Native bacterial cellulose films based on kombucha pellicle as a potential active food packaging

The production of kombucha involves the synthesis of a bacterial cellulose-based native film by a microbial consortium, typically regarded as a waste by-product in commercial kombucha manufacturing. In this study, films were successfully obtained using the microbial consortium of kombucha, combined with infusions of black tea, green tea, rosehip, coffee, and licorice. These films exhibited a flexible rubbery-like structure and demonstrated inherent biological activity. Comparative analysis revealed that the licorice-based films exhibited a regular and less porous structure, while the green and black tea-based films displayed a porous structure, resulting in higher water permeability and swelling. Remarkably, green tea-based films showcased notable antioxidant activity (DPPH: %74.22 ± 2.05, ABTS: %81.59 ± 2.39) and exhibited antimicrobial properties against E. coli, S. aureus, and B. cereus, owing to their high phenolic content (1.62 ± 0.04 μg GAE/g). The antimicrobial efficacy of green tea-based films surpassed that of the other films against pathogenic microorganisms. By enhancing their hydrophobic properties, these innovative films hold promising potential as cost-effective, active, and environmentally friendly materials for food packaging applications.