title: Impact of food model (micro)structure on the microbial inactivation efficacy of cold atmospheric plasma.
abstract: The large potential of cold atmospheric plasma (CAP) for food decontamination has recently been recognized. Room-temperature gas plasmas can decontaminate foods without causing undesired changes. This innovative technology is a promising alternative for treating fresh produce. However, more fundamental studies are needed before its application in the food industry. The impact of the food structure on CAP decontamination efficacy of Salmonella Typhimurium and Listeria monocytogenes was studied. Cells were grown planktonically or as surface colonies in/on model systems. Both microorganisms were grown in lab culture media in petri dishes at 20°C until cells reached the stationary phase. Before CAP treatment, cells were deposited in a liquid carrier, on a solid(like) surface or on a filter. A dielectric barrier discharge reactor generated helium-oxygen plasma, which was used to treat samples up to 10min. Although L. monocytogenes is more resistant to CAP treatment, similar trends in inactivation behavior as for S. Typhimurium are observed, with log reductions in the range [1.0-2.9] for S. Typhimurium and [0.2-2.2] for L. monocytogenes. For both microorganisms, cells grown planktonically are easily inactivated, as compared to surface colonies. More stressing growth conditions, due to cell immobilization, result in more resistant cells during CAP treatment. The main difference between the inactivation support systems is the absence or presence of a shoulder phase. For experiments in the liquid carrier, which exhibit a long shoulder, the plasma components need to diffuse and penetrate through the medium. This explains the higher efficacies of CAP treatment on cells deposited on a solid(like) surface or on a filter. This research demonstrates that the food structure influences the cell inactivation behavior and efficacy of CAP, and indicates that food intrinsic factors need to be accounted when designing plasma treatment.
authors: CPMF(2), - Flemish Cluster Predictive Microbiology in Foods, Belgium(2); BioTeC+ - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Belgium.
authors: C
authors: C
authors: Smet
authors: CPMF(2), - Flemish Cluster Predictive Microbiology in Foods, Belgium(2); BioTeC+ - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Belgium.
authors: E
authors: E
authors: Noriega
authors: BioTeC+ - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Belgium.
authors: F
authors: F
authors: Rosier
authors: Department of Electrical Engineering and Electronics, University of Liverpool, United Kingdom.
authors: J L
authors: JL
authors: Walsh
authors: Department of Food Studies and Environmental Health, Faculty of Health Sciences, University of Malta, Malta.
authors: V P
authors: VP
authors: Valdramidis
authors: CPMF(2), - Flemish Cluster Predictive Microbiology in Foods, Belgium(2); BioTeC+ - Chemical and Biochemical Process Technology and Control, Department of Chemical Engineering, KU Leuven, Belgium. Electronic address: jan.vanimpe@cit.kuleuven.be.
authors: J F
authors: JF
authors: Van Impe
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003080:Cold Temperature; D015169:Colony Count, Microbial; D003666:Decontamination / Q000379:methods*; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control*; D005516:Food Microbiology / Q000379:methods*; D008089:Listeria monocytogenes / Q000254:growth & development*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D058626:Plasma Gases / Q000494:pharmacology*; D012486:Salmonella typhimurium / Q000254:growth & development*
chemical_list: D000900:Anti-Bacterial Agents; D058626:Plasma Gases
keywords: Cold atmospheric gas plasma; Food model (micro)structure; Growth morphology; Inactivation support system; Sublethal injury