[6p-S22-1~9] Plasma application for advanced agriculture: creation and control of novel environments for plant growth

[6p-S22-1] Introduction; Frontiers of Plasma Applications for Advanced Agriculture

〇Koichi Takaki¹ (1.Iwate Univ.)

Keywords:plasma, agriculture, electrostatic

Agricultural and food processing applications of plasma and high-voltage technologies are reviewed. Repetitively operated compact high-voltage power supplies with a moderate peak power have been developed for controlling discharge plasmas for the agricultural and the food processing applications. These applications are mainly based on biological effects of spatially distributed electric field and the chemically active species produced by the plasma. Types of intense pulse electric fields that have biological effects are caused with gas discharges, water discharges and electromagnetic fields. The discharge plasmas produce free radicals, UV radiation, intense electric field and shock waves. Biologically based applications of high-voltage and plasma are performed by selecting the type that gives the target objects the adequate result from among these agents or byproducts. For instance, intense electric fields form pores on the cell membrane, which is called electroporation, or influence the nuclei. The agricultural applications of the plasma are categorized as seed germination promotion; plant growth acceleration; inactivation of bacteria in soil and liquid medium of hydroponics; promotion of fruit-body formation such as mushrooms and fruits in pre-harvest phase. In the post-harvest phase, keeping freshness of the agricultural products is important for sustainable food supply chain. The high-voltage and the plasma technologies can contribute for keeping freshness with decontamination of air and liquid of storage containers of the agricultural product. In food processing phase, intense pulse electric field can be used for extraction of juice, nutritional agent and antioxidant metabolites such as Vitamin C, carotenoid and polyphenol from fruits and vegetables. Some foods and liquors are made by fermenting a food substance. The fermentation is a metabolic process cursed by yeast and bacteria which activity can be controlled by intense electric field.