Effects and Potential Risks of Chiral Penflufen on Pickled Cowpea: Combined Microbiome and Metabolomics

Pesticide residues on vegetables may affect microbes
and metabolites
during the fermentation process, leading to effects and potential
risks. Here, the enantioselective effects and potential risks of chiral
penflufen on pickled cowpea were investigated by using microbiome
and metabolomics analyses. Correlation analysis was conducted to construct
bacterial–metabolite interaction networks. Penflufen enantiomers
were degraded little during the fermentation process. Rac-penflufen treatment significantly decreased the relative abundance
of Lactiplantibacillus while increasing Weissella, but the opposite effects were found in R- and S-penflufen treatments. These shifts were linked to content
and functional changes of metabolites. R-/S-/Rac-penflufen upregulated rose aroma
metabolites (e.g., β-damascenone), while R-
and S-penflufen downregulated floral aroma metabolites
(e.g., β-ionone, 2-nonenal) and green leaf aroma metabolites
(e.g., (E)-2-hexenal). S-Penflufen reduced alcohols
and increased esters more significantly, and altered a higher number
of volatile organic compounds (VOCs) and chiral amino acids than R-penflufen, showing a greater risk to food flavor and nutritional
quality.