Response surface methodology for optimization of process parameters for preparing sweet potato powder

The present study was conducted to optimize key process parameters for preparation of sweet potato powder, focusing on maximizing powder yield while minimizing powder loss by using Tray Dryer. After conducting many trials, three independent variables with three levels were finalized and total 17 experiments were conducted with by using Design Expert Software. Three independent variable slice thickness (20, 25 and 30 mm), drying temperature (40,45 and 50 °C), and air velocity (1,1.5 and 2 m/s) were fixed in Box-Behnken Design for obtaining maximum sweet potato powder yield by minimizing sweet potato powder loss. The responses viz. maximum powder yield (%) and minimum powder loss (%) was effectively determined by Response Surface Methodology (RSM) and superimposed graphs with optimised values of slice thickness (mm), drying temperature (°C) and air velocity (m/s). The experimental results revealed that thinner slices, moderate drying temperatures, and moderate air velocity significantly influenced moisture removal and retention of powder integrity. The statistical analysis indicated strong interactive effects among the process variables. The optimal conditions identified were 21 mm slice thickness, 44 °C drying temperature and 1 m/s air velocity for obtaining 95.56% sweet powder yield and 4.47% powder loss.