Sustainable Extraction and Multimodal Characterization of Fungal Chitosan from Agaricus bisporus

Biologically derived polymers, such as chitosan, have gained attention as sustainable alternatives to synthetic materials for food and biomedical applications. Fungal-derived chitosan offers notable advantages over crustacean-based chitosan, including a renewable origin and lower allergenic potential. In this study, chitosan was extracted from fungal biomass through a sequential process comprising demineralization, deproteinization, and deacetylation. The extracted material was characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), zeta potential measurement, dynamic light scattering (DLS), and color analysis. Compared to commercial chitosan, the fungal chitosan exhibited lower crystallinity and thermal stability, as well as a more porous surface morphology. Its degree of deacetylation and surface charge suggest promising potential for use in biodegradable films and functional materials. These findings highlight the feasibility of using fungal biomass as a sustainable and valuable source of chitosan for technological applications.