Effect of gamma-irradiation on the physicochemical properties of gluten films

To elucidate the effect of gamma-irradiation on the physicochemical properties of gluten films, the molecular and mechanical properties of the films were examined after irradiation at 0, 4, 16, 32, and 50 kGy. Gamma-irradiation of gluten solutions caused disruption of the ordered structure of the gluten molecules, as well as degradation and aggregation of the polypeptide chains, based on a sodium dodecyl sulfate–polyacrylamide gel electrophoresis result. Gamma-irradiation decreased the viscosity of film solution due to the cleavage of the polypeptide chains below 16 kGy and increased it by aggregation of the proteins above 32 kGy. Tensile strength of the gluten films was affected by the gamma-irradiation treatment, resulting in 1.5-fold increase at 50 kGy. The elongation of gluten films was decreased. Alteration of the gluten molecules by gamma-irradiation reduced water vapour permeability by 29%.