vegetable oil
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What is vegetable oil?
Vegetable oil refers to various fatty oils extracted from vegetables, nuts, seeds, fruits, and cereal grains. Examples include olive oil, soybean oil, and corn oil.
Depending on the intended use, vegetable oils undergo processing, such as cracking, pressing, and heating the source material. Some undergo refining and bleaching to remove unwanted odors and flavors.
Vegetable oils are widely used in food and cooking. They can also serve as a source of biodiesel fuel for internal-combustion engines. Additionally, some vegetable oils are used in hair and skin preparations as moisturizing agents.
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How is vegetable oil made?
Vegetable oil is made by extracting oil from oil-bearing tissues from oilseeds, fleshy fruits, and animal by-products. The general extraction methods are rendering, mechanical pressing, and volatile solvents.
Extraction Methods
* Rendering This method is used for animal products and fleshy fruits. One rendering method involves heaping fruits, like olives, in piles exposed to the sun and collecting the oil that exudes.
* Mechanical Pressing Oil-bearing seeds and nuts are broken up and then mechanically pressed to release the oil. Modern continuous screw presses can exert pressures as high as 30,000 pounds per square inch.
* Volatile Solvents This method is employed in large-scale operations for more complete extraction than pressing. The solvent is percolated through the meal, dissolving the oil, which is recovered from the solution by evaporating the solvent.3 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
From which plants can we get vegetable oil?
Vegetable oils come from various plants, including trees, herbaceous plants, and even fungi. These oils are derived from vegetables, nuts, seeds, fruits, and cereal grains.
Examples of plants from which vegetable oils are extracted include oil palm, flax, soybean, and sunflower. Other sources are almond, argan, avocado, canola, coconut, cocoa butter, corn, cottonseed, grape-seed, lemon, linseed, orange, olive, peanut, safflower, walnut, and wheat germ.
The oil is typically found in large amounts in the seeds or fleshy parts of fruits like olives and oil palms.
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How is vegetable oil used in cooking?
Vegetable oils are used in food and food preparation in a variety of ways. They can be used to sauté or fry foods and are a key ingredient in sauces and baked goods.
When cooking with oils, one consideration is the smoke point, or the temperature at which the oil begins to smoke and break down. When oil is heated past its smoke point, its flavor and nutritional value are compromised, and harmful free radicals are released. Unprocessed oils have lower smoke points and are more suitable for non-heated applications like salad dressings.
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What are some health benefits and risks of using vegetable oil?
Vegetable oils, derived from various plants, are used in food, fuel, medicine, and beauty products.
Health Benefits:
* Some vegetable oils contain monounsaturated fatty acids, like oleic acid in olive oil, which help maintain healthy cholesterol levels and reduce heart disease risk.
* Linseed oil has high levels of alpha-linolenic acid (omega-3), while others have linoleic acid (omega-6). These essential fatty acids support cell membranes and help the body metabolize cholesterol and absorb vitamins A, D, E, and K.Health Risks:
* Some vegetable oils, such as coconut, cottonseed, and palm oil, have high saturated fat content, which can increase LDL cholesterol levels and the risk of heart disease.
* Trans fats, formed during the processing of vegetable oils, increase LDL cholesterol and heart disease risk.
* Heating oils to their smoke point can compromise their nutritional value and release harmful free radicals.2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How is vegetable oil processed and refined for use in food products?
Vegetable oils are processed and refined for use in food products through several steps. The raw materials are acquired from vegetables, nuts, seeds, fruits, and cereal grains. The oil is extracted through rendering, mechanical pressing, or volatile solvents. Afterward, the oil goes through refining, which includes water refining or degumming to remove phospholipids, free fatty acids, waxes, and other undesirable materials. Some oils undergo further processing to remove odors and flavors associated with their source.
