Interaction of β-casein and κ-carrageenan. I: Viscosity and turbidity under non-gelling conditions

The relationship between gelling and casein stabilizing ability of κ-carrageenan was investigated using viscosity and turbidity measurements. At low ionic strength, 0.5% β-casein decreased the viscosity of 0. 1 % κ-carrageenan solution in the absence of calcium. In the presence of calcium, the viscometric behavior of κ-carrageenan-β-casein mixture was governed by the properties of β-casein rather than that of κ-carrageenan. A 0.1% κ-carrageenan solution formed a structure above 5 mM.CaCl2 at 5°C. Under the same conditions, the mixture began to gel at lower concentration of calcium than 5 mM. These phenomena suggested the participation of β-casein in the formation of the κ-carrageenan structure.