Air impingement drying characteristics of apricot

For improving the quality of dried apricot and shortening its drying time, air impingement drying technology was applied to apricot drying. The drying curves, moisture effective diffusivity and the activation energy of apricot drying were investigated under different drying temperatures (50, 55, 60 and 65℃) and air velocities (3, 6, 9 and 12 m/s). Experimental results showed that the effect of drying temperature and air velocity on the drying rate was significant, while the effect of drying temperature was more significant than air velocity. Since the whole drying process occurred in the falling rate period, the Fick’s second law of diffusion was used to calculate the moisture effective diffusivity, which increased from 8.346×10-10 to 13.846×10-10 m2/s with increasing the drying tempeature and air velocity. The activation energy determined from Arrhenius equation was 30.62 kJ/mol, which indicated that remove 1 kg water from apricot will take 1 701 kJ energy during its air impingement drying process. This research provides technical basis for applying the air impingement drying technology to apricot drying.