The effect of hydrocolloids on producing stable foams based on the whey protein concentrate (WPC)

• Supplementation with structure-forming hydrocolloids provides stable foams based on the whey protein concentrate.
• Xanthan gum is the most potent foam-stabilizing factor.
• Foams originating from whey protein concentrate and hydrocolloids show a behavior of viscoelastic solids.

The aim of current work was to obtain stable foams that are based on the whey proteins concentrate and selected hydrocolloids. The basic physical (density, volume fraction of gas, equivalent diameters etc.) and rheological properties of the stable foams based on WPC and hydrocolloids such as xanthan gum, gum arabic and carrageenan were determined. The osmotic properties of the starting aqueous mixtures of WPC and selected hydrocolloids were examined. The results of the research provided insights into the nature of the interactions between water-soluble whey proteins and structure-forming hydrocolloids. The time constants of the rheological exponential equation of the state of shear-thinned liquids (De Kee equation) were determined and the influence of the temperature on the apparent viscosity of the foams was analyzed. Supplementation with structure-forming hydrocolloids such as xanthan gum, gum arabic or carrageenan contributes to the generation of stable foams, with rheological properties typical for viscoelastic solids in the linear range of viscoelasticity. The presence of hydrocolloids stimulates time-dependent nature of foams and manifests in hysteresis of flow curves.