β-Carotene/PVP microspheres produced by Supercritical Assisted Atomization

β-carotene (BC) is one of the best known and used bioactive compounds with antioxidant activity. In this work coprecipitation of BC with polyvinylpyrrolidone (PVP) by Supercritical Assisted Atomization (SAA) has been studied, to enhance BC bioavailability and to provide its protection against oxidation. Two solvents have been used: ethanol and a mixture acetone/ethanol 70/30 (v/v). In both cases SAA produced spherical and amorphous microspheres with d 50 ranging between 0.42 and 0.84 μm using ethanol, and 0.28 and 0.48 μm using the solvent mixture. UV–vis analyses revealed a BC content up to 94% and high scavenging activities confirm that PVP is able to protect it from degradation. BC dissolution rate in a phosphate buffered saline solution (PBS) was up to 22 times faster than that of physical mixture. The major difference between coprecipitates was in their dissolution rate: it depended also on the kind solvent used, indicating a possible different internal particles organization during droplet drying.