复合有机酸对鸡肉中单核细胞增生李斯特菌减菌的影响

Composite organic acids for decontamination of Listeria monocytogenes in chicken

摘要:

【背景】单核细胞增生李斯特菌(Listeria monocytogenes,Lm)是重要的人畜共患致病菌，家畜禽携带的Lm沿屠宰和销售产业链逐级放大传播，给消费者的身体健康造成严重影响。【目的】建立和应用绿色高效的减菌技术，用于控制肉鸡产业链中Lm污染。【方法】选用乳酸、柠檬酸作为复合有机酸消毒剂，通过响应面法确定乳酸和柠檬酸联合使用的最佳杀菌条件，在屠宰场中进行初步应用，并对复合有机酸的杀菌机制进行探究。【结果】最佳杀菌条件为：乳酸含量0.98%，柠檬酸含量0.72%，作用时间3.6 min。使用该条件可有效减少鸡肉表面99%以上的Lm，延长鸡肉货架期，并能明显降低肉鸡屠宰场预冷环节、分割环节中刀具和肉鸡胴体表面Lm的分离率。复合有机酸能显著抑制Lm毒力相关基因表达，降低Lm生物膜形成，破坏细菌结构。【结论】经响应面法筛选得到的复合有机酸能在短时间内有效减少肉鸡表面Lm的污染，在防控肉鸡屠宰环节中Lm污染方面具有良好的应用前景。

关键词:单核细胞增生李斯特菌;乳酸;柠檬酸;减菌;生物膜

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.

Key words:Listeria monocytogenes;lactic acid;citric acid;decontamination;biofilm