Physicochemical properties of fungal chitin nanopaper from shiitake (L. edodes), enoki (F. velutipes) and oyster mushrooms (P. ostreatus)

We evaluate the physiochemical properties of chitin nanopaper derived from three commonly cultivated mushrooms: shiitake (Lentinula edodes), oyster (Pleurotus ostreatus), and enoki (Flammulina velutipes). Mild alkaline extraction of fungal sample yields higher chitin recovery per dry weight (23-35%) compared to crustacean source (9.7%). Our extract readily defibrillates into 15-20 nm width fiber after 5 min blending in domestic kitchen blender, implying a simple and cost-effective nanofiber preparation. Enoki nanopaper was found to be more crystalline and possess slightly higher modulus and tensile strength (Eenoki = 2.83 GPa, σenoki = 51 MPa) compared to oyster and shiitake nanopaper (Eoyster = 2.28 GPa, σoyster = 45 MPa; Eshiitake = 2.59 GPa, σshitake = 43 MPa). However, oyster nanopaper exhibit higher toughness (1.92 MJ/m3) and larger strain at break (5.63%) because of their relatively smaller fibers promote a denser fibrous network that can sustain and absorb higher external loading.