Oil-in-water Pickering emulsions via microfluidization with cellulose nanocrystals: 2. In vitro lipid digestion

Bio-based engineered nanomaterials are being explored for their utilization within foods to improve quality and enhance functionality. In this study, we investigated the impact of a naturally-derived particle stabilizer, cellulose nanocrystals (CNC), on the gastrointestinal fate and digestion of corn oil-in-water Pickering emulsions. A static 3-stage gastrointestinal tract (GIT) model was used to simulate the mouth, stomach and small intestine. The digestion of the CNC-coated lipid droplets was monitored by measuring the release of free fatty acids (FFAs) in the small intestine stage over time. The final extent of FFAs released was reduced by ∼40% by using emulsions containing 10 wt% of the dispersed phase, corn oil, stabilized with CNC (0.75 wt% of the aqueous phase). Three main mechanisms are proposed for this effect: (1) the irreversible adsorption of CNC to the lipid droplet surfaces inhibited bile salt and lipase adsorption; (2) coalescence and flocculation of the lipid droplets reduced the surface area available for the bile salts and lipase to bind; and (3) accumulation of FFAs at the surfaces of the lipid droplets inhibited lipolysis. Our findings suggest that CNC can be used as a food-grade particle stabilizer to modulate the digestion of Pickering emulsified lipids, which is useful for the development of given functional foods.