Sol-gel transition of a mixture of gelatin and kappa-carrageenan

The characteristics of sol-gel transition of a mixture made by mixing two k inds of gelling agents of different nature, i.e. gelatin and carrageenan we re examined. The sample solutions consisted of 3.00 wt % gelatin solution, 1.00 Wt % K-carrageenan solution and 4.00 wt % mixed solution which was pre pared by mixing the said gelatin and carrageenan solutions in the ratio 3: 1. In the experiment, the optical rotation and the dynamic viscoelasticity were measured under the same temperature change program. As the sample solu tions were cooled, the carrageenan solution started to show a change in the specific rotation in the first place, followed by the mixed solution and f inally the gelatin solution. The gelatin and the mixed solutions had the sa me increasing tendency in the specific rotation, whereas the carrageenan so lution changed a little. When the mixed solution was chilled to set, it tur ned into a highly elastic gel. In the mixed solution, the gelation of carra geenan was found to precede that of gelatin.