Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716-2150, USA.
Department of Animal and Food Sciences, University of Delaware, Newark, DE 19716-2150, USA.
Int J Food Microbiol. 2021 Feb 2;339:109024. doi: 10.1016/j.ijfoodmicro.2020.109024. Epub 2020 Dec 15.
In-house treatment strategy for fresh produce decontamination has not been emphasized as much as industrial washing. The most common treatment for fresh produce decontamination and cleaning at home and other point-of-use places such as cafeteria is rinsing and/or soaking in a sink. In this study, an appliance utilizing UV and agitated water to decontaminate fresh produce was developed and its effectiveness was investigated in an aim to identify optimum processing parameters. Grape tomato and spinach representing two different surface smoothness were dip-inoculated in a four-strain Salmonella cocktail to reach a final population of 5-8 log CFU/g and air-dried. The produce samples were then washed in 1 gallon tap water under varying conditions, water agitation speed (0-190 RPM), sample size (50-400 g), UV intensity (0-30 mW/cm) and treatment time (2, 5 and 10 min). In general, increasing the agitation speed and UV intensity enhanced Salmonella inactivation for both grape tomato and spinach. Sample size significantly affected the UV inactivation of Salmonella on grape tomato, but not on spinach. The effect of extending treatment time from 2 to 10 min was insignificant for almost all the UV treatments and the controls. The effect of UV intensity and treatment time on inactivation of Salmonella on spot-inoculated grape tomato and spinach was also determined. The most severe treatment used in this study, 30 mW/cm UV for 10 min, resulted in >4 log reductions of Salmonella dip- or spot-inoculated on grape tomato (200 g sample size and 190 RPM agitation speed) and 3.5 log reductions of Salmonella dip- or spot-inoculated on spinach (100 g sample size and 110 RPM agitation speed). We foresee that the UV appliance developed and evaluated in this study could be further fine-tuned and optimized to eventually construct a point-of-use UV appliance that can be used at home, cafeteria, restaurants, and hospitals for fresh produce decontamination and cleaning. The UV appliance could be an inexpensive and effective tool to improve fresh produce safety.
与工业洗涤相比，人们对新鲜农产品内部处理策略的重视程度还不够。家庭和其他使用点（如自助餐厅）中新鲜农产品的最常见的消毒和清洁方法是在水槽中冲洗和/或浸泡。本研究开发了一种利用紫外线和搅动水来消毒新鲜农产品的器具，并研究了其有效性，目的是确定最佳的处理参数。将代表两种不同表面光滑度的葡萄番茄和菠菜浸入含有四种沙门氏菌鸡尾酒的溶液中，达到最终 5-8 log CFU/g 的菌数，并风干。然后将这些农产品样本在 1 加仑自来水中在不同条件下进行洗涤，包括水搅拌速度（0-190 RPM）、样本大小（50-400 g）、紫外线强度（0-30 mW/cm）和处理时间（2、5 和 10 分钟）。一般来说，增加搅拌速度和紫外线强度均可增强葡萄番茄和菠菜上沙门氏菌的灭活效果。样本大小显著影响了葡萄番茄上沙门氏菌的紫外线灭活，但对菠菜无影响。对于几乎所有的紫外线处理和对照组，将处理时间从 2 分钟延长至 10 分钟的效果并不显著。还确定了紫外线强度和处理时间对斑点接种的葡萄番茄和菠菜上沙门氏菌灭活的影响。本研究中使用的最严重的处理方法是 30 mW/cm 的紫外线照射 10 分钟，导致 200 g 样本大小和 190 RPM 搅拌速度下浸泡或斑点接种的葡萄番茄上的沙门氏菌减少了>4 log，100 g 样本大小和 110 RPM 搅拌速度下的沙门氏菌减少了 3.5 log。我们预计，本研究中开发和评估的紫外线器具可以进一步进行微调优化，最终构建一个可在家中、自助餐厅、餐馆和医院使用的现场紫外线器具，用于新鲜农产品的消毒和清洁。紫外线器具可以成为一种廉价且有效的工具，提高新鲜农产品的安全性。
