Property and structure of the edible walleye pollock(Theragra chalcogramma) skin gelatin/alginate composite films

The walleye pollock(Theragra chalcogramma) and alginate were mixed to make edible composite films,it improved the properties of the fish gelatin films. Fish gelatin had good filmogenic property,but its mechanical property and thermal stability were both lower,water resistance were worse. Fish gelatin was miscible with alginate and the gelatin/alginate composite films which had excellent optical transmittance(higher than 80%). The mechanical properties of film were increased,the addition of 60% alginate increased the tensible strength and elongation at break to 67.4% and 112.6%. The thermal denaturation temperature of gelatin/alginate composite films was 8℃ higher than fish gelatin film. The water solubility and hygroscopicity were evidently decreased. The results suggested that fish gelatin/ alginate composite films exhibited better mechanical property,thermal stability and water resistance than fish gelatin film. FTIR,X-ray and SEM analysis revealed that alginate effectively interacted with fish gelatin to form a new macromolecule,and fish gelatin/ alginate composite films had stable structure.