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

【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3.6min。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。

[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.