In vitro and in vivo antifungal activities of various gas species under plasma jet treatment against brown rice cereal spoilage molds

The objective of this study was to compare the effectiveness of various gas species (argon, water vapor and air) of plasma on Aspergillus niger, Aspergillus flavus, Penicillium sp. and Rhizopus sp., the causal agents of mold spoilage in brown rice cereal. Antifungal activities of plasma were obtained from various gas species at 0 W (control), 20 W, and 40 W under plasma discharge and were investigated against mycelium and spore germination of all molds. Argon plasma at 40 W was found to be the most effective agent to inhibit the growth of all molds and to reduce spore germination for in vitro test. Furthermore, in vivo assays determined that Ar plasma at 40 W was the most efficient agent against mold spoilage on brown rice cereal. The results indicated that Ar plasma provided good protection against mold on brown rice cereal for at least 19 days under storage conditions at 25°C and 100%RH. This study showed that Ar plasma is a potential and promising antifungal agent that could be used as a fungicide to protect brown rice cereal against mold spoilage.