Investigation of Sterilization Effect for Overlapping Pieces in Non-Thermal Sterilization Method of Packaged Fresh Foods Using Pulsed Barrier Discharge

It is important to secure food safety. If a packaged food can be sterilized, food poisoning can be reduced considerably because the packaged food in a plastic container is useful to prevent attaching microorganisms. However, a fresh food, e.g., a salad or sashimi, cannot be sterilized by thermal sterilization. Therefore, we are studying sterilization methods for packaged fresh foods, such as packed salads. In this study, we have investigated the applicable probability of the sterilization method using cold plasma applied to the packaged fresh food. Especially, we have investigated the probability of the sterilization of microorganisms living in a small hollow between the overlapped fresh foods. A plastic petri dish with a lid was used for simulating the plastic container. The cold plasma was applied into the petri dish by a barrier discharge generated by a pulsed voltage. E. coli was used for a target of sterilization. The E. coli was set on a culture agar medium instead of the salad. The experimental results showed that the sterilization method combining the plastic film and cold plasma of the barrier discharge generated by the pulsed voltage is applicable to sterilize microorganisms living in the hollow between the overlapped fresh foods for the packaged fresh food.