In the present study, we performed a simultaneous optimization of various inlet temperatures, vacuum pressures, and maltodextrin concentrations to produce chicory root inulin extract powder by the novel approach of ongoing ultrasonic vacuum spray drying. To obtain the optimum conditions, we used a central composite face-centered design of response surface methodology (RSM). Performing this drying approach in a vacuumed drying chamber required lower temperatures compared to the conventional dryers. We used 4–6% (wt/vol) maltodextrin concentrations at inlet temperatures of 50, 65, and 80 C and vacuum pressures of 20, 35, and 50 kPa and evaluated the following responses: total phenolic content (TPC), total flavonoids concentration (TFC), DPPH radical scavenging capacity, moisture content, bulk density, wettability, and solubility. We found that the highest desirability (0.646) was achieved at an inlet temperature, vacuum pressure, and maltodextrin concentration of 50 C, 20 kPa, and 4.7%, respectively.
