In 1956, the nutritional aspects of rapeseed oil were questioned, especially concerning the high eicosenoic and erucic fatty acid contents. In the early 1960s, Canadian plant breeders isolated rapeseed plants with low eicosenoic and erucic acid contents. The Canadian Health and Welfare Department recommended conversion to the production of low erucic acid varieties of rapeseed. Industry responded with a voluntary agreement to limit erucic acid content to five percent in oil products effective December 1, 1973. At that time, animal nutritionists also expressed concerns with the sharp tasting, anti-nutritive glucosinolates that were affecting the meal quality of rapeseed.
Meal is the portion left after canola seed is crushed to remove the oil.
This Brassica napus variety, Tower, was the first variety to meet the specific quality requirements used to identify a greatly improved crop known as Canola . Each canola plant produces yellow flowers which, in turn, produce pods, similar in shape to pea pods but about one-fifth the size. Within the pods are tiny round seeds that are crushed to obtain canola oil. Each seed contains approximately 40 per cent oil. The remainder of the seed is processed into canola meal, which is used as a high-protein livestock feed.