Comparison of physicochemical and rheology properties of Shiitake stipes-derived chitin nanocrystals and nanofibers

Chitin production from fungal sources has gained increased attention in recent years in terms of continuous supply and safety. In this study, we produced chitin from Shiitake stipes through deproteinization, depigmentation, demineralization and removal of glucans, and then prepared chitin nanocrystal (ChNC) and chitin nanofibers (ChNF) by acid hydrolysis or high-pressure homogenizers. Such obtained ChNFs have higher length than the ChNCs with a length of 142.4 +/- 40.4 nm, with the similar diameter (9 nm). In addition, the purity of ChNC and ChNF were over 98 % measured by HPAEC. The zeta potential analysis showed that ChNC is stable in acid form, while ChNF is in the opposite. Finally, we evaluated the rheology properties of samples to find the impact of salt concentrations on nanoparticles interactions. Overall, the fungi-derived chitin nanomaterials with diversity of characters exhibit immense potential for applications in nutraceutical and food industry.