Investigation of the cryoprotective mechanism and effect on quality characteristics of surimi during freezing storage by antifreeze peptides

Freezing technology is important for storage of animal products such as surimi. However, mechanical damage caused by ice crystals would lead to quality deterioration. This study aims to investigate the protective effect of antifreeze peptides (AFPs) on the quality of surimi during freezing storage and its possible mechanism. We found that AFPs exhibited a strong inhibition of ice crystal recrystallization, and the molecular weight ranged from 180 to 3000 Da. AFPs can prevent the degeneration of myofibrillar protein by reducing the loss of Ca2+-ATPase activity, slowing oxidation of sulfhydryl groups to disulfide bonds, and maintaining surface hydrophobicity and solubility of myofibrillar protein. Moreover, AFPs can reduce the influence of freezing stress on water mobility, thereby protecting the surimi from losing immobilized water and bound water during frozen storage. These findings indicate that AFPs could potentially serve as a food ingredient with antifreeze functional for the storage of surimi products.