Wax-Functionalized Bacterial Cellulose Foils as Renewable Food Packaging with Enhanced Barrier and Antimicrobial Performance

This study investigated bacterial cellulose films (BCF) coated with twelve commercially available natural-origin wax and wax-like formulations as potential bio-based food-packaging materials. Bacterial cellulose (BC), produced by Komagataeibacter xylinus, was purified, homogenized, and dehydrated to obtain films suitable for subsequent wax coating. Among the preparation conditions investigated, a BC-to-water mass ratio of 1:2, a wet pulp mass of 45 g per dish, and drying at 60 °C for 24 h were selected. The resulting materials were evaluated for their water-related properties, surface wettability, antimicrobial activity, and antibiofilm performance. Wax coating reduced about threefold water uptake and liquid-water transfer compared with uncoated BCF and increased the mean water contact angle from 47.6° to 94.3°. The antimicrobial and antibiofilm effects varied depending on the wax formulation and the microorganism tested, reaching over 99% reduction in C. albicans and S. aureus for eight of the twelve wax formulations. Among the twelve formulations, the commercially available rapeseed–coconut wax blend (70:30; BCF-RCW) exhibited a favorable combination of water-related and antimicrobial properties and was selected for further surface micromorphology and mechanical characterization. In a preliminary food-storage experiment, all tested food samples wrapped in BCF-RCW exhibited significantly lower microbial counts than those wrapped in conventional polyethylene film or food wrapping paper during 21 days of refrigerated storage (over 99% reduction). These findings support the further development of wax-coated BC films as promising bio-based materials for functional food-packaging applications.