Propolis is a natural resinous material with antimicrobial, anti-inflammatory, antioxidant, antibiotic and anti-carcinogenic properties. Propolis coprecipitation was attempted by Supercritical Assisted Atomization (SAA) using two carriers: hydroxypropyl-beta-cyclodextrin (HP beta CD) and polyvinylpyrrolidone (PVP), with the aim to protect propolis bioactivity against oxidation and to improve its bioavailability. Propolis/carrier ratio and overall solute concentration were investigated to understand their effect on the success of coprecipitation as solid dispersion of propolis in the carrier matrix and on particle morphology and particle size distribution. The results confirmed the efficiency of SAA process: spherical amorphous particles were obtained in which propolis and carrier were coprecipitated, with a mean diameter ranging between about 0.20 and 0.37 mu m for HP beta CD coprecipitates and between about 0.23 and 0.50 mu m for PVP coprecipitates. SAA particles showed a polyphenol loading efficiency up to 100% for HP beta CD coprecipitates and up to 96% for PVP coprecipitates, with a half inhibition concentration of DPPH radical up to (17.2 + 2.8) mu g/mL and (17.3 1.0) mu g/mL, respectively. These particles rich in bioactive compounds can be used as functional component in formulations of new food or pharmaceutical products. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.