Mohammad Zarein, Seyed Hashem Samadi and Barat Ghobadian
The hot air convective drying characteristics of thin layer apple slices were evaluated in a laboratory scale dryer. In this study, the required energy for dehydration of apple slices was supplied of the hot air drying. Drying behavior of apple slices was studied at 4 temperature levels (50, 65, 80, and 95°C), and at three levels of drying material thickness (3, 5, and 7mm) with the constant airflow velocity of 1m/s. Empirical data of experiments with variants of semi-theoretical and empirical models were evaluated. Finally, the results indicated that the Midilli et al. model was most adequate in predicting moisture transfer and root mean square error (RMSE), chi-square (χ2) and coefficient of determination (R2) were used for the determination of the best suitable model. The values of R2, χ2 and RMSE at 95°C of hot air temperature for 3mm of apple slices are obtained as 0.9979, 0.000092 and 0.01044 respectively.