A comparison of commercial enzymes for the aqueous enzymatic extraction of corn oil from corn germ

An aqueous enzymatic method was developed to extract corn oil from corn germ. The basic steps in the method involved "churning" the corn germ with various enzymes and buffer for 4 h at 50degreesC, and an additional 16 h at 65degreesC, followed by centrifugation and removal of the oil layer from the surface. No hexane or other organic solvents are used in this process. By using oven-dried corn germ samples (6 g) from a commercial corn wet mill, corn oil yields of about 80% were achieved using three different commercial cellulases. A fourfold scale-up of the method (to 24 g of germ) resulted in oil yields of about 90%. Nine 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. The chemical compositions of hexane-extracted vs. aqueous enzymatic-extracted corn oils were very similar.