Eco-friendly nanocomposite biofilm based on sage seed gum/gelatin/TiO₂: Fabrication and characterization

In the current study, the sage seed gum/gelatin-TiO₂ (SG/Ge-TiO₂) nanocomposite films were prepared. Their physical, mechanical, chemical, barrier, surface, structural, and microbial characteristics are determined as a function of different ratios of sage seed gum (SG) to gelatin (1 to 2, 2 to 1 and 1 to 1) and different concentrations of TiO₂ nanoparticles (0, 2, 4 % based on biopolymer (w/v)). The results indicated increases in the tensile strength, elongation at break, thickness, brightness (L*), whiteness index (WI), and contact angle, as gelatin content and concentration of TiO₂ nanoparticles increase. In addition, the increases of TiO₂ nanoparticles and the increased content of SG lead to an increase in the surface roughness of the films. As the gelatin content and the concentration of TiO₂ nanoparticles increased, the barrier characteristics against water vapor, oxygen, and light increased, so that the water vapor, oxygen, and light permeability in the SG 1-Ge 2-4 % film decreased by 66.93 %, 80.89 %, and 47.43 %, respectively, compared to the SG 2 Ge 1-0 % film. According to the results of structural and thermal investigation, the crystallinity degree in the films increased as the gelatin content and the concentration of TiO₂ nanoparticles increased, resulting in the enhanced thermal stability of the film. The addition of TiO₂ nanoparticles brought about antimicrobial characteristics in the film, with no significant effect on the antioxidant activity and total phenol content (p > 0.05). The results indicated that SG-Ge-TiO₂ bionanocomposite films (especially SG 1-Ge 2-4 %) can be considered a suitable option for active food packaging as well as medical applications (e.g. active wound adhesive) due to its favorable characteristics.