Chitin-glucan nanofibrils from Inonotus hispidus mycelium as Pickering emulsion stabilizers and lipid digestion...

Polysaccharide-based Pickering stabilizers have been increasingly studied due to their promising potential in developing "clean label" emulsions. In this study, we isolated a novel type of polysaccharide particle, chitin-glucan nanofibrils (CGNFs), from I. hispidus mycelium using a combined process of mild solvent extraction and cyclic low-energy disassembly. The CGNFs are of high chitin to glucan molar ratio (1.1,1), high charge (∼ - 35 mV, which stems from carboxyl generated through H₂O₂ oxidation) and high aspect ratio (∼51). They exhibited good amphiphilicity and excellent emulsification performance, producing stable Pickering emulsions with fine oil droplets (∼8.90 μm) at 0.8 wt%. Under in vitro digestion, the emulsion was digested at a slower rate compared to the oil-water mixture without CGNFs, suggesting that CGNFs are capable of retarding lipid digestion. Cryo-SEM analysis of emulsion structure evolution revealed possible mechanism of CGNF interference in lipid digestion, including mild aggregation and fusion of oil droplets to reduce contact surface, formation of a CGNF physical barrier limiting lipase access, and inhibition of bile salt displacement. Our current study implicates that I. hispidus CGNFs could be applied as a functional ingredient not only for constructing emulsified food systems but also for offering additional health benefits in weight control.