Effect of gelatin additions on the properties and structure of rabbit skin gelatin films

The effect of gelatin additions on the properties and structure of rabbit skin gelatin films was studied by measuring the mechanical properties, water vapor permeabilities, subunit content and structure. The results showed that the thickness increased because gelatin network structure in the gelatin film system increased with increasing the addition of gelatin.Mechanical property results showed that the tensile strength of gelatin films was the highest when the addition of gelatin was4 g/100 m L ( w/v) , however the gelatin films possessed the highest elongation at break as the addition of gelatin was6 g/100 m L ( w/v) . The water vapor permeabilities of gelatin films increased with increasing the gelatin additions.The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis ( SDS-PAGE) indicated that the low molecular weight of protein fraction formed protein-protein cross-linking which resulted in the highest tensile strength as the gelatin addition was4 g/100 m L ( w/v) . FT-IR results showed that amide A band moved to high wave number as the gelatin addition was4 g/100 m L ( w/v) , which indicated that glycerol molecules didn't react with N-H group of peptides. A greater interaction occurring between gelatin functional groups to form a unique network structure conversely.Furthermore, curve-fitting of amideⅠband showed that there were more stable structure in the film matrix as the gelatin addition was 4 g/100 m L ( w/v) , so the films possessed greater stability and film-forming properties.