Effect of cold plasma on storage toxigenic fungi - Aspergillus flavus

Cold plasma is a novel non-thermal food processing technology that uses energetic, reactive gases to inactivate contaminating microorganisms such as fungi and bacteria. This flexible sanitizing method uses electricity and a carrier gas (air, oxygen, nitrogen, or helium) antimicrobial chemical agents are not required. The primary modes of action are due to UV light and reactive chemical products of the cold plasma ionization process. Aspergillus flavus is the predominant species responsible for fungal contamination and subsequent production of aflatoxins mainly in grains during postharvest operations and storage. Due to their relatively high contamination risk, decontamination methods for fungi are of great interest for economic and environmental reasons, as well as in public health. Improved post-harvest processing followed by further prevention of fungal growth is an effective way to restrict aflatoxin contamination and would have major impact on reducing health related risks and on production economics. Thus, the objective is to evaluate the inactivation of A. flavus by cold plasma. The experiment was conducted with 3 mm sample A. flavus in PDA culture medium. Plasma was applied at different durations (2, 5, 10, 12, 15 and 20 min). After application, the Petri dishes with treated samples were stored at 25°C for 6 days. There was fungal growth after 2 days in the treatments with2 and 5 min durations, 4 days with the treatments with 10 and 12 min durations and there was no fungal growth with the treatments of 15 and 20 min after 6 days. The durationof 15 and 20 min with the plasma parameters tested, were efficient for the inactivation of A. flavus. Cold plasma may be a promising green method to be applied in this microorganisms present in grains and other products during storage.