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vegetable oil, any of various fatty oils derived from vegetables, nuts, seeds, fruits, and cereal grains. Examples include (but are not limited to) almond oil, argan oil, avocado oil, canola oil, coconut oil, cocoa butter, corn oil, cottonseed oil, grape-seed oil, lemon oil, linseed oil, orange oil, olive oil, palm oil, peanut oil, safflower oil, soybean oil, sunflower oil, walnut oil, and wheat germ oil. Some vegetable oils are edible, though not all are considered healthy; many have a wide range of uses, including as cattle feed, engine fuel, drying agents in paint, and more. They are also used in medicine and in beauty products.
Depending on their intended use, vegetable oils can be processed by cracking or breaking the source material, pressing it, and sometimes applying heat. In some cases refining, bleaching, and additional processing are used to remove odours and flavours associated with the source material. See also fat and oil processing.
Composition and nutrition
Vegetable oils are primarily composed of triglycerides and are typically liquid at room temperature. They contain a greater variety of fatty acids than animal fats. Olive oil, for example, contains the monounsaturated fatty acid oleic acid, which contributes to healthy cholesterol (HDL, or high-density lipoprotein) levels and may reduce the risk of heart disease. Polyunsaturated fatty acids, specifically alpha-linolenic acid (omega-3) and linoleic acid (omega-6), are found in a number of vegetable oils and contribute to the maintenance of cell membranes, which help to metabolize cholesterol and absorb the fat-soluble vitamins A, D, E, and K. These are considered essential fatty acids because they cannot be synthesized by the human body and must thus be obtained from dietary sources. Linseed oil has the highest level of alpha-linolenic acid of any vegetable oil.
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Some vegetable oils are high in saturated fat, including coconut oil, cottonseed oil, palm oil, and palm kernel oil. These are often more viscous or even semisolid at room temperature. Coconut oil, for example, contains a number of saturated fatty acids, including caprylic acid, capric acid, lauric acid, and myristic acid. Saturated fats raise the levels of low-density lipoprotein (LDL) cholesterol in the bloodstream and thus are associated with increased risk of heart disease.
Trans fats (also known as trans fatty acids or partially hydrogenated fats) occur when vegetable oils are processed with hydrogen to solidify them. Trans fats are primarily used in fried foods and can be found in baked goods such as doughnuts, cookies, pies, crackers, and muffins. Because trans fats increase LDL cholesterol and the risk of heart disease, the U.S. Food and Drug Administration has required listing of trans fat content on food ingredient panels since 2006.
Uses
Vegetable oils are widely used in food and food preparation. Olive oil, for example, has been produced for approximately 8,000 years. Vegetable oils are commonly used to sauté or fry vegetables and meats and are a key ingredient in a wide variety of sauces and baked goods. Vegetable oils have been used in margarine, which may also include animal fats, and in vegan margarine-like spreads.
When used in cooking, fats and oils are measured by the “smoke point,” the temperature at which heated oil begins to smoke and to break down, compromising its flavour and nutritional value and releasing free radicals that can be harmful to health. Depending on a number of variables (such as the number of samples tested, the processing method and age of the oil, and the pan used to heat the oil), an oil’s estimated smoke point can range widely. Unprocessed oils have a lower smoke point than processed oils and are more suitable for non-heat uses, such as in salad dressings. Cold-pressed oils, also known as virgin oils, are processed at temperatures below 49 °C (120 °F) and are said to retain more nutritional value.
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Vegetable oil can be used as a source of biodiesel fuel for internal-combustion engines. Biodiesel is made primarily from soybean or palm oil and can even include waste vegetable oil generated by restaurants in deep-frying food. In the late 1800s, Rudolf Diesel used vegetable oil as fuel and ran his diesel engine on peanut oil when he exhibited it at the Paris Exposition in 1900.
A number of vegetable oils, including argan oil, jojoba oil, and shea butter, are used in hair and skin preparations as a moisturizing agent. Almond and coconut oil are used as a base in massage oils and as carrier oils for the essential oils used in aromatherapy. Some vegetable oils are known as drying oils because they thicken and harden on exposure to air. Linseed oil, for example, is a drying oil that is useful in the production of paints, printing inks, linoleum, wood varnish and stains, and oilcloth. Poppy-seed oil is also used as a drying agent in artists’ paints.