The objective of the research study was to compare the effect of adding a kappa carrageenan and its hydrolysates, and a protein type AFP III, which limits the ice crystallization, on the freezing process of model sucrose solutions. There were studied samples of 30 % sucrose solutions without and with those cryo-protective substances added; the samples were frozen at -20 °C using a cryostat. It was proved that the freezing time of the samples with AFP protein added was the longest. Compared to the samples with no additives, the refreezing phase thereof was extended, whereas the time duration of the transition phase was shorter by 12 minutes. The samples with the hydrolyzed kappa carrageenan added got frozen quicker than the samples containing only the kappa carrageenan. On the other hand, that time was similar to the time of freezing the samples without the biopolymers added. At the same time, the second phase, i.e. the time of refreezing the samples with the hydrolysates was extended by 30 minutes compared to the time of refreezing the samples without the polymers added, and it was by 20 minutes longer than the refreezing time of the samples with the carrageenan added. The addition of the hydrolysates and of the kappa carrageenan reduced the time of the transition phase by about 80 %. Each of the substances used caused the cryoscopic temperature to increase by more than 1 °C.