EC Microbiology

Escherichia coli, Listeria and Salmonella cause most foodborne illnesses and are often harbored on ready-to-eat produce due to their presence in the soil, manure, and water in agricultural environments. Effective sanitation is critical to providing safe food. Conventional post-harvest sanitizing and washing protocols are minimally effective to control microbial contamination of leafy greens. Current practices depend predominantly on chemical disinfection, requiring transportation of chemicals and the need for wastewater management. Enhancements to existing sanitation methods may result in fresh produce that is safer to consume, more profitable; while facilitating improvements in sustainable practice.

Nonthermal plasma generates reactive oxygen species in ambient air. Growing numbers of evaluations demonstrate ROS is highly effective in reducing bacteria and mold in refrigerated and non-refrigerated environments. Growers, shippers, wholesalers, and retailers of perishable commodities may significantly expand their market window, reduce losses due to decay and disease, and reduce operational risk and costs using this technology.

The effects of a modulated dielectric barrier discharge air treatment system generating reactive oxygen species concentration (0.04 ppm) using O₃ as an indicator of reactive oxygen species production, relative humidity 60%, and treatment time (0.5 to 48-hours) to inactivate Escherichia coli, Listeria monocytogenes and Salmonella enteritidis on spinach leaf surfaces were measured using response surface methodology. The destructive effects of a modulated dielectric barrier discharge treatment system on the above pathogens are enumerated.

 Keywords: Modulated Dielectric Barrier Discharge; Dielectric Barrier Discharge; Nonthermal Plasma; Cold Atmospheric Plasma; Produce Safety; Food Biosafety

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