Sterilization efficiency of a cascaded dielectric barrier discharge

Aims: To investigate the microbial inactivation efficiency of a newly developed cascaded dielectric barrier discharge (CDBD) set-up against various micro-organisms on polyethylene terephthalate (PET) foils. Methods and Results: Inactivation kinetics in dependency of time were produced with air as process gas and test strains like Salmonella serotype Mons, Staphylococcus aureus and Escherichia coli and spores of Bacillus atrophaeus, Aspergillus niger and Clostridium botulinum, which were homogeneously distributed on the sample surface by a spray method. Highest count reduction was observed for the vegetative cells with at least 6.6 log(10) within 1 s. Aspergillus niger was the most resistant test strain with an inactivation rate of about 5 log(10) in 5 s. Conclusions: For industrial applications it is necessary to evaluate new sterilization methods against a broad range of different micro-organisms. Significance and Impact of the study: CDBD plasma is a fast and effective technology for decontamination of heat sensitive materials in few seconds.