Decontamination of Aspergillus parasiticus in rice by dielectric barrier discharge cold plasma: Variable effects and mechanism of degradation

Rice is prone to be contaminated with spoilage or toxigenic fungi during harvest, storage and processing, with <i>Aspergillus</i> species being the most frequent. Itiscrucial todevelop effective sterilisation technologies for mycotoxin prevention and food safety. Inthis study, sterilised rice infected by<i>Aspergillus parasiticus </i>strain was treated bydielectric barrier discharge (DBD) cold plasma. Various parameters, including moisture content, oxygen content, treatment time and voltage were tested. Furthermore, sterilisation mechanism of<i>Aspergillus parasiticus</i> bycold plasma was also explored. Results indicated that decontamination effect could besignificantly affected bymoisture content, oxygen concentration, voltage and treatment time. A99.89% degradation rate against<i> Aspergillus parasiticus </i>was achieved at90 kV after 5 min. Cold plasma could reduce the initial concentration of6.05 to2.28 CFU·mL^–1 within 240 s, and tothoroughly decontamination within 360 s. Inaddition, cold plasma treatment destroyed the integrity of<i>Aspergillus parasiticus</i> cell membrane, resulting inareduction inmycelium biomass and dry weight, aswell asasignificant decrease inintracellular Ca²⁺Mg²⁺-adenosine triphosphatase (ATPase) activity. These findings demonstrate the potential of cold plasma technology for environmentally friendly sterilisation of hazardous fungi in grain system.