Tuesday, April 14, 2009

Coconut oil

Coconut oil, also known as coconut butter, is a tropical oil with many applications. It is extracted from copra (the dried meat, or kernel, of the 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.

Contents [hide]
1 Physical properties
2 Types of oil available
2.1 Virgin coconut oil
2.2 Refined oil
2.2.1 Hydrogenated oil
2.2.2 Fractionated oil
3 Health effects
3.1 Heart disease
3.2 Antimicrobial effects
4 Applications
4.1 Cooking
4.2 Manufacturing
4.3 Cosmetics and skin treatments
4.4 Industrial and commercial uses
4.4.1 Traditional use
4.4.2 In diesel engines
4.4.3 Aircraft fuel
4.4.4 Engine lubricant
5 See also
6 References

[edit] 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 , 8.2% palmitic acid and 8% caprylic 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]

In the human body lauric acid is converted into monolaurin. [3]

Unrefined coconut oil melts at 24-25°C (76°F) and smokes at 177°C (350°F),[4] while refined coconut oil has a higher smoke point of 232°C (450°F).

Among the most stable of all oils, coconut oil is slow to oxidize and thus resistant to rancidity, lasting up to two years due to its high saturated fat content.[citation needed] In order to extend shelf life, it is best stored in solid form (i.e. below 24.5°C [76°F]).

[edit] Types of oil available

[edit] Virgin coconut oil
Virgin coconut oil is derived from fresh coconuts (rather than dried, as in copra). Most oils marketed as "virgin" are produced one of three ways:

Quick-drying of fresh coconut meat, which is then used to press out the oil.
Wet-milling (coconut milk). 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.
Wet-milling (direct micro expelling). In this process, the oil is extracted from fresh coconut meat after the adjustment of the water content, then the pressing of the coconut flesh results in the direct extraction of free-flowing oil.
In contrast to olive oil, coconut oil has no world or governing body to set a standard definition or set of guidelines to classify the oil as "virgin". The Philippines has established a Department of Science and Technology (DOST) governmental standard.[5]

[edit] Refined oil

Coconuts sundried in Kozhikode, Kerala for making copra, which is used for making coconut oilRefined 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[citation needed] and must be refined. A recently developed method for extraction of "a high quality" coconut oil involves the enzymatic action of alpha-amylase, polygalacturonases and proteases on diluted coconut paste.[6]

[edit] Hydrogenated oil
Coconut oil is often partially or fully hydrogenated to increase its melting point in warmer temperatures. This increases the amount of saturated fat present in the oil, and may produce trans fats.

[edit] 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 it is primarily the medium-chain triglycerides caprylic and capric acid that 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.[citation needed]

[edit] Health effects

[edit] Heart disease
Blood tests performed on rats showed decreased risk factors for heart disease (reduced total cholesterol, triglycerides and low-density lipoprotein and increased high-density lipoprotein) in rats fed virgin coconut oil, when compared to rats fed copra oil.[7] In addition, the polyphenol fraction of unprocessed coconut oil prevented in vitro oxidation of low-density lipoproteins.[8]

A study of Polynesian populations that consumed mainly coconut meat found that increased consumption of coconut was associated with significantly higher levels of serum cholesterol but this was not associated with higher rates of death due to heart attacks and other forms of cardiovascular disease.[9]

Reducing the consumption of coconut oil and replacing a portion of it with polyunsaturated fats resulted in changes to blood cholesterol levels that are associated with a reduced risk of cardiovascular diseases.[10]

[edit] Antimicrobial effects
Coconut oil has been found effective against certain strains of the Candida yeast, though it is ineffective against others.[11] Coconut oil taken orally was found to be a useful adjunct therapy in children with community-acquired pneumonia.[12] Taken in conjunction with IV ampicillin, coconut oil supplementation resulted in earlier normalization of respiratory rate and earlier normalization of lung sounds vs. IV ampicillin alone. Monolaurin from coconut oil has demonstrated virucidal activity against 14 human RNA and DNA enveloped viruses in vitro.[13] Another laboratory study investigated the effect of monolaurin on primary and secondary skin infections compared with six common antibiotics.[14] In culture isolates from the skin infections, monolaurin showed statistically significant broad-spectrum sensitivity to both Gram-positive and Gram-negative bacterial isolates, such as Staphylococcus aureus, Streptococcus spp. and Enterobacter spp.

[edit] Applications

[edit] Cooking
Coconut oil is commonly used in cooking, especially when frying. In communities where coconut oil is widely used in cooking, the unrefined oil is the one most commonly used. Coconut oil is commonly used to flavor many South Asian curries.

[edit] 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

Coconut oil is an important component of many industrial lubricants, for example in the cold rolling of steel strip.

[edit] Cosmetics and skin treatments
Coconut oil is excellent as a skin moisturizer and softener. A study shows that extra virgin coconut oil is effective and safe when used as a moisturizer, with absence of adverse reactions.[15] Although not suitable for use with condoms, coconut oil may be used as a lubricant for sexual intercourse,[16] though it may cause an allergic reaction in some.

In India and Sri Lanka, coconut oil is commonly used for styling hair, and cooling or soothing the head. People of Tamil Nadu and other coastal areas such as Kerala, Karnataka, Maharashtra and Goa bathe in warm water after applying coconut oil all over the body and leaving it as is for an hour to keep body, skin, and hair healthy.

[edit] Industrial and commercial uses

[edit] Traditional use
Coconut oil is used in oil lamps.

