Synergism of different fish antifreeze proteins and hydrocolloids on recrystallization inhibition of ice in sucrose solutions

The inhibition of ice recrystallization (RI) processes in frozen sucrose solutions containing antifreeze proteins (AFP I, AFP III and AFGP), hydrocolloids (sodium alginate, κ-carrageenan) or mixtures of those was analyzed in detail. Noticeable RI effects were observed in all samples. The impact of the individual antifreeze proteins on the recrystallization process increased in the order AFP III, AFP I and AFGP which follows a different trend than thermal hysteresis activity already reported by other authors. AFP mixtures increased the RI effect compared with the pure AFP. The hydrocolloid κ-carrageenan caused a similar effect like AFPs but at higher concentrations. Sodium alginate in contrast showed only a small influence on RI. The shape of ice crystals in the κ-carrageenan solution were similar to the shapes found in AFP solutions which suggests that κ-carrageenan may act in a way comparable to AFPs. A synergistic effect between hydrocolloids and antifreeze proteins was also observed.