Egg: understand everything in 2 min
In recent years, nutrition experts have faced a dilemma: limiting consumption of eggs, given their high cholesterol content, or recommending it, given their high content of high quality protein as well as in several vitamins and minerals. Recent scientific data tend to show that the egg is a food of choice and that the consumption of one egg per day, even in people with high blood cholesterol, can be acceptable. Indeed, there is no substantial evidence demonstrating a real association between consumption of dietary cholesterol and blood cholesterol levels. The egg is nutritious, versatile and offers excellent nutritional value at low cost.
Active ingredients and properties
|Brown or white?
There is no difference in nutritional value or flavor between the white shell egg and the brown shell egg. The color of the shell depends on the breed of the hen. The brown eggs, however, would have the thicker shell and the darker yellow.
Carotenoids . Egg yolk contains two powerful antioxidants from the carotenoid family: lutein and zeaxanthin . Moreover, these two compounds confer the color to the yolk of the egg. Carotenoids, substances related to vitamin A, are antioxidants known to help prevent diseases related to aging, such as cataracts, macular degeneration, cardiovascular disease and certain cancers 1 . These antioxidants neutralize or reduce the free radicals present in the body and thus limit the damage caused to cells. Observational studies indicate that consuming foods rich in lutein, such as eggs, may help preventage- related macular degeneration , one of the main causes of blindness in people aged 65 and over, and to decrease the risk of cataracts 2 , 3 . The possible role of carotenoids in the prevention of cardiovascular disease (CVD) would be to decrease the oxidation of LDL-cholesterol (“bad cholesterol”) and to reduce the formation of plaque in the artery wall 4 . Finally, carotenoids could reduce the risk of certain cancers by protecting them against the development of tumors. Data from a prospective studyThe Nurses’ Health Study, involving 83,234 nurses showed that more intake of lutein and zeaxanthin, the higher the risk of breast cancer was low among perimenopausal women 5 .
Proteins . The egg is made up of proteins of high biological value. Proteins are used primarily to form, repair, and maintain tissue, such as the skin, muscles, and bones, in good condition. They are also used for the formation of digestive enzymes and hormones. The proteins in the egg are said to be complete, because they contain the nine essential amino acids in the body, and this in optimal proportions. Indeed, the protein quality of the egg is such that it is used as a reference food to assess the quality of other food proteins. Note that amino acids are said to be essential when the body cannot produce them. They must therefore come from food. Nearly 60% of the proteins in the egg are found in the white while the remaining 30% is in the yolk.
Choline . Eggs are an excellent source of choline, a compound that plays an important role in the development and functioning of the brain , primarily the center of the memory 6 . Choline is mainly found in the yellow part of the egg. The need for choline is important during embryonic development since during pregnancy and lactation, low intakes of choline can have effects on the development of the brain of the child in the long term 6 . An animal study has shown that supplementing with choline, during rat embryonic development or immediately after birth, improves cognitive function and, thereby, attention and memory 7. In addition, authors reported in a study of pregnant women with low folic acid intakes that mothers with the lowest choline intakes were four times more likely to give birth to a child with a neural tube defect than those with the highest intakes, regardless of folic acid intakes 8 .
|Egg and blood cholesterol
Since it is now known that high blood cholesterol levels are associated with an increased incidence of cardiovascular disease (CVD) 14 , most nutritional recommendations for the treatment of these diseases aim to decrease the consumption of foods rich in cholesterol and thus limit the egg yolks to two or three per week.
However, these recommendations have been questioned since many studies find a weak relationship between dietary cholesterol and the incidence of cardiovascular disease. It seems that consumption as high as one egg per day has no significant impact on cardiovascular risk 15 . A prospective study of 117,000 healthy men and women found no significant link between egg consumption and cardiovascular disease 15 . According to this study, the risk was not higher in those who consumed less than one egg per week than in those who consumed more than one per day.
