Abstract
The second stage convective drying behavior of osmo-dehydrated blueberries was evaluated in a forced-air cabinet dryer (temperature: 50°C, relative humidity: 14%, air velocity: 0.6 m/s) with a cross-flow tray arrangement. Fick's second law of unsteady state diffusion was used to model the air drying kinetics. The results showed that the convective-air drying of the blueberries occurred in two falling rate periods. The effective diffusion coefficients, Deff, during the first falling rate period ranged from 1.19 × 10−10 m2/s to 2.14 × 10−10 m2s and ranged from 4.04 × 10−11 m2/s to 1.32 × 10−10 m2/s during the second falling rate period. Among the pre-treatment conditions, the temperature and sucrose concentration during osmotic dehydration significantly (p < 0.05) influenced the air drying time, while the effect of contact time was not significant (p > 0.05).