Cooking oil

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

Cooking oil is purified fat of plant 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 flavored 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).

Contents

[edit] Health and nutrition

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.[1] Other nutritionists recommend that no more than 10% of a person's daily calories come from fat.[2] 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 that are particularly high in saturated fats include coconut, palm oil and palm kernel oil.[3] Oils with lower amounts of saturated fats, and higher amounts of unsaturated (preferably monounsaturated) fats, are generally healthier.[3].

[edit] Health and particular oils

While such general principles can provide general dietary guidelines, it's also important to consider the dietary characteristics of individual oils. Olive oil, for example, raises "good" HDL cholesterol, a heart-healthy effect that need not be limited by an arbitrary figure.

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.

[edit] Trans fats

Trans fats are unsaturated fats that are not required or beneficial for health. Hydrogenation, a process that adds hydrogen atoms to fat molecules to make them more saturated, is responsible for most dietary transfats. Oils are hydrogenated to increase their melting point (for example in making margarine).

[edit] Cooking with oils

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 230°C/445°F) because of their high smoke point include:

Oils suitable for medium-temperature frying (above 190°C/375°F) include:

Unrefined oils should not be used for frying, but are safe for simmering.

[edit] 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 (olive oil will 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.

[edit] Types of oils and their characteristics

A rough guide is that lighter, more refined oils have higher smoke points. Experience using an oil is generally a sufficiently reliable guide. Although outcomes of empirical tests are sensitive to the qualities of particular samples (brand, composition, refinement, process), the data below should be helpful in comparing the properties of different oils.

Smoking oil indicates a risk of combustion, and left unchecked can also set off a fire alarm. When using any cooking oil, should it begin to smoke, heat should be reduced immediately. Generally, one should be fully prepared to extinguish a burning oil fire before heating, typically by having to hand the lid to place on the pan, or (for the worst case) having to hand the proper fire extinguisher.

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% 190-250°C (375-485°F) Deep frying, cooking, sautéeing, condiment, flavoring
Canola oil 6% 62% 32% 242°C (468°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% 2% 138-201°C (280-395°F)[5] Baking, frying
Margarine, hard 80% 14% 6% 150°C (320°F)[6] Cooking, baking, condiment
Margarine, soft 20% 47% 33% 150-160°C (300-320°F) Cooking, baking, condiment
Diacylglycerol (DAG) oil 3.5% 37.95 % 59% 215°C (420°F) Frying, baking, salad oil
Olive Oil (Extra Virgin) 14% 73% 11% 190°C (375°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
Rice bran oil 20% 47% 33% 254°C (490°F) Cooking, stir frying, deep frying
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

[edit] 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 litre of oil can contaminate as much as 1 million litres of water.[7] 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.[8]

Cooking oil can be recycled. It can be used to produce soap and biodiesel.[9]

[edit] Notes and References

  1. ^ "The Food Pyramid". FDA Consumer. http://www.cfsan.fda.gov/~dms/fdpyrmid.html. Retrieved on 2006-09-18. 
  2. ^ Dean Ornish, MD, Lifestyle Program
  3. ^ a b wiseGeek. "What is the Healthiest Oil to Use for Cooking?". http://www.wisegeek.com/what-is-the-healthiest-oil-to-use-for-cooking.htm. Retrieved on 2008-02-11. 
  4. ^ Orna Izakson (March/April 2003). "Oil right: choose wisely for heart-healthy cooking - Eating Right". E: The Environmental Magazine. http://findarticles.com/p/articles/mi_m1594/is_2_14/ai_98469943/pg_2. Retrieved on 2008-02-11. 
  5. ^ 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.
  6. ^ 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.
  7. ^ "Tips to avoid water waste and to require the preservation of hydro-resources". Natureba - Educação Ambiental. http://www.natureba.com.br/nature/saving-water.htm. Retrieved on 2007-09-05. 
  8. ^ "Grease Disposal Tips to Help the City's Environment". NYC Department of Environmental Protection. http://nyc.gov/html/dep/html/residents/congrease.shtml. Retrieved on 2007-08-05. 
  9. ^ "Production of biodiesel based on waste oils and/or waste fats from biogenic origin for use as fuel" (PDF). CDM - Executive Board. http://www.mct.gov.br/upd_blob/0016/16059.pdf. Retrieved on 2007-09-05. 

[edit] 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. pp. 359–80, 402–7. 

[edit] See also

[edit] External links

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