Other studies, including a recent one, have shown that foods high in cholesterol but low in saturated fat like egg yolks have minor effects on blood cholesterol levels 16 , 17 . Several studies indicate that the control of blood lipids is better achieved by reducing the consumption of trans and saturated fats, instead of eliminating dietary cholesterol 18 . Moreover, the American Heart Association (AHA) mentions that the consumption of one egg yolk per day can be acceptable, even for people with high cholesterol , if the consumption of other foods rich in cholesterol, such as cheeses, cream, butter and red meats are limited 19 .
|Is the egg antioxidant?||Data not available.|
|Is the egg acidifying?||Moderately : The egg has a PRAL index of 8.2 / 100 g|
|Does the egg have a high glycemic load?||There is no glycemic load for eggs.|
Most important nutrients
See the meaning of the nutrient source classification symbols
Vitamin B2 . Eggs are a good source of vitamin B2. This vitamin is also known as riboflavin. Like vitamin B1, riboflavin plays a role in the energy metabolism of all cells. In addition, it contributes to tissue growth and repair, hormone production and the formation of red blood cells. Most of the riboflavin is found in the egg white.
Vitamin B12 . Eggs are a good source of vitamin B12. This vitamin works together with folic acid (vitamin B9) to make red blood cells in the blood. It also ensures the maintenance of nerve cells and cells that make bone tissue.
Phosphorus . Eggs are a source of phosphorus (see our fact sheet on Phosphorus nutrients ). Phosphorus is the second most abundant mineral in the body after calcium. It plays an essential role in the formation and maintenance of healthy bones and teeth. In addition, it participates among other things in the growth and regeneration of tissues and helps to maintain normal blood pH . Finally, phosphorus is one of the constituents of cell membranes.
Zinc . The egg is a source of zinc. Zinc is involved in particular in immune reactions, the production of genetic material, the perception of taste, scarring and the development of the fetus. Zinc also interacts with sex and thyroid hormones, and participates in the pancreas in the synthesis (manufacturing), storage and release of insulin.
Pantothenic acid . The egg is a source of pantothenic acid. Also called vitamin B5, pantothenic acid is part of a key coenzyme that allows us to adequately use the energy present in the food we eat. It also participates in several stages of the synthesis (manufacture) of steroid hormones, neurotransmitters (messengers in nerve impulses) and hemoglobin.
Folate . Eggs are a source of folate. Folate (vitamin B9) is involved in the production of all cells in the body, including red blood cells. This vitamin plays an essential role in the production of genetic material (DNA, RNA), in the functioning of the nervous system and the immune system, as well as in the healing of wounds and wounds. As it is necessary for the production of new cells, adequate consumption is essential during periods of growth and for the development of the fetus.
Vitamin A . The egg is a source of vitamin A. This vitamin is one of the most versatile, playing a role in several body functions. It promotes, among other things, the growth of bones and teeth. It keeps the skin healthy and protects against infections. In addition, it plays an antioxidant role and promotes good vision, especially in the dark. Most of the vitamin A is found in egg yolk.
Vitamin D . The egg is a source of vitamin D. Vitamin D interacts closely in the health of bones and teeth, making available calcium and phosphorus in the blood, among other things for the growth of bone structure. Vitamin D also plays a role in the maturation of cells, including those of the immune system. Most of the vitamin A is found in egg yolk.
Vitamin E . The egg is a source of vitamin E. A major antioxidant, vitamin E protects the membrane that surrounds the cells of the body, in particular red blood cells and white blood cells (cells of the immune system).
|What is a “portion” of egg worth?|
|Volume / weight||One egg, large size, boiled (boiled or hard boiled), 50 g|
|Fat||5.3 g (of which 32% saturated fatty acids, 38% monounsaturated, 14% polyunsaturated, 5% cholesterol (216 mg / egg)
100% of the lipids are found in the yolk of the egg.
|Dietary fiber||0.0 g|
Source : Health Canada. Canadian Nutrient File , 2005.
|The Omega-3 Egg Omega-3
eggs are identical to conventional eggs in terms of the total fat and cholesterol content. Only the omega-3 polyunsaturated fatty acid content of one differentiates it from the other. Eggs enriched with omega-3 are produced by adding flaxseed to the chicken’s ration. The latter is rich in alpha-linolenic acid (ALA), a type of omega-3 fatty acids.
An omega-3 egg covers 25% to 30% of our ALA needs, which can represent a complementary supply of these fatty acids. It is interesting to note that some liquid egg products have been enriched with omega-3 from marine sources. Unlike ALA, these fats from marine sources do not require a longer chain transformation before being used for certain functions in the body. However, it is important to mention that the eggs of hens fed flax seeds also contain long-chain omega-3s, since the hen metabolizes part of the ALAs to EPA and DHA (two omega-3s found in abundance in fish). bold).
