Role of particulate carbon dioxide on removal of Salmonella and Listeria attached to stainless steel surfaces

摘要

Attachment of bacteria to abiotic surfaces is the initial phase of attachment process which enables pathogens to persist in food processing environments. The objective of this study was to assess the antimicrobial efficacy of pressurized particulate carbon dioxide (PPCD) against cells of Salmonella Typhimurium and Listeria monocytogenes allowed to attach to stainless steel for 24 h. Model cell attachment systems were produced on stainless steel coupons and treated with PPCD for variable durations up to 10 s and employing multiple blast treatments. The reduction in attached cells recovered by surface swabbing was significantly affected by interaction of bacterium x treatment (p < 0.01). Blasts of 1 s duration and 2 blasts of 1 s separated by 30 s resulted in approximately 1 log10 CFU/coupon reduction. Average reduction (2 log10 CFU/coupon) in Salmonella cells was significant (p < 0.01) for 4 s blasting treatment. Longer blast durations of 7 s and 10 s provided approximately 3 log10 CFU/coupon reduction for both the bacteria. These results demonstrate the antimicrobial effect of pressurized particulate carbon dioxide against attached cells of pathogenic bacteria and suggest a scope for further improving this technology.