Effect of Different Drying Conditions on The Kinetics and Physical Properties of Kombucha Bacterial Cellulose

Abstract

Kombucha bacterial cellulose (KBC), obtained as a by-product of tea fermentation, has potential applications in diverse fields, including wound dressing, food production and packaging, optoelectronics and sensor-based technologies, polymer electrolyte membranes, and various medical applications such as implants and scaffolds, as well as drug delivery carriers. The high water content and presence of post-fermentation residues observed at the beginning of downstream processing necessitate the implementation of suitable drying conditions that can significantly affect the final characteristics of this versatile biopolymer. Thus, preliminary work was carried out to determine the impact of hot oven drying on the dry weight and thickness of the dried KBC. Further, to study the effect of different drying methods on its properties, it was subjected to microwave drying (180- 900W), hot air oven drying (30-70°C), and room temperature drying. Additionally, the acquired data were fitted into different models to study the drying kinetics of KBC. The dried sheets were then analyzed to study the changes in water-holding capacity, rehydration, browning index, crystallinity, optical transmittance, and mechanical properties. Hence, optimizing the drying conditions will help in reducing the time and cost without comprising any properties that allow it to be processed into various value-added products.