The supercritical carbon dioxide extraction of polyphenols from Propolis: A central composite design approach

Abstract The influence of different parameters on the Supercritical Carbon Dioxide (SCO 2 ) extraction of Italian Propolis were studied with attention to extraction yield and chemical composition of obtained fractions. Operating parameters of SCO 2 were optimized using central composite design. Analysis by multiple regression indicated that pressure and time have a major linear effect on the extraction yield and extract composition. Propolis SCO 2 extracts present different chemical content compared to the ethanolic extract obtained with ultrasound assisted extraction (UAE). SCO 2 extract can be used to perform further UAE ethanol extraction obtaining a flavonoid containing extract. These findings indicate two possible applications of supercritical carbon dioxide for Propolis extraction, one to obtain lipophilic fractions enriched in specific constituents, the other as pre-treatment of the crude material to facilitate the further extraction with ethanol.