Effective inactivation of fungi in grain using atmospheric pressure cold plasma

Abstract

Cereal grains are a staple food globally, but fungal contamination during storage poses significant challenges. Conventional decontamination methods have limitations, creating a demand for rapid, cost-effective alternatives without toxic by-products. This study evaluated a lab-scale atmospheric pressure cold plasma system, or MINI ACP, for inactivating grain-related fungi such as Aspergillus fumigatus, Fusarium species, and Candida albicans on PDA agar plates, milled rice, paddy rice, and rice bran. The MINI ACP system achieved over a 4-log reduction in fungal counts within 2 min, with a 5-log reduction observed upon extending the treatment duration. In milled rice, up to about 2-log (∼99 %) of Aspergillus fumigatus was inactivated after 5 min, while rice bran showed a 2-log reduction after 20 min. Reactive oxygen and nitrogen species (ROS and RNS) generated by the plasma disrupted fungal cell membranes and proteins, resulting in effective fungal inactivation. This Fungal inactivation using MINI ACP depended on both treatment time and sample type. These findings highlight cold plasma treatment as an efficient and environmentally friendly alternative to conventional chemical methods, providing rapid fungal inactivation without leaving pesticide residues. Cold plasma processing offers significant potential as a non-thermal, residue-free solution to enhance grain preservation and food safety without compromising the environment.