[edit] 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 generators and transport using diesel engines. Since straight coconut oil has a high gelling temperature (22-25°C), a high viscosity, and a minimum combustion chamber temperature of 500 °C (932 °F) (to avoid polymerization of the fuel), coconut oil is typically transesterified to make biodiesel. Use of B100 (100% biodiesel) is only possible in temperate climates as the gel point is approximately 10°C (50 degrees Fahrenheit). The oil needs to meet the Weihenstephan standard[17] for pure vegetable oil used as a fuel since otherwise moderate to severe damage from carbonisation and clogging will occur in an unmodified engine.

Coconut oil is currently used as a fuel for transport in the Philippines.[18] Further research into the oil's potential as a fuel for electricity generation is being carried out in the islands of the Pacific.[19][20] In the 1990s Bougainville conflict, islanders cut off from supplies due to a blockade used it to fuel their vehicles.[21]

[edit] Aircraft fuel
During February 2008, a mixture of coconut oil and babassu oil was used to partially power one engine of a Boeing 747, in a biofuel trial sponsored by Virgin Atlantic.[22]

[edit] Engine lubricant
Coconut oil has been tested for use as an engine lubricant; the company producing the oil claims the oil reduces fuel consumption, smoke emissions and allows the engine to run at a cooler temperature.[23]

[edit] See also

[edit] References
^ Nutrition Facts and Information for Vegetable oil, coconut
^ Nutrient analysis of coconut oil - USDA
^ Hegde B. (2006). Coconut oil - ideal fat next to mother's miok (scanning coconut's horoscope). JIACM. 7:16-19.
^ Cooking For Engineers - Kitchen Notes: Smoke Points of Various Fats
^ Joint Statement on Philippine National Standard for Virgin Coconut Oil as food
^ McGlone OC, Canales A, Carter JV. (2006). "Coconut oil extraction by a new enzymatic process." Journal of Food Science. 51:695-697.
^ Nevin KG, Rajamohan T (September 2004). "Beneficial effects of virgin coconut oil on lipid parameters and in vitro LDL oxidation". Clin. Biochem. 37 (9): 830–5. doi:10.1016/j.clinbiochem.2004.04.010. PMID 15329324.
^ Nevin KG, Rajamohan T (September 2004). "Beneficial effects of virgin coconut oil on lipid parameters and in vitro LDL oxidation". Clin. Biochem. 37 (9): 830–5. doi:10.1016/j.clinbiochem.2004.04.010. PMID 15329324.
^ Prior IA, Davidson F, Salmond CE, Czochanska Z (August 1981). "Cholesterol, coconuts, and diet on Polynesian atolls: a natural experiment: the Pukapuka and Tokelau island studies" (pdf). Am. J. Clin. Nutr. 34 (8): 1552–61. PMID 7270479. http://www.ajcn.org/cgi/reprint/34/8/1552?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&searchid=1&FIRSTINDEX=0&sortspec=relevance&volume=34&firstpage=1552&resourcetype=HWCIT. Retrieved on 2008-07-14.
^ Mendis S, Samarajeewa U, Thattil RO (May 2001). "Coconut fat and serum lipoproteins: effects of partial replacement with unsaturated fats". Br. J. Nutr. 85 (5): 583–9. doi:10.1079/BJN2001331. PMID 11348573. http://journals.cambridge.org/abstract_S0007114501000836.
^ Ogbolu DO, Oni AA, Daini OA, Oloko AP (June 2007). "In vitro antimicrobial properties of coconut oil on Candida species in Ibadan, Nigeria". J Med Food 10 (2): 384–7. doi:10.1089/jmf.2006.209. PMID 17651080.
^ Chest Journal. American College of Chest Physicians. Erguiza G, Jiao A, Reley M et al. (2008). "The effect of virgin coconut oil supplementation for community-acquired pneumonia in children aged 3 months to 60 months admitted at the phillipine children's medical center: a single blinded randomized controlled trial." http://meeting.chestjournal.org/cgi/content/abstract/134/4/p139001. Accessed on 3/11/09.
^ Hierholzer JC, Kabara JJ. (1982). In vitro effects of monolaurin compounds on enveloped RNA and DNA viruses. Journal of Food Safety. 4:1-12.
^ Carpo BG, Verallo-Rowell VM, Kabara J. (2007). Novel antibacterial activity of monolaurin compared with conventional antibiotics against organisms from skin infections: an in vitro study. J Drugs Dermatol. 6:991-998.
^ 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
^ Vaginal Dryness, Menopause and Sex, Libido, Sexual Desire, Relationships at Menopause
^ Weihenstephan vegetable oil fuel standard (German Rapeseed Fuel Standard)
^ Coconut fuel - PRI's The World
^ Coconut Oil for Power Generation by EPC in Samoa - Jan Cloin
^ "Coconut oil powers island's cars". BBC. 2007-05-08. http://news.bbc.co.uk/1/hi/world/asia-pacific/6634221.stm.
^ The Coconut Revolution: a documentary film
^ "First biofuel flight" BBC News, February 24, 2008
^ Romares-Sevilla, J (2008-01-17). "Davao-based firm sees expansion of bio-tech oil market". Sun.Star Superbalita Davao. http://www2.sunstar.com.ph/static/dav/2008/01/17/bus/davao.based.firm.sees.expansion.of.bio.tech.oil.market.html. Retrieved on 2008-07-14.

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