静電気の農業・食品分野での利用

抄録

This paper describes high-voltage and plasma applications in agriculture, fishery, and food processing. Repetitively operated, compact, pulsed-power generators with a moderate peak power were developed for application in various stages of agriculture and food processing. A high-voltage pulse produces an intense high-electric field that can cause biological effects such as a stress response (stimulation) or electroporation. Other types of pulsed power that have biological effects can be caused using gas and water discharges that include reactive species such as reactive oxygen species (ROS) and reactive nitrogen species (RNS). A repetitive, pulsed discharge was used to promotethe growth of vegetables and fruits. The growth rate of the vegetables and the sugar content in strawberries harvested after cultivation increased due to the plasma irradiation of the hydroponic solution. The leaf sizes of the plants increased with the plasma treatment time. The number of colony-forming units (CFU) of R. solanacearum in the liquid fertilizer decreased from 107 to 102 CFU/mL using the plasma treatment. Seedlings that underwent the plasma treatment were relatively healthy; in contrast, all seedlings in the positive control wilted and died from infection by R. solanacearum. The yield rate of shiitake mushrooms (L. edodes) was improved by high-voltage stimulation in the fruiting-body formation phase. The AC high-voltage treatmentcan ensure the freshness of agricultural produce for a relatively longer time-period. The electrostatic effects can contribute to the removal of airborne bacteria and fungal spores from storage houses and containers,thus reducing the risk of infection fromfungi and bacteria. These applications can therefore contribute positively to the global food supply chain.