Experimental optimization of chicory root (Cichorium intybus L.) aqueous extracts formulation by novel approach of ongoing ultrasonic vacuum spray drying using response surface methodology

Abstract

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. Practical applications In this research, we developed an ultrasonic vacuum spray dryer (UVSD) that performs spray drying in a vacuum chamber at lower temperatures than the conventional spray drying. This procedure can be considered as a novel technique to produce powder from the Chicory Root (Cichorium intybus L.) Aqueous Extract. Minimization of the oxidative and thermal stresses during the drying is the main advantage of this process. Drying conditions were optimized by using a central composite face‐centered design of response surface methodology (RSM) to improve the chemical and physical properties of the produced powder. Nutritional and pharmaceutical properties of the chicory root are associated with their special chemical composition such as high levels of polyphenolic compounds. Drying temperature was reduced via controlling the vacuum condition in the drying chamber of the UVSD such that to continuously obtain a powder rich in heat‐sensitive ingredients.