Processing of Corn Oil

Processing of corn oil is a highly technique work. Corn oil and corn meal obtained from corn are included in useful products. The corn oil is extracted from the corn to form the corn meal by certain oil extraction machinery. Corn oil is extracted from the corn germ therefore it requires an additional degermination process to separate the germ from the endosperm.

Steps of processing of corn oil

The corn oil processing generally includes the steps of cracking corn grain having a total oil content of from about 3% by weight to about 30% by weight and extracting a corn oil from the cracked corn grain. The corn oil is useful for making nutritionally enhanced edible oil or cooking oil, lubricants, biodiesel, fuel, cosmetics and oil-based or oil-containing chemical products. The extracted corn meal is useful for making enhanced animal feed rations, snack food, blended food products, cosmetics, and fermentation broth additive.

Almost all corn oil is expeller pressed, then solvent extracted using hexane or isohexane. The solvent is evaporated from the corn oil, recovered, and re-used. After extraction, the corn oil is then refined by degumming and/or alkali treatment, both of which remove phosphatides. Alkali treatment also neutralizes free fatty acids and removes color (bleaching). Final steps in refining include winterization (the removal of waxes), and deodorization by steam distillation of the oil at 232 - 260C (450 - 500F) under a high vacuum. Some specialty oil producers manufacture unrefined, 100% expeller pressed corn oil. This is a more expensive product since it has a much lower yield than the combination expeller and solvent process, as well as smaller market share.