The Role of Ovalbumin in the Stability of Whipped Egg White Prepared in Copper Bowl

Abstract

The properties of whipped egg white prepared in the copper bowl were investigated from the view point of the interaction between Cu ion and ovalbumin. Cu ion did not concern with the foamability of egg white but with the foam stability. The measurement of dynamic viscoelasticity of whipped egg white in the copper bowl showed larger viscoelasticity and more stable structure than those in the glass bowl. In order to clarify the role of ovalbumin, the interaction of ovalbumin and Cu ion was investigated. Cu ion reduced free SH group and hydrophobicity and increased viscoelasticity of ovalbumin solution. Furthermore, SDS-PAGE suggested that Cu ion promote the intermolecular cross-linkage of ovalbumin to produce protein having larger molecular weight. According to whipping egg white in the copper bowl, S-Cu-S cross-linkage formed by Cu ion easily transferred from copper bowl increase viscoelasticity of membrane of whipped egg white, which might suppress the collapse of bubbles by disproportionation and thinning membrane to increase the foam stability.