US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania 190382 USA.
J Food Prot. 2012 Sep;75(9):1611-8. doi: 10.4315/0362-028X.JFP-12-103.
A novel in-package ozonation device was evaluated for its efficacy in inactivating three microorganisms (viz., Listeria innocua, attenuated Salmonella Typhimurium, and Escherichia coli O157:H7) on tomatoes and for its effect on fruit quality. The device produced ozone inside sealed film bags, reaching a concentration of 1,000 ppm within 1 min of activation. The three bacterial cultures were inoculated onto either the smooth surface or the stem scar areas of the tomatoes, which were then sealed in plastic film bags and subjected to in-package ozonation. L. innocua on tomatoes was reduced to nondetectable levels within 40 s of treatment on the tomato surface, with inactivation of ca. 4 log CFU per fruit on the stem scar area. An increase in treatment time did not result in a proportional increase in bacterial reduction. For E. coli O157:H7 and Salmonella, there was little difference (<1 log) in the effectiveness of the system when comparing surface and scar-inoculated bacteria. Both bacteria were typically reduced by 2 to 3 log CFU per fruit after 2- to 3-min treatments. No negative effects on fruit color or texture were observed during a 22-day posttreatment storage study of ozone-treated tomatoes. These results suggest that the three bacteria responded differently to ozonation and that in-package ozonation may provide an alternative to chemical sanitizers commonly used by the industry.
一种新型的内包装臭氧装置，用于评估其在消灭三种微生物（即无害李斯特菌、减毒鼠伤寒沙门氏菌和大肠杆菌 O157:H7）的效力，以及对水果质量的影响。该装置在密封薄膜袋内产生臭氧，在激活后 1 分钟内达到 1000ppm 的浓度。将三种细菌培养物接种到番茄的光滑表面或茎痕区域，然后将其密封在塑料袋中进行内包装臭氧处理。在番茄表面处理 40 秒内，无害李斯特菌的数量减少到无法检测的水平，在茎痕区域，每个果实的失活率约为 4 个对数 CFU。增加处理时间并不会导致细菌减少呈比例增加。对于大肠杆菌 O157:H7 和沙门氏菌，在比较表面和伤痕接种细菌时，该系统的有效性差异不大（<1 个对数）。两种细菌在 2 到 3 分钟的处理后通常会减少 2 到 3 个对数 CFU 每个果实。在对臭氧处理的番茄进行 22 天的储存研究中，没有观察到果实颜色或质地的负面影响。这些结果表明，三种细菌对臭氧处理的反应不同，内包装臭氧处理可能为行业常用的化学消毒剂提供替代方案。
