Dewatering and drying of Kombucha Bacterial Cellulose for preparation of biodegradable film for food packaging.

Kombucha Bacterial Cellulose (KBC), obtained from waste products of kombucha fermentation, has potential applications in diverse fields. The present study used tea waste as a raw material for producing kombucha-like beverages and bacterial cellulose (BC). The in-situ dewatering and drying operations were performed to remove the high-water content from fermented KBC. Herein, the performance of BC in pressure-driven separation has been investigated as a function of dewatering pressure, drying temperature, and drying time in a multifunctional filtration cell. The Central Composite Design (CCD) was used to optimize the dewatering and drying parameters. The optimum conditions were found to be 4 bar pressure, 99 °C drying temperature, and 5 min drying time with a desirability value of 0.921. The predicted response values agreed with actual responses within 2.3-2.7 %. The dried films were prepared at optimized conditions and used to investigate thickness, density, mechanical properties, Fourier transform infrared, and scanning electron microscopy. The properties of KBC film varied as fermentation days increased. The KBC films' transparency decreased as thickness and density increased. The KBC film exhibits excellent mechanical properties such as tensile strength, maximum load, extension at the break, load at the break, and Young's modulus. The KBC films have been reported to be biodegradable and non-toxic and may be used for food packaging. Moreover, the present study successfully demonstrated that KBC packaging material could extend the shelf life of tomatoes by 13-15 days under accelerated conditions.