Chemistry - Vegetable Oils and Their Uses

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.

One of the ways in which your knowledge of vegetable oils could be tested is that you are asked to evaluate given data about an oil that you have probably never heard of. In such cases, keep calm and think about what you do know, then look how it can be applied to the questions. For example, that type of question could test your knowledge of the economic, ethical and environmental issues surrounding the use of vegetable oils as fuels or why certain fats and oils are used in cakes and pastries!

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.