Surface Modification of Cellulose Nanocrystals by Physically Adsorbing Lactoferrin as Pickering Stabilizers: Emulsion Stabilization and in vitro Lipid Digestion

Surface modification is a prerequisite procedure for using cellulose nanocrystals (CNCs) in food and other industries. This study reports a simple and safe procedure for CNCs surface modification using physically absorbing food protein (lactoferrin, LF) that could improve the emulsification performance and modulating emulsion lipid digestion in vitro. Modification of CNCs by LF was characterized by adsorption percentage (%), zeta-potential, atom force microscopy, and contact angle. The modification occurred electrostatically between negatively CNCs and positively LF. LF-modified CNCs are more hydrophobic and aggregation-prone depending on the ratio of protein to CNCs and pH. Emulsions stabilized by LF-modified CNCs which are characterized by visual appearance, microstructure, droplet size, and stability against lipid oxidation. Modification of CNCs by LF could improve the emulsification performance of CNCs and show high stability against lipid oxidation. In vitro gastrointestinal digestion of emulsions stabilized by LF-modified CNCs was also investigated by Free fatty acid released (FFA, %) and microstructure. Overall, emulsions stabilized by CNCs particles have lower lipid digestion extent than that of tween 20. The findings would have potential applications in fabrication of novel functional emulsions in food and other industries.