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 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.
Rapeseed is grown for the production of animal feed, vegetable oil for human consumption, and biodiesel; leading producers include theEuropean Union, Canada, the United States, Australia, China, and India. In India, 6.7 million tons are produced annually. According to the United States Department of Agriculture, rapeseed was the third-leading source of vegetable oil in the world in 2000, after soybeanand palm oil; the world’s second-leading source of protein meal; and forms one-fifth of the production of the leading soybean meal.