Composition of chicken eggs. The chemical composition of a chicken egg

2024 Author: Isabella Gilson | [email protected]. Last modified: 2023-12-17 03:14

Since ancient times, eggs have been a traditional Slavic food. They symbolize the rebirth of nature and spring, so for every Easter people prepare krashenka and pysanky, and the celebration traditionally begins with a holy egg.

General information

Egg is a protein product with a very high nutritional and biological value. Waterfowl eggs are not used in cooking because they can cause infectious diseases. The chemical composition of a chicken egg includes protein (12.7%), fats (11.5%), carbohydrates (0.6%), mineral s alts (1%), water (74%), vitamins D, E, carotene, choline and many other substances. The energy value of one hundred grams of eggs is about 157 kcal. Nutritionally, one egg is equal to 40 grams of meat or 200 ml of milk.

Shell

A chicken egg consists of 12% shell, 56% protein and 32% yolk. The shell has a porous structure that protects the product from the ingress of harmful microorganisms. The composition of the shell of a chicken egg includes calcium carbonate, calcium phosphate, magnesium and other organic elements. Under it there is a denseshell membrane, the main component of which is protein. The shell helps protect the egg from pathogenic microflora, but nevertheless passes gas and water vapor. At the blunt end, between the shell and the albumen, there is an air chamber, which increases during long-term storage of the egg, as its contents dries out.

Composition of chicken egg protein

Protein consists of many layers of a transparent, viscous, almost colorless liquid that foams when whipped. The density of the protein in the egg is not the same, the most dense is in the middle, near the yolk, as it keeps it in the center.

The composition of the protein includes many elements, among which, in particular, there are ovoalbumin and conalbumin. These substances contain many amino acids in optimal ratios. This leads to the fact that eggs are 98% absorbed by the body. Ovoalbumin guarantees high protein solubility in water; ovoglobulin contributes to the appearance of foam during whipping; ovomucin stabilizes the foam. Also an important element is lysozyme, which has bactericidal properties that disappear with the aging of eggs.

The protein contains a lot of minerals. It also contains vitamins B1, B2 and B6. The energy value per hundred grams of the product is 47 kcal.

Composition of egg yolk

The most valuable part of an egg is without a doubt the yolk. It is a thick liquid consisting of light and dark alternating layers. On top of the yolk is covered verya thin protective shell, and on the surface of this part of the egg is the embryo. The yolk contains a lot of proteins (16.2%), fats (32.6%), carbohydrates and minerals. The yellow color is given to it by carotene, which, when ingested, is transformed into vitamin A.

Composition of chicken eggs. Useful substances and their effects on the body

The chemical composition of chicken eggs includes the protein avidin, which binds vitamin H (biotin), regulates neuroreflex activity, forming the avidobiotin complex. When exposed to heat, the complex decomposes into its constituent elements, i.e. the constant consumption of raw eggs can lead to H-vitaminosis, which can adversely affect he alth.

Ovomucoid protein, which is also part of the egg, destabilizes the work of trypsin, a pancreatic enzyme, leading to poor absorption of not only the egg itself, but also other products. In addition, since ovomucoid can be absorbed undigested, regular consumption of ovomucoid can lead to allergic reactions. This is especially true for children, since their immune system is weaker than that of an adult. When exposed to heat, the properties of ovomucoid completely disappear, and when whipped, they are significantly reduced.

The enzyme lysozyme, which is found in protein, can be destroyed if storage conditions are not observed, which leads to the reproduction of harmful microorganisms. For this reason, eggs can become a source of severe infections.

Nutrition

Chicken eggs contain a largethe amount of fat, most of which is concentrated in the yolk. They have a very low melting point, therefore, they are perfectly absorbed by the human body. The yolk also contains unsaturated fatty acids such as arachidonic, linoleic and oleic.

Eggs contain a small amount of cholesterol, approximately 1.6%, which, however, can accelerate the development of atherosclerosis. Therefore, older people are advised to reduce their consumption of eggs.

Egg classification

Chicken eggs are categorized according to criteria such as shelf life, weight and quality. Diet eggs should be sold within 7 days after they were laid, and table eggs can be stored longer. The composition of chicken eggs causes such a short shelf life. Table eggs, in turn, are divided into fresh, refrigerated and limed.

Diet eggs

This subspecies has a very small yolk located in the center, and the albumen is dense. The air chamber does not move. There are two categories that differ in weight: 1st category - at least 54 grams, 2nd - at least 44 grams. Each egg must be stamped with the date of production, type and category of product.

Fresh, refrigerated and limed eggs

Eggs that are classified as fresh, refrigerated and limed, have a small but viscous yolk, a slight deviation is allowedposition from the center. Protein should be dense, and the size of the air chamber - no more than 7 mm.

Fresh eggs include eggs that were stored for no more than 30 days at a temperature of -1 to +2 degrees; to refrigerator - stored more than 30 days. Limed eggs are eggs that are stored in lime for any period of time.

The most valuable for consumption are dietary and fresh eggs. The reason for this is the composition of chicken eggs, all the useful substances of which are preserved during short-term storage. They are used in absolutely any form. Refrigeration and lime eggs are also used to make confectionery and bakery products.

Melange and egg powder

At mass catering establishments, not only chicken eggs are used for cooking, but also their processed products: melange and egg powder.

Melange is a mixture of mixed yolks and proteins that have been filtered, pasteurized, chilled and frozen at -18 degrees. Dishes are prepared from this product that do not require separation of the protein from the yolk, for example, dough for various pastries. To replace one egg, you need to use 40 grams of melange.

Egg powder is a mixture of dried whites and yolks. It is used for the same dishes as melange, but in proportions of 1:0, 28.

Conclusion

The chemical composition of a chicken egg determines the terms and conditions of its storage both at home and on a production scale. However, care must be taken toin the refrigerator, the eggs were kept away from products with a pronounced odor. This will provide optimal conditions to help keep the product in a usable condition.