cooking oil

 

Plant oils
Types
Vegetable fats	(list)
Essential oil	(list)
Macerated	(list)
Uses
Drying oil - Oil paint
Cooking oil
Fuel - Biodiesel
Aromatherapy
Components
Saturated fat
Monounsaturated fat
Polyunsaturated fat
Trans fat

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 and so forth in the oil for an extended period of time. However, care must be taken when using garlic and onions to prevent the growth of Clostridium botulinum (the bacterium which causes botulism) in this medium.

Health and nutrition

Generally speaking, all oil is fat and the daily intake of fats should always be kept very low. However as it is still required for cooking and as a very limited amount of fat still need to be taken in daily (no more than 10% of a persons day's worth of calories)^[1], it is best to divert to a cooking oil which is atleast more healthy. The healthiest oils are those that are composed of the lowest amount of saturated fatty acids and the highest amount of unsaturated (preferably monounsaturated) fats. ^[2]. Also, to prevent overheating of the oil (which makes the oils very unhealthy and turns them into cancer-causing agents), the cooking oil must always be chosen based on the function it is to serve (high-heat, medium-heat or low-heat frying/baking)^[3][4].

On a whole, the common oils which are considered the most healthy can be divided into 3 categories, one for each temperature range between 500 and less than 320 degrees fahrenheit. They are marked on the table below.

high-temperature frying (260 degrees Celsius / 500 degrees fahrenheit and above)	super canola oil, almond oil, apricot kernel oil, high-oleic safflower oil or sunflower oil, peanut or soybean oils
medium temperature frying (below 190 degrees Celsius / 375 degrees fahrenheit)	canola, walnut, sunflower or sesame. Use or any of the higher-heat oils for sauces
low-temperature frying (less than 160 degrees Celsius / 320 degrees fahrenheit)	olive, corn,

The cooking oils which are considered least healthy ^[5][6] (being made up of mostly saturated fats) are:

 [[coconut oil]], [[palm oil]], ... 

Extra considerations

Although the examples above mention which oils are generally most healthy, there are some exeptions:

Peanut allergy

Peanut, cashew and other nut-based oils may also present a hazard to persons with a nut allergy. A severe allergic reaction may cause anaphylactic shock and result in death.

Transfats

Cooking oil is a special problem, as hydrogenation of oils makes them more stable, but also creates trans fats which are unhealthy.

Animal products (dairy and lard) can create trans fats for certain usage however the traces of trans fat from animals and other products which have saturated fats are significantly less than the concentration found in oils that has been through hydrogenation and isn't hazardous when consumed normally in a balanced diet. Coconut oil is an exception to the idea.

Some hydrogenation of oils occurs during cooking, causing normally healthy unsaturated fats like olive oil to convert to trans fats. But in non-industrial settings this process does not occur at appreciable quantities.^[7]

Storing and keeping oil

Whether refined or not, all oils are sensitive to heat, light and exposure to oxygen. Rancid oil has an unpleasant aroma and acrid taste, and its nutrient value is greatly diminished. To delay the development of rancid oil, a blanket of an inert gas, usually nitrogen, is applied to the vapor space in the storage container immediately after production. This is referred to as tank blanketing.

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, while those high in polyunsaturated fats keep about six months. Extra-virgin and virgin olive oils keep about a year after opening. Olive and other monounsaturated oils keep well up to eight months; unrefined polyunsaturated oils only about half as long. Some comparisons have been made to vegetable oil relating to its biomass.

Types of oils and their characteristics

Saturated fats are unhealthy in excess, but the consumption of small amounts of these oils is essential. Unsaturated fats (monounsaturated, polyunsaturated) are generally healthier for those consuming Western-style diets. Nutrition experts recommend that no more than 30% of a Western-style diet be composed of fats. In extremely cold environments, a diet that is up to two-thirds fat is acceptable and can, in fact, be critical to survival in that type of environment.

