EFFECT OF PRE-TREATMENT AND AIR TEMPERATURE ON DRYING KINETICS AND QUALITY OF JERUSALEM ARTICHOKE

Abstract

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 degrees 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 x 10(-10) to 1.90x10(-9) m(2).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.