title: Decontamination of Aspergillus flavus and Aspergillus parasiticus spores on hazelnuts via atmospheric pressure fluidized bed plasma reactor.
abstract: In this study, an atmospheric pressure fluidized bed plasma (APFBP) system was designed and its decontamination effect on aflatoxigenic fungi (Aspergillus flavus and Aspergillus parasiticus) on the surface of hazelnuts was investigated. Hazelnuts were artificially contaminated with A. flavus and A. parasiticus and then were treated with dry air plasma for up to 5min in the APFBP system at various plasma parameters. Significant reductions of 4.50 log (cfu/g) in A. flavus and 4.19 log (cfu/g) in A. parasiticus were achieved after 5min treatments at 100% V - 25kHz (655W) by using dry air as the plasma forming gas. The decontamination effect of APFBP on A. flavus and A. parasiticus spores inoculated on hazelnuts was increased with the applied reference voltage and the frequency. No change or slight reductions were observed in A. flavus and A. parasiticus load during the storage of plasma treated hazelnuts whereas on the control samples fungi continued to grow under storage conditions (30days at 25°C). Temperature change on hazelnut surfaces in the range between 35 and 90°C was monitored with a thermal camera, and it was demonstrated that the temperature increase taking place during plasma treatment did not have a lethal effect on A. flavus and A. parasiticus spores. The damage caused by APFBP treatment on Aspergillus spp. spores was also observed by scanning electron microscopy.
authors.affiliation: Department of Food Engineering, Faculty of Engineering, Hacettepe University, Beytepe, 06800 Ankara, Turkey.
authors.forename: Beyhan Gunaydin
authors.initials: BG
authors.lastname: Dasan
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, TOBB University of Economics and Technology, Sogutozu, 06560 Ankara, Turkey. Electronic address: m.mutlu@etu.edu.tr.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Mutlu
authors.affiliation: Department of Food Engineering, Faculty of Engineering, Hacettepe University, Beytepe, 06800 Ankara, Turkey; Food Research Center, Hacettepe University, Beytepe, 06800 Ankara, Turkey.
authors.forename: Ismail Hakki
authors.initials: IH
authors.lastname: Boyaci
mesh_terms: D000348:Aflatoxins / Q000032:analysis; D000935:Antifungal Agents / Q000494:pharmacology*; D001231:Aspergillus flavus / Q000254:growth & development*; D001274:Atmospheric Pressure; D031211:Corylus / Q000382:microbiology*; D003666:Decontamination / Q000379:methods*; D061353:Food Storage; D008855:Microscopy, Electron, Scanning; D058626:Plasma Gases / Q000494:pharmacology*; D013172:Spores, Fungal / Q000187:drug effects*
chemical_list: D000348:Aflatoxins; D000935:Antifungal Agents; D058626:Plasma Gases
keywords: Aspergillus flavus; Aspergillus parasiticus; Atmospheric pressure plasma; Decontamination; Fluidized bed reactor