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|The examples and perspective in this article deal primarily with North America and do not represent a worldwide view of the subject. (May 2012)|
Canola refers to both an edible oil (also known as canola oil) produced from the seed of any of several varieties of the rape plant, and to those plants, namely a cultivar of either rapeseed (Brassica napus L.) or field mustard/turnip rape (Brassica rapa subsp. oleifera, syn. B. campestris L.). Consumption of the oil is common and does not cause harm in humans and livestock. It is also used as a source of biodiesel.
Canola was bred naturally from rapeseed at the University of Manitoba, Canada, by Keith Downey and Baldur R. Stefansson in the early 1970s, and had a different nutritional profile, in addition to much less erucic acid. In the international community, canola is generally referred to as rapeseed 00 or double zero rapeseed to denote both low glucosinolates and low erucic acid. In addition to varieties from the traditional B. rapa and B. napus species, recent cross-breeding of multiple lines of B. juncea have enabled this mustard variety to be classified as a canola variety by lowering both erucic acid and glucosinolates to the market standards, achieving 'LEAR' status (for low erucic acid rapeseed). It may also be referred to as canola oil and is considered safe for human consumption.
The name "canola" was chosen by the board of the Rapeseed Association of Canada in the 1970s. The "Can" part stands for Canada and "ola" refers to oil. However, a number of sources, including dictionaries, continue to claim it stands for "Can(ada)+o(il)+l(ow)+a(cid). These dictionaries include the American Heritage Dictionary of the English Language and Random House Kernerman Webster's College Dictionary. The name was coined partially to avoid the negative connotations of rape.
Canola was developed through conventional plant breeding from rapeseed, an oilseed plant already used in ancient civilization as a fuel. The word "rape" in rapeseed comes from the Latin word rapum meaning turnip. Turnip, rutabaga, cabbage, Brussels sprouts, mustard, and many other vegetables are related to the two natural canola varieties commonly grown, which are cultivars of B. napus and B. rapa. The change in name serves to distinguish it from natural rapeseed oil, which has much higher erucic acid content.
Brassica oilseed varieties are some of the oldest plants cultivated by humanity, with documentation of its use in India 4,000 years ago, and use in China and Japan 2,000 years ago.:55 Its use in Northern Europe for oil lamps is documented to the 13th century. Its use was limited until the development of steam power, when machinists found rapeseed oil clung to water- and steam-washed metal surfaces better than other lubricants. World War II caused high demand for the oil as a lubricant for the rapidly increasing number of steam engines in naval and merchant ships. When the war blocked European and Asian sources of rapeseed oil, a critical shortage developed, and Canada began to expand its limited rapeseed production.
After the war, demand declined sharply, and farmers began to look for other uses for the plant and its products. Rapeseed oil extracts were first put on the market in 1956–1957 as food products, but these suffered from several unacceptable characteristics. Rapeseed oil had a distinctive taste and a disagreeable greenish color, due to the presence of chlorophyll. It also contained a high concentration of erucic acid. Experiments on animals have pointed to the possibility that erucic acid, consumed in large quantities, may cause heart damage, although Indian researchers have published findings that call into question these conclusions and the implication that the consumption of mustard or rapeseed oil is dangerous. Feed meal from the rapeseed plant also was not particularly appealing to livestock, because of high levels of sharp-tasting compounds called glucosinolates.
Canola was bred from rapeseed at the University of Manitoba, Canada, by Keith Downey and Baldur R. Stefansson in the early 1970s, and had a very different nutritional profile in addition to much less erucic acid.
A variety developed in 1998 is considered to be the most disease- and drought-resistant canola variety to date. This and other recent varieties have been produced using genetic engineering. In 2011, 26% of the acres sown were genetically modified (biotech) canola.
Canola was originally a trademark, but is now a generic term for edible varieties of rapeseed oil in North America and Australia. In Canada, an official definition of canola is codified in Canadian law.
Rapeseed was once considered a specialty crop in Canada, but now has become a major American cash crop. Canada and the United States produce between 7 and 10 million tonnes of canola seed per year. Annual Canadian exports total 3 to 4 million tonnes of the seed, 800,000 tonnes of canola oil, and 1 million tonnes of canola meal. GM canola may not be grown in jurisdictions that have not approved GMOs. In the United States, 90% of the canola crop is grown in North Dakota.
Rapeseed is the highest-producing oilseed crop in the United States. Winter growing of hybrid canola seed appears possible in central Oregon; however, the state prohibits it from being grown in Deschutes, Jefferson, and Crook Counties because it may attract bees from specialty seed crops, such as carrots, which require them for pollination. The rapeseed blossom is a major source of nectar for honeybees.
The major customers of canola seed are Japan, Mexico, China, and Pakistan, while the bulk of canola oil and meal goes to the United States, with smaller amounts shipped to Mexico, China, and Europe. World production of rapeseed oil in the 2002–2003 season was about 14 million metric tons. In the 2010–2011 season, world production is estimated to be at 58.4 million tonnes. The United States is a net consumer of canola oil, having used 3 billion pounds in 2010, 2.5 billion of which was imported from Canada.
Canola oil is made at a processing facility by slightly heating and then crushing the seed. Almost all commercial canola oil is then refined using hexane. Finally, the crude oil is refined using water precipitation and organic acid, "bleaching" with clay, and deodorizing using steam distillation. About 43% of a seed is oil; the remainder is a rapeseed meal that is used as high quality animal feed. About 23 kg (51 lb) of rapeseed makes 10 L (2.64 US gal) of canola oil. Canola oil is a key ingredient in many foods. Its reputation as a healthy oil has created high demand in markets around the world, and overall it is the third-most widely consumed vegetable oil.
