HEAT DENATURATION AND EMULSIFYING PROPERTIES OF EGG-YOLK PHOSVITIN

Phosvitin in water at pH 7 had a denaturation temperature (T-d) of 79.7 +/- 1.4 degrees C when heated at 10 degrees C/min. When dissolved in 0.1M and 1.0M NaCl, the T-d decreased to 77.7 +/- 1.2 degrees C and 77.2 +/- 1.3 degrees C, respectively, and in 10 and 20% sucrose there was no change in T-d. Heat treatment of phosvitin solutions at greater than or equal to 65 degrees C led to decreased emulsifying activity (EA). The emulsion stability (ES) decreased when phosvitin solutions were heated at 70, 80 or 96 degrees C for up to 60 min. The ES was not affected (p < 0.05) for phosvitin solutions after heating at less than or equal to 67.5 degrees C for up to 60 min.