Xu Wenqing, Wu Changqing
Dept. of Animal and Food Sciences, Univ. of Delaware, Newark, DE, 19716-2150, U.S.A.
J Food Sci. 2014 Mar;79(3):M378-83. doi: 10.1111/1750-3841.12359. Epub 2014 Jan 27.
Ozonated water washing is one of the emerging techniques to inactivate foodborne pathogens on produce, and limited information is available to optimize processing parameters (treatment time, temperature, and pH) to improve ozone efficacy on Salmonella inactivation for different produce. The efficacy of ozonated water washing for inactivation of Salmonella enterica Typhimurium on green onions, grape tomatoes and green leaf lettuces were studied in our research. Surface inoculated fresh produce were washed by ozonated water for 1, 5, or 10 min at room temperature and pH 5.60 ± 0.03. Then efficacy of ozonated water washing at mild heated (50 °C) and refrigerated (4 °C) temperature for 5 min with pH 5.60 ± 0.03 was investigated. Salmonella inactivation efficacy under pH 5.60 ± 0.03 and 2.64 ± 0.02 with 5 min washing at room temperature were also compared. Our results showed that Salmonella inactivation by ozonated water was time-dependent for 3 fresh produce. Mild heated temperature (50 °C) and pH 2.64 ± 0.02 improved efficacy of ozonated water to inactivate Salmonella on tomatoes and lettuces, but not on green onions. It is suggested that different surface structures of fresh produce significantly impact the antimicrobial efficacy of ozonated water washing operated under various parameters (time, temperature, and pH).
Washing is the essential step for green onions and lettuces in the packinghouse and grape tomatoes in the restaurants and grocery stores having salad bars. Ozonated water can be used as disinfectant to reduce microbial contamination (FDA). The effectiveness of this disinfectant depends on the type of product and treatment conditions, such as water temperature, acidity, contact time. Our study showed that Salmonella inactivation by ozonated water washing was time-dependent. Mild heat and low pH improved inactivation efficacy on tomatoes and lettuces, but not on green onions. Processors should consider adjustments that are most appropriate for their produce.
臭氧水冲洗是一种新兴的用于灭活农产品上食源性病原体的技术，目前关于优化处理参数（处理时间、温度和pH值）以提高臭氧对不同农产品中沙门氏菌灭活效果的信息有限。我们的研究考察了臭氧水冲洗对青葱、葡萄番茄和绿叶生菜上鼠伤寒沙门氏菌的灭活效果。将表面接种了菌的新鲜农产品在室温及pH值5.60±0.03条件下用臭氧水冲洗1、5或10分钟。然后研究了在温和加热（50℃）和冷藏（4℃）温度下，pH值为5.60±0.03时用臭氧水冲洗5分钟的效果。还比较了在室温下pH值为5.60±0.03和2.64±0.02时，冲洗5分钟的沙门氏菌灭活效果。我们的结果表明，对于这三种新鲜农产品，臭氧水对沙门氏菌的灭活具有时间依赖性。温和加热温度（50℃）和pH值2.64±0.02提高了臭氧水对番茄和生菜上沙门氏菌的灭活效果，但对青葱无效。这表明新鲜农产品不同的表面结构显著影响了在各种参数（时间、温度和pH值）下进行的臭氧水冲洗的抗菌效果。
冲洗是包装厂中青葱和生菜以及餐厅和设有沙拉吧的杂货店中葡萄番茄的必要步骤。臭氧水可作为消毒剂用于减少微生物污染（美国食品药品监督管理局）。这种消毒剂 的有效性取决于产品类型和处理条件，如水温、酸度、接触时间。我们的研究表明，臭氧水冲洗对沙门氏菌的灭活具有时间依赖性。温和加热和低pH值提高了对番茄和生菜的灭活效果，但对青葱无效。加工者应考虑针对其产品最适宜的调整方法。
