engleski

Modelling of drying and rehydration of carrots using Peleg's model

The drying and rehydration process of conventionally and organically cultivated carrots was studied and the resulting data were fitted to Peleg’ s model. Carrots were fluid-bed and halogen dried at 60, 70, 80, 90 °C and after that soaked in water at room temperature during 120 minutes. The Peleg’ s model gave a good prediction of water removal and water uptake in all the experiments (R > 0, 994). During drying process the Peleg rate constant (K_1) was affected by the temperature. K_1 values decreased with the increase of the drying temperature. This relation was linear for fluid bed drying and exponential for halogen drying, which implies the higher impact of drying temperature on the dehydration kinetics during the halogen drying. The lower K_1 values for fluid bed drying suggest the higher initial drying rates in comparison with halogen drying at all drying temperatures. The temperature dependence of 1/K_1 followed an Arrhenius-type relationship. Both Peleg’ s rehydration constants (K_1 and K_2) increased with the increase of the drying temperature. This implies regular decrease in initial rehydration rate and water uptake with the increase of the drying temperature.

Peleg's model; drying; rehydration; carrot

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