Barbara English, age 13, of White Plains, N.Y., for her question:
WHERE DO WE GET VEGETABLE OIL?
Vegetable oil is a fatty substance obtained from certain plants. 105Z We get most of our vegetable oil from fruit or seeds. Oil extracted from fruit includes olive and palm oil. Seeds provide coconut, corn, cottonseed, linseed, palm kernel, peanut, safflower and soybean oil.
People use vegetable oils in various foods and in making paint, soap and other products.
The chief vegetable oils used in the United States are corn, cottonseed and soybean oil. People use these oils, as well as olive and peanut oil, in frying food and as salad oil. Most salad dressings include soybean oil.
Margarine and other solid shortenings are made from corn, cottonseed, safflower or soybean oil. Candy manufacturers use cocoa butter, coconut oil and palm kernel oil.
Production of vegetable oils starts with their extraction from fruit or seeds. Many oils are simply squeezed out. For example, processors use a powerful machine called a high pressured press to squeeze out coconut and palm oil and some cottonseed oil.
This procedure removes nearly all the oil from the fruit or seeds.
But the high pressure heats the oil, which develops a dark color and a strong flavor as a result. Many oils, therefore, are squeezed out under low pressure in a process called cold pressing. This process, which does not heat the oil, results in a light colored, mild flavored product.
But low pressure extraction does not remove all the oil from the plant. Manufacturers use cold pressing chiefly to obtain olive oil.
A process known as solvent extraction is sometimes used to remove the oil. In this process, the manufacturer soaks the fruit or seeds in a liquid called a solvent that dissolves oil. A mixture of plant material, solvent and oil results. Machines then remove the plant material and evaporate the solvent to obtain the oil. Most soybean oil is produced by solvent extraction.
Processors squeeze part of the oil from some sources, including corn, cottonseed and peanuts. They then remove the remaining oil from the seeds with solvents.
Oils obtained by high pressure or solvent extraction are bleached, deodorized and purified to produce a high quality product. Cold pressed oils require no further processing.
Many nonfood products contain vegetable oil. As an example, manufacturers make cosmetics, shampoos and soaps from coconut, palm and palm kernel oil.
Some medicines contain cocoa butter or caster, olive or wheat germ oil.
Many paints and varnishes include a drying oil, such as linseed, soybean or tung oil. Drying oils combine with oyxgen from the air to form a tough coating.
Most vegetable oils are liquids. But several, including cocoa butter, coconut oil and palm oil, are solids at temperatures below 75 degrees fahrenheit.