Evaluation of the properties of dry bacterial cellulose synthesized from coffee kombucha fermentation dried with different drying methods

Abstract

AbstractThe fermentation of coffee kombucha (CK) utilizes carbohydrate substrates to produce bacterial cellulose (BC), a naturally occurring material synthesized by some bacteria including Gluconacetobacter spp. BC can be used to develop materials for biomedical and food industry applications including biomaterial and biodegradable packaging materials, medical devices, biosensors, or drug delivery systems. BC contains approximately 97% water, which is not convenient and portable for many applications. Drying increases the stability of BC and may influence the properties of BC. The effect of drying methods on the BC properties can determine the suitability of the material for various applications. The objectives of this study were to use four drying methods to synthesize BCs from the fermentation of CK and evaluate their physicochemical, mechanical, and morphological properties. The drying methods included: oven-drying (OD), freeze-drying, vacuum-oven-drying, and Büchner funnel vacuum-drying (BFVD). FTIR analyses confirmed the structure of cellulose for all methods. OD-BCs had the highest tensile stress at break with 24.67 ± 4.40 (MPa). SEM images showed randomly structured fibers with diameters ranging from 61.58 to 72.18 nm. XRD analysis revealed that OD had the highest degree of crystallinity with 78.67%. All BCs decomposed between 230 and 400 °C. This study demonstrated that using different drying methods could alter the structural properties of BCs potentially providing distinctive applications in various industries.Keywords: Bacterial cellulosecellulosic fiberscoffeekombuchacrystallinitiesdrying methods Authors’ ContributionsFederico Bueno: Investigation, Formal analysis, Methodology, Writing – Original draft. David A. Spivak: Methodology and Investigation. Subramaniam Sathivel: Funding acquisition, Investigation, Methodology, Supervision, Project administration.Disclosure statementThe authors confirm that they have no conflicts of interest with respect to the work described in this manuscript.Data availability statementThe authors declare that the data supporting the findings of the study entitled “Evaluation of the properties of dry bacterial cellulose synthesized from coffee kombucha dried with different drying methods” are available within the article.Additional informationFundingThis research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.