Infrared Drying Kinetics and Quality Characteristics of Carrot Slices

The effect of different infrared powers on the drying kinetics of carrot slices was investigated. The carrot slices were dried at 62, 74, 88, 104 and 125 W infrared powers and constant slice thickness of 0.5 cm. The results showed that the infrared power has a significant effect on the drying and quality characteristics such as rehydration and color. The whole drying process occurred within the falling rate period. Six thin-layer drying models were fitted to the experimental data. The Midilli et al. model was best fitted to the experimental data. Fick's law of diffusion was used to determine the effective moisture diffusivity, which varied between 2.45 × 10−9 and 7.38 × 10−9 m2/s. Activation energy was estimated by a modified Arrhenius type equation as 4.247 kW/kg. Practical Applications Drying is one of the widely used methods of food product preservation. The main objective in drying food products is the reduction of moisture content to minimize the microbiological spoilage and deteriorative chemical reactions. Besides, drying process has had a significant effect on the drying kinetics and quality of the dried product. Infrared drying has gained popularity as an alternative drying method for agricultural products. This method is proven to be efficient for preserving the main characteristics and quality of products, and additionally leads to shortened drying time. The main objectives of this study were to investigate the effect of infrared power on the drying time, rehydration ratio and color; to fit the experimental data to six thin-layer drying models; and to compute the effective moisture diffusivity and activation energy of carrot slices. This study is useful for producers of not only dried carrots but also other agricultural products.