Effect of moisture content variation on dielectric properties of seeds of multipurpose species in 20 MHz-3 GHz frequency range

The study presents measurements and analysis of complex dielectric permittivity spectra of seeds of multipurpose crop species such as mustard, buckwheat, phacelia, and crimson clover. These species due to their ecosystem service properties such as the improvement of soil health, carbon sequestration and pollinator support, can be part of sustainable food production.Seeds with different moisture content were measured in a coaxial cell system covering 20 MHz to 3 GHz frequency range. The results indicate that dielectric parameters such as the square root of dielectric permittivity, loss tangent, penetration depth, and effective electrical conductivity are influenced by factors including volumetric water content and measurement frequency. Additionally, significant variations in dielectric properties are observed among different seed types and species. Dielectric permittivity, in particular, shows potential as a reliable indicator of seed water content, making it a valuable tool for assessing seed quality and monitoring changes during storage under various conditions. These findings highlight the importance of dielectric measurements in seed quality assessment and storage management as well provide valuable information for modelling and designing efficient dielectric heating and microwave-assisted conditions.