Development of functional bacterial cellulose composites from Kombucha waste for biodegradable food packaging

The aim of this study was to investigate the production of biodegradable bacterial cellulose (BC) composite films from kombucha production residues, thus providing a sustainable alternative to petrochemical food packaging. The aberration of plastic packaging as commonly understood today accordingly contributes to microplastic pollution, increased degradation periods, and environmental toxicity. Modified with BAC50, glycine, calcium chloride (CaCl₂), and cinnamaldehyde, the composite showed improved mechanical strength, antimicrobial activity, and moisture retention, rendering it fit for food preservation. The composite absorbed 88.5% moisture, had a water vapor transmission rate of 0.283 g/m²/day, and an oxygen transmission rate (OTR) of 433 cc/m²/day, which acts to reduce permeability compared to pure BC. Antimicrobial studies showed strong inhibition against Escherichia coli and Staphylococcus aureus, and thermal stability analysis (TGA, DSC) showed high thermal stability. This study shows an example of a circular economy for upcycling kombucha waste into functional materials with benefits such as ecological footprint reduction and the dependence on fossil petrol-derived plastic. Whereas plastic packaging is purposely designed to exist within the biosphere for centuries, BC biodegraded in a matter of months, thus further reducing the ecological footprint over time.