In the world of plants, green is usually good . . . except in canola seeds. Freezing temperatures can prevent maturation, causing the seed to stay green.
Seeds can reach maturity and have a high oil content, but if they're green, their price drops.
Seed crushers remove the green from the oil with bleaching clays, which produce an added expense and pose an environmental problem. Canola is an oilseed crop grown mainly in parts of western Canada, with some acreage in Ontario and the Pacific Northwest, north-central, and southeastern United States. Its yellow flowers produce pea-shaped pods that contain tiny seeds harvested for their oil. Canola oil contains omega 3 fatty acids, acclaimed for improving human immune and vascular systems. Many plants break down chlorophyll even after a freeze.