When eggs are heated, the transparent liquid portion around yolk turns solid and turbid white. This happens due to the thermal denaturation of

Egg white (albumen) is composed mostly of water and proteins, with ovalbumin being the predominant protein along with ovotransferrin, ovomucoid, and lysozyme. On heating, these proteins undergo denaturation — their tertiary and quaternary structures unfold and then coagulate by forming new intermolecular bonds, producing the opaque, solid white texture. Fats and carbohydrates do not undergo this coagulation; ribose sugar is not significantly present in egg white.