Department of Food Science, Rutgers University, New Brunswick, NJ 08901, United States.
Department of Food Science, Rutgers University, New Brunswick, NJ 08901, United States.
Int J Food Microbiol. 2020 Jun 16;323:108593. doi: 10.1016/j.ijfoodmicro.2020.108593. Epub 2020 Mar 19.
Fresh produce shall be thoroughly washed at the retail level prior to serving to the consumer with potable water. Foodborne pathogens if present on a product may transfer to the wash water and cross-contaminate other products immersed in the water. Typically, an entire carton of lettuce (24 heads) is washed together increasing the likelihood of cross-contamination due to the close contact between each head. This study aimed to compare the effects of two wash batch volumes - "low" (8 heads) and "high" (24 heads) on the efficacy of two commercial water antimicrobials and cross-contamination. Red leaf lettuce was spot-inoculated (~5.0 log CFU/g) with Shiga toxin-producing Escherichia coli (STEC) and Listeria monocytogenes. In the first batch of washing, inoculated lettuce was washed with non-inoculated lettuce, followed by reuse of the water/antimicrobials twice washing only non-inoculated lettuce. Samples of inoculated and non-inoculated lettuce were collected to determine aerobic plate count (APC) as well as the populations of STEC and L. monocytogenes. Microbiological analysis of the wash water was also conducted. Wash volume (8 versus 24 lettuce heads) had limited effects on the antimicrobial activities of the interventions evaluated. Instead, high-volume wash increased the rate of cross-contamination between non-inoculated and inoculated lettuce, and cross-contamination of non-inoculated lettuce through wash water reuse. Retailers should consider volume of product processed per batch, reuse of wash water, and use of an appropriate water antimicrobial in consideration of mitigating potential product cross-contamination.
新鲜农产品在供应给消费者之前，应在零售层面用饮用水彻底清洗。如果产品上存在食源性致病菌，可能会转移到洗涤水中，并污染其他浸泡在水中的产品。通常，一整箱生菜（24 个头）一起清洗，由于每个头之间的紧密接触，增加了交叉污染的可能性。本研究旨在比较两种洗涤批次体积——“低”（8 个头）和“高”（24 个头）对两种商业水抗菌剂效果和交叉污染的影响。红色皱叶生菜（Red leaf lettuce）用产志贺毒素大肠杆菌（Shiga toxin-producing Escherichia coli，STEC）和单核细胞增生李斯特菌（Listeria monocytogenes）点接种（~5.0 log CFU/g）。在第一批洗涤中，将接种的生菜与未接种的生菜一起洗涤，然后重复使用水/抗菌剂两次，仅洗涤未接种的生菜。收集接种和未接种生菜的样本，以确定需氧平板计数（aerobic plate count，APC）以及 STEC 和单核细胞增生李斯特菌的数量。还对洗涤水进行了微生物分析。洗涤量（8 个头和 24 个头生菜）对评估的干预措施的抗菌活性影响有限。相反，大容量洗涤增加了未接种和接种生菜之间的交叉污染速度，以及通过洗涤水重复使用污染未接种生菜的速度。零售商应考虑每批处理的产品量、洗涤水的重复使用以及使用适当的水抗菌剂，以减轻潜在的产品交叉污染风险。
