Frequency Dependence of Dielectric Properties of Four Cultivars of Apple at Microwave Frequencies

The dielectric constant (’) and loss factor (’') of fresh apple of four cultivars, (i) Red delicious apple (ii) Delicious Apple, (iii) Granny Smith apple and (iv) Fuji apple, are measured at room temperature (28 °C) and at four microwave frequencies 3.43 GHz, 7.31 GHz, 9.30 GHz and 14.70 GHz by two point method using microwave benches at C, J, X and Ku bands. It has been observed that the dielectric constant of all the four cultivars decreases with increase in frequency, whereas the loss factor is observed to first increase and thendecrease with a minor qualitative difference for the four cultivars.