Effect of Ovomucin on the Viscosity and Foaming Properties of Emu Egg White

Abstract

　The effect of ovomucin, a glycoprotein, on the viscosity and foaming properties of emu egg white was determined. Compared to Gallus gallusdomesticus (hen) egg white, emu egg white was more viscose and had better foaming properties and stability. Sodium dodecyl sulfate - polyacrylamide gel electrophoresis followed by periodic acid-Schiff staining were performed for emu egg white, and carbohydrate chain bands of size 52, 78, and 207 kDa were observed. The N-terminal amino acid sequence of the 207-kDa protein showed 62.5% homology with the N-terminal region of α2-ovomucin obtained from hen. The ovomucin content in emu egg white was approximately 6.3%, over one from hen egg white. In addition, the ovomucin solution prepared from emu egg white was more viscose than that prepared from hen egg white. The viscosity of ovomucin obtained from each egg white was closely related to the viscosity of the egg white. Therefore, these results suggest that ovomucin affects the viscosity and foaming properties of emu egg white.