Impact of different NaOH treatments on biocellulose properties from coconut water fermented by Lentilactobacillus parafarraginis

Background: Biocellulose is a natural polymer produced by bacteria with distinct physicochemical properties, although it has a chemical composition identical to plant cellulose. Before use, biocellulose was purified by chemical treatment to increase its properties. Objective: The study aimed to evaluate biocellulose properties using NaOH solution as a purification agent. Method: After harvesting, all samples were purified using NaOH of 0.25 M (BC0.25), 0.5 M (BC0.5), and 1 M (BC1) and determined for their properties, such as mechanical strength, swelling degree, water vapour transmission, and moisture content. Analysis of scanning electron microscope (SEM) images and Fourier Transform Infrared Spectroscopy (FTIR) spectra were also performed for characterisation. Result: BC0.5 exhibited the highest tensile strength of 15.38±0.45 MPa and elongation at a break of 38.40±0.58%. BC1 had the highest swelling degree of 131.24±0.70%, water vapour transmission of 400.00±0.36 g/m2, and moisture content of 6.44±0.14%. Nevertheless, there were slight alterations in morphological structure and spectral peaks because of the high concentration of NaOH. Conclusion: The use of NaOH treatment of 0.5 M in biocellulose purification removed more contaminants and resulted in better properties than other concentrations.