Nutritionists have always regarded eggs to be one of nature’s most perfect foods. Eggs are cheap quality protein but they are also fit for a king - nutrient in an eggshell. Owing to their versatility Dutchmen have always regarded eggs as magical. While albumin can be beaten into a fluffy white foam and egg yolks oil in a frame to form a stable emulsion, the egg as a whole is famous for its binding and congealing qualities. French cooks regard eggs as the cement that holds the culinary art together. They also boast that they can prepare an egg dish a day for a year without repeating a single one. A South African household without eggs is unimaginable. Traditionally eggs are a breakfast food in South Africa and it is here that most eggs are consumed. However, because eggs are the cheapest protein, they are becoming more and more popular as light meals. COMPOSITION OF EGGS The shell represents about 11% of the mass of an average egg, the albumin 58% and the yolk 31%. The composition of the albumin and the yolk differs remarkably. The yolk is more concentrated than the albumin and therefore contains more nutrients, as illustrated in the following table. Nutrients Units Whole White Yolk Mass g 50 33 17 KJ   331 68 263 Protein g 6.25 (12,5%) 3.5 (11%) 2.7 (16.1%) Total fat g 5.01 (10%)   5.01 (29.5%) Minerals g 0.5 (1%) 0.23 (0.6%) 0.27 (1.6%) Water g 38.25 (76.5%) 29.2 (76.5%) 9 (52.8%) EGGS IN A BALANCED DIET Eggs are included in the diet as a protein portion. The protein in an egg is regarded as the best quality protein and is therefore used as a worldwide standard for measuring the quality of other food proteins. The "best quality protein" means that egg protein contains all the essential amino acids in the right quantities to assure optimal growth and the repair of damaged and worn tissues, albeit body, muscle or brain tissue, and to maintain the nitrogen balance in the body. The amino acid composition of egg protein is the nearest to that in mothers milk. That is why egg protein is regarded as the complete protein with the highest biological value. The housewife traditionally cooks eggs for breakfast, probably because it is a cheap protein that can be prepared in a jiffy. Medical science, however, has an excellent explanation for why eggs are the ideal breakfast food. With breakfast, as with any other meal, the emphasis should be on a balanced diet with protein, carbohydrates, fruit and vegetables. Fats are usually included with the proteins and carbohydrates. Fruit and vegetables are essential for the vitamins and minerals they supply and they generate energy to the body together with fats and carbohydrates. Protein is essential for growth, the repair of damaged and worn tissue and numerous other necessary functions. After a nights rest the body is in the process of fasting and the blood glucose level is very low. This must be raised if the day is to be started energetically. When only refined carbohydrates such as in rusks or toast with jam are taken, the blood glucose level rises quickly and abnormally, and the body releases insulin to lower it again. When normal values have been restored, the insulin is still present with the result that the blood glucose level falls to below normal again, causing headaches and dizziness. The ideal situation is for the glucose level to be raised gradually and over a longer period, which makes one feel excellent until the next meal. This means that protein, fat or fibre should be taken together with carbohydrates. An ideal balanced breakfast consists of a protein like eggs, carbohydrate like whole wheat bread and a fruit or vegetable, preferably a rich source of Vitamin C such as a orange or a tomato. This ensures that one can keep pace productively until the next meal. There is a misconception that the consumption of eggs should be limited because of their high cholesterol content, high blood cholesterol being one of the risk factors of coronary heart disease. Extensive research worldwide, however, has proved that dietary cholesterol, as consumed in eggs, has very little affect on blood cholesterol, while a high intake of saturated fatty acids directly influences blood cholesterol levels. Thus, limiting dietary cholesterol intake will not limit body and blood cholesterol levels when enzyme control of the process is normal. On the other hand poly and mono unsaturated fatty acids tend to lower blood cholesterol levels. Saturated fatty acids tend to lower blood cholesterol levels. One egg contains 6g fat of which 2g are saturated fatty acids and the rest poly and mono- unsaturated fatty acids. This clearly suggests the possibility of the negative effect of the saturated fat in an egg being concentrated by the poly and mono-unsaturated fatty acids. Equally important is the way in which eggs are prepared and whether or not the meal is balanced. The healthiest way is to cook or poach eggs, and when scrambled or baked as little oil as possible should be used. The spray type or vegetable oil is preferable. Those suffering from familial cholesterolaemia must, however, limit their egg intake together with their intake of saturated fat. QUALITY PROTEIN The word protein has been derived from the Greek, which means "to take first place". The ideal recommended amount of protein required per day is 0.8-1g for every kilogram of body mass. If a man weighs 75kg he should therefore consume 60 to 75g of protein per day. An egg contains 6.6g proteins. This protein requirement is higher during pregnancy, breast-feeding or sickness, after an operation or when recovering from burns. With increased activity such as cycling, long distance running etc. the protein requirement increases together with the energy consumed to 1.2g per kilogram body mass per day. Egg protein is the best quality protein available and, as such, best able to fulfil all protein functions: 1. In growing children proteins builds new tissue whether it is body, muscle or brain tissue. When they hurt themselves it is the protein that repairs the damaged tissue. In adults catabolism or the demolition of tissue occurs continuously and thus protein is essential for tissue repair. 