Type of Oil or Fat	Saturated	Monounsaturated	Polyunsaturated	Smoke point	Uses
Butter	66%	30%	4%	150°C (302°F)	Cooking, baking, condiment, sauces, flavoring
Ghee, clarified butter	65%	32%	3%	190°C (374°F)	Deep frying, cooking, sautéeing, condiment, flavoring
Canola oil	6%	62%	32%	238°C (460°F)	Frying, baking, salad dressings
Coconut oil	92%	6%	2%	177°C (350°F)	Commercial baked goods, candy and sweets, whipped toppings, nondairy coffee creamers, shortening
Corn oil	13%	25%	62%	236°C (457°F)	Frying, baking, salad dressings, margarine, shortening
Cottonseed oil	24%	26%	50%	216°C (420°F)	Margarine, shortening, salad dressings, commercially fried products
Grape seed oil	12%	17%	71%	204°C (400°F)	Cooking, salad dressings, margarine
Lard	41%	47%	12%	138-201°C (280-395°F)[8]	Baking, frying
Margarine, hard	80%	14%	16%	150°C (320°F)[9]	Cooking, baking, condiment
Margarine, soft	20%	47%	33%	150-160°C (300-320°F)	Cooking, baking, condiment
Diacylglycerol (DAG) oil	3.5%	37%	59%	215°C (420°F)	Frying, baking, salad oil
Olive Oil (Extra Virgin)	14%	73%	11%	207°C (406°F)	Cooking, salad oils, margarine
Olive oil (Virgin)	14%	73%	11%	215°C (420°F)	Cooking, salad oils, margarine
Olive Oil (Refined)	14%	73%	11%	225°C (438°F)	Sautee, Stir frying, cooking, salad oils, margarine
Olive Oil (Extra Light)	14%	73%	11%	242°C (468°F)	Sautee, Stir frying, frying, cooking, salad oils, margarine
Palm oil	52%	38%	10%	230°C (446°F)	Cooking, flavoring, vegetable oil, shortening
Peanut oil	18%	49%	33%	231°C (448°F)	Frying, cooking, salad oils, margarine
Safflower oil	10%	13%	77%	265°C (509°F)	Cooking, salad dressings, margarine
Sesame oil (Unrefined)	14%	43%	43%	177°C (350°F)	Cooking, deep frying
Sesame oil (Semi-refined)	14%	43%	43%	232°C (450°F)	Cooking, deep frying
Soybean oil	15%	24%	61%	241°C (466°F)	Cooking, salad dressings, vegetable oil, margarine, shortening
Sunflower oil	11%	20%	69%	246°C (475°F)	Cooking, salad dressings, margarine, shortening

There is a general lack of consensus on the smoke points of many popular oils, as well as a lack of standardization for qualifiers such as "refined". Empirical tests are heavily dependent on the qualities of the particular samples (brand, composition, process) available, but appear to be the major source of available data. In the field, experience trumps references, and there is no source that seems truly authoritative. A crude guide is that lighter, more refined oils have higher smoke points. If there is any doubt at all, be fully prepared to extinguish a burning oil fire before heating.

Waste cooking oil

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 liter of oil can contaminate as much as 1 million liters of water.^[10] 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.^[11]

Better yet, cooking oil can be recycled. It can be used to produce soap and biodiesel.^[12]

Notes and References

1. ^ "The Food Pyramid". FDA Consumer. Retrieved on 2006-09-18. 
2. ^ Cooking oils with the least amount of saturated fats and highest amount of unsaturated fats are most healthy
3. ^ [http://findarticles.com/p/articles/mi_m1594/is_2_14/ai_98469943/ Choosing the right oil depending on the temperature employed
4. ^ http://findarticles.com/p/articles/mi_m1594/is_2_14/ai_98469943/pg_2 Choosing the right oil depending on the temperature employed
5. ^ Least healthy oils
6. ^ Palm oil one of the least healthy oils
7. ^ Olive Oil Source Cooking with Olive Oil Retrieved December 12, 2006
8. ^ The smoke point of oils depends primarily on their free fatty acid content (FFA) and molecular weight. Through repeated use, as in a deep fryer, food residues or by-products of the cooking process will accumulate within the oil and lower its smoke point. The values shown in the above table must therefore be taken as approximate, and are not suitable for accurate or scientific use.
9. ^ The smoke point of margarine varies depending on the types of oils used in its formulation, but can be generally assumed to be similar to that of butter.
10. ^ Tips to avoid water waste and to require the preservation of hydro-resources. Natureba - Educação Ambiental. Retrieved on 2007-09-05.
11. ^ Grease Disposal Tips to Help the City's Environment. NYC Department of Environmental Protection. Retrieved on 2007-08-05.
12. ^ Production of biodiesel based on waste oils and/or waste fats from biogenic origin for use as fuel. CDM - Executive Board. Retrieved on 2007-09-05.

Other references

• O'Brien, R.D. (1998). Fats and Oils: Formulating and Processing for Applications. Technomic Publishing Co., Inc.. 
• Potter, N.N. and J.H. Hotchkiss (1995). Food Science - Fifth Edition. Chapman & Hall, 359-80, 402-7. 

See also

• Cooking spray

External links

• American Oil Chemical Society official website.

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