Optimization of watermelon powder production in a spray dryer

Powder production from agricultural products that cultivated in large area is important to prevent losses in harvesting time and changing harvested material to valuable product with longer shelf life. The aim of this study was to optimize the drying of watermelon juice in a radiant spray dryer using response surface methodology (RSM). Experiments were conducted in three levels of air temperatures (60, 75 and 90 °C) and three levels of maltodextrin concentration (5, 7.5 and 10% w/v) as an additive material. Dependent parameters were lycopene value, color change, pH, solubility, moisture content, bulk density and antioxidant capacity. Coefficient of determination for prediction of lycopene value, color change, solubility, moisture content and antioxidant capacity were derived 98.70, 94.19, 96.27, 98.50 and 98.71, respectively. With respect to the desired conditions in this research (the lowest change in color and the highest value for lycopene, solubility and antioxidant capacity), the optimized condition with RSM for air temperature, maltodextrin concentration, lycopene value, color change, solubility, moisture content and antioxidant capacity were 79.67 °C, 5% (w/v), 24.84 mg/100g, 37.86, 35.12%, 26.58% (d.b.) and 25.05%, respectively.