Corn oil is a vegetable oil extracted from the germ of corn kernels. It is odorless and almost tasteless. Refined corn oil has a pale, yellow color, and is a mixture of polyunsaturated, monounsaturated and saturated fatty acids.
Corn is a food plant that is widely consumed all over the world today. However, it is believed to have originated in Mexico or Central America, some 5000 years ago. Corn has been cultivated and developed from a type of wild grass. It has to be looked after and protected by humans, as it does not grow naturally.
Corn is an important part of the diet of people not only throughout America, but its use ranges from as far South as Chile in South America to Canada in North America. It was popularized in Europe by Spanish and Portuguese travelers, and is consumed in most parts of the world today. Hybrid varieties of corn are popular today, as they not only increase the yield, but also produce varieties which are sweeter and tastier.
The first step in extraction of oil from corn is cleaning the corn to remove dust, foreign particles and the cob. After cleaning, corn kernels are steeped (soaked) in water at fifty degree centigrade, for thirty to forty hours. The kernels swell by absorbing water, increase in size and the starch inside is softened. The released starch is coarsely ground to break the germ which contains oil.
The germ is separated and oil extracted, either by squeezing (mechanical method) or solvent extraction (chemical method). It is then refined and filtered. Finally, the free fatty acids and phospholipids are removed to give corn oil the desired quality of a high smoking point, which makes it suitable for frying.
Uses of Corn Oil
Corn oil is mainly used as a cooking and salad oil. It is suitable for frying because of its resistance to smoking or discoloration. It provides all other benefits of an oil, for example, being a concentrated source of energy, acting as a medium for fat soluble vitamins, and providing palatability to food.
Other suggested uses of corn oil include using it as a moisturizer, as an ingredient for bubble bath, to condition hair, remove oil paint from skin and even remove glue from furniture.
The nutritional benefits of corn oil arise from the fact that it is rich in polyunsaturated fats, while being low in saturated fats. Saturated fats are believed to cause heart problems, and hence, the low saturated fat content of corn oil is desirable. Also, corn oil has moderate amounts of monounsaturated fats, which further prove beneficial for the heart. Some studies have even suggested cholesterol lowering effects, though more studies are needed to support these claims. To achieve any possible beneficial effects, saturated fats need to be replaced by corn oil gram for gram, so that the total number of calories does not increase per day.
While corn oil may be low in saturated fats (13%), the high percentage of polyunsaturated fats (59%) makes it susceptible to oxidative damage and production of free radicals. As with other oils, total fat consumption is also important along with the composition of the oil in deciding the health benefits. Balanced nutrition can be achieved by eating foods from various food groups, choosing a diet low in saturated fats and cholesterol, and moderate in total fat.