The effect of κ-carrageenan on whey protein concentrate gelation.

The effect of κ-carrageenan addition on rheological properties of whey protein solutions obtained from different whey protein concentrates (WPCs) was determined. The heat induced mixed gels exhibited different rheological properties as determined by using a small and large deformation rheology. In the case of WPC 35, the addition of 0.1 % carrageenan improved the rheological properties of the mixed gels with respect to those gels obtained from whey protein only. At 0.1 % carrageenan and 10 % WPC, the hardness of the gel was 3.5 N and at 0.5 % carrageenan hardness decreased to 2.2 N. However, in the case of WPC 80 gels with 0.1% polysaccharide concentration, the obtained gels exhibited lower hardness and G' values than gels obtained from the WPC 80 only. At the higher polysaccharide concentration, mixed gels were harder than protein gels. This kind of behavior can be explained by the segregative phase separation which probably occurred between κ-carrageenan and whey proteins and its effect on rheological properties of mixed gels depended on WPC composition, concentrations of protein and polysaccharide.