Functional properties of chemically modified egg white proteins

Functional properties of egg white proteins can be altered through selected chemical reactions. Acylations with acid anhydrides have received the greatest amount of attention. Oleic acid and sodium dodecyl sulfate (SDS) have also been used to affect function of egg white proteins. The charge characteristics of acylated proteins are altered through modification of the N-terminal and epsilon-amino groups. The acid anhydride used and the extent of modification have a major effect on the ionic properties of the protein. The altered ionic properties have been shown to affect the optical properties of protein sols, heat stability, foaming, performance in angel cakes, initiation of gelation, ultimate strength and freeze-thaw stability of heat-set gels. Although exact explanations of the mechanisms for the interactions of oleic acid and SDS with egg white protein are not available, increases in charge occur and result in gels with physical properties very similar to gels made from succinylated egg protein.