The main reasons for freezing-induced damage to proteins, ice formations and recrystallization, dehydration, salt concentration, acidification, changes in the lipid groups and the release of certain cellular metabolites. Freeze-induced denaturation of protein, related functionality and losses are observed in frozen fish, meat, poultry, eggs and products of dough.
During the freeze, proteins are subjected to high concentration of salts in a frost-free phase; high ionic strength can produce in competition with the existing electrostatic bonds, change the native structure. Loss of functional properties of proteins usually analyzed by comparing the ability to retain water, viscosity, gelation, emulsification, foaming and whipping properties. Freezing has an important impact on the reduction of the water-holding capacity of the muscular system for defrosting, producing changes in the solubility of proteins. This reduction occurs during freezing, because the water-protein associations are replaced by protein-protein Association or other interactions.
Proteins in the aquatic environment, biological tissues, possess waterproof interior, and charged (or polar) side chains in the surface.
Migration of water molecules from the interior of the fabric in the extracellular freezing leads to more dehydrated state disrupting protein-solvent interactions. Protein molecules are less polar environment have a greater impact hydrophobic chains, the change in the conformation of the protein. To maintain the minimum free energy, protein-protein interactions through hydrophobic and ionic interactions lead to the denaturation of proteins and education units.
Oxidative processes in time, frozen storage, can also cause denaturation of proteins; oxidizing substances (enzymes, heme and transition metals) may react with proteins...