Assessment of thermophysical properties of the temperature profile created on peach by microwave energy.

Microwave energy is based on creating heat in the structure by creating vibrations in the moisture in the product used. In drying processes, drying kinetics, energy consumption, quality, and so on features are evaluated based on the temperature equivalent of the heat created by the heat source in the product. For this reason, the temperature value formed in the product in microwave drying processes is important. In this study, the effects of microwave drying powers (180, 540, 720, and 900 W) on the surface temperature profile, drying kinetics, thermophysical properties, and color values of peach slices were investigated. For drying processes performed at 180, 540, 720, and 900 W microwave powers, the surface temperatures of peach slices were 34.5-83.40, 49.60-89.60, 55.90-94.06, and 68.20-145.20°C, respectively. Effective diffusion values varied between 1.01 × 10 and 2.12 × 10, and the activation energy value was measured as 20.73 kJ/mol. Specific heat values varied between 871.62 and 838.21 J/kg K, density values varied between 839.41 and 697.93 kg/m, thermal diffusivity values varied between 5.69 × 10 and 2.344 × 10 m/s and thermal conductance values ranged between 0.44 and 0.08 W/m K. As compared to the fresh fruits, the best color values of dried material were achieved at 720 W microwave power. It is recommended to determine the microwave drying power value well and to determine the drying kinetic properties of each agricultural product specifically for the product.