Composite organic acids for decontamination of Listeria monocytogenes in chicken

Abstract:

[Background] Listeria monocytogenes (Lm) is a major zoonotic pathogen. Lm carried by domesticated animals can spread along slaughter and sale chains, posing a threat to consumers’ health. [Objective] To establish and apply a green efficient technology for the control of Lm contamination in the broiler industrial chain. [Methods] We prepared a composite organic acid disinfectant composed of lactic acid and citric acid, optimized the sterilization conditions by response surface methodology, conducted preliminary applications of the disinfectant in slaughterhouses, and explored the sterilization mechanism. [Results] The optimal sterilization conditions were as follows: lactic acid content of 0.98%, citric acid content of 0.72%, and treatment for 3.6 min. The treatment under these conditions reduced the Lm on the chicken surface by more than 99%, extended the shelf life of chicken, and decreased the isolation rate of Lm on the surface of knives and broiler carcasses in the pre-cooling and segmentation stages in broiler slaughterhouses. Moreover, the composite organic acid disinfect significantly down-regulated the expression of genes associated with Lm virulence, inhibited the biofilm formation, and destroyed the cell structure of Lm. [Conclusion] The composite organic acid disinfect prepared in this study can effectively reduce Lm on the broiler surface in a short time, demonstrating good application prospects in preventing and controlling Lm contamination in the slaughter process of broilers.