Fabrication of Environmentally Compatible Biopolymer Films of Pullulan/Piscean Collagen/ZnO Nanocomposite and Their Antifungal Activity

Polysaccharide pullulan acts as a base matrix for the fabrication of pullulan/collagen blend film with dopant ZnO nanoparticles. From the FTIR data, it could be confirmed that there was significant interaction among the pullulan/collagen/ZnO-NPs. The weak interactions like H-bonding was evident by shift absorption band of hydroxyl groups into the lower frequency region. The powder X-ray diffraction study revealed the amorphous nature of pullulan/collagen blended film which was modified into a crystalline structure after the addition of ZnO nanoparticles. The transformation of the films into crystallinity and the presence of the Zn element was confirmed by SEM-EDAX. Further, the results of TGA revealed that the addition of nanoparticles influenced the thermal stability of the pullulan/collagen blended films. The addition of ZnO nanoparticles lead to an increase of the stiffness and mechanical resistance of the nanocomposite films; which showed an increase in their tensile strength evidenced by an increase in Young's modulus. The fabricated films exhibited antifungal activity against Aspergillus niger with a maximum zone of inhibition of 18 mm for pullulan/collagen/ZnO-NPs (0.5%). However, the nanocomposite films easily dissolved in an aqueous medium, indicating their possible use as edible packaging films in the food industry.