Generation of Spherical Microparticles of Moringa Leaves through a Supercritical Antisolvent Extraction Process

The objective of this work was evaluation of the supercritical antisolvent extraction (SAE) process to generate microparticles with antioxidant activity from Moringa leaves. A biodegradable polymer was used as an inductor of particle precipitation. An ethanolic extract of 25 mg/mL was used in the SAE process, during which the influences of pressure (100–200 bar), temperature (35–55 °C) and extract–polymer ratio (0.11–0.33) on particle size and antioxidant activity were evaluated. An extract flow rate of 3 mL/min, a supercritical CO2 (scCO2) flow rate of 30 g CO2/min and a nozzle diameter of 100 µm were kept constant. The identification of several compounds of Moringa leaves, namely, coumaric acid and quercetin 3D glucoside, were determined with ultra-performance liquid chromatography coupled with mass spectrometry. The antioxidant activity of the extract and the precipitates was measured with 2,2-Diphenyl-1-picrylhydrazyl. Spherical microparticles with diameters in the range of 2–5 µm were obtained, with moderate antioxidant activity.