The role of hydrocolloids in mechanical properties of fresh foams based on egg white proteins

The paper presents results of studies on the preparation of fresh food foams based on egg white, and hydrocolloids (xanthan gum and carrageenan). The basic physical parameters of the obtained foams such as density, gas volume fraction and size of gas bubbles were measured. Rheological measurements were also performed, and continuous Maxwell model was applied to describe viscoelastic properties. The analysis of the obtained results concerned the impact of individual hydrocolloids and their mixtures on the changes of the rheological properties as well as their influence on the stability of the obtained foams. It was shown, that addition of pure xanthan preserved native properties of the egg white protein foams; the resulting foams, however, created difficulties during further processing. Foams containing only carrageenan were unstable, but exhibited desirable rheological properties. As a result of mixing xanthan gum and carrageenan, stable viscoelastic foams with unique theological and technological properties were obtained. (C) 2013 Elsevier Ltd. All rights reserved.