2. Protein forms an integral part of all body secretions and liquids excluding urine and bile. Enzymes, hormones, mucus, milk, semen, and semen liquids all contain protein or amino acid components. 3. Albumin, one of the proteins in the blood, maintains the ratio between the body liquids inside and outside cells and therefore a protein deficiency becomes visible as oedema or swelling as a result of excessive body liquid inside and between cells. 4. Protein maintains the acid alkaline balance in the blood and tissue. As protein has the exceptional ability to bind acid and alkaline, it is able to reduce the effect of, for example, too much acid. 5. Plasma protein is responsible for the transportation of substances through the body. It is in this way, lipids-carrying protein transport triglycerides, cholesterol, phospholipids and fat-soluble vitamins. Proteins also bind iron, calcium, free fatty acids and medication to transport it through the body. 6. Resistance to illness is dependent on the working of protein in the form of immunoglobin or antibodies. 7. Diet protein supplies amino acids that are necessary for various metabolic processes - supplying the amino acids tryptophne, tyrosine, choline, histidine and treonine and prototypes in the nervous system. COMPLETE NUTRIENT PACKAGE In addition to the high quality protein in an egg, it also contains certain quantities of all other nutrients, i.e. fats, carbohydrates, minerals and vitamins (except Vitamin C). The yolk is an excellent source of iron and, as such, essential in the diets of anaemic patients and during pregnancy. From the age of three months, babies have to have a teaspoon of soft-boiled egg yolk as an iron supplement to their diet. Eggs contain very few kilojoules. A hard-boiled egg is ideal for dieting because it is a very neat precise portion and a large egg supplies only 331 kJ. Eggs contain only a small amount of carbohydrates. This is not a problem as eggs are usually served with carbohydrates, such as a slice of bread. To summarise, a table indicating the nutrient content of the edible portion (50g) of one large egg (56g with shell): Nutrients Units Whole White Yolk Mass g 50 33 17 KJ   331 68 263 Protein g 6.25 (12,5%) 3.5 (11%) 2.7 (16.1%) Total fat g 5.01 (10%)   5.01 (29.5%) Minerals g 0.5 (1%) 0.23 (0.6%) 0.27 (1.6%) Water g 38.25 (76.5%) 29.2 (76.5%) 9 (52.8%) RICH IN NUTRIENTS Eggs are a handy food parcel containing all the nutrients we need except Vitamin C, but they are especially renowned for the high quality of the protein they contain and are therefore an important part of a balanced diet. With the addition of only carbohydrates (a slice of whole-wheat bread) and Vitamin C (a tomato or a glass of orange juice) eggs form a fully balanced meal. EMULSIFICATION The egg yolk contains an emulsifying agent, lecithin, which acts as a stabilising emulsion between oil and water. This prevents oil and water mixtures from separating. Lecithin attracts oil and water particles and forms a thin layer around them to keep them from dispersing. When making mayonnaise, the egg lecithin surrounds the oil particles, preventing them from joining and discharging oil. Butter sauces, such as Hollandaise sauce for example, are an emulsion of butter in combination with water or vinegar, stabilised with egg lecithin. In cakes prepared by using the creaming method, the emulsifying quality of eggs is essential to ensure a light texture. When whipped egg is added to creamed butter and sugar, the sugar dissolves in the egg lecithin stabilises the butter and water emulsion. Air is trapped in this emulsion. When heated, the air expands to give a lighter texture when baking. FOAMING ABILITY A foam is created when air molecules are surrounded by egg protein and captured. When egg whites are whisked, air is included. At the same time, the twisted protein spiral unfolds and stretches, capturing and surrounding the air in stable foam. Egg white protein is elastic, enabling captured air to expand with heat without damaging the foam. Owing to the coagulation of the egg protein, the foam is able to set in the risen position. Egg white foams easiest at a temperature of 14°C. For maximum foaming, it is important to use a clean glass or porcelain bowl and a clean egg whisk. The egg yolk and white must be separated carefully, because a drop of yolk will lessen the foaming ability of the egg white. Whisked egg white is used for meringues when sugar is added. When heated, the protein coagulates to a light crisp texture. When egg and sugar are whipped over water, the volume of the foam increases. Whisked egg white is added to soufflés or mixtures for baking, to include more air. The air expands with heat and thus acts as a raising agent. Whole whisked egg has the same ability as egg white, but to a lesser extent. In the preparation of sweets, the addition of egg white makes the inclusion of air possible as a solution of sugar and water alone cannot. COAGULATION (CONGEALING) Coagulating properties, the egg protein, together with the milk and flour, lends structure to baking. When food is dipped in egg and fried in oil the egg forms a protective layer around the food, which prevents the oil from being absorbed by the food. Coagulation is also important when binding ingredients, for example in fish or pumpkin cakes, for glazing when baking, to clarify fluids, to thicken sauces like custard sauce and to set tart fillings and baked custard.