Coconut Oil
| Infobox on Coconut Oil | |
|---|---|
| Example of Coconut Oil |  |
| Facts | |
| Origin | This table shows only a selection of the most important countries of origin and should not be thought of as exhaustive.
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| Density (in t/m3) | {{{density}}} |
| Temperature (in oC) | Density:
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| Humidity / moisture | Fats and fatty oils are insoluble in water. However, contact with water may give rise to soluble lower fatty acids and glycerol, which cause rancidity together with changes in color (yellow to brown), odor and taste as well as gelling and thickening. For this reason, the tanks must be absolutely dry after cleaning. |
| Ventilation | Ventilation must not be carried out under any circumstances, as it would supply fresh oxygen to the cargo, which would promote oxidation processes and premature rancidity. |
| Self-heating / spontaneous combustion | - |
| Risk factors | The oil may ignite spontaneously in conjunction with sawdust or material residues. Coconut oil exhibits only a slight tendency to evaporate. Losses due to adhesion of the cargo to the tank walls are minimal (< 0.3%), because coconut oil is a nondrying oil. |
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.
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
To be able to pump the oil out of the tanks, it must be at the required pumping temperature. This is only possible, however, if the oil has been kept liquid during the voyage (above a minimum temperature). Loading, travel and pumping temperatures must be precisely complied with, since any change in consistency which occurs during transport may prove irreversible. If the oil solidifies in the tanks, it cannot be liquefied again even by forced heating. In the vicinity of the heating coils, the oil melts, scorches, discolors and becomes rancid.
Pumping out may be difficult in cold weather. The oil may cool too rapidly in the long lines and solid deposits form on the outer walls, which cannot be pumped out and prevent the still liquid cargo from reaching the suction valve. This problem can be solved by appropriate heating or insulation of the lines.
Where the oil is packaged in barrels, the latter have to be handled with appropriate care. Damaged barrels quickly lead to oil leakage and thus to loss of volume or to damage to other parts of the cargo.
All fats and oils have a particular density (approx. 0.9 g/cm3). With a rise in temperature, however, density diminishes, thereby leading at the same time to an increase in volume. This behavior is described by the coefficient of cubic expansion and is known as thermal dilatation.
The coefficient of cubic expansion amounts to: g = approx. 0.00072°C-1 As a rule of thumb, oils may be expected to increase in volume by 1% of their total volume for each 14°C temperature increase. In particular in the case of oils requiring heating, such as coconut oil, the ullage space must be calculated accordingly. When filling the barrels or tanks, attention must however be paid to the expansion behavior of the cargo in the event of a rise in temperature (risk of bursting of barrels).
In the case of liquid cargoes, it is important for the ullage space above the cargo to be as small as possible, so that only slight movement of the cargo is possible. Movement in liquid cargoes may have a negative effect on the stability of the means of transport (e.g. during cornering in the case of trucks and trains or when ships roll and pitch).
Barrels have to be secured in such a way that they cannot slip in the hold or on the loading area and suffer damage.
Temperature
Coconut oil requires particular temperature conditions. A written heating order must be obtained from the consignor before loading is begun. This order must always be complied with during the entire transport chain.
The solidification temperature is of considerable significance in the transport of fatty oils and fats. They must remain liquid during loading, during the voyage and during unloading. Chill haze (separation) begins if cooling causes the temperature of the oil to approach solidification point, the oil becoming ointment-like and finally solid, such that it is no longer pumpable.
Separation and the associated change in consistency from liquid to solid occurs more readily upon cooling, the higher is the solidification point. The oils must only be heated by a few °C per day, otherwise the risk of rancidity and other negative changes arises.
The following table merely constitutes a rough estimate of appropriate temperature ranges. Temperatures may deviate from these values, depending on the particular transport conditions.
| Designation | Temperature | |
| Loading temperature | 35°C | |
| Favorable travel temperature | 24°C | |
| 25°C | ||
| 27 - 32°C | ||
| Solidification temperature | 14 - 25°C | |
| approx. 25°C | ||
| Pumping temperature | > 55°C | |
| 45°C | ||
| 40 - 45°C |
Phase changes: at 25°C coconut oil thickens, at 21 - 14°C it hardens and solidifies. The rate of heating should be no greater than 8°C/day.
The travel temperature must be complied with as far as possible during transport, to minimize oxidation processes. Towards the end of the voyage, the temperature of the oil must be slowly raised to the appropriate pumping temperature.
Unless otherwise recommended by the consignor, the following plan may, for example, be used for heating:
- 1st day heat to 27°C
- 2nd day heat to 30°C
- 3rd day heat to 38°C
- 4th day heat to 46°C
- 5th day heat to 55°C and keep at 55 - 60°C until port of discharge.
Too great or rapid an increase in temperature entails considerable losses in quality.
Humidity/Moisture
Fats and fatty oils are insoluble in water. However, contact with water may give rise to soluble lower Fatty Acids and glycerol, which cause rancidity together with changes in color (yellow to brown), odor and taste as well as gelling and thickening. For this reason, the tanks must be absolutely dry after cleaning.
Ventilation
Ventilation must not be carried out under any circumstances, as it would supply fresh oxygen to the cargo, which would promote oxidation processes and premature rancidity.
Biotic activity
Coconut oil displays 3rd order biotic activity. It belongs to the class of goods in which respiration processes are suspended, but in which biochemical, microbial and other decomposition processes still proceed. Care of the cargo during the voyage must be aimed at keeping decomposition processes to a low level.
Gases
Before anybody enters an empty tank, it must be ventilated and a gas measurement carried out. Oxidation processes may lead to a life-threatening shortage of O2.
Risk factors
Self-heating / Spontaneous combustion
The oil may ignite spontaneously in conjunction with sawdust or material residues.
Odor
Active behavior: Coconut oil has a pleasant odor when fresh but a rancid odor when old.
Passive behavior: Since coconut oil is used in the food sector, care must be taken to ensure that it is not odor-tainted by other goods.
Contamination
Active behavior: Leaking oil leads to massive contamination and may make whole cargoes unusable. Of considerable significance with regard to tank cleaning is the iodine value, which is a measure of how strong a tendency the oil has to oxidation and thus to drying. Drying is particularly detrimental to tank cleaning, as the oil/fat sticks to the walls and can be removed only with difficulty. On the basis of drying capacity , oils are divided into nondrying, semidrying and drying oils. With an iodine value of 7 - 10, coconut oil is a nondrying oil, which means that it does not dry significantly on contact with atmospheric oxygen and the tanks are easily cleaned.
Passive behavior: Coconut oil is sensitive to contamination by ferrous and rust particles and water (especially seawater), therefore rub the tanks with coconut oil before loading and allow to dry. Contamination with foreign substances is a particular risk, especially because coconut oil is used in the food sector. The tanks or barrels must be clean and in a thoroughly hygienic condition before filling.
Mechanical influences
In the case of transport in barrels, extreme mechanical stresses, such as dropping, tipping over or bumping, may lead to breakage of the barrels and thus to leakage.
Toxicity / Hazards to health
Before anybody enters a tank, it must be ventilated and a gas measurement carried out. Oxidation processes may lead to a life-threatening shortage of O2.
Shrinkage/Shortage
Where this oil is packaged in barrels, weight loss from leakage is always to be expected. Coconut oil exhibits only a slight tendency to evaporate. Losses due to adhesion of the cargo to the tank walls are minimal (< 0.3%), because coconut oil is a nondrying oil.
Note:(Source including Transport Information Service of the GDV)