Modulating in vitro gastrointestinal digestion of nanocellulose-stabilized Pickering emulsions by altering cellulose lengths

Abstract The application of oil-in-water emulsions to control lipid digestion is of significance in the food and pharmaceutical industry for targeted release of bioactive components and also has attracted great interest in counteracting obesity. In the present work, we focus on the effect of the length of cellulose nanoparticles on the gastrointestinal fate and lipid digestion of emulsions (10% oil, v/v). The changes in the gastrointestinal fate of emulsions were characterized by measurements of droplet size, zeta potential, and emulsion structure. The lipid digestion of emulsions was evaluated by determining the release of free fatty acids (FFAs). We found that (i) gastric environment induced that negatively charged nanocellulose-stabilized emulsion systems formed the gel structure, leading to oil droplets aggregation but not coalescence. (ii) The length of cellulose nanoparticles influenced the strength of this emulsion structure, which was shown in the stronger gel structure observed in emulsions stabilized by longer cellulose nanoparticles. (iii) These formed emulsion structures reduced the lipid digestion of emulsions due to the limited surface areas for the adsorption of bile salts and lipases. Moreover, the lower the release of FFAs was obtained in emulsions stabilized by longer cellulose nanoparticles. The results indicate that the emulsion structure formed in the gastric stage could modulate intestinal lipolysis. This study provides a convenient and easy method to tailor gastrointestinal digestion of emulsion by changing cellulose lengths.