Air impingement drying characteristics and drying model of Hami melon flake

In this paper air impingement drying technology was applied to drying Hami melon to improve the drying quality and decrease the drying time. The drying curves, moisture effective diffusivity and the activation energy of Hami melon drying were investigated under different drying temperatures (60、65、70、75 and 80℃) and air velocities (5、10、15 and 20 m/s). The mathematical model of air impingement drying Hami melon flake was obtained. The Fick’s second law of diffusion was used to calculate the moisture effective diffusivity, which increased from 2.38×10-9 to 4.55×10-9 m2/s with increasing the drying temperature and air velocity. The activation energy was 29.44 kJ/mol, which was determined from Arrhenius equation. According to the statistical parameters as the correlation coefficient(R2)、root mean square error(RMSE) and 2 , the modified Page model was best for predicting the moisture ratio change kinetics of Hami melon flakes during its drying process. The research can provide technical basis for industrial drying of Hami melon by air impingement drying technology.