Structural and physical properties of carboxymethyl cellulose/gelatin films functionalized with antioxidant of bamboo leaves.

In this study functional film enrichment with antioxidant of bamboo leaves (AOB) was prepared based on carboxymethyl cellulose-gelatin (CMC-Gel) mixture using casting method. Microstructures of the films were performed on atomic force microscope, Fourier transform infrared spectrometer, and X-ray diffraction (XRD). The physical properties, including the viscosity of film forming solutions, the water vapor permeability, mechanical properties, thermodynamics and transparence of CMC-Gel films were determined. The addition of AOB had not induced notable change on the surface structure features. The good compatibility among AOB, CMC and gelatin was illustrated by XRD for that the crystallization disappeared of gelatin in CMC-Gel composite film and no diffraction peaks in functionalized films. Viscosity and glass transition temperature of the film with 0.2% AOB were 779.2 ± 26.2 mPa·s and 83.24 °C, respectively, which were higher than those of all other samples. The water vapor permeation resistance and elongation at break of the films significantly decreased when the concentration of AOB exceeded 0.2%. The light barrier properties and scavenging rate of DPPH radicals were enhanced with the increasing of AOB content. Consequently, the antioxidant films utilized for food packaging could protect food quality from the destruction of heat, mechanical force, light, and oxidative free radicals.