Influence of Ultrasonic Vacuum Spray Drying Conditions on the Functional, Reconstitution and Chemical Properties of Artichoke Leaves Extract Powders

In this study, ultrasonic vacuum spray dryer was used to produce a dried powder of artichoke leaves extract.The drying process was performed in a vacuumed drying chamber at a lower temperature than the conventional spray dryers. The effects of independent variables (inlet temperature of 55-75 °C, vacuum pressure of 20-40 kPa, and solution concentration of 2-3%) were investigated on the functional (moisture content, particle size, bulk and tapped densities, flowability, and cohesiveness), reconstitution (wettability, dispersibility, and solubility) and chemical properties (total phenol content and DPPH scavening activity) of artichoke leaves extract powder with monohydrate lactose as a carrier in order to achieve the high process yield and desirable properties.The powders produced with the solution concentration of 3% showed the highest mean diameter of particle, bulk, and tapped densities, wetting angle (decreasing wettability) and total phenol content (TPC), while the values of dispersibility and solubility were the lowest. The increase in the inlet temperature and decrease in the vacuum pressure resulted in the particles with lower moisture content, bulk, and tapped densities as well as higher dispersibility and solubility. Chemical properties were influenced by the vacuum pressure and inlet temperature variables, both in a negative manner. The key results indicated that the solution concentration of 3%, inlet air temperature of 75 °C, and vacuum pressure of 20 kPa were the best conditions for artichoke leaves extract drying under the vacuum spray drying conditions.