Response surface optimization of quality parameters of turmeric slices in an innovative infrared assisted hybrid solar dryer

Abstract

Drying of pre-treated turmeric slices was performed in an innovative infrared assisted hybrid solar dryer. The study evaluated the effect on the drying time and quality parameters (color, antioxidant activity) of the pre-treated turmeric slices by the independent parameters. Numerical optimization of process parameters for solar drying of turmeric slices was done through response surface methodology approach with Box-Behnken experimental design. Three levels of independent parameters including dryer temperature (50 to 70ºC), power of infrared (1000 to 1500 W) and drying tray to infrared source distance (11 to 35 cm) were used for the experiment. At the optimized values of dependent parameters (69.16ºC, 1500 W and 11 cm), the color variation, antioxidant activity (EC50 value) and drying time was 13.684, 5.131 and 307.2 min respectively.