Gastrointestinal digestion of Pickering emulsions stabilised by hydrophobically modified cellulose nanocrystals: Release of short-chain fatty acids

Abstract

This study aimed to deliver short-chain fatty acids (SCFAs, including propionic and butyric acids) using Pickering emulsions stabilised by hydrophobically modified cellulose nanocrystals (MCNCs). The emulsions (20 wt% oil, 1 wt% MCNCs) were subjected to two in vitro digestion pathways. In the first pathway, the emulsions were used for direct intestinal digestion by bypassing the gastric phase while in the second pathway, the emulsions were subjected to sequential gastrointestinal digestion. Flocculation of emulsion droplets occurred because of charge screening effects by the gastric electrolytes. Such gastric flocculation reduced the droplet surface area, overall lipolysis kinetics and consequently decreased the extent of SCFA release, latter was 40-45% in the gastric-bypassed emulsions and 30-35% in the sequentially-digested emulsions. High proportion of SCFAs remaining after the intestinal digestion (~65%) shows promise in the use of Pickering emulsions for the colon-targeted delivery of SCFAs.

Keywords: Butyric acid (PubChem CID 264); Cellulose nanocrystals; Hydrophobic modification; Lipid digestion; Pickering emulsions; Propionic acid (PubChem CID 1032); Short-chain fatty acids; Tributyrin (PubChem CID 6050); Tripropionin (PubChem CID 8763).