Effect of CaCl2 on the stability and rheological properties of foams and high-sugar aerated systems produced by preheated egg white protein

Abstract

This study aimed to evaluate foams and meringues produced from preheated egg white protein (PH-EWP) in the presence of CaCl2 as compared to those from native egg white protein (native EWP). EWP solution was heated at alkaline condition (pH 11.3) to form a solution of denatured protein. While both the native and PH-EWP solutions showed similar foaming capacity, liquid drainage was significantly lower for the latter foams than the former ones. Furthermore, while CaCl2 had no significant effect on drainage of native EWP based foams, the addition of CaCl2 significantly decreased the drainage of the PH-EWP foams probably by forming a viscoelastic network at the bubble surface. As a proof-of-concept for the application of the PH-EWP in an actual food product, stability and rheological properties of French meringues produced by native EWP and PH-EWP were investigated. While French meringues prepared from native EWP showed an undesirable runny texture, French meringues made with PH-EWP, particularly those supplemented with CaCl2, had a stronger viscoelastic network with a higher zero-shear viscosity, yield stress, and elastic modulus so that the meringues could support its weight under gravity, rather like a dollop of whipped dairy cream. This research has developed a new method to stabilize food foam systems by using PH-EWP as a dual function ingredient, not only facilitating foam formation but also as the thickening and structuring agents to stabilized them in the presence of Ca2+.