Canola is an oilseed crop that was developed from traditional rapeseed by Canadian plant breeders during the 1970s. Canola is distinguished from traditional rapeseed by the greatly reduced levels of fatty acids, erucic acid and anti-nutritional compounds called glucosinolates. It is widely grown across Canada and several European countries.
For the canola oil processing, it begins with preconditioning, after which canola seeds are crushed and flaked for later slight heated. The canola flakes are then "pre-pressed" in screw presses or expellers to reduce oil content from about 42% in the seeds (on 80% moisture content basis) to between 16%-20%. Screw press also compresses the flakes into more dense cakes (called “press cake”) which facilitate later oil extraction.
Graded seed is cleaned by different methods including air aspiration, indent cylinder cleaning, sieve screening, or a combination of these. Cleaning ensures that the seed is free of extraneous plant and the other foreign material which is referred to in the industry as "dockage". Seed generally contains less than 2.5% dockage following the cleaning process. Seed that has been cleaned is ready for subsequent export or for crushing into canola oil and meal.
To get canola oil and meal, canola seeds are preconditioned by mild heat treatment, and moisture is then adjusted to improve subsequent oil extraction.