Emulsifying properties of α-chitin nanofibrils prepared by aqueous counter collision

Renewable and biocompatible nanofibrils derived from natural polysaccharides attract a great attention not only for fiber-reinforced composite materials, but for fibrous emulsifiers for Pickering emulsions (PEs) in the fields of food emulsions, cosmetics, and drug delivery. The PEs are usually stabilized by adsorption of Pickering emulsifiers at oil-water interfaces. This study attempts to examine emulsifying efficiency of chitin nanofibrils that are prepared by aqueous counter collision (ACC) process. Namely, the obtained chitin nanofibrils (ACC-ChNFs) worked to assist formation of PEs from the mixture of water and typical organic solvents as well as an edible canola oil. Their oil-water interfacial tension, droplet diameter distribution and surface potential of oil droplets were compared with the case using ACC-cellulose nanofibrils as an emulsifier. As a result, ACC-ChNFs exhibited superior properties allowing stabilization of oil droplets with various oil-water interfacial tension values. Moreover, emulsification characteristics of canola oil-based emulsions in the system of ACC-ChNFs were quite different from those of the ACC-CNFs. This might be based on the unique interfacial adsorption of cationic ACC-ChNFs onto canola oils involved in complexing with anionic fatty acids. © 2021 The Society of Fiber Science and Technology, Japan