Application of underwater elctric barrier discharfe as a washing system to inactivate salmonella typhimurium on perillar leaves

An underwater dielectric barrier discharge (DBD) system was applied to inactivate Salmonella Typhimurium. Reduction of S. Typhimurium ATCC 14028 in water suspension was 4.3 log after treatment with underwater DBD system for 1 min. Scanning electron microscope observation showed membrane destruction in S. Typhimurium by underwater DBD treatment, and amount of genomic DNA from cytoplasm was decreased by the underwater DBD treatment. These results reflected that DNA might be released from cytoplasm by membrane damage induced by underwater DBD. And reduction of S. Typhimurium ATCC 14028 on perilla leaves by underwater DBD treatment for 1 min was 1.8 log. Consequently, the underwater DBD could potentially be used in washing step to reduce pathogen such as S. Typhimurium on perilla leaves. Further study on the reduction effects by various types of electrodes and operation conditions were needed for efficiency improvement in microbial reduction on perillar leaves.