Comparative Evaluation of Drying Kinetics of Carrot Slices in Hot air and Microwave Drying

Abstract

Carrot is most the important vegetable grown throughout the World. It is also a very good source of βcarotene, α-carotene and zeaxanthin. The post-harvest losses because of having high moisture content limit the utilization of carrot. In the present investigation, the comparative analysis was done between hot air drying and microwave drying for different thickness of carrot slices. The quality analysis for both the dried products was performed and compared. The drying time was varied between 3.5 h to 10 h for try drying whereas for microwave drying it was 240 sec to 681.6 sec. The drying time reduces drastically in case of microwave drying in comparison to hot air drying. The moisture ratio for both dried techniques was found to decreasing with an increase in drying time. The microwave dried samples showed a better rehydration ratio than the hot air dried sample. Also, the dehydration ratio of dried carrot sample using microwave drying was found to be lowest compared to the hot air dried sample. The microwave dried carrot slices showed a better sensory score in terms of colour and shape than hot air dried sample. Therefore, microwave drying may be recommended to dry carrot slices to have better energy efficiencies.