Influence of gamma irradiation on the properties of bacterial cellulose produced with concord grape and red cabbage extracts

Abstract

Bacterial cellulose (BC) is a biopolymer produced by microorganisms that has high purity, non-toxicity, biodegradability, and biocompatibility. These characteristics make BC suitable for applications in sectors such as the cosmetic, biomedical, and packaging industries. To ensure biosafety for use in these fields, an efficient sterilisation process is necessary. Gamma irradiation is often used as a sterilisation technique, but it has high penetration power. Therefore, evaluating its effects on the physicochemical properties of BC after exposure is important. To date, few studies have reported BC produced with alternative media and sterilised with 60Co radiolytic irradiation. In this work, the bacterium Komagataeibacter hansenii (formerly known as Gluconacetobacter hansenii) was used for the production of BC in standard Hestrin-Schramm medium and alternative media formulated with different compositions of concord grape and red cabbage extracts. The samples were sterilised with 60Co irradiation. Comparisons of the samples before and after exposure to gamma irradiation were performed with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis, and scanning electron microscopy (SEM). The results revealed no substantial changes in the membrane characteristics after irradiation with a dose of 25 kGy. SEM and FTIR analyses demonstrated the preservation of the polymeric structure of the BC. XRD demonstrated that the process did not create new planes of symmetry. With the exception of one sample, the mean reduction in crystallinity was 9.96%. The present findings show that the polymer is safe and has potential for use in the cosmetic, biomedical, and food industries.