EFFECT OF PRE-TREATMENT AND AIR TEMPERATURE ON DRYING KINETICS AND QUALITY OF JERUSALEM ARTICHOKE
Ä°BRAHIM DOYMAZ* Yildiz Technical University, Faculty of Chemical and Metallurgical Engineering, Department of Chemical Engineering, 34210 Esenler, Istanbul, Turkey
*Corresponding author: doymaz@yildiz.edu.tr
The effect of pre-treatment and air temperature on the drying kinetics and some quality criteria of Jerusalem artichoke were investigated. The pre-treated and untreated of Jerusalem artichoke slices were dried in a cabinet dryer at temperatures of 60, 70 and 80 °C. It was found that air temperature and pre-treatment had more significant effects on drying kinetics, color and rehydration ratio. The experimental data were adjusted to seven thin-layer drying models in the representation of vegetable and fruit drying. The Midilli & Kucuk model was best fitted to measurements. The effective moisture diffusivity at each temperature was determined by Fick’s second law of diffusion, in which their value varied from 5.49×10–10 to 1.90×10-9 m2·s-1 over the mentioned temperature range. The values of the activation energy of moisture diffusion were 50.74 and 40.21 kJ·mol-1 for citric acid and control samples, respectively.
