Stabilization of αS-Casein by Carrageenan

The hydrophilic colloid, earrageenan, stabilizes a~-easein against precipitation by calcium ions by an interaction between a,casein and a component which may be present in both K-and X-carrageenan. This component occurs predominantly in the Kfraction. The resulting complex resembles the alpha-casein complex, but it is not acted upon by rennin. The ~-carrageenan fraction imparted stability when mixed with a,-casein in the weight ratio of 1:5, whereas the k-carrageenan fraction was fully effective only at a ratio above 2:5. The heat stability of the calcium/carrageenan/a~casein complex was greater than the corresponding caleium/~-casein/~-easein complex. No significant stabilization of a~-casein was produced by chondroitin sulphate, heparin, alginate, carboxymethyleellulose, guar gum, or locust bean gum.