Abstract Environmental contamination caused by chemical plastic packaging has increased the demand for environmentally friendly biofilms with antibacterial properties. This work studies the preparation of biodegradable chitosan (CS) composite films containing zinc oxide (ZnO) at various concentrations. ZnO was synthesized by a simple hydrothermal method using D + glucose as a reducing agent and blended into chitosan matrix (CS–ZnO composite) to enhance mechanical and antimicrobial properties. The surface morphology of the sample was analyzed using field-emission scanning electron microscopy and energy dispersive X-ray spectroscopy. The flower-like ZnO structure is 7.7 μm in size and composed of small flakes with a thickness of approximately 30 nm. ZnO was found to be uniformly distributed throughout the chitosan matrix. Fourier transform infrared spectroscopy confirmed the functional groups of ZnO. X-ray diffractometer confirmed the presence of ZnO with a hexagonal wurtzite structure. The antibacterial activity of the films was tested against the pathogenic bacteria Staphylococcus aureus , Bacillus cereus , Escherichia coli, and Klebsiella pneumoniae . Antibacterial effectiveness was demonstrated against both Gram-positive and Gram-negative bacteria. CS-ZnO 1 %(w/v) exhibited the highest antibacterial activity against B. cereus , with an inhibition zone of 17.33 ± 1.41 mm. The composite film also showed a good preservation effect against tomato spoilage and weight loss. CS-ZnO 1 %(w/v) film reduced tomato weight loss to 85 % after 10 days, compared to 90 % for the control group. These results indicated that CS-ZnO composite films are a sustainable alternative to traditional plastic packaging, reducing the risk of bacterial contamination.
Audtarat et al. (2026) studied this question.