Dielectric Properties of in-Shell and Shelled Peanuts at Microwave Frequencies

Dielectric properties (..,.. ) of ground samples of in-shell and shelled peanuts (Arachis hypogaea L.) weremeasured for several densities, temperatures, and moisture contents in the range of 300 to 3000 MHz. Dielectric mixtureequations were used to correlate the dielectric properties with density. The coefficients of quadratic and linear dielectricmixture equations are tabulated for 915 and 2450 MHz, for different temperatures and moisture contents. The values of thedielectric constant (..) and loss factor (.. ) of bulk in-shell and shelled peanuts were determined by extrapolation of the firstandsecond-order polynomials that relate .. and .. with density. An equation that determines the dielectric properties ofnominal peanut pods (in-shell peanuts) and kernels (shelled peanuts) as a function of their temperature and moisturecontent was determined by using multiple linear regression.