This study was conducted to dry tomato using thin layer Halogen dryer with the thickness of 10 mm in the temperature range of 60-80°C. The impact of temperature on the drying kinetics of the tomato slices was determined. The Fick’s diffusion model was applied to describe the water transport during tomato dehydration. The effective moisture diffusion was found to vary between 7.96×10-9 and 1.07×10-8 m2/s. Three mathematical models available in the literatures and the proposed model were used to fit with the experiments drying curves. The required time to dry tomato slices perfectly was ranged between 105 and150 minutes. The models were compared by using the root mean square error, reduced chi square and determination of coefficient. The proposed model was a better fit to the experimental data compared with the other models. Experimental drying curves indicated only a falling drying rate period. The color parameters (L*, a*, b*, and ∆E) of dried tomato slices were significantly affected by increasing drying temperature, and developed by using new empirical models. In addition, the browning index was increased with the increase of the drying temperature. Mass transfer coefficient was increased significantly (p<0.05) with the increase of the drying temperature.

Keywords: Activation energy, Drying time, Effective moisture diffusion, Halogen dryer