|Infobox on Rapeseed oil
|Example of Rapeseed oil
|This table shows only a selection of the most important countries of origin and should not be thought of as exhaustive.
|Density (in t/m3)
|Temperature (in oC)
|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 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
|The oil may ignite spontaneously in conjunction with sawdust or material residues.Tanks and barrels must always be odor-free, since there is a risk that quality will be diminished in particular where the previous cargo had a strong odor. Rapeseed oil is sensitive to contamination by ferrous and rust particles and water (especially seawater). 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.
Rapeseed (Brassica napus), also known as rape, oilseed rape, rapa, rappi, rapaseed (and in the case of one particular group of cultivars, canola), is a bright yellow flowering member of the family Brassicaceae (mustard or cabbage family).
Brassica napus is cultivated mainly for its oil-rich seed, the third largest source of vegetable oil in the world.
Rapeseed oil was produced in the 19th century as a source of a lubricant for steam engines. It was less useful as food for animals or humans because it has a bitter taste due to high levels of glucosinolates. Varieties have now however been bred to reduce the amount of glucosinolates, yielding a more palatable oil. This has had the side-effect that the oil contains much less erucic acid.
Rapeseed is grown for the production of animal feed, vegetable oil for human consumption, and biodiesel; leading producers include the European Union, Canada, the United States, Australia, China and India. In India, it is grown on 13% of cropped land. Rapeseed is the third leading source of vegetable oil in the world in 2000, after soybean and oil palm, and also the world's second leading source of protein meal, although only one-fifth of the production of the leading soybean meal.
In Europe, rapeseed is primarily cultivated for animal feed, owing to its very high lipid and medium protein content, and is a leading option for Europeans to avoid importation of genetically modified organism (GMO) products.
Natural rapeseed oil contains 50% erucic acid. Wild type seeds also contain high levels of glucosinolates (mustard oil glucosindes), chemical compounds that significantly lower the nutritional value of rape seed press cakes for animal feed.
Rapeseed oil had a distinctive taste and a disagreeable greenish colour due to the presence of chlorophyll. It also contained a high concentration of erucic acid.
Rapeseed oil contains both omega-6 and omega-3 Fatty Acids in a ratio of 2:1, although flax oil is higher in omega-3 fatty acid, as are other oils such as chia (Salvia hispanica) oil. Canola oil's proponents claim that it is one of the most heart-healthy oils and has been reported to reduce cholesterol levels, lower serum tryglyceride levels, and keep platelets from sticking together. While only very long chain omega-3 fatty acids have been shown to improve cholesterol levels, and these are absent from most plant foods, the body can convert some of the short chain into long chain omega 3's.
Processing of rapeseed for oil production produces rapeseed meal as a by-product. The by-product is a high-protein animal feed, competitive with soya. The feed is mostly employed for cattle feeding, but also for pigs and chickens (though less valuable for these). The meal has a very low content of the glucosinolates responsible for metabolism disruption in cattle and pigs.
Rapeseed "Oil Cake" is also used as a fertilizer in China, and may be used for ornamentals, such as Bonsai, as well.
Rapeseed leaves and stems are also edible, similar to those of the related bok choy or kale. Some varieties of rapeseed are sold as greens, primarily in Asian groceries, including those in California where it is known as yao choy or tender greens. They are eaten as sag (spinach) in Indian and Nepalese cuisine, usually stir-fried with salt, garlic and spices.
Rapeseed produces great amounts of nectar, and honeybees produce a light colored, but peppery honey from it. It must be extracted immediately after processing is finished, as it will quickly granulate in the honeycomb and will be impossible to extract. The honey is usually blended with milder honeys, if used for table use or sold as bakery grade. Rapeseed growers contract with beekeepers for the pollination of the crop.
"Total loss" chain and bar oil for chainsaws have been developed which are typically 70% or more canola/rapeseed oil. These lubricants are claimed to be less harmful to the environment and less hazardous to users than traditional mineral oil products, although they are currently typically 2-5 times more expensive, leading some to use inexpensive cooking oil instead. Some countries, such as Austria, have banned the use of petroleum-based chainsaw oil. These "bio-lubricants" are generally reported to be functionally comparable to traditional mineral oil products with some reports claiming one or other is superior, but with no overall consensus yet evident.
Rapeseed oil is used as diesel fuel, either as biodiesel, straight in heated fuel systems, or blended with petroleum distillates for powering motor vehicles. Biodiesel may be used in pure form in newer engines without engine damage and is frequently combined with fossil-fuel diesel in ratios varying from 2% to 20% biodiesel. Owing to the costs of growing, crushing, and refining rapeseed biodiesel, rapeseed-derived biodiesel from new oil costs more to produce than standard diesel fuel, so diesel fuels are commonly made from the used oil. Rapeseed oil is the preferred oil stock for biodiesel production in most of Europe, accounting for about 80% of the feedstock, partly because rapeseed produces more oil per unit of land area compared to other oil sources, such as soy beans, but primarily because canola oil has a significantly lower gel point than most other vegetable oils.
Shipment / storage / usage
Rapeseed oil should have an acid value of at most 0.6 - 2.0%. Oils and fats spoil by readily becoming rancid which is promoted by light, atmospheric oxygen and moisture and leads to changes in odor and taste.
Subject to compliance with the appropriate temperature ranges, duration of storage is not a limiting factor as regards transport and storage life. Normally, the oil does not need to be heated, since its solidification point is relatively low.
Rapeseed oil has no particular requirements as to storage climate conditions.
Travel temperature (favorable temperature range): 15°C (12 - 24°C)
Pumping temperature: approx. 15°C
Solidification temperature: 0 - -15°C
Under normal transport conditions, rapeseed oil is liquid and therefore need not be heated. However, if temperatures should arise during the voyage which are in the solidification range, the oil has to be heated to achieve pumpability. Solidification temperatures are 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.
For further details on deterioration, contamination, oxidation, transit and handling etc., we may refer to Bulk Oils and Fats and Fats and Oils.
- Self-heating / Spontaneous combustion
- Mechanical influences
- Toxicity / Hazards to health
- Shrinkage / Shortage