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 similar to 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.