An ongoing study funded by the Center for Produce Safety (CPS) is examining the survival of Salmonella and Listeria monocytogenes on surfaces in dry food packaging facilities, as well as the efficacy of dry cleaning processes on pathogen reduction. The study, led by Clemson University researchers Paul Dawson, Ph.D., and Kay Cooksey, Ph.D., aims to improve produce safety by identifying and investigating critical areas for microbial risk that exist in packinghouse environments after the washing, waxing, and drying steps.
Dr. Dawson chose to focus on Salmonella and L. monocytogenes due to their prevalence in produce packaging facilities, as well as their differing physiological characteristics. For instance, packaging facilities issued recalls for stone fruits contaminated with L. monocytogenes and peaches contaminated with Salmonella in 2016 and 2020, respectively. Additionally, while Salmonella is resistant to drying and can persist on surfaces with low water activity, L. monocytogenes survives and grows under cool, damp conditions. Salmonella can still survive in lower temperatures, but its growth is inhibited.