Protein. Growth Repair Maintenance of the Body Energy (in cases where fats and carboyhdrates are not available).

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1 Protein Protein is a macro-nutrient. Our body is composed of millions of cells which are constantly being replaced and repaired. As the body grows new cells are added. Protein is required for: Growth Repair Maintenance of the Body Energy (in cases where fats and carboyhdrates are not available). The daily percentage intake of protein should be 15% of the total energy intake. 1g of protein = 4Kcal The Nature of Proteins Protein is made up of the elements joined together called amino acids. Each shape represents a different amino acid. Essential Amino Acids These amino acids must be obtained from food. They are also referred to as indispensable amino acids. Non Essential Amino Acids These amino acids can be produced by our own body therefore they do not have to be obtained from food. They are also referred to as dispensable amino acids. 1

2 Animal Protein Plant Protein Foods that are high in these essential amino acids have a High Biological Value Protein. HBV Proteins are found mainly in animal foods such as meat, fish, milk, cheese and eggs. Foods that are low in these essential amino acids have a Low Biological Value Protein. LBV Proteins are found mainly in plant foods such as cereals, beans, peas, lentils and vegetables. Complete Proteins Incomplete Proteins High Biological Value Protein ( HBV ) Animal Foods Complete Proteins Low Biological Value Protein ( LBV ) Plant Foods Incomplete Proteins There are 2 exceptions: Soya Beans (plant) contain HBV Protein. Gelatine (animal) contains LBV Protein. 2

3 What are Complementary Proteins? Complementary proteins are when two or more incomplete proteins (plant foods) are eaten together in order to provide adequate amounts of all the essential amino acids. Example: Beans on Toast, Hummus with Bread, Rice with Beans, Soup with Lentils and Peas 3

4 Protein Requirements Babies and children: they are growing up rapidly, Adolescents: rapid spurt of growth, Pregnant woman: for their growing baby, Nursing mother: for milk production during breast feeding, Vegetarians and vegans should emphasize on a variety of plant protein. Deficiency Protein Energy Malnutrition, Marasmus Severe undernourishment causing the child s wieght to be very low for their age, Kwashiorkor It is caused by severe malnutrition amongst children. 4 Excess Poor kidney function, Obesity - Lots of animal protein foods contain high amounts of fat expecially saturated fat.

5 Effect of Heat on Protein When proteins are heated, their chemical structure is denatured (changed). This is a permanent alteration and cannot be reversed. As heating continues, proteins coagulate (set) and become less soluble. If overheated, they become less digestible. In milk, proteins coagulate and form a skin on the surface. Under 100 C, coagulation is slow, over 100 C coagulation is rapid and the protein becomes hard and less digestible. In liquid, the protein becomes gelatine. In dry heat, protein coagulates quickly to a rubbery texture and then to a crisp texture which is hard to digest. Egg white: At 60 C the protein coagulates. The white becomes solid and opaque. Egg yolk: At 70 C proteins start to denature and continue until the yolk becomes dry and hard. At 80 C gluten in wheat starts to coagulate. In this way it helps to form the structure of cakes, bread and other baked goods. High Protein Diets 1. High protein diets are NOT RECOMMENDED! Some of these diets restrict healthy foods that provide essential nutrients and do not provide the variety of foods needed to adequately meet nutritional needs. 2. People who stay on these diets for long period of time may not get enough vitamins and minerals and may face other potential health risks. Foods that contain HBV Proteins contain saturated fat therefore high protein diets can lead to obesity, coronary heart disease, diabtetes, stroke and several types of cancers, as well as problems in the liver. 5

6 Novel Sources of Protein Textured Vegetable Protein It is a meat substitute made from soya flour that has been processed and dried. It is a byproduct of soya beans. Tofu Tofu is made from soy milk and it is similar to the production of cheese from milk. Some tofu is made by processing non-soy products such as almonds or black beans. Quorn All qourn products contain mycoprotein which is a fungus that contains high quality proteins enabling us to offer an alternative purely vegetarian source of protein to meat. 6