Drying of carrots in microwave and halogen lamp-microwave combination ovens

Carrot slices were dried by using microwave, halogen lamp-microwave combination and hot-air drying. Microwave and halogen lamp-microwave combination drying were applied after carrots were dried to 0.47 kg moisture/kg dry solid by hot-air drying. Drying time, rehydration capacity and colour of the carrots dried by different methods were compared. The increase in microwave oven power level decreased the drying time. Microwave drying at the highest power and halogen lamp-microwave combination drying reduced the drying time to an extend of 98% in comparison to conventional hot-air drying and a high-quality dried product was obtained. Moreover, in the case of halogen lamp microwave combination drying, moisture level was reduced to a level, which is lower than the one achieved by other methods. Less colour change occurred when microwave and halogen lamp-microwave combination drying were applied. Carrots dried in microwave and halogen lamp microwave combination oven had lower L*, higher a* and b* values and had higher rehydration capacity as compared to hot-air drying. (c) 2004 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.