ARS | Publication request: A COMPARISON OF COMMERCIAL ENZYMES FOR THE AQUEOUS ENZYMATIC EXTRACTION OF CORN OIL FROM CORN GERM

Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 1, 2005
Publication Date: December 15, 2004
Citation: Moreau, R.A., Johnston, D., Powell, M.J., Hicks, K.B. 2004. A comparison of commercial enzymes for the aqueous enzymatic extraction of corn oil from corn germ. Journal of the American Oil Chemists' Society, V.81, No. 11, p.1071-1075.

Interpretive Summary: Currently, all corn oil is produced by extracting corn germ with hexane. Hexane is a flammable and toxic solvent and because of the costly safety and environmental issues associated with hexane extraction, alternative extraction methods are needed. Others have suggested that an extraction method based on water and enzymes could be used to extract corn and other vegetable oils, but so far the low oil yields and high cost of enzymes have prevented these methods from being able to compete economically with hexane extraction. This manuscript describes a new aqueous enzymatic process which was developed to extract corn oil from corn germ with yields of greater than 90%. If our new process can be coupled with some of the new lower cost enzymes that are being developed for the fuel ethanol industry, it may offer a competitively priced safe replacement for hexane extraction. This process, which could be implemented with modest capital investment, could benefit small and large corn millers and processors as well as lower the overall price for ethanol made from corn.

Technical Abstract: An aqueous, enzymatic method was developed to extract corn oil from corn germ. Using commercial oven dried corn germ from wet milling, corn oil yields of 80 to 90% were achieved using two commercial enzymes in the process. Ten other commercial enzymes were evaluated and resulted in significant, but lower oil yields. In the absence of enzymes, oil yields of 27 to 37% were achieved. No hexane or other organic solvents are used in this process.