Eggs, along with milk, peanuts and shellfish, are one of the main causes of food allergies. Egg allergy is usually caused by the immune system’s reaction to one of the protein fractions in egg white 9. However, in some people, it is the proteins in egg yolk that cause the allergy. Since it is impossible to separate the yolk and the egg white 100%, the only solution to avoid the allergic reaction is to exclude foods or products containing eggs or egg derivatives as well as foods likely to have been in contact with eggs. People with an allergy to raw eggs cannot usually eat cooked eggs. Even if cooking alters the protein of a raw egg, it is not enough to prevent an allergic reaction.
Fortunately, egg allergy disappears in the majority of children after the age of five 10 . However, when the allergy is severe, it is likely to last a lifetime. As a preventive measure, egg white should not be introduced into the child’s diet before the age of one year.
The most common symptoms of egg allergy affect the gastrointestinal system (vomiting, diarrhea), the respiratory system (asthma, bronchitis) and are also often linked to skin problems (eczema) 11 .
Egg safety is of prime importance, given the risk of contamination by bacteria or viruses (for example salmonella and the H5N1 virus). The Canadian Egg Marketing Agency has worked to improve the egg’s natural defenses (hard shell, two membranes and antimicrobial properties in albumen), through the Cleanliness First – Cleanliness Always ™ program , founded on a hazard management method. In Canada, in 2003 and 2004, the compliance rate for inspected egg products was 97% (3% of eggs were non-compliant or unsafe) 12. Although the risk of salmonella infection is minimal, to eliminate these risks, Health Canada recommends that consumers, primarily pregnant women, the elderly, very young children, and those with compromised immune systems following ‘a disease, to cook the eggs until the white and the yolk have a solid consistency 13 . There are preparations on the market based on pasteurized liquid eggs that can be used in place of raw eggs, since pasteurization has destroyed bacteria, including salmonella, that could be contained in the egg.
The egg over time
|Before taking its final shape in the XIV th century, “egg” was written succession “of”, “uef” and “oef” at the XII th century. The word comes from the Latin ovum .|
The eggs of various bird species have undoubtedly been consumed since ancient times. The Phoenicians feasted on ostrich eggs, while in Antiquity the Romans consumed those of the blue peacock and the Chinese consumed those of the pigeon. In reality, the eggs of any laying species, including the turtle and the alligator, can be used as food.
|The Hundred Years ‘Egg
A true classic in Chinese cuisine, the Hundred Years’ Egg is actually only kept for a few months in a mixture of saltpetre, tea leaves, clay and other materials which effect of coloring the shell black and giving the flesh a greenish color and the texture of a hard-boiled egg. They are generally finely sliced and served as an appetizer with other fine products.
However, over the course of evolution, the chicken egg has gradually taken precedence over all the others, but this has happened rather recently. Although Apicius, famous gastronomist of Roman Antiquity, has given in his culinary work various recipes for custards and omelettes, the egg will remain a marginal food for a long time, on the one hand because of religious prohibitions and beliefs superstitious, on the other hand for economic reasons: indeed, the people in general believed that it was much more profitable to wait for the egg to turn into a chicken or a rooster. The Chinese were an exception to this rule, who considered it an excellent nutritional source and spread its use throughout eastern Asia.
The egg is not mentioned in the few writings available on the Middle Ages in Europe, perhaps because, like meat, it was prohibited by the Catholic Church to consume it on days skinny, that is, for more than 160 days a year. However, the hens, who did not follow the liturgical calendar, but that of the seasons and their biological cycle, laid abundantly during Lent, a period when daylight was again abundant. To avoid losing this precious resource, they were kept in liquid fat or wax until Easter, a splendid day par excellence. To improve their appearance after their prolonged stay in the vault, they were decorated in various ways. This is how the tradition of Easter eggs was born. In the middle of the XVII th century, we know at least 60 recipes to cook this food that appears more and more often on the menu.
In the XVIII th century, the discovery by a French technique artificial breeding practiced by the Egyptians by using low temperature furnaces raise the greatest interest among farmers, which multiply the crossings. In the XIX th century, significantly more productive chicken breeds, selected by the Chinese, will appear in the West, creating a real stir among farmers who want all possess some of these “new” bird, very different from those of known Mediterranean and European races. During this century, a hundred other breeds will be created, some of which we breed only for the flesh, others for the eggs, others finally for the two uses.
