What does it mean for a substance to coagulate?

Coagulation refers to the process by which a substance transitions from a liquid state to a solid state or becomes more solid. This term is frequently used in food preparation and cooking, particularly in relation to proteins. For instance, when eggs are cooked, the proteins in the egg whites coagulate, transforming from a liquid into a firm, solid structure. This change occurs due to the application of heat, which causes the proteins to denature and then aggregate, forming a solid mass.

In culinary contexts, understanding coagulation is essential for making various dishes such as custards, sauces, or even cheese, where the desired texture relies heavily on this process. The other options provided do not accurately represent this transformation; for example, liquefying and dissolving pertain to turning solids into liquids rather than the solidification process. Emulsification, on the other hand, refers to mixing two immiscible liquids, which is a different culinary concept entirely.