Experimental and theoretical analysis of drying carrots

The drying characteristics of carrots are investigated experimentally and theoretically for different drying conditions. Carrot slices with three different thicknesses are used. Initially, sorption isotherms of the dried carrot slices are determined for different temperatures and equilibrium relative humidity (e.r.h.). Experiments are conducted for drying air temperatures of 35, 45 and 55 degrees C, mean velocities of 0.2, 0.4 and 0.6 m/s and, relative humidity values of 40, 55 and 70%. In the covered ranges, the values of the effective moisture diffusivity, D-eff, are obtained from the Fick's diffusion model varying from 1.257x10(-9) to 2.200x10(-9). The effects of the governing drying parameters on the total drying time are determined. A mathematical model based on the Fickian model was established to describe the mass transfer in a carrot slice. Comparison of experimental and calculated results shows good agreement.