Impact of Different Application Parameters of Cold Atmospheric Plasma on Foodborne Pathogen Inactivation

Foodborne pathogens are a major public health concern, causing millions of illnesses and deaths yearly. Traditional thermal processing methods, such as cooking and pasteurization, are effective at killing pathogens, but they can also damage food quality. Cold atmospheric plasma (CAP) can inactivate foodborne pathogens without damaging food quality. CAP has several advantages over traditional thermal processing methods. It is a non-thermal process, meaning that it does not heat food. This can help to preserve the nutritional and sensory quality of food. CAP can be targeted to specific areas of food, such as the surface or interior. This can help to reduce the overall processing time and energy consumption. In the study, two Gram (+) (Staphylococcus aureus ATCC 25923, Listeria monocytogenes ATCC 7644), three Gram (-) (Salmonella typhimurium CCM 5445, Salmonella enteridis ATCC 13076, Escherichia coli O157:H7), and one yeast culture (Candida albicans ATCC 10231), known as pathogens, were used to examine the influence of CAP on microorganisms. The samples were treated with CAP at different power rates (100, 150, and 200 W) and exposure times (30, 60, 180, and 300 s) with different application parameters (directly to microorganisms, distilled water, microorganism + distilled water combination). Then, the number of viable cells was determined after the procedure. Among the methods, it was found that the direct cold plasma application is the most effective for the inhibition of microorganisms. Besides, it was designated that the inhibition of pathogen microorganisms increased as the power rate and contact time enhanced. Cold plasma treatment induced membrane damage in microorganism cells, with the severity of damage increased with longer treatment times. A 300-s direct plasma exposure induced cell lysis and membrane disintegration, highlighting the potential of this technology. This study aimed to investigate the potential of CAP technology to control microbial contamination in food and agriculture, focusing on determining optimal treatment parameters and understanding the morphological changes induced in bacteria by the plasma.