Application of Heat

FOOD SCIENCE AND PROCESSING 3 (2+1)
Lesson 19 :Eggs - Processing, Preparation and Preservation

Application of Heat

The terms denaturation, coagulation and gelation are used in egg cookery. Denaturation refers to loss of certain properties of the raw egg proteins. Gelatin is used to denote the formation of gel. Coagulation refers to the separation of the protein as an insoluble mass.

  • Coagulation temperature of egg white: As a result of coagulation by heat, the egg white changes from a clear transparent mass to a white opaque one. The undiluted egg white coagulates at about 60oC. The coagulation process is endothermic near the coagulation point, the temperature may remain stationary for a minute.

  • Coagulation temperature of egg yolk: The egg yolk requires a higher temperature for coagulation than egg white. It begins to thicken at 65oC and the coagulation is complete at about 70oC.

  • Temperature coefficient of coagulation: The time taken for coagulation increases with temperature and at higher temperature near the coagulation point, the coagulation is almost instantaneous.
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Last modified: Monday, 12 December 2011, 6:40 AM