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. What makes coconut oil different from most other dietary oils is the basic building blocks or fatty acids making up the oil. Coconut oil is composed predominately of a special group of fat molecules known as medium chain fatty acids (MCFA). The majority of fats in the human diet are composed almost entirely of long chain fatty acids (LCFA).

The primary difference between MCFA and LCFA is the size of the molecule, or more precisely, the length of the carbon chain that makes up the backbone of the fatty acid. MCFA have a chain length of 6 to 12 carbons. LCFA contain 14 or more carbons.

The length of the carbon chain influences many of the oil’s physical and chemical properties. When consumed, the body processes and metabolizes each fatty acid differently depending on the size of the carbon chain. Therefore, the physiological effects of the MCFA in coconut are significantly different from those of the LCFA that are more commonly found in the diet.

MCFA and LCFA can also be classified as saturated, monounsaturated, or polyunsaturated fatty acids. Coconut oil contains 92% saturated fatty acids. All of the MCFA in coconut oil are saturated. They, however, are very much different chemically from the long chain saturated fatty acids found in animal fat and other vegetable oils.

Because coconut oil has a high amount of saturated fatty acids it also has a relatively high melting point. Above 76°F (24°C) coconut oil is a colorless liquid. Below this temperature it solidifies into a pure white solid.

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 Profile of Coconut Oil

Fatty Acid	Saturation	Carbons	Percent
Caproic	Saturated	6	0.5
Caprylic	Saturated	8	7.8
Capric	Saturated	10	6.7
Lauric	Saturated	12	47.5
Myristic	Saturated	14	18.1
Palmitic	Saturated	16	8.8
Stearic	Saturated	18	2.6
Arachidic	Saturated	20	0.1
Oleic	Monounsaturated	18	6.2
Linoleic	Polyunsaturated	18	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.

Production

In the wet process, coconut milk is made first and then the oil is extracted from the milk. Coconut kernel is shredded, mixed with a little water, and then squeezed or pressed to extract the oil. The resulting oil/water mixture produces coconut cream or coconut milk depending on the percentage of oil. The coconut milk is then allowed to separate naturally. Since oil is lighter than water, the oil rises to the surface. This takes 12 to 24 hours. The oil can then be skimmed off. This is the traditional method of making coconut oil from coconut milk and is the way many people make the oil at home. Other methods incorporate heating, fermentation, refrigeration, or centrifugal force to separate the oil from the water. Some minor heating is generally done afterwards (often in a low temperature vacuum chamber) to drive off excess moisture and produce a more purified product and to extend shelf life.

In the dry process the oil is extracted directly from the kernel. The coconut kernel is first shredded and dried in an oven to about 10 to 12% moisture. The dried, shredded coconut is then placed into a press and the virgin oil is expelled.

The Asian and Pacific Coconut Community (APCC), whose 18 members produce about 85% 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.

RBD coconut oil

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.

Hydrogenated coconut oil

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, such as chocolate, 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 bombarded with hydrogen atoms 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.

Fractionated coconut oil

Fractionated coconut oil is a fraction of the whole oil, in which the long-chain fatty acids are removed so that only medium chain saturated fatty acids remain. Lauric acid, a 12 carbon chain fatty acid, is often removed as well 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.

Health effects debate

Historically, many populations within the tropics have used coconut medicinally as a treatment for a wide variety of ailments.

A study into the effects of a "diet rich in.." medium-chain fatty acids (it should be noted that the study uses the processed MCFAs of MCTs (66% 8:0 and 34% 10:0) [i.e. Caprylic acid-C8 and Capric acid-C10 respectively] which is similar to processed fractionated coconut oil [see above]) concluded that "MCFAs in the form of MCTs significantly increased plasma triacylglycerol and LDL-cholesterol concentrations and the ratio of LDL to HDL cholesterol and thereby resulted in a less beneficial lipid profile overall."

Furthermore, research done by nutritionist Mary Enig has found that non-hydrogenated coconut oil (i.e. extra-virgin) consumed in moderate amounts "is at worst neutral with respect to atherogenicity of fats and oils and, in fact, is likely to be a beneficial oil for prevention and treatment of some heart disease." The lack of negative effects of a diet rich in coconut oil on cardiovascular health is born out in studies of Polynesian populations who consume as much as 65% of their calories in the form of coconut oil and yet, have almost no incidence of heart disease and normal blood lipid profiles.

Food Uses

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. It does not create any harmful byproducts when heated.

Hydrogenated or partially-hydrogenated coconut oil is often used in non-dairy creamers, and snack foods.

Industrial and commercial 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.

Fractionated coconut oil is also used in the manufacture of essences, massage oils and cosmetics.

In India and Sri Lanka, coconut oil is commonly used for styling hair, and cooling or soothing the head.

Soaps and detergents

Coconut oil is used as a base oils for soap, shampoo and detergent making.

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 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 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, 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. 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.

Personal Health Uses

Sexual Lubricant

There are widespread reports of the use of coconut oil as a sexual lubricant. Because the melting temperature of coconut oil is slightly above room temperature, it will often stay in containers as a solid but then will melt upon contact with genitalia. Like other oil-based intimate lubricants, coconut oil should not be used with latex condoms. There have been no formal investigations of the efficacy or safety of coconut oil as a sexual lubricant, though some users claim a reduced frequency of vaginal yeast infections.

Keratosis pilaris (KP, also follicular keratosis)

There is anecdotal evidence that application of non-hydrogenated, organic, expeller pressed coconut oil is an effective treatment for keratosis pilaris (follicular keratosis). Anecdotal reports recommend liberal application of coconut oil to affected areas after showering.

See also

• Copha
• Palm Oil