Optimization and Characterization of Bioactive Biocomposite Film Based on Orange Peel Incorporated with Gum Arabic Reinforced by Cr2O3 Nanoparticles

In this paper, the effect of adding gum arabic at levels of 0–5%, and chromium oxide nanoparticles (Cr2O3 NPs) at levels of 0–3%, were optimized on orange peel-based films by response surface methodology. The obtained results reveal a significant increase in water vapor permeability, weight loss, tensile strength, and Young's modulus of film samples by increasing the percentage of both gum and nanoparticles (p < 0.05). Moreover, the addition of gum arabic and Cr2O3 NPs decreases the thickness, water-solubility, L*, a*, b* indexes while increasing the elongation to the breaking point. Furthermore, the moisture content of the film samples was decreased by the addition of nanoparticles, however, the addition of gum arabic increased this parameter. The obtained results from the morphology of the samples indicated an increase in both roughness and cracks by increasing the percentage of nanoparticles as well as creating a smooth surface with the addition of gum arabic. Besides, the results of Fourier-transform infrared spectroscopy revealed no new peak in the prepared samples, as compared to the control sample. The results of X-ray diffraction indicated that the addition of gum arabic and nanoparticles simultaneously caused the formation of new crystals and increasing the crystallinity of the films. Based on Thermogravimetric analysis results, the thermal stability of films containing the nanoparticles increased, as compared to the control sample. In the meantime, the addition of gum and nanoparticles increased the antimicrobial properties of the film samples, as compared to the control. Overall, those films created by the orange peel including gum arabic and Cr2O3 NPs could enhance the mechanical properties and water vapor permeability of the samples.