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All foods are made up of a framework of different substances and have different parts to play. You need to be familiar with the three main food groups - proteins, carbohydrates and fats. You may also need to know about minerals, vitamins and fibre.
Different foods such as oil, eggs, fruit, milk and flour, have different properties, including flavouring, preserving, sweetening and thickening. These properties are very useful when preparing foods.
Proteins
Proteins are vital to all diets as they assist with growth/repair of the body. They are made up of amino acids [amino acids: complex molecules which form the building-blocks of proteins ].
Fish a source of high biological value proteins
- High Biological Value (HBV) proteins contain all the essential 10 amino acids (the building blocks of protein). HBV proteins can be found in meat, fish, cheese, milk, eggs and soya-bean products.
- Low Biological Value (LBV) proteins contain a limited number of amino acids. LBV proteins are found in foods like pulses (peas, beans, lentils) and nuts.
The key property of protein is that when it is cooked it denatures (changes its properties), before coagulating and setting. Egg white, for example, is a clear, runny substance when raw. But as it is cooked it changes to become solid, white and firm in texture.
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