Why are egg whites important for the texture of baked goods?

Egg whites are essential in baking primarily for their role as a texturizing agent. Because they consist of approximately 12 percent solids—mostly protein—they are capable of forming stable, low-density foams when whipped.12

These foams provide the fundamental structure for items like meringues and angel food cakes. When used in significant quantities, egg whites promote a small, uniform cell size and contribute to a larger overall volume in the finished product. While the resulting structure is highly extended, it often requires support from other proteins, such as the gluten found in flour, to maintain its shape during the baking process.12

Unlike egg yolks, which are used for color, flavor, and emulsification due to their high fat content, egg whites provide an elastic structure that differs from the more tender, crumbly texture produced by fat-heavy emulsions. Even in recipes containing shortening, egg whites help maintain structural integrity.12