Development and characterization of irradiated-corn-starch films.

The effect of 60Co gamma ray irradiation on the physicochemical and crystalline properties of native corn starch were investigated. Fourier transform infrared spectroscopy and X-ray diffraction showed that irradiation had a slight effect on the molecular structure of corn starch with crystallinity decreasing with increasing irradiation dose. Particle size analysis showed that 59.1% of native corn starch granules had sizes of ≥8 μm, which decreased to only 24.1% after treatment with an irradiation dose of 40 kGy. Irradiated-corn-starch films were prepared by casting gelatinized irradiated-corn-starch solutions. An increased irradiation dose was found to increase the tensile strength of the resultant films, but caused a significant decrease in water vapor permeability. The irradiated-corn-starch films showed potential for the development of biodegradable starch films with improved properties.