INFLUENCE OF ELECTROMAGNETIC FIELD OF EXTREMELY LOW FREQUENCIES ON HYGROSCOPIC PROPERTIES OF WHEAT GRAIN MASS

• Main Authors: G. Stankevych, Yu. Kovra, A. Kats
• Format: Article
• Language: English
• Published: Odessa National Academy of Food Technologies 2021-09-01
• Series: Zernovì Produkti ì Kombìkorma
• Subjects: wheat; hygroscopic properties; sorption isotherms; equilibrium moisture content; processing by electromagnetic fields; extremely low frequencies
• Online Access: https://journals.onaft.edu.ua/index.php/gpmf/article/view/2088

The research results of the influence of electromagnetic field (EMF) of extremely low frequencies (ELF) on hygroscopic properties of Shestopalivka wheat variety of 2019 harvest have been given. Grain processing was performed on the experimental stand that consisted of the polymeric cylindrical container for grain, solenoid coil, generator of electromagnetic waves GZ-112/1 and a power amplifier of low frequency. The output signal of generator was set in the form of sine wave and controlled by oscillograph C1-78. The studies were performed at EMF frequencies of 10, 16, 24 and 30 Hz. Magnetic induction of grain treatment was constant and equaled 10 mTl. The duration of grain processing was 6 minutes. The equilibrium moisture content of wheat grain was determined by the tensometric method at temperatures t 9 °C and 23 °C and relative humidity φ 33…36 % and 82…82.5 %. The necessary conditions of air were created in desiccators with solutions of sulfuric acid placed in thermostats and refrigerators. It has been determined that the equilibrium moisture of wheat grain processed by EMFof ELF – is in the range of 12.17…20.56 %, and unprocessed grain – in the range of 12.62…21.03 %. Regardless of the frequency of EMF, equilibrium moisture content of the grain wheat processed by EMF varies according to the known laws – decreases with temperature increase and increases with increasing of air relative humidity. It has been shown that the impact of processing by EMF of ELF on the equilibrium moisture contentof wheat grain is manifested at different frequencies in different ways, which is likely due to the resonance phenomena. It has been established that the processing of grain by EMF with frequencies of 10...30 Hz practically has no effect on the equilibrium moisture content of grain at 23 °C and a relative humidity of 33...82.5 % which remains practically at the level of the unprocessed grain. It has been shown that the processing of grain by EMF with frequencies of 24 and 30 Hz under conditions of t = 9 °C and φ = 33 % leads to higher equilibrium moisture content compared to unprocessed wheat grain from 14.45 % to 16.85...16.95 %. Processing of grain with frequencies of 10 and 16 Hz under the same conditions, on the contrary – leads to a decrease in the level of equilibrium moisture content to 13.74…13.86 %. Empirical coefficients have been determined and the equation has been proposed that describes the dependence of equilibrium moisture content of not processed and processed wheat grain by EMF with frequency 10...30 Hz on temperature and relative humidity of the ambient air.