Effect of atmospheric cold plasma on carnauba wax coating on inactivation of Colletotrichum brevisporum

ABSTRACT

Carnauba wax is successfully used in fruit coating to produce a barrier against moisture loss, gas exchange and microbial action. The present study aims to improve this latter property by plasma treatment. Plasma produced by dielectric barrier discharge (DBD), using voltage pulses of 45 kV, repeated at the frequency of 405 Hz, for 9 min, was applied directly to spores of the fungus Colletotrichum brevisporum (4x10⁴ conidia.cm^-1) or on the surface of wax coatings. It was found that the coating, after being treated by plasma, presented antifungal resistance equivalent to that existing when applied directly to the fungi. This result was justified based on the literature, in which plasma treatment with lipids stimulates the oxidation of lipid chains, resulting in the formation of carboxylic compounds, which have antimicrobial properties.

Keywords
DBD Plasma; coplanar electrode; anti-fungal; atmospheric; inactivation