Effect of Bleaching Conditions on the Physicochemical, Crystallinity, and Thermal Properties of Bacterial Cellulose Leather from Kombucha SCOBY

SCOBY is a symbiotic consortium of bacteria and yeasts that forms a cellulose-rich pellicle during kombucha fermentation. Our aim was to study different bleaching processes to produce bacterial cellulose (BC) leather with improved properties. The fermentation process was carried out for 6 days and the SCOBY layer was removed and submitted to a sanitization using NaOCl (48 h) followed by a bleaching process using two H2O2 concentrations (23% and 17.5% (v/v)) at 40˚C and 50 ˚C, followed by oven dry. BC leathers were evaluated of dry weight yield, integrity and malleability by visual inspection. The purity of bacterial cellulose was evaluated by DSC, FT-IR, XRD, and SEM, along with color, water-holding capacity (WHC), and water vapor permeability (WVP) analyses. The highest yield was 15.72%, corresponding to 44.46 g of cellulose after bleaching with 50% at 40˚C. DSC, FT-IR, DRX and SEM confirmed the BC leather good purity indicated the treatment 17.5% (v/v) H2O2 at 40˚C as promising. The BC leathers instrumental color, WHC and WVP, characterization indicates the treatment with 23% (v/v) H2O2 at 40˚C with improved whiteness and WVP. Bleaching conditions directly affect the properties of BC leathers. Therefore, the selection of treatment parameters should consider the intended application, such as maximizing yield, enhancing purity, or improving color and WVP, focusing on the application.