Interpolymeric complexing between egg white proteins and xanthan gum: Effect of salt and protein/polysaccharide ratio

The aim of this work was to characterize the complexes lysozyme (Lyso)/xanthan gum (XG) and ovalbumin (Ova)/xanthan gum in terms of their physicochemical properties and to study the influence of salt and protein/polysaccharide ratio on rheological properties. As the protein/polysaccharide ratio was increased from 1:1 to 10:1, critical structure events shifted to higher pHs, resulting in the formation of insoluble complexes even at pH 12.0. Lyso/XG complex formed a stronger gel-like complex with smaller loss tangents compared with the Ova/XG complex; however, those gels showed a slight tendency to breakdown under higher frequency variation when compared with Ova/XG complex. The correlation between rheological data, the effect of ionic strength and FTIR analysis suggests that although an electrostatic interaction is the main mechanism of interaction between biopolymers, non-electrostatic interactions also plays a role in the strength of the interaction. Egg white protein/XG complexes represent a great technological to formulate functional hydrogels. (C) 2016 Elsevier Ltd. All rights reserved.