Department of Food Science, University of Arkansas System Division of Agriculture, 1371 West Altheimer Dr., Fayetteville, AR, 72704, USA.
Taney County Health Department, Branson, MO, USA.
Food Environ Virol. 2021 Sep;13(3):390-400. doi: 10.1007/s12560-021-09476-y. Epub 2021 Apr 20.
Retail foodservice establishments (FSE) frequently utilize washes with sanitizing agents during fresh produce preparation. This study evaluated the efficacy of ozonated water on the inactivation of viruses, bacteria, and viruses in association with bacteria on produce surfaces. Boston bibb lettuce (BB) and cherry tomatoes were spot inoculated with viruses (murine norovirus (MNV) and MS2 bacteriophage), bacteria (Enterobacter cloacae and Bacillus cereus), or MNV associated with E. cloacae or B. cereus. Following inoculation, produce was held at 4 °C for 90 min (virus, virus + bacteria) or 24 h (virus, bacteria) prior to treatment. A batch wash ozone sanitation system (BWOSS) was prepared with ice (3-5 °C) and 0.5 ppm initial ozone concentration or no ozone. Produce samples were treated for 40 min with an ozonated water (0.86-0.99 ppm) or water-only wash with samples taken every 10 min. Samples were processed for microbial recovery, and plaque forming units (PFU) and colony forming units remaining on the produce were determined. Although microbial reductions of 99 to 99.99% were achieved during ozone treatments, few statistically significant differences (P > 0.1) were detected when comparing the ozonated water to water-only wash. Notably, a significant difference (P = 0.009) in log reduction of MNV + bacteria and MNV alone on BB was observed after 40 min ozonated water wash. Specifically, MNV with B. cereus achieved a 1-log greater reduction (2.60 log PFU/ml) compared to MNV alone (1.63 log PFU/ml). Overall, washing produce in ozonated water did not significantly increase microbial inactivation compared to water alone under the conditions presented here. Variables impacting ozone wash effectiveness should be considered when implementing produce wash sanitation systems within FSE.
零售食品服务机构（FSE）在准备新鲜农产品时经常使用含有消毒剂的洗涤液。本研究评估了臭氧水对病毒、细菌以及与细菌相关联的病毒在农产品表面失活的效果。将波士顿bibb 生菜（BB）和樱桃番茄用病毒（鼠诺如病毒（MNV）和 MS2 噬菌体）、细菌（阴沟肠杆菌和蜡样芽孢杆菌）或 MNV 与 E. cloacae 或 B. cereus 进行点接种。接种后，将农产品在 4°C 下保持 90min（病毒、病毒+细菌）或 24h（病毒、细菌），然后进行处理。使用冰（3-5°C）和 0.5ppm 初始臭氧浓度或无臭氧制备批次洗涤臭氧消毒系统（BWOSS）。用臭氧水（0.86-0.99ppm）或仅用水处理农产品 40min，每隔 10min 取样。对样品进行微生物回收处理，并确定剩余在农产品上的菌斑形成单位（PFU）和菌落形成单位。尽管臭氧处理可实现 99%至 99.99%的微生物减少，但在比较臭氧水和仅用水处理时，很少检测到统计学上的显著差异（P>0.1）。值得注意的是，在用臭氧水清洗 40min 后，在 BB 上观察到 MNV+细菌和 MNV 单独处理之间的对数减少有显著差异（P=0.009）。具体来说，与 MNV 单独处理（1.63log PFU/ml）相比，与 B. cereus 相关联的 MNV 实现了 1 个对数的更大减少（2.60log PFU/ml）。总体而言，与单独用水相比，在本研究中提出的条件下，用臭氧水清洗农产品并没有显著增加微生物失活。在 FSE 中实施农产品清洗消毒系统时，应考虑影响臭氧清洗效果的变量。