There followed a prosperous period for the egg which, until the 1980s, was considered a perfect food. However, its popularity will decrease when it is discovered that its yolk is particularly rich in cholesterol , accused of being the cause of cardiovascular disease. In this decade alone, sales of fresh eggs will drop 25%. The multiplication of epidemics of salmonellosis during the same period and until recently will further add to this fatality. It is therefore not recommended to eat the raw egg which was previously included in many dishes, especially in mayonnaise. In recent years, the egg has regained some of its lost popularity, after various clinical studies have shown that, for the majority of the population, it constitutes aexcellent quality food .
In addition to fresh eggs, today we find on the market preparations based on dehydrated eggs, liquid and frozen (albumen only, yolk alone, whole egg, albumen and yolk mixed in various proportions).
To access other recipes, you can go to the CuisineAZ.com kitchen recipe site, which offers, among other things, the following recipes: casserole egg, mimosa egg, easter egg
|Egg, are you fresh?
If you are not sure of the freshness of an egg, you can immerse it in a bowl of water. The air pocket being of little importance in the fresh egg, it sinks to the bottom while resting on the side. Since its air pocket is larger, the aged egg floats with the big end turned upwards.
Keep eggs in the fridge at all times. All in all, they should not be kept out of the refrigerator for more than two hours (including cooking time and service). If the eggs must be at room temperature for the preparation of a recipe, take them out half an hour in advance or reheat them in lukewarm water for a few minutes before using them.
To avoid the risk of cross-contamination, wash your hands and clean kitchen utensils after handling meat and fish and before handling eggs (and vice versa).
Do not use broken or cracked eggs, which may be contaminated.
The occasional stain of blood in an egg is harmless. You can remove it if you want with the tip of a knife.
|Since it is not recommended to consume raw eggs (even for classic preparations such as mayonnaises, soufflés and mousses), here is the way to prepare them.
Cooking Yellow employees normally raw kitchen: simmer in a heavy pot by adding about 2 tablespoons water table or other liquid yellow. Stir continuously and cook until the mixture forms a thin film on a metal spoon, or until the internal temperature reaches 71 ºC (160 ºF). Place the pan in ice water until the mixture cools and use immediately.
Cooking the white wines normally used in cooking: cook them over low heat in a double boiler with 2 tablespoons of sugar, 1 tablespoon of water and 1/8 teaspoon of cream of tartar per white, stirring continuously at low speed with a hand blender until they reach an internal temperature of 71 ºC (160 ºF). Pour into a large bowl and beat on high speed until the mixture forms fluffy peaks. Then follow the recipe normally.
If eggs are the basis of soufflés , flans , quiches or pancakes , here are some other suggestions for primers.
- As a salad . Serve the soft-boiled eggs on a salad of fine greens. The boiled eggs can be added to a vegetable salad of your choice, or in the salad from Nice, with cubes of potatoes, tomatoes, snow peas, tuna, olives and young greens. Drizzle with Dijon mustard vinaigrette. Or make it as a sandwich garnish, adding parsley and chives or other herbs.
- Devil’s hard-boiled eggs . Cook the eggs and cut them in half lengthwise. Remove the yolk that will be crushed with mustard, mayonnaise, sour cream or yogurt, lemon juice, capers, salt and pepper and fill in the egg whites with this mixture. Refrigerate before serving. You can vary by replacing the capers with chopped olives and adding hot pepper or Tabasco sauce.
- Omelettes. Chives, watercress, parsley, tarragon and lemon balm go perfectly with the eggs.
- Pickled hard-boiled eggs . Put boiled eggs in a jar. Heat a few minutes in a saucepan of vinegar and concentrated orange juice, a stick of cinnamon and cloves. Pour over the eggs, close the jar and let cool to room temperature, then put in the refrigerator. Wait at least a week, and up to three or four weeks, before consuming.
- Egg in shell , egg calf , egg hard. What is the difference ? In fact, only the cooking time varies. The boiled egg is an egg whose white begins to coagulate and whose yolk is still liquid. The soft-boiled egg is an egg whose white is solid but the yellow still runny. Finally, the hard-boiled egg is an egg with firm whites and yolks.
- The egg alone can also be poached, scrambled, fried or spun, fried or spun.
