Coumarin solubility and extraction from emburana (Torresea cearensis) seeds with supercritical carbon dioxide

Coumarin is an active principle found in several vegetable species with a characteristic smell of vanilla. It is widely used as a perfume fixer, paint and spray additive, and in cleaning products. It also possesses clinical value due to antibiotic and analgesic properties, besides its potential use in the treatment of cancer and AIDS. The objective of this work was to obtain solubility data for coumarin under several conditions, as well as to evaluate process parameters for its extraction from emburana seeds with supercritical CO2. The process parameters studied were temperature, pressure, CO2 flow rate and particle size of the seeds. The solubility in supercritical CO2 was correlated using the Peng-Robinson equation. Solid-supercritical fluid and liquid-supercritical fluid equilibria were considered and correlated separately, with L-SC presenting better results due to the effect of the melting point depression of coumarin under high pressure. The results showed significant effects of pressure and temperature on the extraction yield and also, the smaller the particle size of the seeds, the better the yield. (C) 2007 Elsevier B.V. All rights reserved.