HTM 2700 Lecture Notes - Lecture 13: Egg White, Room Temperature, Georgian Lari

• School: University of Guelph
• Department: Hospitality and Tourism Management
• Course: HTM 2700
• Professor: Alison Crerar

Document Summary

October 28th: sugar, forms a hydrogen bonds with egg proteins = slower rate of denaturation and coagulation. Egg white foam: = colloidal dispersion in which air bubbles (dispersed phase) are trapped in a liquid (continuous phase, egg whites are 87% h2o and 10% protein. Incorporates air bubbles into the liquid portion of the egg whites: denatures egg white proteins, denatures egg white proteins collect on surface of air bubbles, stabilize the foam (longer time before foam collapses) Baking egg white foam: causes egg whites proteins to coagulate, makes foam permanent. Grey- green coloured in cooked eggs: hydrogen sulfide (h2s) in egg white combines with iron (fe ) in egg yolk to form ferrous sulfide (fes2) = gray-green colour. Reduces pressure on outside of egg drawing h2s away from yolk. Cause: keeping eggs hot for too long after cooking. Solution: prepare in small batches, limiting heating time. Tough texture due to over coagulation of proteins.