The structure of an egg consists of seven parts: eggshell, eggshell membrane, air chamber, egg white, yolk, lace and embryo. Among them, eggshell and eggshell membrane play a protective role. Because the main component of eggshell is calcium carbonate, there are pores on eggshell to ensure gas exchange during embryo development.

The highest content of eggs is protein, and protein is easily denatured when heated. Eggs, also known as chicken eggs and chicken eggs, are eggs laid by hens.

The complete eggshell is oval, with one end big and one end small, accounting for about11%~1.5% of the whole egg volume. Eggshell can be divided into upper shell membrane, lower shell skin and air chamber.

The main component of eggshell is calcium carbonate, accounting for 9 1% ~ 95% of the whole eggshell. Its calcium-containing components are the same as those of pearls, oysters, beef bones and dried fish, and it is a good source of calcium. In addition, the eggshell also contains about 5% magnesium carbonate, and 2% calcium phosphate and colloid.

Shell membrane: an opaque and unstructured membrane outside the eggshell; The function is to prevent the water of eggs from evaporating.

Subshell skin: the membrane in the eggshell, which has two layers; Air can pass through this film freely.