Plasma inactivation of Aspergillus flavus on hazelnut surface in a diffuse barrier discharge using different working gases

Autor: Mária Gregová, Anna Mikulajová, Juliána Tomeková, Anna Zahoranová, Veronika Medvecká, Silvia Mošovská, Ľubomír Valík
Jazyk: angličtina
Předmět:
Zdroj: Food Control
ISSN: 0956-7135
DOI: 10.1016/j.foodcont.2019.05.003
Popis: The aim of the study is the comparison of inactivation efficiency of low-temperature plasma generated in different working gases for A. flavus inoculated on hazelnut surface. Plasma was generated by Diffuse Coplanar Surface Barrier Discharge (DCSBD) in gases interesting in term of plasma properties – diffusiveness (nitrogen), oxidative potential (oxygen), role of OH radical formation (synthetic air with and without water vapour) and applicability (ambient air). The inactivation kinetics, explained by Weibull model, was strongly depended on used gas. Decimal reduction time (D-values) for tested fungi using oxygen, synthetic air with or without water vapour, ambient air and nitrogen plasma was 10 s, 32 s, 39 s, 41 s and 55 s, respectively. Reduction of A. flavus spore in oxygen and synthetic air with water vapour was from initial population of 4.6 CFU/g to below detection level (1.0 log10 CFU/g). Synthetic air without water vapour inactivated 2.56 log10 CFU/g, ambient air 2.95 log10 CFU/g and N2 1.69 log10 CFU/g after 180 s treatment. The characterization of plasma using optical emission spectrometry (OES) and Fourier Transform Infrared Spectroscopy (FTIR) was used for identification of active species in mentioned working gases participating in decontamination process – ozone, hydroxyl (OH) radicals, nitrogen oxides (NOx) and excited nitrogen species. A more complete characterization of the factors involved in inactivation by various plasmas will contribute to its better implementation in food quality.
Databáze: OpenAIRE