Protein Denaturation and Emulsifying Properties of Plasma and Granules of Egg Yolk as Related to Heat Treatment

ABSTRACT Solubility, electrophoresis, viscosity and emulsifying properties of heated solutions of yolk, plasma and granules were determined. Plasma and yolk were not affected when heated under 69°C. Above 69°C, protein solubility dropped sharply and apparent viscosity rose sharply because of aggregation of proteins. For granules, protein solubility and apparent viscosity were not modified up to 76°C. The constituents of granules were not denatured. Emulsifying activity of yolk and plasma decreased after heating at 72°C but remained steady for granules. Emulsion stabilization properties of yolk, plasma and granules were not influenced up to 76°C. Results suggested that intact granules withstood more severe heat treatments than egg yolk without lessening their emulsifying properties.