An experimental study on drying of pistacia terebinthus in a fixed beddryer

In this study, drying behaviours of the outer shell peeled Bittim (Pistacia terebinthus) with initial moisture content of 42.2% (dry basis (d.b))was investigated in a novel fixed bed drying system. The drying experimentswere performed at different temperatures (40°C, 60°C and 80 oC), air velocities (0.5 m/s and 1 m/s) and weights (30 g and 40 g). A constant rate period was not observed in the drying of bittims; all the drying process occurred in falling rate period. Three models in literature were selected to fitthe experimental data. The fit quality of models was evaluated using the coefficient of determination (R2), sum square error (SSE) and root mean square error (RMSE). Balbay and Sahin model has a good agreement with the experimental data and gave the best results for bittims in a fixed bed system.