Dielectric Properties of Fresh Roma and Cherry Tomato Samples at Different Frequencies and Temperatures

Abstract

The dielectric properties of two different tomato varieties, Roma, and Cherry, were measured with an LCR meter, at 50 KHz, 90 KHz and 120 KHz frequencies. The measurement was carried out at 35 ^oC, 45 ^oC and 55 ^oC temperature. The tomato samples are obtained from the farm within nine days period, washed and sliced with sharp knife. Two samples of matured and pre-mature, from each of the varieties were used to prepare four fresh samples. The samples were loaded on test cell, connected to an LCR meter. The experimental result show that both dielectric constant and dielectric loss factor decreased with increasing frequency, for all the samples. As the temperature increases, dielectric constant was found to decrease, while the dielectric loss increases, for all the samples. Cherry was found to have higher dielectric constant and dielectric loss than Roma. At 50 KHz, for example, the dielectric constants for Cherry matured are 32.41, 31.68 and 30.44, for Roma matured are 25.66, 24.79 and 23.92, at 35 ^oC, 45 ^oC and 55 ^oC temperatures respectively. While the results also shows that, at 50 KHz, the dielectric loss for the pre-mature  samples are 6.41, 7.75 and 8.91, for Cherry and 5.30, 6.10 and 7.57, for Roma, at  35 ^oC, 45 ^oC and 55 ^oC temperatures respectively, which indicated the increase in dielectric loss with increasing temperature. While the dielectric constant and dielectric loss decreases with increasing frequencies.