Food Science and Agriculture: Research Highlights Vol. 7

Atmospheric cold plasma (ACP) is a nonthermal technology that shows promise for use in food processing. Although several studies have demonstrated the antimicrobial potential of cold atmospheric plasma against selected microorganisms, limited information is available regarding the comparative inactivation efficiency of Dielectric Barrier Discharge (DBD) atmospheric cold plasma on different food-related pathogenic microorganisms under identical treatment conditions. This study aims to evaluate the effect of the cold atmospheric plasma (ACP) technique on the inactivation of selected microorganisms. A DBD cold plasma system operated with argon gas at 17 kV, 50 Hz, 55 W, and a gas flow rate of 10 L/min was used for microbial treatment on nutrient agar surfaces. The inactivation of yeast, Saccharomyces cerevisiae, and four foodborne pathogens, Salmonella typhimurium, Listeria monocytogenes, Escherichia coli, and Staphylococcus aureus, was evaluated at different treatment times. In addition, the synergistic effect of aerosolised hydrogen peroxide (2% and 5%) combined with DBD plasma treatment was investigated. The results revealed that yeast can be effectively inactivated on an agar plate within 5 minutes of cold plasma treatment. Adding H₂O₂ in concentrations of 2 or 5% on an agar plate improved the inactivation of microorganisms using cold plasma. Furthermore, it was observed that it is possible to inactivate pathogen microorganisms on an agar plate using DBD cold plasma within a 3 to 5 min treatment time. Up to 57%, 96%, 91% and 94% pathogen microorganisms inactivation was achieved after 1 min DBD plasma treatments of S. aureus, L. monocytogenes, E. coli, and S. typhimurium, respectively. The study demonstrated that DBD atmospheric cold plasma, particularly when combined with hydrogen peroxide, is an effective non-thermal approach for the inactivation of food-related microorganisms.