Thursday, 30 March 2017: 15:30
Arc (The Square)
As a non-thermal decontamination technology, cold atmospheric plasma (CAP) offers great potential for treatment of heat-sensitive food products, as well as food contact surfaces for reducing energy consumption. CAP is created by applying a high voltage to a gas stream, resulting in microbial inactivation. CAP research is case specific, due to its focus on specific target microorganisms, food products or surfaces. As the efficacy of CAP depends on multiple factors, most existing studies have a limited applicability. Additionally, little is known about the effect of CAP on biofilm inactivation. In this study, factors affecting the CAP efficiency on colonial and planktonic growth morphologies are assessed: CAP set-up, type of microorganism, sample (model system properties) and experimental protocol. By using (food) model systems, the influence of the properties of the understudy products is accurately investigated. Considering all influencing factors, this work provides guidelines and critical points that need to be included to ensure successful treatment in the experimental design for studies with CAP. Additionally, taking into account the existing knowledge on the CAP efficiency for inactivation of colonies and planktonic cells, guidelines for effectual experimental design are provided for using CAP as a novel non-thermal technology for biofilm inactivation present on abiotic surfaces. Moreover, biofilm inactivation kinetics are provided and the results are compared with inactivation kinetics of Listeria monocytogenes and Salmonella Typhimurium in planktonic and colonial growth morphology. Inactivation curves and estimation of inactivation parameters, allowing comparison, were obtained by fitting the model of Geeraerd et al. (2000) on the experimental data. The findings of this study provide promising results for using CAP as a novel non-thermal technology for biofilm inactivation formed on abiotic surfaces.