Inlet Temperature Affects Spray Drying Quality of Watermelon Powder

The effect of the inlet temperature on the quality of watermelon powder after spray drying was evaluated. Inlet temperatures of the drying air of 120, 130, 140, and 150 degrees C maintained water solubility of the watermelon powder at 96%. At 253 mu M/g, the ORAC value of the watermelon powder dried at 130 degrees C was the highest among all tested powders. The D-50 of the watermelon powder dried at 130 degrees C was 18.21 +/- 0.22 mu m with a span of 1.73 +/- 0.038, which was more uniform than that of other powders. The crystallinity of the powder dried at 130 degrees C was higher than that dried at both 120 and 150 degrees C and showed stronger thermal stability. Moreover, watermelon powder dried at 130 degrees C presented a similar aroma as the fresh watermelon juice when being solved. Hence, an inlet temperature of the drying air of 130 degrees C was the optimal temperature for the production of watermelon powder.