Coconut oil

Traditional way of making coconut oil using a bullock-powered mill in Seychelles

Coconut oil is extracted from the kernel or meat of matured coconut harvested from the coconut palm (Cocos nucifera). Throughout the tropical world it has provided the primary source of fat in the diets of millions of people for generations. It has various applications in food, medicine, and industry. Coconut oil is very heat stable so it makes an excellent cooking and frying oil. It has a smoke point of about 360 °F (180 °C). Because of its stability it is slow to oxidize and thus resistant to rancidity, lasting up to two years due to high saturated fat content.

Fatty acid content of coconut oil
Type of fatty acid			pct
Lauric saturated C12			47.5%
Myristic saturated C14			18.1%
Palmitic saturated C16			8.8%
Caprylic saturated C8			7.8%
Capric saturated C10			6.7%
Stearic saturated C18			2.6%
Caproic saturated C6			0.5%
Oleic monounsaturated C18			6.2%
Linoleic polyunsaturated C18			1.6%
Coconut oil contains approximately 92.1% saturated fatty acids, 6.2% monounsaturated fatty acids, 1.6% polyunsaturated fatty acids. The above numbers are averages based on samples taken. Numbers can vary slightly depending on age of the coconut, growing conditions, and variety. red: Saturated; orange: Monounsaturated; blue: Polyunsaturated

Production

The wet process for making coconut oil is the original and variations of it are still the best and cleanest way to extract coconut oil. The dry process was invented as a way to mass produce a food/industrial grade oil although there are some drawbacks to its extraction method.

In the wet process, coconut milk is made first and then the oil is extracted from the milk. Coconut kernel is shredded and mixed with water. Then it is pressed and the oil is extracted. The resulting oil/water mixture is left to sit and it separates into two layers, watery on the bottom, creamy on top. The thicker cream is decanted off the top and the original method of separation involved heating or fermenting the milk to separate the oil. This traditional method made a very unstable oil with a short shelf life meant for quick daily use.

All high volume modern methods incorporate heating, fermentation, and or centrifugal force to separate the oil from the water. The use of a cool temperature vacuum separator has been suggested but the technology is currently cost prohibitive for all but the biggest manufacture and isn't nearly as efficient as the other techniques.

Proper harvesting of the coconut (the age of a coconut can be 2 to 20 months when picked) makes a significant difference in the efficacy of the oil making process and the use of a centrifuge process makes the best final extracted product. Any coconut oil made from a non-copra style of extraction can be called virgin organic coconut oil but only the centrifuge process can make raw oil. When done properly it doesn't need to be heated or fermented to remove moisture.

In the dry process, the oil is extracted directly from the kernel. The kernel can be dried (under the sun or in a kiln/oven) shredded or whole, then is compressed and the oil is extracted. This is a most inefficient and dirty way to remove the oil from the kernel and requires more processing to reclaim the rest of the oil from the left over cake from compressing. The oil commonly has bits of shell and kernel left in it along with a high moisture content which discolor it and make it go rancid quickly. Superheated steam, boiling and fermentation are some of methods use to remove the color, debris and moisture from the oil.

RBD

Coconuts sundried in Kozhikode, Kerala for making copra, which is used for making coconut oil

Coconut Oil expelled from Copra at an oil mill in Tripunithura, Kerala, India

RBD stands for "refined, bleached, and deodorized." RBD oil is usually made from copra (dried coconut kernel). Copra can be made by smoke drying, sun drying, or kiln drying. The dried copra is then placed in a powerful hydraulic press with added heat and the oil is extracted. This yields up practically all the oil present, amounting to more than 60% of the dry weight of the coconut.

This "crude" coconut oil is not suitable for consumption because it contains contaminants and must be refined with further heating and filtering.

Another method for extraction of a "high quality" coconut oil involves the enzymatic action of alpha-amylase, polygalacturonases and proteases on diluted coconut paste.

Unlike virgin coconut oil, refined coconut oil has no coconut taste or aroma. RBD oil is used for home cooking, commercial food processing, and cosmetic, industrial, and pharmaceutical purposes.

Hydrogenation

RBD coconut oil can be processed further into partially or fully hydrogenated oil to increase its melting point. Since virgin and RBD coconut oils melt at 76 °F (24 °C), foods containing coconut oil tend to melt in warm climates. A higher melting point is desirable in these warm climates so the oil is hydrogenated. The melting point of hydrogenated coconut oil is 97–104 °F (36–40 °C).

In the process of hydrogenation, unsaturated fats (monounsaturated and polyunsaturated fatty acids) are combined with hydrogen in a catalytic process to make them more saturated. Coconut oil contains only 6% monounsaturated and 2% polyunsaturated fatty acids. In this process some of these are transformed into trans fatty acids.

Fractionation

Fractionated coconut oil is a fraction of the whole oil, in which the different medium chain fatty acids are separated for specific uses. Lauric acid, a 12 carbon chain fatty acid, is often removed because of its high value for industrial and medical purposes. Fractionated coconut oil may also be referred to as caprylic/capric triglyceride oil or medium chain triglyceride (MCT) oil because it is primarily the medium chain caprylic (8 carbons) and capric (10 carbons) acids that make up the bulk of the oil. MCT oil is most frequently used for medical applications and special diets.

