Supercritical carbon dioxide extraction of cuphea seed oil

• Published in: Industrial crops and products Vol. 33; no. 2; pp. 554 - 557
• Main Authors: Eller, F.J., Cermak, S.C., Taylor, S.L.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2011; [Amsterdam; New York, NY]: Elsevier Science
• Subjects: Acid value; carbon dioxide; chlorophyll; color; Cuphea; Cuphea seed oil; economic analysis; ethers; extraction; Free fatty acid; free fatty acids; Gardner color; lipid composition; medium chain fatty acids; oil refining; pressure; screw pressing; Solvent extraction; solvents; Supercritical carbon dioxide; supercritical fluid extraction; temperature; Acid value; Supercritical carbon dioxide; Free fatty acid; Solvent extraction; Cuphea seed oil; Gardner color
• ISSN: 0926-6690; 1872-633X
• DOI: 10.1016/j.indcrop.2010.12.017

▶ Cuphea seed oil is effectively extracted with CO2 at 50°C and 20.7MPa. ▶ CO2 derived cuphea seed oil has both low free fatty acid content and acid value. ▶ CO2 derived cuphea seed oil is lighter in color than petroleum ether derived oil. ▶ The fatty acid profiles of the CO2 and pet ether derived oils are nearly identical. Cuphea seed oil (CSO) is a potential domestic source of medium chain fatty acids. Although CSO has been obtained using solvent extraction and screw pressing, both methods suffer from disadvantages. Supercritical carbon dioxide (SC-CO2) extraction is a promising alternative extraction technology. It is a very effective means to extract vegetable oils, non-toxic, non-flammable, easy to separate from extracts (i.e., no solvent residues) and there are no solvent disposal costs. This research compared SC-CO2 and soxtec petroleum ether for the extraction of CSO. The CSO yield for the petroleum ether was 29.7% while the SC-CO2 was 28.1%. The free fatty acid content for the SC-CO2 extract was only 8.8% while the petroleum ether extract was 15.0%. The acid values were also much higher for the petroleum ether extract (i.e., 29.8) than for the SC-CO2 extract (i.e., 17.4). The Gardner color of the SC-CO2 extract was determined to be 2+ while the color of the petroleum ether soxtec extract could not be determined because it was very dark due to the presence of chlorophyll. Although the two extraction methods differed slightly in their individual fatty acid compositions, the magnitudes of the differences were inconsequential. This research demonstrated that CSO can be effectively extracted using SC-CO2 at a relatively low temperature and pressure (i.e., 50°C and 20.7MPa) to give a very high quality oil. Cuphea seed oil's status as a specialty oil and its corresponding higher value make its extraction using SC-CO2 an economically viable option.