Abstract:Pigskin gelatin was hydrolyzed with alkaline protease.Based on the ice crystal size of the cold plate，the strongest antifreeze activity was displayed by the 1 kDa-3 kDa fractions obtained by ultrafiltration.These fractions were added to pork at 4% and were compared with commercial antifreeze（4% sucrose+4% sorbitol） by sodium dodecyl sulfate polyacrylamide gel electrophoresis（SDS-PAGE），Raman spectroscopy，and endogenous fluorescence spectroscopy analyses of the thawing loss of muscle after freezing，degree of myofibrillar protein degradation，and changes in the protein secondary and tertiary structure.The thawing loss of muscle was significantly reduced in the 4% antifreeze peptide group（4 mL/100 g）.SDS-PAGE revealed a reduced degree of myofibrillar protein degradation and significantly increased myosin and actin contents compared with commercial antifreeze（4% sucrose+4% sorbitol）.Good protection，increased α-helix content，and endogenous fluorescence intensity were evident in myofibrillar proteins.Compared with commercial antifreeze，porcine skin gelatin antifreeze polypeptide better maintains the state of myofibrillar protein to protect muscle.