Evaluation of the Antimicrobial Efficacy of a Large-Area Surface Dielectric Barrier Discharge on Food Contact Surfaces

The food industry, as a consequence of globalization and in particular with the outbreak of the COVID-19 pandemic, is calling for additional measures to reduce the risks of contamination throughout the steps of the food chain. Several methods are used to avoid this problem, such as hot water or chemical procedures. However, they have some disadvantages like high economic costs or the fact that they are not eco-friendly technologies. For those reasons, novel strategies are being sought in order to substitute or work in synergy with conventional decontamination systems. Cold atmospheric pressure plasma (CAP) can be produced by many various sources for a wide range of different applications, including decontamination. In this study, a Large-Area Surface Dielectric Barrier Discharge plasma source has been used with the aim of inactivating Staphylococcus epidermidis inoculated on polypropylene food packaging samples inside a treatment chamber. Moreover, electrical and chemical analysis of the plasma source has been carried out, as well as temperature measurements. A homogenous distribution of the reactive species inside the treatment chamber was suggested, achieving almost 2 log of bacteria reduction for every plasma treatment. Finally, it was suggested that the inactivation rates reached were not caused by the thermal effect. Thus, it is strongly believed that CAP could be an eco-friendly, cheap, and sustainable technology for food packaging and food tools decontamination.