COMPARATIVE ANALYSIS OF THE PROCESSED GRAINS DIELECTRIC PROPERTIES

The purpose of research is to study the dielectric properties of grains processed by mechanical activation using the example of wheat, barley and oats, which are widely used in the agro-industrial complex and the food industry. Objective: to identify the relationship between the dielectric parameters of processed grain and its structural parameters (fraction size) in a wide range of variations in the external electric field from 50 Hz to 1 KHz, which may be useful in optimizing grain processing technologies and choosing optimal storage conditions. A series of experiments was carried out for samples of wheat, oats and barley, varying the degree of fractions from 50 to 1000 μm in a wide frequency range. An algorithm has been developed for calculating dielectric constant and dielectric loss tangent based on measurements of electrical capacitance and conductivity using a certified E7-20 voltage immittance meter and a measuring cell (flat capacitor). An analysis of variations in electrical capacitance, the real part of dielectric constant, electrical conductivity and dielectric loss tangent on the particle size of grain crops was carried out. It has been established that there is a correlation between the dielectric properties of grain processed by mechanical activation and the size of the fractions, which is most significant for small-sized samples with a particle size of no more than 250 microns. A smoothing of variations in dielectric constant and losses was noted as the electric field frequency increased above 100 Hz. The existence of a relationship between the energy properties of the studied fine heterogeneous medium and the degree of grinding in the frequency range under study has been experimentally confirmed. An optimal size for grain processing has been proposed, which will, along with saving energy resources, allow optimizing energy value, improving the quality of food products and the efficiency of agricultural production in general.