Cooking Oil

Cooking oil is purified fat of plant or animal origin, which is liquid at room temperature.

Some of the many different kinds of edible vegetable oils include:olive oil, palm oil, soybean oil, canola oil, pumpkin seed oil, corn oil, sunflower oil, safflower oil, peanut oil, grape seed oil, sesame oil, argan oil and rice bran oil. Many other kinds of vegetable oils are also used for cooking.

The generic term "vegetable oil" when used to label a cooking oil product refers to a blend of a variety of oils often based on palm, corn, soybean or sunflower oils.

Oil can be flavoured by immersing aromatic food stuffs such as fresh herbs, peppers, garlic and so forth in the oil for a period of time. However, care must be taken when storing flavored oils to prevent the growth of Clostridium botulinum (the bacteria that produces toxins that can lead to botulism).

The appropriate amount of fat as a component of daily food consumption is the topic of some controversy. Some fat is required in the diet, and fat (in the form of oil) is also essential in many types of cooking. The FDA recommends that 30% or less of calories consumed daily should be from fat.Other nutritionists recommend that no more than 10% of a person's daily calories come from fat.In extremely cold environments, a diet that is up to two-thirds fat is acceptable and can, in fact, be critical to survival.

While consumption of small amounts of saturated fats is essential, excessive amounts of such fats has been shown to be correlated with coronary heart disease. Oils with lower amounts of saturated fats, and higher amounts of unsaturated (preferably monounsaturated) fats, are generally healthier.

Heating an oil changes its characteristics. Some oils that are healthy at room temperature can become unhealthy when heated above certain temperatures. When choosing a cooking oil, it is therefore important to note the oil's heat tolerance, and to match the oil to its use in cooking.^[4]. Oils that are suitable for high temperature frying (above 280°C/500°F) include:

• Canola oil
• Almond oil
• Apricot kernel oil
• High-oleic safflower oil or sunflower oil
• Peanut oil (marketed as 'groundnut oil' in the UK)
• Soybean oil
• Grape seed oil

Oils suitable for medium temperature frying include:

• Walnut oil
• Sunflower oil
• Sesame oil

Unrefined oils should be restricted to temperatures below 105°C/225°F.

It is best to store all oils in the refrigerator or a cool, dry place. Oils may thicken, but if you let them stand at room temperature they will soon return to liquid. To prevent negative effects of heat and light, take oils out of cold storage just long enough to use them. Refined oils high in monounsaturated fats keep up to a year (if they are olive oil, they'll keep up to a few years), while those high in polyunsaturated fats keep about six months. Extra-virgin and virgin olive oils keep at least 9 months after opening. Other monounsaturated oils keep well up to a high eight months; unrefined polyunsaturated oils only about half as long.

Proper disposal of used cooking oil is an important waste-management concern. Oil is lighter than water and tends to spread into thin and broad membranes which hinder the oxygenation of water. Because of this, a single litre of oil can contaminate as much as 1 million litres of water.Also, oil can congeal on pipes provoking blockages.

Because of this, cooking oil should never be dumped on the kitchen sink or in the toilet bowl. The proper way to dispose of oil is to put it in a sealed non-recyclable container and discard it with regular garbage.

Source : Wikipedia