Antimicrobial efficacy of cold plasma treatment against food-borne pathogens on various foods

Abstract

The objective of this study was to assess the antimicrobial effects of atmospheric cold plasma decontamination treatment on foodborne pathogens on various foods. The study employed a 30 l chamber using surface dielectric barrier discharge as a plasma source applying an atmospheric pressure and ambient gases. The inactivation rates of three foodborne pathogens, E. coli O157:H7, S. Typhimurium, and L. monocytogenes, were examined in fresh vegetables, fruits, nuts, and powdered food samples in response to cold plasma treatment; several strains of each pathogen were evaluated. The hydrophobicity and surface roughness of selected samples were examined using the water contact angle and non-contact three-dimensional surface profiling measurements, respectively. Samples were then inoculated with the food pathogens and treated in cold atmospheric plasma for up to 20 min. As the treatment time increased, different levels of microbial reduction were observed among the samples and pathogens. Surface roughness was negatively correlated with the inactivation rate. Even surfaces showed higher microbial reduction. Taken together, these results indicate that surface roughness is an important factor for the antimicrobial efficacy of cold plasma treatment.