Application of whey protein-polysaccharide complexes in aerated dairy gels

Previous research has shown that heated soluble complexes of whey protein isolate (WPI) with polysaccharides can improve both foam stability and acid-induced gel strength.We utilized these complexes in aerated dairy gels, which could be formulated into novel-textured high-protein desserts.Two families of polysaccharides having different degrees of charge density were chosen.The first included: low methoxyl pectin (high charge), high methoxyl type D pectin (low charge), and guar gum (neutral charge).The second had three carrageenans, λ-(high charge), ι-(medium charge), and κ-(low charge).WPI-polysaccharide complexes were prepared by heating the mixed solutions (8% protein, 0 to 1% polysaccharide) at pH 7 and then mixing with heated skim milk powder (8% protein).To form aerated gels, 2% glucono-δ-lactone (GDL) was added and foam was generated by whipping with a handheld frother.The foam set into a gel as the GDL acidified to a final pH of 4.2.The aerated gels were evaluated for stability, overrun, and rheological properties.Overall stability was indicated by measuring liquid separation drained from the foam before it set as a gel.Rheological results showed no significant difference in