Infrared drying of carrot slices: Effect of power levels on kinetics and energy efficiency

The aim of this study is to optimize the drying conditions for yellow carrots by investigating the effects of varying infrared (IR) power levels on drying kinetics. Following drying tests at IR power levels of 38, 50, 62, 74, and 88 W, the initial moisture content of carrot slices (6.95 kg water/kg dry matter) was decreased to 0.11 kg water/kg dry matter. Drying times ranged from 300 minutes at 38 W to 110 minutes at 88 W, demonstrating an inverse relationship between IR power and drying duration. Higher IR power levels accelerated the drying rate by enhancing energy transfer, which promoted moisture removal efficiency. Effective diffusion coefficients, calculated as ranging from 7.73? 10^{-10} to 2.21? 10^{-9} m?/s for the power levels of 38 W to 88 W, indicate an increase in moisture migration with higher power. The process's energy requirements were reflected in the activation energy for moisture diffusion (1.967 kW/kg). The Midilli and Kucuk model offered the best fit for characterizing the drying behaviour, and statistical analysis validated the model's correctness. These findings provide valuable insights for optimizing IR drying conditions to enhance the efficiency and quality of yellow carrot drying processes.