2007 Annual Report
b. Research was conducted under a CRADA (58-3K95-5-1087) between ARS and the Illinois Corn Marketing Board which was initiated on 01/01/05 and will terminate on 12/31/07.
This report serves to document research conducted under a CRADA (58-3K95-5-1087) between ARS and the Illinois Corn Marketing Board which was initiated on 01/01/05 and will terminate on 12/31/07. Additional details of this research can be found in the report for the subordinate project 1935-41000-069-01T. During the last year researchers at ERRC continued to compare the composition of conventional corn oil (corn oil obtained by pressing and/or hexane extraction of corn germ) versus corn oil obtained by extracting ground corn with ethanol. The analyses focused on comparing the levels of xanthophylls (lutein and zeaxanthin) in the two oils. The results indicated that the levels of each of these functional lipids were about one-hundred-fold higher in the corn oil from ethanol-extracted ground corn than in conventional corn oil.
During the year three meetings were held and numerous telephone and e-mail messages were exchanged to monitor progress of the collaboration. On September 12, 2006 and February 27, 2007, the ARS cooperator traveled to Illinois to visit with the CRADA partner to discuss CRADA research progress. On July 29-31, 2007, the ARS cooperator traveled with the CRADA partner to the International Food Technology Annual Meeting in Chicago, IL, to meet with prospective companies to discuss technology transfer options.
b. Development of an Aqueous Enzymatic Oil Extraction Process for Corn Germ from New Generation Ethanol Plants – Several strategies have been developed to remove the oil-rich corn "germ" from corn kernels before their fermentation to fuel ethanol. Some of these processes are "dry," where the germ is physically removed from the unwetted germ, and some processes are "wet," where the kernel is soaked or steeped before germ separation. The corn germ can then be extracted to obtain a valuable coproduct, corn oil (~$0.30/lb). During the last year we identified an appropriate combination of commercial enzymes (a combination of a cellulase and a protease) and developed a process which allowed us to achieve oil yields of 80-90% from several samples of "new generation" corn germ. This new aqueous enzymatic oil extraction process may provide a way for ethanol plants to be able to produce a new valuable coproduct on-site, without the use of hexane or other hazardous solvents. This research supports the ARS National Program 307, Bioenergy and Energy Alternatives, Component 1, Ethanol Coproduct Development. Goal "To develop higher-valued new coproducts or improve the existing ones from the non-starch portion of the grain, resulting in a reduced net cost of the starch used for producing ethanol."
c. Ethanol Extracted Corn Kernel Oil is a Rich Source of Health-Promoting Nutraceuticals Lutein and Zeaxanthin - All commercial corn oil is obtained by pressing corn germ and/or extracting the germ with hexane. During the last year we developed a process to extract a unique type of corn oil by extracting ground corn with 100% ethanol. The levels of lutein + zeaxanthin in this "ethanol-extracted corn kernel oil" were about 220 µg/g, which is about 100 times higher than the concentration in commercial corn oil (from corn germ). This new type of corn oil contains about 3 mg of lutein + zeaxanthin per tablespoon of corn oil, so consumption of 2 tablespoons per day would supply the amount (~6 mg) that that most experts currently believe is required to slow the progression of age-related macular degeneration. If such an oil was commercially available, all consumers, and especially the aged, could greatly benefit from its composition. Because we have demonstrated that this new type of corn oil contains high levels of these valuable phytonutrients, we anticipate that it will sell for a higher price than commodity corn oil, thus returning more coproduct value to the producer. This research supports the ARS National Program 307, Bioenergy and Energy Alternatives, Component 1, Ethanol Coproduct Development. Goal "To develop higher-valued new coproducts or improve the existing ones from the non-starch portion of the grain, resulting in a reduced net cost of the starch used for producing ethanol."
Moreau, R.A. 2006. The quantitative analysis of lipids via hplc with a charged aerosol detector. Lipids Journal V.41, No. 7., p.727-734.
Moreau, R.A., Hicks, K.B. 2006. A reinvestigation of the effect of heat pretreatment of corn fiber and corn germ on the levels of extractable tocopherols and tocotrienols. Journal of Agriculture and Food Chemistry. 54, p.8093-8102.
Nystrom, L., Achrenius, T., Lampi, A., Moreau, R.A., Piironen, V. 2007. A comparison of the antioxidant properties of steryl ferulates with tocopherol at high temperatures. Food Chemistry 101, p.947-954.
Choi, S., Lee, S., Kim, E., Yoon, K., Parris, N., Hicks, K.B., Moreau, R.A. 2007. Antioxidant and Antimelanogenic activities of polyamine conjugates from corn bran and related hydroxycinnamic acids. Journal of Agriculture and Food Chemistry 55, p.3920-3925.
Dickey, L.C., Cooke, P.H., Kurantz, M.J., Mcaloon, A.J., Parris, N., Moreau, R.A. 2007. Using microwave heating to determine optimal corn germ oil yield with a bench-scale press. 2007. Journal of the American Oil Chemists' Society 84(5):489-495.