Abstract
The rheological changes in a mixture of two different gelling agents were studied. A 0.9% (w/v) κ-carrageenan solution (C(1)), a 4% (w/v) gelatin solution (G(1)) and mixed samples in three proportions were prepared. The gelling temperature and melting temperature were measured. Changes in the dynamic viscoelasticity when the state of the gel changed were determined with a Rheolograph-Sol instrument, and the endothermic reaction during melting was also examined by DSC. The gelling and melting temperatures for C(1) were the highest among all the samples. These values for the mixed samples were reduced according to the decreasing ratio of carrageenan. Gelling and melting of the samples were observed when the storage modulus was in the range of 6-8 N/m2.
This suggests that the change point for state exists in this range. The DSC result revealed that the peak heights of the mixed gelatin-carrageenan samples were lower and their shapes were broader than those of the pure samples. The peak temperature of the endothermic reaction and the melting temperature corresponded well.
