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

When eggs are heated, the transparent liquid portion (albumen) turns into a solid, turbid white substance due to the thermal denaturation and subsequent coagulation of proteins [1]. Egg white consists primarily of water and proteins like ovalbumin. Heat provides energy that disrupts the weak bonds maintaining the protein's complex tertiary structure, causing the molecules to unfold or denature. As these unfolded protein chains aggregate and form a three-dimensional network, they trap water, resulting in a firm gel or solid state. This process is irreversible, meaning the solidified white cannot return to its liquid form. While eggs contain fats in the yolk and trace carbohydrates, the specific transformation of the clear liquid white into an opaque solid is a hallmark of protein coagulation [1].

Sources

1. [1] https://www.sciencedirect.com/topics/medicine-and-dentistry/coagulated-protein