If you have trouble digesting cooked eggs, the cause may be in the fat that you use for cooking, not the egg itself.
- Scrambled eggs. Incorporate various ingredients into the eggs: grated cheese, diced tomatoes seasoned with basil, sour cream flavored with chives, pieces of canned sardines or anchovies, crab meat seasoned with curry, capers, pieces of bacon or sausage, mushrooms , finely cut vegetables, etc.
- Huevos rancheros . Prepare a more or less spicy salsa according to its taste, pour it into a baking dish and dig “nests” in which you will lay raw eggs. Garnish with strips of pimiento (pepper) and sprinkle with grated cheese. Bake until eggs are firm in an oven set to 215 ºC (420 ºF).
- Florentine soup . Heat the finely chopped spinach for a few minutes in chicken or vegetable broth with nutmeg added. Add beaten eggs to this soup, stirring well. Remove from heat immediately. Serve in bowls with grated Parmesan cheese, if desired.
- Provencal omelet . First cook five slobbery omelets, the first with green onions, the second with spinach or another green leafy plant, the third with garlic, the fourth with tomato and the fifth with herbs. Stack them in order in a buttered or oiled round pan. Put the mold in the oven for about twenty minutes in a container half full of water. Serve hot or cold, slicing to expose the various colors.
- French toast . Dip slices of bread in beaten eggs with milk, fry in a pan and serve with maple syrup or brown sugar.
- Frittata or “western omelet” . Almost all countries have their version of this preparation, which consists of sautéing vegetables (potatoes, tomatoes, zucchini, broccoli, spinach, depending on the season), mushrooms, diced ham or sausage, and other foods of choice until cooked, then pour over beaten eggs flavored with herbs and grated cheese. You can vary by putting pasta or oriental noodles, shrimp or smoked salmon, and dried tomatoes.
- Egg in the hole . Remove part of the crumb on a slice of bread. Put the latter to brown in a pan and break an egg in the opening. Cook until the white is firm and serve. You can do the same thing with partially cored potato slices, which you will bake in the oven for about 15 minutes.
The whole egg in its shell keeps five weeks from the date of packaging (about three weeks after buying it) without significantly losing quality. After this time, the flesh may dry out. Once the shell is removed, the whites and yolks will keep for two days. Hard-boiled eggs keep on average for a week.
- If needed, the whites can be frozen separately for later use. Put them in the ice cube tray, freeze and transfer to a freezer bag. Thaw in the refrigerator, not at room temperature.
- To freeze the whole egg, thoroughly mix white and yellow before putting in the freezer in a sealed container. Do not freeze the whole egg as the shell will burst when cold.
- To freeze the yolks, we recommend adding the equivalent of a teaspoon and a half to sugar or corn syrup (for four eggs) if you plan to use them in a sweet preparation, or 1/8 of teaspoon of salt for other types of preparations. This treatment will prevent them from becoming lumpy when frozen.
Ecology and environment
Organic eggs are now on the market. These eggs are laid by free-range hens in open area chicken coops equipped with nests and perches. The hens are fed organic feed prepared according to strict specifications. Organic egg producers 20 are certified by an official body, which guarantees the consumer that these products meet organic farming standards.
Until the Second World War, the egg was mainly produced on small family farms, which had on average only 400 laying hens. Various innovations, notably in veterinary medicine and in the formulation of enriched feeds, as well as the creation of complex mechanical equipment, will lead to battery farming as we know it today, with its hundreds of thousands, even its millions. hens per production unit. For example, in the United States, one of the largest producing countries in the world, 95% of production is provided by 260 farms, of which 65 have more than one million hens and 9, more than five million. In this country, the smallest farms have a minimum of 30,000 hens.
In these farms, the hens are, in most cases, confined to narrow cages in which they can barely move. They have no access to outside air or daylight, their production cycle being entirely controlled by artificial lighting. The conditions in which they live, in particular the large number of individuals in the same space, create in them a permanent state of stress which has the effect of weakening their immune system, which requires administering antibiotics to them. In addition, the manure produced by the hens of these farms is an important source of pollution of surface and groundwater, particularly phosphorus.
In Europe, for humanitarian and public health reasons, the current of battery farming seems to want to reverse. In several countries of this continent, cage farming is banned. In Germany, we go even further since it is now prohibited by law to keep more than 6,000 hens in the same chicken coop.