Coconut Oil
| Infobox on Coconut Oil | |
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| Example of Coconut Oil |  |
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| Origin | Chiefly Philippines and Indonesia |
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Coconut Oil
Description
Coconut oil is an edible oil extracted from the kernel or meat of matured coconuts 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, which makes it suited to methods of cooking at high temperatures like frying. 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. As with dairy and meat products, the United States Food and Drug Administration, World Health Organization, International College of Nutrition, United States Department of Health and Human Services, American Dietetic Association, American Heart Association, British National Health Service, and Dietitians of Canada recommend limiting the consumption of significant amounts of coconut oil due to its high levels of saturated fat.
Edible oil, by international standards should have less than 0.1% free fatty acid content. The oil obtained from good quality crop with a free fatty acid content of < 0.1%, is used as cooking oil without any further processing. Even if the free fatty acid content is 3-5%, the international standard of < 0.1% can be obtained by refining and deodorizing.
Edible oils will suffer quality (essentially flavor) deterioration because of chemical changes within them. In addition they may be contaminated by substances which promote quality deterioration or other adverse chemical changes or which may themselves pose a public health hazard, or simply push the oil out of specification.
Dry process
Coconut oil can be extracted through "dry" or "wet" processing. Dry processing requires the meat to 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. The preparation and storage of copra often occurs in unhygienic conditions, yielding poor quality oil that requires refining. A portion of the oil extracted from copra is lost to spoilage, to insects or rodents, and to the process of extraction.
Wet process
The all-wet process uses raw coconut rather than dried copra, and the protein in the coconut creates 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, or some combination of them. Despite numerous variations and technologies, wet processing is less viable than dry processing due to a 10-15% lower yield, even compared to the losses due to spoilage and pests with dry processing. Wet processes also require investment of equipment and energy, incurring high capital and operating costs.
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 uses hexane as a solvent to extract up to 10% more oil than just using rotary mills and expellers. The oil is then refined to remove certain free fatty acids, in order 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 and adding salt or citric acid. Virgin coconut oil (VCO) can be produced from fresh coconut meat, milk or residue. Producing it from the fresh meat involves removing the shell and washing, then 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.
RBD
RBD stands for "refined, bleached, and deodorized." RBD oil is usually made from copra (dried coconut kernel).The dried copra is placed in a 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 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 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. If hydrogenation is taken to completion (i.e., the oil is "fully hydrogenated"), there are no trans fats remaining. There are no natural cis-fats either. Only partial hydrogenation produces trans fats.
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.
Applications
Coconut oil is commonly used in cooking, especially for frying. Other culinary uses include replacing solid fats produced through hydrogenation in baked and confectionery goods.
Hydrogenated or partially hydrogenated coconut oil is often used in non-dairy creamers, and snack foods including popcorn. Coconut oil has been tested for use as a feedstock for biodiesel to be used as a diesel engine fuel.
Coconut oil has been tested for use as an engine lubricant and a transformer oil.
Acids derived from coconut oil can be used as herbicides.
Coconut oil (and derivatives, such as coconut fatty acid) are used as raw materials in the manufacture of surfactants such as cocamidopropyl betaine, cocamide MEA and cocamide DEA.
Coconut oil is an important base ingredient for the manufacture of soap.
Shipment/Storage
Storage duration of coconut oil: approx. 6 months at 24°C
Loading temperature: 35°C
Favorable carrying temperature: 25°C/30°C
Pumping temperature: 40°C/55°C
Solidification temperature: approx. 15°/25°C
Phase changes: at 25°C coconut oil thickens, at approx. 20°/15°C it hardens and solidifies.
The rate of heating should be no greater than 8°C/day.
For further details on deterioration, contamination, oxidation, transit and handling etc., we may refer to Bulk Oils and Fats.
Risk factors
- Self-heating / Spontaneous combustion
- Odor
- Oxidation (rancidity; due to contact with air, excessive light, heat, metal affection, water, microbiological changes)
- Contamination
- Mechanical influences
- Toxicity / Hazards to health
- Shrinkage/Shortage
Note:(Source including Transport Information Service of the GDV)