Silver-Bacterial Cellulose-Areca catechu Extract Nanocomposite Biofilm for Sustainable Food Packaging: Synthesis, Characterization, and Antibacterial Activity.

Bacterial cellulose (BC) is a low-cost, biodegradable biopolymer with excellent mechanical strength and water-holding capacity. It is an attractive material for sustainable food packaging; however, native BC lacks intrinsic antibacterial activity. In this study, silver-bacterial cellulose-Areca catechu nanocomposite biofilms were synthesized through in situ reduction of Ag+ on BC films, followed by impregnation with A. catechu fruit extract at concentrations of 0-30 mg/mL. The resulting films were characterized by scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), swelling capacity, and color analysis. The films were evaluated for antibacterial activity against Escherichia coli and Staphylococcus aureus using the disk-diffusion method. SEM-EDX confirmed the successful deposition of silver nanoparticles within the BC matrix, while FTIR and XRD indicated changes in functional groups and crystallinity following film modification. The swelling capacity of the films ranged from approximately 145 to 370%, with the film containing 20 mg/mL extract exhibiting the highest capacity. The film containing 10 mg/mL extract exhibited the strongest antibacterial activity, with inhibition zones of 6.50 mm against both S. aureus and E. coli, outperforming the pure BC and Ag-BC films as well as the higher-concentration formulations. Liquid chromatography-high-resolution mass spectrometry (LC-HRMS) profiling of the A. catechu extract putatively identified more than 120 metabolites dominated by alkaloids such as arecoline and guvacoline. Other detected metabolites include catechin, protocatechuic acid, penicillic acid, nootkatone, and phytosphingosine, which are known to have antibacterial activity. Taken together, these findings demonstrate that the developed nanocomposite biofilms are promising candidates, low-cost, and environmentally friendly antibacterial materials with potential for further development as active food packaging materials. Further safety and migration assessments are required to establish their suitability for direct food-contact applications.