Reduction of Listeria monocytogenes contamination on produce - A quantitative analysis of common liquid fresh produce wash compounds

Contaminated produce has been identified as the cause of several listeriosis outbreaks in recent years. Listeria monocytogenes is widely distributed in the environment and complete prevention of produce contamination is therefore challenging. Mitigation options that reduce contamination on produce are valuable, especially for produce commodities that are commonly consumed fresh or minimally processed. We performed a systematic review and meta-analysis of the available peer-reviewed literature to evaluate the efficacy of liquid fresh produce wash compounds in reducing produce contamination with L. monocytogenes, and derive quantitative estimates of treatment efficacy for a variety of common liquid fresh produce wash compounds. Treatment efficacy differed considerably across produce commodities, with liquid fresh produce wash compounds generally showing considerably greater efficacy for some tested commodities than for other commodities. Most but not all of the evaluated liquid fresh produce wash compounds were significantly more effective in reducing L. monocytogenes contamination than water alone, with mean reductions in L. monocytogenes levels ranging from less than 1 log10 cfu to more than 5 log10 cfu. Liquid fresh produce wash compounds are therefore a possible tool for reducing contamination with L. monocytogenes, for certain produce commodities.