Which part of an egg contains the most protein?

The egg white, also known as albumen, contains the highest amount of protein in an egg. It accounts for approximately 60% of the total protein content of the egg, while the yolk provides the remaining protein along with fats, vitamins, and minerals.

Egg white is composed mainly of water (about 90%) and protein (about 10%), with negligible fat. The primary proteins in egg white include ovalbumin, ovotransferrin, ovomucoid, and lysozyme, which serve various biological functions such as providing nutrition, antimicrobial protection, and supporting embryo development in fertilized eggs.

The egg yolk contains less protein compared to the egg white but is rich in fats, cholesterol, vitamins (A, D, E, K), and minerals. While the yolk is nutritionally dense, it is not the main source of protein. The eggshell is mostly calcium carbonate and contains almost no protein.

Eggs are considered a complete protein source, meaning they provide all essential amino acids required for human health. Proteins from egg whites are highly bioavailable, making them a popular choice in diets focused on muscle building, weight management, and overall nutrition. Athletes and bodybuilders often consume egg whites for their high protein content without extra fats from the yolk.

In cooking and food science, egg whites are known for their foaming and binding properties, which are due to their protein composition. They are essential in recipes like meringues, soufflés, and certain baked goods.

Therefore, among the options, the correct answer is Egg white (Option A), as it contains the majority of protein in an egg and is a critical source of high-quality protein in human diets.