3-phenyllactic acid, and saponins. However, Lactiplantibacillus plantarum 10 demonstrated a decrease in saponin levels, whereas Lactiplantibacillus plantarum 5 increased the abundance of aglycones, highlighting strain-specific differences. Notably, principal component analysis revealed less differences between inoculated samples and control, indicating potential contribution of the native microbiota to the fermentation. This study enhances the understanding of interactions between starter cultures, native microbiota, and bioactive compounds in plant-based fermented beverages.

•The initial microbiome of quinoa is dominated by Proteobacteria, but fermentation encourages the growth of Firmicutes.•NGS and viable counts showed variations in Enterobacteriaceae with different strains.•Most changes in phenolic and saponin content were attributed to the action of native microorganisms.•L. plantarum 3 and 9 displayed elevated glycosylated flavonoid content after fermentation.•L. plantarum 5 increased aglycone abundance, while L. plantarum 10 decreased saponin content.

The initial microbiome of quinoa is dominated by Proteobacteria, but fermentation encourages the growth of Firmicutes.

NGS and viable counts showed variations in Enterobacteriaceae with different strains.

Most changes in phenolic and saponin content were attributed to the action of native microorganisms.

L. plantarum 3 and 9 displayed elevated glycosylated flavonoid content after fermentation.

L. plantarum 5 increased aglycone abundance, while L. plantarum 10 decreased saponin content.