Abstract The aim of this study was to investigate the effect of X-ray irradiation in reducing the population of Salmonella Typhimurium, Escherichia coli O157:H7, and Listeria monocytogenes in ready-to-eat (RTE) sliced ham and to verify the mechanisms underlying the lethal effect of X-ray irradiation. In addition, the effect of the X-ray treatment on food quality was determined by measuring color and texture changes. Sample surfaces were inoculated with cocktails of three pathogens and subjected to X-ray irradiation, with doses ranging from 0.2 to 0.8 kGy. After 0.8 kGy of X-ray irradiation, the numbers of S. Typhimurium , E. coli O157:H7, and L. monocytogenes were reduced by 5.7, 7.2, and 6.9 log CFU/g, respectively, without generating sublethally injured cells with potential to recover. The mechanism of X-ray-associated lethality was determined using fluorescent staining. We confirmed that the primary factors contributing to the lethal effect of X-ray treatment are related to intracellular enzyme inactivation and damage to cellular DNA rather than disruption of the cell membrane. Following X-ray irradiation, color values and textural characteristics of sliced ham products were not significantly altered compared to that of the control. The results of this study suggest that X-ray irradiation can be potentially used as a novel non-thermal process for inactivating foodborne pathogens in post-packaged RTE deli food products without compromising product quality.

中文翻译：

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X射线灭活即食火腿片食源性病原体的应用及杀菌作用机制

摘要 本研究的目的是研究 X 射线照射对减少即食 (RTE) 切片火腿中鼠伤寒沙门氏菌、大肠杆菌 O157:H7 和单核细胞增生李斯特氏菌数量的影响，并验证其背后的机制。 X 射线辐射的致死效应。此外，通过测量颜色和质地变化来确定 X 射线处理对食品质量的影响。样品表面接种三种病原体的混合物并进行 X 射线照射，剂量范围为 0.2 至 0.8 kGy。在 0.8 kGy 的 X 射线照射后，鼠伤寒沙门氏菌、大肠杆菌O157:H7 和单核细胞增生李斯特氏菌的数量分别减少了 5.7、7.2 和 6.9 log CFU/g，而不会产生具有潜在亚致死性损伤的细胞恢复。使用荧光染色确定 X 射线相关致死率的机制。我们证实，导致 X 射线治疗致死作用的主要因素与细胞内酶失活和细胞 DNA 损伤有关，而不是细胞膜的破坏。在 X 射线照射后，与对照相比，切片火腿产品的颜色值和质地特征没有显着改变。这项研究的结果表明，X 射线辐射可潜在地用作一种新的非热过程，用于灭活后包装 RTE 熟食食品中的食源性病原体，而不会影响产品质量。我们证实，导致 X 射线治疗致死作用的主要因素与细胞内酶失活和细胞 DNA 损伤有关，而不是细胞膜的破坏。在 X 射线照射后，与对照相比，切片火腿产品的颜色值和质地特征没有显着改变。这项研究的结果表明，X 射线辐射可潜在地用作一种新的非热过程，用于灭活后包装 RTE 熟食食品中的食源性病原体，而不会影响产品质量。我们证实，导致 X 射线治疗致死作用的主要因素与细胞内酶失活和细胞 DNA 损伤有关，而不是细胞膜的破坏。在 X 射线照射后，与对照相比，切片火腿产品的颜色值和质地特征没有显着改变。这项研究的结果表明，X 射线辐射可潜在地用作一种新的非热过程，用于灭活后包装 RTE 熟食食品中的食源性病原体，而不会影响产品质量。