Eggs for health
Both the white and yolk of an egg are rich in nutrients - proteins, vitamins and minerals with the yolk also containing cholesterol, fat soluble vitamins and essential fatty acids. Eggs are also an important and versatile ingredient for cooking, as their particular chemical make up is literally the glue of many important baking reactions.
Eggs are a very good source of inexpensive, high quality protein. More than half the protein of an egg is found in the egg white along with vitamin B2 and lower amounts of fat than the yolk. Eggs are rich sources of selenium, vitamin D, B6, B12 and minerals such as zinc, iron and copper. Egg yolks contain more calories and fat than the whites. They are a source of fat soluble vitamins A, D, E and K and lecithin - the compound that enables emulsification in recipes such as hollandaise or mayonnaise.
Some brands of egg now contain omega-3 fatty acids, depending on what the chickens have been fed (always check the box). Eggs are regarded a 'complete' source of protein as they contain all nine essential amino acids; the ones we cannot synthesise in our bodies and must obtain from our diet.
Eggs are rich in several nutrients that promote heart health such as betaine and choline. A recent study of nearly half a million people in China suggests that eating one egg a day may reduce the risk of heart disease and stroke, although experts stress that eggs need to be consumed as part of a healthy lifestyle in order to be beneficial.
During pregnancy and breast feeding, an adequate supply of choline is particularly important, since choline is essential for normal brain development.
Eggs are a useful source of Vitamin D which helps to protect bones, preventing osteoporosis and rickets. Shop wisely because the method of production – free range, organic or indoor raised can make a difference to vitamin D content. Eggs should be included as part of a varied and balanced diet. They are filling and when enjoyed for breakfast may help with weight management as part of a weight loss programme, as the high protein content helps us to feel fuller for longer.
Quail eggs have a similar flavour to chicken eggs, but their petite size (five quail eggs are usually equal to one large chicken egg) and pretty, speckled shell have made them popular in gourmet cooking. The shells range in color from dark brown to blue or white. Quail eggs are often hard-boiled and served with sea salt.
Duck eggs look like chicken eggs but are larger. As with chicken eggs, they are sold in sizes ranging from small to large. Duck eggs have more protein and are richer than chicken eggs, but they also have a higher fat content. When boiled, the white turns bluish and the yolk turns red-orange. - BBC.