Many plants produce useful oils that have many uses. They can be converted into various things including processed foods like margarine, fuels like biodiesel, cosmetics and cleaning products. The oils themselves are frequently used in emulsions like salad dressings. But one of the main uses of vegetable oils is in cooking. They have much higher boiling points than water and so can be used to cook foods at higher temperatures than by boiling. Food can therefore be cooked faster than it would have been by cooking in water and different flavors are developed. The drawback to this is that it... Show more

Many plants produce useful oils that have many uses. They can be converted into various things including processed foods like margarine, fuels like biodiesel, cosmetics and cleaning products. The oils themselves are frequently used in emulsions like salad dressings. But one of the main uses of vegetable oils is in cooking. They have much higher boiling points than water and so can be used to cook foods at higher temperatures than by boiling. Food can therefore be cooked faster than it would have been by cooking in water and different flavors are developed. The drawback to this is that it increases the energy that the food releases when it is eaten so eating too many foods that have been fried or deep fried can have negative consequences for your health.

Some, but not all, fruits, seeds and nuts are rich in oils that can be extracted. To obtain the pure plant oil, the fruit, seeds or nuts are crushed and the oil is removed by pressing. In some cases, it is obtained by distillation, for example corn oils and soyabean oils. The seeds are crushed and the oil is extracted by using a solvent to dissolve it from the mixture. The solvent/oil mixture is then distilled to obtain the oil. Water and other impurities are removed during processing.

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