Effects of Chemical Modifications on the Physicochemical and Cake-Baking Properties of Egg White

Abstract

Egg white solids (EWS) were modified with succinic anhydride and a water-soluble carbodiimide. Both succinylation and carboxyl modification caused a shift in net charge but no marked changes in surface hydrophobicity or SH content. The surface and interfacial tensions were increased by succinylation. The denaturation temperatures (Td) of the proteins from both unmodified and carboxyl-modified EWS were increased by the addition of 50% sucrose, whereas the Td's of the highly succinylated egg white proteins were not changed. Succinylation improved the emulsification properties and lowered the foaming performance of EWS. The heat coagulability of egg white proteins at pH 7.2 was decreased by both modifications, while at pH 5.8, the highly succinylated (91.6%) EWS was relatively heat stable. The layer cake baking performance was improved by succinylation at both low (24.5%) and high (91.6%) levels of modification. Highly succinylated EWS, however, showed poor performance in an angel food cake system; this could be attributed to poor foaming properties and low heat coagulability. Carboxyl modification did not cause marked changes in functional and baking properties of EWS.