The oil has many nonfood uses and, like soybean oil, is often used interchangeably with non-renewable petroleum-based oils in products, including industrial lubricants, biofuels, candles, lipsticks, and newspaper inks depending on the price on the spot market. Canola oil is also recommended by the American Society for Reproductive Medicine for use as a fertility-preserving vaginal lubrication.
The average density of canola oil is 0.92 g/ml.
|Compound||Family||% of total|
Canola oil is low in saturated fat and contains both omega-6 and omega-3 fatty acids in a ratio of 2:1. If consumed, it also reduces low-density lipoprotein and overall cholesterol levels, and as a significant source of the essential omega-3 fatty acid is associated with reduced all-cause and cardiovascular mortality. Canola oil has been given a qualified health claim from the United States Food and Drug Administration due to its high levels of cholesterol-lowering fats.
Although wild rapeseed oil contains significant amounts of erucic acid, the cultivar used to produce commercial, food-grade canola oil was bred to contain less than 2% erucic acid, levels that are not believed to cause harm in humans, and no health effects have been associated with consumption by humans of erucic acid nor genetically modified canola oil. Although rumors that canola oil can cause dangerous health problems circulated, there is no evidence to support the conclusion that canola oil poses unusual health risks, and its consumption in food-grade forms is generally recognized as safe by the United States Food and Drug Administration.
Chinese and Indian cultures have used rapeseed oils for thousands of years, but the form used was unrefined (natural), which may make a difference in effect on health.
Because of the lower levels of the toxic and irritating properties of genetically modified rapeseed oil, canola oil is a more promising source for manufacturing biodiesel than the natural oil as a renewable alternative to fossil fuels.
|Polyunsaturated fatty acids||Oleic acid|
|Total poly||linolenic acid|
|Canola (rapeseed)||-||7.365||63.276||28.142||9-11||19-21||-||400 °F (204 °C)|
|Coconut||-||91.00||6.000||3.000||-||2||6||350 °F (177 °C)|
|Corn||-||12.948||27.576||54.677||1||58||28||450 °F (232 °C)|
|Cottonseed||-||25.900||17.800||51.900||1||54||19||420 °F (216 °C)|
|Flaxseed/Linseed (European)||-||6 - 9||10 - 22||68 - 89||56 - 71||12 - 18||10 - 22||225 °F (107 °C)|
|Olive||-||14.00||72.00||14.00||<1.5||9–20||-||380 °F (193 °C)|
|Palm||-||49.300||37.000||9.300||-||10||40||455 °F (235 °C)|
|Peanut||-||16.900||46.200||32.000||-||32||48||437 °F (225 °C)|
|Safflower (>70% linoleic)||-||8.00||15.00||75.00||-||-||-||410 °F (210 °C)|
|Safflower (high oleic)||-||7.541||75.221||12.820||-||-||-||410 °F (210 °C)|
|Soybean||-||15.650||22.783||57.740||7||50||24||460 °F (238 °C)|
|Sunflower (<60% linoleic)||-||10.100||45.400||40.100||0.200||39.800||45.300||440 °F (227 °C)|
|Sunflower (>70% oleic)||-||9.859||83.689||3.798||-||-||-||440 °F (227 °C)|
|Values as percent (%) by weight of total fat.|
A genetically engineered rapeseed that is tolerant to herbicide was first introduced to Canada in 1995 (Roundup Ready canola). In 2009, 90% of the Canadian crop was herbicide-tolerant. As of 2005, 87% of the canola grown in the US was genetically modified. A 2010 study conducted in North Dakota found glyphosate- or glufosinate-resistance transgenes in 80% of wild natural rapeseed plants, and a few plants that were resistant to both herbicides. The escape of the genetically modified plants has raised concerns that the build-up of herbicide resistance in feral canola could make it more difficult to manage these plants using herbicides. However one of the researchers agrees that ".. feral populations could have become established after trucks carrying cultivated GM seeds spilled some of their load during transportation." She also notes that the GM canola results they found may have been biased as they only sampled along roadsides.
Genetically modified canola has become a point of controversy and contentious legal battles. In one high-profile case (Monsanto Canada Inc. v. Schmeiser) the Monsanto Company sued Percy Schmeiser for patent infringement after he replanted canola seed he had harvested from his field, which he discovered was contaminated with Monsanto's patented glyphosate-tolerant canola by spraying it with glyphosate, leaving only the resistant plants. The Supreme Court ruled that Percy was in violation of Monsanto's patent because he knowingly replanted the resistant seed that he had harvested and also imposing fees of over $200,000 on Schmeiser, but he was not required to pay Monsanto damages since he did not benefit financially from its presence. On 19 March 2008, Schmeiser and Monsanto Canada Inc. came to an out-of-court settlement whereby Monsanto would pay for the clean-up costs of the contamination, which came to a total of C$660.
In 2003, Australia's gene technology regulator approved the release of canola altered to make it resistant to glufosinate ammonium, a herbicide. The introduction of the genetically modified crop to Australia generated considerable controversy. Canola is Australia's third biggest crop, and is used often by wheat farmers as a break crop to improve soil quality. As of 2008, the only genetically modified crops in Australia were canola, cotton, and carnations.
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