Coconut oil
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Coconut oil, also known as coconut butter, is a tropical oil with many applications. It is extracted from copra (derived from Malayalam word "kopra" which means dried coconut). Coconut oil constitutes seven percent of the total export income of the Philippines, the world's largest exporter of the product.
Coconut oil was developed as a commercial product by merchants in the South Seas and South Asia in the 1860s.
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Physical properties
Coconut oil is a fat consisting of about 90% saturated fat. The oil contains predominantly medium chain triglycerides,[1] with roughly 92% saturated fatty acids, 6% monounsaturated fatty acids, and 2% polyunsaturated fatty acids. Of the saturated fatty acids, coconut oil is primarily 44.6% lauric acid, 16.8% myristic acid and 8.2% palmitic acid, although it contains seven different saturated fatty acids in total. Its only monounsaturated fatty acid is oleic acid while its only polyunsaturated fatty acid is linoleic acid.[2]
Unrefined coconut oil melts at 24-25°C (76°F) and smokes at 170°C (350°F),[3] while refined coconut oil has a higher smoke point of 232°C (450°F).
Coconut oil has a long shelf life compared to other oils, lasting up to two years due to its high saturated fat content; saturated fats resist rancidity. Coconut oil is best stored in solid form—i.e., at temperatures lower than 24.5°C (76°F)—in order to extend shelf life. However, unlike most oils, coconut oil will not be damaged by warmer temperatures.
Chemical properties
Among the most stable of all oils, coconut oil is slow to oxidize and thus resistant to rancidity.
Types of oil available
Unrefined coconut oil (Virgin Coconut Oil VCO)
This is coconut oil that is derived from fresh coconuts, not copra, and has not undergone the RBD (refined, bleached, deodorized) process that refined coconut oil derived from copra goes through.
Almost all of the "unrefined" coconut oils on the market being marketed as "Virgin" are produced one of two ways:
1. Quick drying of fresh coconut meat which is then used to press out the oil. Using this method, the coconut meat is quick dried, and the oil is then pressed out via mechanical means.
2. Wet-milling. With this method the oil is extracted from fresh coconut meat without drying first. "Coconut milk" is expressed first by pressing. The oil is then further separated from the water. Methods which can be used to separate the oil from the water include boiling, fermentation, refrigeration, enzymes and mechanical centrifuge.[4]
Unlike olive oil, there is no world or governing body that sets a standard definition or set of guidelines to classify coconut oil as "virgin." but the Philippines being the largest producer/exporter has recently established a Department of Science and Technology (DOST) governmental standard see: PNS for VCO.
Refined oil
Refined coconut oil is referred to in the coconut industry as RBD (refined, bleached, and deodorized) coconut oil. The starting point is "copra", the dried coconut meat. Copra can be made by smoke drying, sun drying, or kiln drying. The unrefined coconut oil extracted from copra (called "crude coconut oil") is not suitable for consumption and must be refined.[5]
Hydrogenated oil
Hydrogenated coconut oil may either be fully or partially hydrogenated. This happens mostly in tropical climates, since the natural melting point of coconut oil is about 76 degrees F, and already naturally a solid in most colder climates.
Fractionated oil
"Fractionated coconut oil" is a fraction of the whole oil, in which most of the long-chain triglycerides are removed so that only saturated fats remain. It may also referred to as "caprylic/capric triglyceride" or medium-chain triglyceride (MCT) oil because mostly the medium-chain triglycerides caprylic and capric acid) are left in the oil.
Because it is completely saturated, fractionated oil is even more heat stable than other forms of coconut oil and has a nearly indefinite shelf life.
Effects on health
There is widespread misunderstanding about coconut oil that the saturated fat content is somehow different.[6] [7] [8] [9] [10] During the 1980s, the American Heart Association issued statements indicating that coconut oil's high saturated fat content was detrimental to cardiovascular health and promoted heart disease.[11] The American Heart Association maintains such recommendations to this day, advising that individuals reduce their consumption of saturated fats, including those found in coconut oil, to less than 7% of one's caloric intake. [12] [13] This concurs with similar conclusions made by the World Health Organization and the FDA, both of which determined that reduced consumption of saturated fat, including that from coconut oil, would positively affect health and reduce the prevalence of heart attacks. [14] [15]
A research study at the Heart Research Institute in Sydney, Australia used coconut oil and safflower oil (high in polyunsaturated fat) in two otherwise identical meals for the study's participants.[16] The study found the following: "Consumption of a saturated fat reduces the anti-inflammatory potential of HDL and impairs arterial endothelial function. In contrast, the anti-inflammatory activity of HDL improves after consumption of polyunsaturated fat." Because endothelial dysfunction is a key early event in atherogenesis, coconut oil may be associated with atherogenesis.
