Convective drying characteristics of pretreated and untreated carrot shreds were studied at 50, 55, 60, 65, and 70C with Page model providing a better fit than other models in all cases. Drying rate increased by more than twofolds when drying temperature was increased by 20 from an initial value of 50C. The moisture diffusivity varied from 6.78 × 10−11 to 6.03 × 10−10 whereas activation energy ranged from 28.47 to 46.51 kJ/mol. The degradation of total carotenoids at lower drying temperatures was more than at higher temperatures while non enzymatic browning increased upon increase in temperature.
Practical Application
The potential of drying as a preservation process is known to everybody that involves the use of thermal treatment resulting in the preservation of edible food products for longer periods of time. This preservation process has a drawback of negatively affecting the nutritional characteristics of the food products and is mainly responsible for the loss of bioactive components of the same. The present study was undertaken to find the ways of minimizing the losses of bioactive component (carotene) of the carrot. The dehydration kinetics of the samples at varying temperatures was employed along with few treatments for achieving the same. Overall utilization of the correct procedures during dehydration of an agricultural produce greatly minimizes its nutritional losses.