Thin‐layer mathematical modeling for drying of turmeric slices in infrared dryer

Abstract

Drying is an important unit operation in the turmeric processing chain. This research investigates the kinetics of drying turmeric slices using infrared dryer. The drying was performed at temperatures of 50, 60, and 70°C for slice thickness of 2, 4, and 6 mm. The drying temperature 70°C and slice thickness of 2 mm showed the highest drying rate. The highest curcumin and oleoresin yield with color retention was observed at the drying temperature of 60°C at 2‐mm slice thickness. Thirteen thin‐layer drying models were employed to evaluate the experimental drying kinetics of turmeric slices. The model Verma et al. showed the best fit with an R2 value of 0.99 with the least RMSE and chi‐squared values as 0.0193 and 3.73E−04, respectively. The activation energy for the turmeric slices of thickness 2, 4, and 6 mm ranged between 37.31 and 52.95, 48.78 and 57.51, and 46.79 and 57.37 kJ/mol for 50, 60, and 70°C, respectively.Practical applicationsThis research offers significant potential for improving the efficiency and quality of turmeric drying in industrial settings. The infrared drying enables accelerated drying of turmeric. The optimized infrared drying conditions (60°C and 2‐mm slice thickness) can significantly reduce drying time compared to conventional methods. This translates to increased throughput and minimized postharvest losses, especially in large‐scale turmeric processing facilities. The preservation of curcumin, oleoresin, and color at the optimized conditions ensures the production of high‐value turmeric products with superior nutritional and sensory attributes. This can lead to increased consumer appeal, brand differentiation, and potentially higher market prices for turmeric‐based foods, supplements, and nutraceuticals. The infrared drying technology can be prescribed to the industries over the existing industrial drying techniques. The cost‐effectiveness of the method, coupled with its potential for quality improvements and reduced drying time, makes it a viable option for turmeric processors seeking to enhance their operations.