The solidification actually is a complex process consisting of a sequence of structural changes. Macroscopically, the translucent viscous mass turns white and solid. The hardening is due to ovalbumin, which is the main eggwhite protein. On subsequent cooling and reheating, the hardness is not much affected. This in contrast to gelatin, another well-known protein, which, after gel formation, dissolves again on heating.
Proteins play an important role in many food systems.
Food technologists, who understand structure formation and relationships between macroscopic properties microstructure and molecular properties, may fruitfully apply this information in the development and the processing of food products. The latter was performed by stretching a small sheet of the gel and measuring the elongation as a function of the applied force. In addition, changes in the conformation of the protein molecules were examined. A heat-set ovalbumin gel at pH 5. Dark area represents protein.