Which term describes the change of a protein from a liquid to a solid or thicker liquid?

• A. Denaturation
• B. Protein Coagulation
• C. Gelatinization
• D. Hydrolysis

Answer: (B)

Coagulation is when proteins unfold and then link together to form a network that thickens the mixture or turns it into a solid. Heating or altering conditions causes the proteins to interact with each other, trapping water and creating a firmer texture. This is why dishes like eggs set as they’re cooked or milk curdles when heated or acidified—proteins have coagulated. Denaturation is the initial unfolding of the protein’s structure, which can lead to coagulation but isn’t itself the thickening step. Gelatinization involves starch, not proteins, and hydrolysis breaks proteins into smaller pieces rather than forming a solid network. So the change from liquid to solid or thicker liquid is coagulation.