The potential risks of paclobutrazol residue on yogurt fermentation from the level of chiral enantiomers

摘要

In recent years, pesticide residues in food haveincreasingly become the focus of public attention.However, the standard system of pesticide maximumresidue limits in fermented food is imperfect, whichcan lead to potential safety risks to consumers. In thiscontext, the aim of the study was to assess the potentialeffects of paclobutrazol residue on the yogurtfermentation process. We examined the stereoselectivebehaviors of the 2 paclobutrazol enantiomers from theperspective of chirality during the yogurt fermentationprocess. The results indicated that no significant degradationoccurred for either of the 2 enantiomers (2R,3R-paclobutrazol, 2S, 3S-paclobutrazol), and no visibleenantiomer conversion behavior was observed. In addition,the reason paclobutrazol did not significantlydegrade was explained from the perspective of the microbialfunction. Results from 16S rRNA sequencingindicated that paclobutrazol significantly affected themicrobial composition and inhibited metabolic functionof microorganisms to exogenous substances, which impededthe degradation of residual pesticide in yogurt.Furthermore, the stable residue of exogenous substancemay cause potential food safety problems. Microbialα-diversity analysis indicated that fermentation timeplayed a more important role on diversity than didpaclobutrazol concentration. Moreover, Staphylococcuswas found in yogurt after treatment with paclobutrazol;Staphylococcus aureus causes dangerous infectiousdiseases in humans. We devised a method to investigatethe presence of pesticide residues during food fermentationand provided a theoretical basis for food safetyassessment.