Coconut oil (or coconut fat) is an edible oil derived from the meat of the coconut palm fruit. Coconut oil is a white solid fat below around 25 °C (77 °F), and a clear thin liquid oil at higher temperatures. Unrefined varieties have a distinct coconut aroma. Coconut oil is used as a food oil, and in industrial applications for cosmetics and detergent production. The oil is rich in medium-chain fatty acids. Due to its high levels of saturated fat, numerous health authorities recommend limiting its consumption as a food. Coconut oil is widely used for cooking and baking due to its high smoke point and distinct flavor.
Manufacturing Coconut oil can be extracted through a wet or dry process. More simply (but perhaps less effectively), oil can be produced by heating the meat via boiling water, the sun or a slow fire.
Wet process
The all-wet process uses coconut milk extracted from raw coconut rather than dried copra. The proteins in the coconut milk create an emulsion of oil and water. The more problematic step is breaking up the emulsion to recover the oil. This used to be done by prolonged boiling, but this produces a discolored oil and is not economical. Modern techniques use centrifuges and pre-treatments including cold, heat, acids, salts, enzymes, electrolysis, shock waves, steam distillation, or some combination thereof. Despite numerous variations and technologies, wet processing is less viable than dry processing due to a 10–15% lower yield, even taking into account the losses due to spoilage and pests with dry processing. Wet processes also require investment in equipment and energy, incurring high capital and operating costs.
Dry process
Dry processing requires that the meat be extracted from the shell and dried using fire, sunlight, or kilns to create copra. The copra is pressed or dissolved with solvents, producing the coconut oil and a high-protein, high-fiber mash. The mash is of poor quality for human consumption and is instead fed to ruminants; there is no process to extract protein from the mash. 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. Copra made from immature nuts is more difficult to work with and produces an inferior product with lower yields. Conventional coconut oil processors use hexane as a solvent to extract up to 10% more oil than is produced with just rotary mills and expellers. They then refine the oil to remove certain free fatty acids to reduce susceptibility to rancidification. Other processes to increase shelf life include using copra with a moisture content below 6%, keeping the moisture content of the oil below 0.2%, heating the oil to 130–150 °C (266–302 °F) and adding salt or citric acid.
Virgin oil Virgin coconut oil (VCO) can be produced from fresh coconut milk, meat, or residue. Producing it from the fresh meat involves either wet-milling or drying the residue, and using a screw press to extract the oil. VCO can also be extracted from fresh meat by grating and drying it to a moisture content of 10–12%, then using a manual press to extract the oil. Producing it from coconut milk involves grating the coconut and mixing it with water, then squeezing out the oil. The milk can also be fermented for 36–48 hours, the oil removed, and the cream heated to remove any remaining oil. A third option involves using a centrifuge to separate the oil from the other liquids. Coconut oil can also be extracted from the dry residue left over from the production of coconut milk. A thousand mature coconuts weighing approximately 1,440 kilograms (3,170 pounds) yield around 170 kg (370 lb) of copra from which around 70 litres (15 imp gal) of coconut oil can be extracted.
Refined oil
Refined, bleached, and deodorized (RBD) oil is usually made from copra and dried coconut kernels, which are pressed in a heated hydraulic press to extract the oil. This yields 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 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 24 °C (75 °F), 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 36–40 °C (97–104 °F). 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 the partial hydrogenation process, some of these are transformed into trans fatty acids.
Fractionation Fractionated coconut oil provides fractions of the whole oil so that its different fatty acids can be 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. The fractionation of coconut oil can also be used to isolate caprylic acid and capric acid, which are medium-chain triglycerides, as these are used for medical applications, special diets and cosmetics, sometimes also being used as a carrier oil for fragrances.
Standards The World Health Organization's Codex Alimentarius guidelines on food, food production, and food safety, published by the Food and Agriculture Organization, includes standards for commercial partners who produce coconut oil for human consumption. The Asian and Pacific Coconut Community (APCC), whose 18 members produce about 90 per cent of the coconut sold commercially, has published its standards for virgin coconut oil (VCO), defining virgin coconut oil as obtained from fresh, mature coconut kernels through means that do not "lead to alteration of the oil."
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