Cold plasma decontamination of stainless steel food processing surfaces assessed using an industrial disinfection protocol

Cold atmospheric pressure plasma (CAP) stands out among new decontamination technologies, as it offers rapid antimicrobial action against a broad spectrum of foodborne pathogens, while minimally affecting the exposed target. Furthermore, it is low-cost, environmentally friendly and requires no consumables, allowing for scale-up and adaptation to meet industrial needs. This study evaluated an indirect CAP device against two common foodborne pathogens on stainless steel surfaces. The EN 13697:2015 protocol for chemical disinfectants was adopted, which simulates realistic conditions typically found in a food-processing facility. The impact of distance from the CAP source, treatment time and protocol parameters were investigated. It was demonstrated that distance from the CAP source was the most important factor. The system achieved a >3.55 logCFU/mL and 2.06 logCFU/mL reduction of Listeria monocytogenes and Salmonella typhimurium, respectively at 5 mm distance within 3 min. It was observed that the CAP exposure had a negligible effect on the stainless steel surface morphology. The results demonstrate that CAP is an effective means of reducing microbial loading in such environments.