Particulates of harvest debris are common in tomato packinghouse dump tanks, but their role in food safety is unclear. In this study we investigated the survival of Salmonella enterica and the shifts in relative abundance of culturable mesophilic aerobic bacteria (cMAB) as impacted by particulate size and interaction with chlorine treatment. Particulates suspended in grape tomato wash water spanned a wide size range, but the largest contribution came from particles of 3-20 μm. Filtration of wash water through 330 μm, applied after 100 mg/L free chlorine (FC) wash, reduced surviving cMAB by 98%. The combination of filtration (at 330 μm or smaller pore sizes) and chlorinated wash also altered the cMAB community, with the survivors shifting toward Gram-positive and spore producers (in both lab-simulated and industrial conditions). When tomatoes and harvest debris inoculated with differentially tagged Salmonella were washed in 100 mg/L FC for 1 min followed by filtration, only cells originating from harvest debris survived, with 85 and 93% of the surviving cells associated with particulates larger than 330 and 63 μm, respectively. This suggests that particulates suspended in wash water can protect Salmonella cells from chlorine action, and serve as a vector for cross-contamination.

中文翻译：

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肠杆菌沙门氏菌的存活和可培养的中温需氧细菌群落的变化，受到番茄洗净水颗粒大小和氯处理的影响。

番茄包装厂的垃圾箱中常见有收获碎片的微粒，但它们在食品安全中的作用尚不清楚。在这项研究中，我们调查了沙门氏菌的存活率以及可培养的嗜温性好氧细菌（cMAB）相对丰度的变化，这些变化受颗粒大小和与氯处理的相互作用的影响。葡萄番茄洗涤水中悬浮的颗粒尺寸范围很广，但最大的贡献来自3-20μm的颗粒。在100 mg / L游离氯（FC）洗涤后施加的330μm洗涤水过滤，可使存活的cMAB降低98％。过滤（330μm或更小孔径）和氯化洗涤的结合也改变了cMAB群落，幸存者转向革兰氏阳性和孢子生产者（在实验室模拟和工业条件下）。当用差异标记的沙门氏菌接种的番茄和收获物碎片在100 mg / L FC中洗涤1分钟，然后过滤时，只有来自收获物碎片的细胞得以存活，幸存的细胞中有85％和93％与大于330和63的颗粒相关分别为 这表明悬浮在洗涤水中的颗粒可以保护沙门氏菌细胞免受氯作用，并作为交叉污染的载体。