Rapeseed is a bright-yellow flowering member of the family Brassicaceae, 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, because 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 been bred to reduce the content of glucosinolates, yielding a more palatable oil. This has had the side effect that the oil contains much less erucic acid.
Nowadays, rapeseed is grown for the production of animal feed, vegetable oil for human consumption, and biodiesel. Worldwide production of rapeseed/canola rose to 47 million metric tons in 2006, of which the total EU-25 production accounts for 16 million metric tons.
Rapeseed contains from 40 to 52% slabosahneshto oil, up to 20% proteins and 17% carbohydrates. The nutritional qualities of rapeseed oil is determined by the oil-acid composition. It contains vitamins A, E, K and D, phosphates and tocopherols. About 85% of the composition of rapeseed oil are essential fatty acids - Linoleic 20% and 65% oleic acid.
Processing of rapeseed for oil production provides rapeseed animal meal as a by-product. The by-product is a high-protein animal feed. The feed is mostly employed for cattle feeding, but also for hogs and poultry (though less valuable for these).