Microwave Dielectric Properties of Rice Kernels

New data are reported for the relative complex permittivity (dielectric constant and loss factor) of the kernels of rough rice and white (milled) rice at frequencies of 11 and 22 GHz. Dielectric properties were measured on ground samples of grain of long-grain and medium-grain rice cultivars at two moisture contents over a range of densities at 24°C. Values for the dielectric constants and loss factors of individual kernels were then determined from both second-order polynomials relating these properties to density and by extrapolating functions of the dielectric constant and loss factor, which are linear with density, to the density of the kernels. Dielectric properties of rough rice and white rice kernels are tabulated at two different moisture levels.