Egg (food)
Categories: Egg | Breakfast foods
- This article is about bird eggs as food; for the edible eggs of sea animals, see roe and caviar, and for other meanings, see egg.
Bird eggs are a common food source. The most commonly used bird eggs are those from the chicken, duck, and goose, but smaller eggs such as quail eggs are occasionally used as a gourmet ingredient, as are the largest bird eggs, from ostriches. The eggs of turtles are sometimes used for food also. Eggs are frequently used in both sweet and savoury dishes as a source of protein and/or to bind the other ingredients in a recipe together. Sometimes the egg yolk is used separately from the egg white (or albumen).
The egg yolk is suspended in the egg white by one or two spiral bands of tissue called the chalaza (Greek word from "khalaza" meaning hailstone, or hard lump.)
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Nutrition of chicken eggs
Chicken eggs are the most commonly eaten egg. They are highly nutritious. Eggs are high in complete protein and provide significant amounts of several vitamins and minerals (Vitamin A, Riboflavin, Folic Acid, Vitamin B6 and Vitamin B12, and Iron). Eggs are among the cheapest single-food source of complete protein available, which is essential to health and well being.All of the egg's vitamin A, D and E are in the yolk. They are one of the few foods naturally containing vitamin D (though this nutrient is naturally produced in the human body with exposure to sunlight). A large egg yolk contains approximately 60 calories (250 kilojoules); the egg white contains about 15 calories (60 kilojoules). A large yolk contains more than two-thirds of the recommended daily limit of 300 mg of cholesterol. The yolk makes up about 33% of the liquid weight of the egg. It contains all of the fat in the egg and almost half of the protein.
Recently chicken eggs that are especially high in Omega 3 fatty acids have come on the market. These eggs are made by feeding laying hens a diet containing polyunsaturated fats and kelp meal. Two brands available in the UK are Columbus Eggs[1] and The Hearty Egg[2]. Nutrition information on the packaging is different for each of the brands.
Health issues of eating chicken eggs
Cholesterol and fat
Chicken egg yolks contain a small amount of fat. People on a low-cholesterol diet may feel the need to cut down on egg consumption, although most of the fat in egg is unsaturated fat and may not be harmful. The egg white consists primarily of water (87%) and protein (13%) and contains no cholesterol and little if any fat.
Some people try to avoid eggs in their diet because they are high in cholesterol which is concentrated in the yolk. This issue is sometimes addressed by removing some or all of the eggs' yolks. People sometimes do this themselves, or may use prepared egg substitutes such as Egg Beaters.
In addition, the United States egg industry launched its continuing "Incredible Edible Egg" campaign, which touts eggs as a healthy part of a balanced diet. The American Egg Board publicizes modern research which shows that dietary cholesterol has less effect on blood cholesterol than previously thought. Eggs are an excellent component of a low-carbohydrate diet
Contamination
A health issue associated with eggs is contamination by pathogenic bacteria like Salmonella. Eggs exit a female bird via the cloaca, so care must be taken to avoid the eggs being contaminated with fecal matter. In commercial practice, eggs are quickly washed with a sanitizing solutions within minutes of being laid.
Most health experts advise people to cook their eggs thoroughly before eating them, as the heat is necessary to kill any infectious micro-organisms that may be present. Raw and undercooked eggs have been associated with salmonella infection. As with meat, ready-to-eat food should not come in contact with containers and surfaces that have been used to process raw eggs.
The risk of infection from raw or undercooked eggs is dependent in part upon the sanitary conditions under which the hens are kept. Some smaller egg producers make a point of keeping their hens in cleaner (and, in their view more humane) conditions, and observe few or no cases of salmonella in the birds themselves.
Ethical issues
Many who practice vegetarianism feel it is acceptable to eat eggs as the bird is not killed and the eggs remain unfertilised. People concerned about animal welfare (especially vegans) are reluctant to eat mass-produced eggs as factory farming is considered cruel. Even free-range eggs are sometimes unacceptable to those who are concerned about animal welfare as it is felt that alleged free-range birds may not be much better off than confined birds. Many vegans believe it is inaccurate that eating eggs does not cause an animal to be killed since most farms (both free-range and factory farms) kill the chickens once their egg production declines. Most farms also buy the chicks from hatcheries where the male chicks are killed at birth. From a religious standpoint some vegetarians such as certain practitioners of Buddhism feel that eggs are the same as "liquid meat" and thus unacceptable for consumption.
Cooking and preparation
Image:Potato galettes with quail eggs.jpg Potato galettes, served with quail eggs. The eggs of the quail are edible and are a popular delicacy. |
Image:Egg carton.jpg Chicken eggs |
Image:Raw egg.jpg The yolk of a raw egg |
The primary cooking techniques for eggs are:
Some common egg dishes are
Eggs, particularly their yolks, are important as binding agents in many preparations in European cooking due to the emulsifying action of lecithin. This property is crucial for sauces such as mayonnaise and Hollandaise, custards such as crème anglaise, crème brûlée, flan and lemon custard, and meat dishes such as sausages and pâté.
