THE THIN-LAYER DRYING CHARACTERISTICS OF GARLIC SLICES

The thin-layer drying characteristics of garlic slices (2-4 mm) were i nvestigated for a temperature range 50-90 degrees C, a relative humidi ty range 8-24%, and an airflow range 0.5-1 m/s. An analysis of varianc e (ANOVA) revealed that temperature and slice thickness significantly affected the drying rare while relative humidity and airflow rate were insignificant factors during drying. Effective diffusivity of water v aried from 2 to 4.2 x 10(-10) m(2)/s over the temperature range invest igated, with an energy of activation of 989 kJ/kg. Four mathematical m odels available in the literature were fitted to the experimental data , with the Page and the two-compartment models giving better predictio ns than the single-term exponential and Thompson's model. The temperat ure dependence of the diffusivity coefficients was described satisfact orily by a simple Arrhenius-type relationship. Copyright (C) 1996 Else vier Science Limited.