Epidemiological studies have been performed on tropical cultures that get a majority of their caloric intake from coconut oil. The most popular study was conducted in the early 1980s on the Polynesian islands of Pukapuka and Tokelau - two cultures relatively untouched by western food at the time. Both cultures had an high intake of saturated fat, with one of the island's population consuming 63% of their caloric intake from coconut. The people were found to be very healthy, and the authors of the study concluded: "Vascular disease is uncommon in both populations and there is no evidence of the high saturated fat intake having a harmful effect in these populations."[17] However, these results may not necessarily be applicable to other populations, nor can the fact that these people's high saturated fat content be determined to be the cause of their good health. Being untouched from western culture could have resulted in islanders living an active lifestyle with a diet low in carbohydrates and sugar-laden foods, explaining the positive health observation.
Epidemiological studies have found that those whose diets are high in saturated fatty acids, including lauric, myristic, palmitic, and stearic acid, found in coconut oil, were strong predictors of coronary heart disease risk. [18] [19] [20] [21] In postmenopausal women with relatively low total fat intake, a greater saturated fat intake is associated with less progression of coronary atherosclerosis, whereas carbohydrate intake is associated with a greater progression. [1][2]
Still, some researchers believe that the studies that have been conducted unfairly link coconut oil to health problems and that there are health benefits to coconut oil [22]. Some researchers believe that coconut oil is different from other saturated fats because it is composed of medium-chain fatty acids.[23]
Applications
Cooking
Coconut oil is commonly used in cooking, especially when frying, and it has a high smoke point which makes it good for this purpose. In communities where coconut oil is widely used in cooking, the refined oil is the one most commonly used.
Coconut oil is often used in making a curry or in popcorn machines at movie theaters.
Manufacturing
Coconut oil is used in volume quantities for making margarine, soap and cosmetics.
Hydrogenated or partially-hydrogenated coconut oil is often used in non-dairy creamers, and snack foods.
Fractionated coconut oil is also used in the manufacture of essences, massage oils and cosmetics
Cosmetics and skin treatments
Coconut oil is excellent as a skin moisturiser. A study shows that extra virgin coconut oil is as effective and safe as mineral oil when used as a moisturiser, with absence of adverse reactions.[24] Although not suitable for use with condoms, coconut oil is an excellent, inexpensive lubricant for sexual intercourse. Before coconut oil is used as a sexual lubricant, however, it is recommended to do an allergy test.
Coconut oil can also help in healing Keratosis pilaris by moisturising the affected area. The coconut oil should be applied in the shower, and may cause the KP bumps to disappear permanently.[citation needed]
In India and Sri Lanka, coconut oil is commonly used for styling hair, and cooling or soothing the head (stress relief). People of TamilNadu and coastal districts of Kerala,Karnataka bathe in warm water after applying coconut oil all over the body and leaving it as is for an hour. It is suggested by elders that this ritual must be done at least once in a week, to keep body, skin, and hair healthy.
As a fuel
Traditional use
Coconut oil is used in oil lamps.
In diesel engines
- See also Vegetable oil used as fuel.
Coconut oil has been tested for use as a feedstock for biodiesel to be used as a diesel engine fuel. In this manner it can be applied to power generation and transport using diesel engines.
Coconut oil is blended to make biodiesel but can also be used straight, without blending. However, only blends with 10% or less of coconut oil can be safely used in unmodified engines. The oil needs to meet the Weihenstephan standard[25] for pure vegetable oil used as a fuel since otherwise moderate to severe damage from coking and clogging will occur in an unmodified engine . Stationary engines that are continuously loaded (>70%) may possibly be used without engine modifications but there is divergent opinion about this.
The physical constraints of using raw coconut oil in a diesel engine are formed by:
- higher viscosity of coconut oil (up to 10 times as high as diesel), leading to altered spray pattern of injected fuel, additional stress on injection pump
- minimum combustion chamber temperature of 500 °C to avoid polymerisation of the fuel, leading to clogged injectors, sticking piston rings and lubrication oil deterioration
- solidification point between 22-25 °C requires an additional fuel tank heater in temperate climates.
Raw coconut oil can be used as a fuel for generating electricity by remote communities that have an abundant supply of coconuts and milling capacity, provided diesel engines are adapted.
Coconut oil is currently used as a fuel for transport and electricity generation in the Philippines[citation needed] and India[citation needed] while research is being carried out in the islands of the Pacific.[26][27] In the 1990s Bougainville conflict, islanders cut off from supplies due to a blockade used it to fuel their vehicles.[28]
Availability to consumers
While coconut oil is widely available in some countries, it can be hard to find in others. In the UK it is not generally available in big supermarkets, but can be easily obtained from smaller convenience stores at very cheap prices (from £1 to £2 for 500ml). Some people are unaware of this and resort to buying it online or from health food shops, which generally charge a lot more (from £5 to £20 for 500ml). Some sellers explain their prices by saying that their product is not refined (eg. "extra virgin"). However, as saturated fats do not contain any double bonds, they are highly heat stable, and as coconut oil is about 90% saturated fat, the quality of the oil itself is not affected very much by the processing. Interestingly enough, some sellers even advertise their product as being both "made without heat processing" and as being heat stable. The main difference between these two oils is the amount of extra nutrients that may remain in the unrefined oil, and the taste which in the refined oil is nearly non-existent.
