Drying of carrot slices using infrared radiation

Abstract

SummaryCarrot slices were dried from initial moisture content of 8.52 kg water kg−1 dry matter to 0.11 kg water kg−1 dry matter by infrared dryer. Experiments were conducted using three levels of infrared power (300, 400 and 500 W) and at air velocities (1.0, 1.5 and 2.0 m s−1). The effects of process variables on the drying kinetics of carrot, drying time, specific energy consumption and quality parameters of dried carrot (shrinkage, rehydration ratio and colour) were investigated. The drying time at infrared power of 300, 400 and 500 W was 252 and 277 min, 205 and 236 min, and 145 and 155 min at air velocities of 1.0 and 2.0 m s−1, respectively. The drying rate increased with increasing infrared power. The specific energy consumption values varied between 12.22 and 14.58 MJ kg−1‐evaporated water for all the drying conditions. Shrinkage, rehydration ratio and colour parameters were found to be affected by process variables.