Vegetable oil is a mixture of higher fatty acids and associated substances derived from plant oilseeds. The main methods of obtaining vegetable oils are squeezing (compression) and extraction (organic solvents, or liquefied carbon dioxide). Squeezing is the traditional method of producing vegetable oils. Edible vegetable oils contain a number of substances that are important for the life of the human body and the body cannot synthesize these substances on their own. Daily use of vegetable oils in food allows you to keep a proper balance of vitamins. On the degree of purification vegetable oils are divided into raw, unrefined and refined (purified) one. Vegetable oil called raw, if it after squeezing only filtered. Raw oils have an intense aroma, rich color and personal taste. They contain all the necessary vitamins and biologically active substances and are therefore ideally suited for salads, cereal, boiled potatoes and other food. These oils are stored not for long, they do not tolerate heat and totally unsuitable for frying. These vegetable oils have a higher per (protein efficiency ratio) than other oils. Vegetable oil subjected to partial purification - defending, filtration, neutralization of free fatty acids (they are rapidly oxidized when exposed to air) and the hydration process which removes phospholipids, mucus and other substances is known as unrefined. Unrefined oils are less biological value than the raw and retain good taste. They tolerate heat, but use them for frying is not recommended. Refined oils are obtained by a full cleaning cycle, which consists in refining (removal of various contaminants and impurities), freezing and deodorization. Refined oils are transparent and consist only of triglyceride fatty acids. They have not own taste, and they have the lowest biological value. Sometimes refined oils are artificially enriched phospholipids and vitamins. On the labels glued to the bottle, in addition to specifying what kind of processing oil has passed, you can find also the following notation: hydrated, neutralized, frozen and deodorized oil. Hydrated oil undergoes hydration and mechanical cleaning (removal of phospholipids). There are triglycerides, fatty acids, free fatty acids, and fat-soluble vitamins, wax-like and aromatic substances in it. All refined oils used are recommended for frying and other ways of cooking food.
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