Figures

The United States Department of Agriculture has published historical production figures for coconut oil for years beginning October 1 and ending September 30. Coconut oil makes up around 2.5% of world vegetable oil production. Over the last few years coconut oil production is estimated to have been as follows:

Year	2005–06	2006–07	2007–08	2008–09	2009–10	Jan 2010–11
Production, Million Tonne	3.46	3.22	3.53	3.53	3.62	3.67

Standards

The Asian and Pacific Coconut Community (APCC), whose 17 members produce about 90% of the coconut sold commercially, has published its Standards for Virgin Coconut Oil. The Philippines has established a Department of Science and Technology (DOST) governmental standard.

Health

The United States Food and Drug Administration, World Health Organization, International College of Nutrition, the United States Department of Health and Human Services, American Dietetic Association, American Heart Association, British National Health Service, and Dietitians of Canada recommend against the consumption of coconut oil due to its high levels of saturated fat.

Coconut oil contains a large proportion of lauric acid, a saturated fat that raises blood cholesterol levels by increasing the amount of high-density lipoprotein cholesterol. This may create a more favourable blood cholesterol profile, though it is unclear if coconut oil may promote atherosclerosis through other pathways. Because much of the saturated fat of coconut oil is in the form of lauric acid, coconut oil may be a better alternative to partially hydrogenated vegetable oil when solid fats are required. In addition virgin coconut oil contains large amounts of medium-chain triglycerides, which may not carry the same risks as other saturated fats. Early studies on the health effects of coconut oil used partially hydrogenated coconut oil, which creates trans fats, and not virgin coconut oil which has a different health risk profile.

A repellent made from coconut oil can be used to prevent tungiasis-causing sand fleas from invading the body.

Uses

Culinary arts

Coconut oil is commonly used in cooking, especially for frying. In communities where coconut oil is widely used in cooking, the unrefined oil is frequently the one most commonly used.

In recent years virgin coconut oil has increasingly become popular in natural food circles and with vegans. It has been described as having a "haunting, nutty, vanilla flavor" that also has a touch of sweetness that works well in baked goods, pastries, and sautés. Coconut oil is commonly used to flavor many South Asian curries.

The caloric content of coconut oil is very nearly the same as that of other dietary fats, being reduced only slightly by the presence of medium chain triglycerides which constitute less than half of the total fat content. A value of 8.3 kcal/g has been quoted for dietary medium-chain triglycerides.

Hydrogenated or partially hydrogenated coconut oil is often used in non-dairy creamers, and snack foods including popcorn. Hydrogenated coconut oil is also sold in Australia under the brand-name Copha and is the main ingredient in Australian snacks such as Chocolate crackles and White Christmas.

Industry

Engine feedstock

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 °F). The oil needs to meet the Weihenstephan standard for pure vegetable oil used as a fuel otherwise moderate to severe damage from carbonisation and clogging will occur in an unmodified engine.

The Philippines, Vanuatu, Samoa, and several other tropical island countries are using coconut oil as an alternative fuel source to run automobiles, trucks, and buses, and to power generators. Coconut oil is currently used as a fuel for transport in the Philippines. Further research into the oil's potential as a fuel for electricity generation is being carried out in the islands of the Pacific. In the 1990s Bougainville conflict, islanders cut off from supplies due to a blockade used it to fuel their vehicles.

Engine lubricant

Coconut oil has been tested for use as an engine lubricant; the producer claims the oil reduces fuel consumption and smoke emissions, and allows the engine to run at a cooler temperature.

Transformer oil

Transformer oil acts as an insulating and cooling medium in transformers. The insulating oil fills up pores in fibrous insulation and also the gaps between the coil conductors and the spacing between the siding and the tank, and thus increases the dielectric strength of the insulation. A transformer in operation generates heat in the winding, and that heat is transferred to the oil via conduction. Heated oil then flows to the radiators by convection. Oil supplied from the radiators, being cooler, cools the winding. There are several important properties such as dielectric strength, flash point, viscosity, specific gravity and pour point and all of them have to be considered when qualifying an oil for use in transformers. Normally mineral oil is used, but coconut oil has been shown to possess all the properties needed to function as an environmentally friendly and economic replacement to mineral oil for this purpose.

Herbicide

Acids derived from coconut oil can be used as herbicides, for a more environmentally friendly way of combating weeds. It is also considered unproblematic for people who have sensitivity to synthetic herbicides.

Personal uses

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. A study found that coconut oil helped prevent protein loss from the wet combing of hair when used for fourteen hours as a conditioner before washing the hair.

Sexual lubrication

There are widespread reports of the use of coconut oil as a sexual lubricant. Like other oil-based intimate lubricants, coconut oil should not be used with latex condoms.

See also

• Copha
• Copra
• Lipid hypothesis
• Palm oil

Further reading

• Coconut revival – new possibilities for the ‘tree of life’. Proceedings of the International Coconut Forum, 22–24 November 2005 (PDF). Cairns, Australia: ACIAR Proceedings. 2006. ISBN 1 86320 515 2. {{cite book}}: Unknown parameter |editors= ignored (|editor= suggested) (help)