References
- ↑ http://www.nutritiondata.com/facts-C00001-01c208C.html
- ↑ Nutrient analysis of coconut oil - USDA
- ↑ Cooking For Engineers - Kitchen Notes: Smoke Points of Various Fats
- ↑ http://www.coconutoil.com/coconut_oil_production.htm
- ↑ http://www.coconutoil.com/coconut_oil_production.htm
- ↑ Origins Of The Anti-Saturated Fat Agenda, "Coconut: In Support of Good Health in the 21st Century, Mary G. Enig, Ph.D., F.A.C.N.
- ↑ Kurup PA, Rajmohan T. Consumption of coconut oil and coconut kernel and the incidence of atherosclerosis. Coconut and Coconut Oil in Human Nutrition, Proceedings. Symposium on Coconut and Coconut Oil in Human Nutrition. 27 March 1994. Coconut Development Board, Kochi, India, pp 35-59 (1995)
- ↑ "Coconut Oil – Ideal Fat next only to Mother’s Milk", Hegde, BM, Journal, Indian Academy of Clinical Medicine 2006; 7(1): 16-9
- ↑ "Coconut Oil".
- ↑ "Good Fat, Bad Fat".
- ↑ http://www.newstarget.com/001587.html
- ↑ http://www.americanheart.org/presenter.jhtml?identifier=532
- ↑ Alice H. Lichtenstein, Lawrence J. Appel, Michael Brands, Mercedes Carnethon et al Diet and Lifestyle Recommendations Revision 2006: A Scientific Statement From the American Heart Association Nutrition Committee Circulation 2006;114;82-96
- ↑ Joint WHO/FAO Expert Consultation on Diet, Nutrition and the Prevention of Chronic Diseases Diet, nutrition and the prevention of chronic diseases: report of a joint WHO/FAO expert consultation ISBN 92-4-120916-X ISSN 0512-3054
- ↑ U.S. Department of Health and Human Services Dietary Guidelines for Americans 2005
- ↑ Nicholls SJ, Lundman P, Harmer JA, Cutri B, Griffiths KA, et al, Consumption of Saturated Fat Impairs the Anti-Inflammatory Properties of High-Density Lipoproteins and Endothelial FunctionJ Am Coll Cardiol, 2006; 48:715-720, doi:10.1016/j.jacc.2006.04.080 (Published online 21 July 2006). PMID 16904539.
- ↑ Prior IA, Davidson F, Salmond CE, Czochanska Z Cholesterol, coconuts, and diet on Polynesian atolls: a natural experiment: the Pukapuka and Tokelau island studies Am J Clin Nutr 1981 Aug;34(8):1552-61
- ↑ Kromhout D, Menotti A, Bloemberg B, Aravanis C, Blackburn H, Buzina R, Dontas AS, Fidanza F, Giampaoli S, Jansen A, et al Dietary saturated and trans fatty acids and cholesterol and 25-year mortality from coronary heart disease: the Seven Countries Study Prev Med 1995 May;24(3):308-15
- ↑ Frank B Hu, Meir J Stampfer, JoAnn E Manson, Alberto Ascherio, Graham A Colditz, Frank E Speizer, Charles H Hennekens, and Walter C Willett Dietary saturated fats and their food sources in relation to the risk of coronary heart disease in women Am J Clin Nutr 1999;70:1001–8
- ↑ Ancel Keys Coronary heart disease in seven countries Nutrition Volume 13, Issue 3, March 1997, Page 249
- ↑ Beegom R, Singh RB Association of higher saturated fat intake with higher risk of hypertension in an urban population of Trivandrum in south India Int J Cardiol 1997 Jan 3;58(1):63-70
- ↑ Mary G. Enig A New Look at Coconut Oil
- ↑ Coconut Research Center
- ↑ Agero AL, Verallo-Rowell VM A randomized double-blind controlled trial comparing extra virgin coconut oil with mineral oil as a moisturizer for mild to moderate xerosis Dermatitis 2004 Sep;15(3):109-16
- ↑ Weihenstephan vegetable oil fuel standard (German Rapeseed Fuel Standard)
- ↑ Coconut Oil for Power Generation by EPC in Samoa - Jan Cloin
- ↑ Template:Cite news
- ↑ The coconut revolution - a documentary film.
