Certified soybean seed (as well as other certified crop seeds) consists of quality seed of Superior varieties grown and distributed to insure genetic identity and purity. In the United States, the production of such seeds is controlled largely by private seed companies. Certified seed covered in a separate summary.
Cottonseed is a byproduct of cotton ginning. About one-half (48 percent) of domestic output of cottonseed is used to produce vegetable oil, the other one half (52 percent) is used largely for cattle feed. Cottonseed yields 16 to 17 percent of its weight as cottonseed oil; the remainder consists of oilcake, linters, and hulls. In 2000, about 44 percent of the reported U.S. consumption of cottonseed oil was to make salad or cooking oil, 24 percent for baking and frying fats, and the remaining 32 percent mostly for other edible food products. Since cottonseed is bulky and perishable, most of the crop is processed as quickly as possible after harvest. Because of its bulk and perishability, little cottonseed enters international commerce.
Sunflower seed, one of the world’s major oil-bearing seeds, is obtained from the sunflower,
a hardy drought-resistant plant well suited to the colder or arid areas where many other
oilseed crops cannot be grown. Although primarily used as a source of vegetable oil,
sunflower seed also is eaten as an edible snack nut and used in bird feed mixtures. The
varieties of sunflower seeds grown in the United States for bird feed and human food have
a larger kernel than those grown for oil.
Flaxseed produced in the United States (except that used for seeding)
is used for extracting linseed oil. Flax grown for fiber is a different type, and is not suitable
for oil production, owing to its low seed yield. In the United States, little or no flax is grown
specifically for fiber. Flaxseed yields about 36 percent of its weight in linseed oil, with the
residual linseed cake or meal used for feeding livestock. The value of linseed oil obtained
from flaxseed represents three-quarters of the combined value of the linseed oil and the
linseed meal. Linseed oil can be used only for inedible purposes in the United States; in
2000, the most important uses were in the production of resins and plastics (40 percent of
reported U.S. consumption), and paint and varnish (39 percent).9
Rapeseed/Canola is the seed obtained from several species of the genus Brassica, which also
includes mustard, turnips, and cabbage. Traditional rapeseed, when pressed, typically yields
about 40 percent of its weight in inedible rapeseed oil, which is noted for its high content of
erucic acid, a known carcinogen. The edible variety of rapeseed that has very low or no
erucic acid is called “Canola.” In 2000, three-quarters of reported U.S. consumption all types
of rapeseed oil was in the form of salad and cooking oils, 20 percent in the form of baking
and frying fats and margarine, and about 5 percent in industrial products.10