The oil that we use in our kitchen or for the manufacture of margarine and other goods is obtained from the seeds of many plants. The world production of major oilseed crops (in millions of metric tons) is Soyabeans 46.5, Peanuts 18.1, Cottonseed 22.1 and Copra 3.4. The other sources of vegetable oils are mustard, rapeseed, sunflower etc.
The basic process for extracting oil is essentially the same for all oilseeds. It involves either pressing or solvent extraction or a combination of both. The material that remains after removal of the oil contains primarily fibres, carbohydrates and proteins. This may contain protein upto 50%. This material is discarded and used as fertilizer or animal feed.
Most of the world’s supply of coconut oil comes from West Africa. It is taken from the dried kernel of the nut called copra which contains 70% oil. Palm oil also comes from West Africa and from South-East Asia. These oils are produced in a hard fatty form called stearine, which is used in the manufacture of chocolate, cooking fats and medicines. Crude oil is used in soaps and shampoos.
Cottonseed provides about 37% oil. The cotton plant is grown commercially in the United States, India and Egypt. The fruit of the plant splits open to reveal fluffy white fibres and a number of seeds – each about six millimeters long. Cottonseed oil is used in margarine, cooking fat, and salad oil. It is also used in soaps, resins, grease and lubricants.
Linseed is the seed of the flax plant which is grown primarily in the United States, Russia, Argentina, India and Canada. Flax fibres are woven into linen cloth and the seeds are used for extracting oil. Linseed oil is used in paints, varnishes, printing and lithographic inks, linoleum, oil cloth and as a water-proofing agent. The residue is a valuable cattle food.
Groundnut or peanut is the seed of the plant Arachis Lypogea. The seeds of this plant yield oil and are cultivated mainly in China, West Africa, the United States and South-East Asia. It is mainly used as a cooking medium.
Soyabean is the most important of all the oil seeds. It is extensively grown in China and the Far East. Soyabean oil is used for cooking and as a base for paints, plastics, adhesives, etc. It is a rich source of protein. The seeds can be ground into protein-rich flour which can be used in many foods.
Sunflower is becoming increasingly popular in European oil markets, and so is rapeseed in Canada and Northern-Europe. Sunflower is now grown in countries like Mexico, Russia, erstwhile Yugoslavia, Turkey and South Africa.
