Abstract:

In this study, collagens from different sources were prepared by means of enzymatic hydrolysis, and their purity
and amino acid composition were identified. Differential scanning calorimetry (DSC) was used to determine the thermal
hysteresis activity (THA), and the ice recrystallization inhibition (IRI) was evaluated by cryomicroscopy. The results
showed that all the collagens prepared were typical type I collagen with high purity and molecular weight of about 330 kD.
The collagens from different sources had common amino acid composition with glycine, proline and alanine as the most
abundant amino acids. Compared with bovine serum albumin (BSA), the T0 of pig skin collagen revealed a higher THA value
(0.52 ℃), and the ice crystal content φ was equal to or less than 5% at a retention temperature Th of -0.2 ℃. As observed
under a microscope, pig skin collagen extracts formed a large number of hexagonal ice crystal, demonstrating the antifreeze
activity when compared with chicken skin collagen and fish skin collagen.

Key words: antifreeze activity, collagen, thermal hysteresis activity, ice recrystallization inhibition