Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/6/2006
Publication Date: 10/1/2006
Citation: Eisenmenger, M., Dunford, N.T., Eller, F.J., Taylor, S.L., Martinez, J. 2006. Pilot scale supercritical carbon dioxide extraction and fractionation of wheat germ oil. Journal of the American Oil Chemists' Society. 10:863-868.
Interpretive Summary: New processing techniques are needed to extract and refine vegetable oils which maintain the nutritional aspects of the oil and have minimal impact on the environment. Researchers at the National Center for Agricultural Utilization Research, Peoria, Illinois, in cooperation with scientists at the Agricultural Products Research and Technology Center, Oklahoma State University, studied the use of supercritical carbon dioxide (SC-CO2) as an alternative extraction and refining method to for wheat germ oil (WGO). SC-CO2 was demonstrated to effectively extract the WGO and the oil contained the same proportions of fatty acids as oil obtained using conventional hexane extraction. Supercritical fluid fractionation (SFF) was also investigated as a means to remove unwanted free fatty acids from the WGO. SFF effectively separated the free fatty acids from the WGO while leaving behind the bioactive component, alpha-tocopherol, in the final product. This study demonstrated that SC-CO2 extraction and SFF can effectively extract and purify WGO.
Technical Abstract: There is a need for the development of new processing techniques which will facilitate vegetable oil extraction and refining while sustaining the nutritional components naturally present in edible oils and reducing the adverse impact of oil processing on the environment. In this study supercritical carbon dioxide (SC-CO2) extraction and fractionation techniques were examined as alternative methods to obtain wheat germ oil (WGO) of high quality and purity. It was shown that the SC-CO2 extraction technique is effective in extraction of WGO. There was no significant difference in fatty acid composition of SC-CO2 and hexane extracted WGO. Both hexane and SC-CO2 extracted WGO were rich in alpha-tocopherol. Moisture content of the SC-CO2 extracted oil was higher than the hexane extracted oil. Solvent/feed ratio had a significant effect on the SC-CO2 extraction yields. This study demonstrated that SFF was a viable process to remove free fatty acids efficiently from both hexane and SC-CO2 extracted WGO while retaining bioactive oil components in the final product.