Eggs may also be pickled, hard-boiled and refrigerated, or eaten raw, though the latter is not recommended for people who may be susceptible to salmonella, such as the old, the infirm, or pregnant women.
If an egg is overcooked a greenish ring sometimes appears around egg yolk, this is the result of iron and sulfur compounds in the egg. It can also occur when there is much iron in the cooking water. The green ring affects neither taste nor nutrition.
When eggs become rotten, the yolk will turn green and the egg will emit a sulfurous smell when broken. Although deemed offensive by most Western palates, fermented eggs are considered a delicacy by some in China, when prepared using a special method which includes letting them sit for three months to age (or rot, depending on one's interpretation).
Egg substitutes for baking
For those who choose not to or are unable to consume eggs, alternatives used in baking include other rising agents, such as Ener-G egg replacer, or binding materials, such as ground flax seeds. Tofu can also act as a partial binding agent, since it is high in lecithin due to its soy content. Extracted soybean lecithin, in turn, is often used in packaged foods as a cheap substitute for egg-derived lecithin.
Egg characteristics
The shape of an egg is approximately an oblate ellipsoid, but, while keeping cylindrical symmetry, there is typically not quite symmetry in a plane perpendicular to the long axis. See also oval (geometry).
Shell color
Different breeds of chicken can lay eggs with shells varying from whites through to brown and rarer colours such as speckled green. Although there are absolutely no nutritional differences, there is often a cultural preference for one colour over another. For example, in most regions of the United States eggs are generally white, while in the northeast of that country, and in the United Kingdom eggs are generally light-brown. These habits may be associated with perceptions of greater purity in white-shelled eggs or greater wholesomeness in brown-shelled eggs.
Yolk color
Yolk colour depends on the diet of the hen, if the diet contains yellow/orange plant pigments known as xanthophylls, then they are deposited in the yolk, colouring it. A colourless diet, can produce an almost colourless yolk. Farmers may add natural pigments to enhance yolk colour, but artificial colours are banned.
Abnormalities
Some hens will lay double-yolked eggs as the result of unsynchronized production cycles, although heredity causes some hens to have a higher propensity to lay double-yolked eggs. Double-yolked eggs only rarely, and even then only with human intervention, lead to the successful development of two embryos [3].
It is also possible for a young hen to produce an egg with no yolk at all.
Trivia
- If a raw egg is spun, abruptly stopped and then quickly released, it will start to spin again as the liquid inside continues to rotate. This technique can be used to reliably determine whether an egg is raw or already boiled – a solid egg will remain stationary once halted.
- It is difficult (some say impossible) to break a chicken egg by squeezing it from end-to-end on its long axis.
- An ostrich egg can make omelets for ten people and takes forty-five minutes of boiling to harden through.
- An egg that floats in water is likely to have been spoiled by bacteria that entered through the pores in the shell and created gas inside it. The increased pressure due to the gas production may push some of the white through the shell, which may also signify a bad egg.
Pop culture
- There is a famous nursery rhyme about an anthropomorphic egg named Humpty Dumpty. When he fell off a wall, all the King's horses and men could not fix him.
- In The Neverending Story, the Old Man of Wandering Mountain lives in a giant egg at the summit of, you guessed it, a wandering mountain. This is where he eternally writes the Neverending Story, as it happens.
- Billy Hatcher and the Giant Egg is a video game about a boy in a chicken outfit pushing around giant eggs in order to defeat his enemies. Occasionally, the eggs hatch into helpful animals.
- In the video game The Legend of Zelda: Link's Awakening, a giant egg atop a mountain is central to the plot.
- There is a Pokémon known as Exeggcute which consists of a group of egg-like beings. Pokémon also reproduce by laying eggs under certain conditions, these conditions are nearly always at a daycare centre, if you have a female and a male pokémon that are friendly with each other they will give birth to one of the parenting pokémon, sometimes baby form, new baby pokémon have been introduced, these are what the eggs hatch into.
- In RahXephon, a giant egg is central to the plot.
- A popular Easter tradition in some parts of the world is the decoration of hard-boiled eggs (usually by dyeing). Occasionally, adults hide the eggs for children to find, an activity known as an Easter egg hunt. See Egg decorating and Easter eggs.
Egg Attacks
Although a food, they have been used to throw at people or things, a minor criminal offence. On Halloween for example, if you do not give trick or treaters anything, they have been known to throw eggs at property or people.
John Major, a former British prime minister had an egg thrown at him in protest by a student. Current deputy prime minister John Prescott also had an egg thrown at him by a protester (in addition to this he has also been attacked with iced water and even been punched).
See also
External links
- cruelty investigations at egg factory farms
- criticism of the "Animal Care Certified" logo found on most eggs in the United States
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