Extraction of sunflower (Heliantus annuus L.) oil with supercritical CO2 and subcritical propane: Experimental and modeling

This study evaluated the temperature and pressure effects in the extraction of the sunflower seed (Heliantus annuus L) oil using as solvents carbon dioxide and propane. The experiments were performed at the temperature range of 30-60 degrees C and pressure range of 8-25 MPa. A factorial experimental design 2(2) with triplicate at the central point was effectuated in order to evaluate the influence of this two variable in the mass of oil extracted ratio by mass of solvent consumed. Analysis of oxidative stability and chemical composition of the oil were performed as well. The best extraction for sunflower seed oil was obtained with propane as solvent, because of the high extraction yield in comparison with carbon dioxide. The quantity of fatty acids detected in the samples of oil extracted with carbon dioxide and propane were similar and presented a high time of oxidative induction than the sample extracted with hexane. However, the oil extract obtained with propane showed a high concentration of vitamin E (alpha-tocopherol). To describe the extraction kinetic was used the Sovova mathematical model, which showed a high precision in all the conditions investigated. (C) 2011 Elsevier B.V. All rights reserved.