Marine products are mainly conserved by being frozen.
During the freezing process, factors like temperature, freezing speed and size of the food determinates its quality. When a food product is slowly frozen, or affected by temperature changes during its storage time, ice crystals start growing, taking water off the proteins. The proteins cannot bind this water anymore, which generated nutritional, textural and flavor problems.
The use of cryoprotectants improves the homogeneous ice crystal formation, avoiding protein damage during the thawing process.