Inactivation of foodborne viruses: Opportunities for cold atmospheric plasma

Microbial food contamination can be caused by bacteria, viruses or protozoa at different stages during food processing and storage. The resulting foodborne disease in humans are common and can be severe, especially in children, the elderly or immunocompromised persons. Several viruses have been recognised to account for a large proportion of foodborne illnesses, including human norovirus (HNoV) and hepatitis A virus (HAV). Disinfection methods are needed in all areas of the food processing environment and cold atmospheric plasma (CAP) has emerged as a new technology with antimicrobial activity. CAP is generated by applying an electric field to a gas causing the formation of many active species including reactive oxygen and nitrogen species. This review evaluates the available data on CAP as a potential use for the inactivation of foodborne viruses, including studies using surrogates. We demonstrate the different types of CAP delivery for virus inactivation, including direct and indirect treatments using dielectric barrier discharges (DBD), atmospheric pressure plasma jets (APPJ) and plasma-activated water (PAW). The effect of particular CAP species and the resulting mode of action is also discussed. CAP can successfully inactivate foodborne viruses and its potential as a non-toxic, residue-free sanitation system for fresh foods makes it highly attractive to the industry. However, the lack of standard devices or protocols makes it difficult to meaningfully translate findings. Thus, we propose future research steps that are necessary for upscaling, dose standardisation and following translation to the industry in the near future.