Effect of the addition of cosolvent on the supercritical fluid extraction of bioactive compounds from Helianthus annuus L.

An analysis of the application of supercritical carbon dioxide in the extraction of bioactive compounds from Helianthus annuus L. (sunflower) has been carried out. The influence of different variables, including pre-treatment of the sample, temperature, pressure and modifiers, was investigated. The samples were either dried or not dried and the extraction conditions were as follows: 35-50 degrees C, 100-500 bar, and addition of 5% of methanol, water or dimethyl sulphoxide (DMSO) as a modifier. The best extraction yields were achieved on a dried sample at a temperature of 50 degrees C and a pressure of 500 bar using a 5% water as a modifier. The bioactivities of the extracts obtained under the different conditions were compared. The best activity profiles were obtained for the non-dried samples extracted at 50 degrees C and 500 bar with supercritical carbon dioxide. (c) 2006 Elsevier B.V. All rights reserved.