The effect of low-current spark discharge treatment on the dielectric and electrical properties of plant raw materials

The dielectric and electrical properties of plant materials in the frequency range from 1 kHz to 100 kHz treated with low-current atmospheric spark discharge (ASD) are investigated. The aim of the work was to evaluate the changes in the dielectric constant and electrical conductivity of plant materials (apple and carrot) under different processing modes and sample thickness. The permeability or dielectric properties of food materials are important for understanding the behavior of these materials when exposed to electromagnetic fields in processing processes, exposure to an electromagnetic field, or in other process-ses involving electrophysical processing. Understanding these properties is also promising for tuning and adapting radio frequency and microwave devices. To measure the dielectric and electrical properties, a measuring cell with plane-parallel titanium electrodes was used. The treatment was carried out by a low-current atmospheric spark discharge with a current value from 1 mA to 4 mA. It is established that the dielectric permittivity and electrical conductivity are greatly influenced by the magnitude of the discharge current of the air treatment. The dielectric permittivity and electrical conductivity of the material correlated with each other and increased with an increase in the discharge current from 1 mA to 4 mA, followed by a plateau. With an increase in the thickness of the material, the change in the dielectric constant and electrical conductivity decreased. To describe and predict the relationship between the dielectric and electrical properties of the plant materials processed by ASD, the corresponding dependencies are derived. The conducted dielectric measurements provide new information about the dependence of the dielectric properties of plant materials on the thickness, the magnitude of the discharge current and the density of air treatment in the frequency range.