The white part of an egg is called albumen.

Albumen is a clear, viscous fluid that surrounds the yolk of an egg. It is commonly referred to as the egg white and is responsible for providing nutrients and protection to the developing embryo.

Composition of Albumen:
The albumen is made up of approximately 90% water and 10% proteins. These proteins include ovalbumin, ovotransferrin, ovomucin, and lysozyme. It also contains small amounts of vitamins, minerals, and glucose.

Functions of Albumen:
The albumen serves several important functions in an egg:

1. Protection: The albumen acts as a protective cushion for the developing embryo, shielding it from mechanical damage.

2. Nutrition: It provides the necessary nutrients, such as proteins and water, for the development of the embryo.

3. Moisture regulation: The albumen helps regulate the moisture content of the egg, preventing dehydration.

4. Antibacterial properties: Lysozyme, an enzyme present in the albumen, helps protect the egg against bacterial contamination.

5. Heat insulation: The albumen acts as an insulating layer, preventing rapid temperature changes and maintaining a stable environment for the developing embryo.

Formation of Albumen:
The albumen is formed in the hen's oviduct, a long, coiled tube where eggs are produced. As the egg passes through the oviduct, the albumen is secreted by specialized cells in the oviduct walls. It gets deposited around the yolk, forming a protective layer.

Egg White Variations:
The albumen can vary in consistency depending on the freshness of the egg. Fresh albumen is thick and viscous, while older albumen becomes thinner and more watery. Additionally, some eggs may have a cloudy appearance due to the presence of carbon dioxide, which gradually dissipates over time.

Cooking with Albumen:
Albumen is a versatile ingredient used in cooking and baking. It can be whipped to create meringues or used as a binding agent in recipes. When cooked, the albumen coagulates and becomes firm, providing structure to foods like omelets and cakes.

In conclusion, the white part of an egg is called albumen. It serves essential functions in protecting and nourishing the developing embryo.