Modulating in vitro digestibility of Pickering emulsions stabilized by food-grade polysaccharides particles. (1st January 2020) - Costa, Ana Letícia Rodrigues
Graphical abstract: Highlights: Lipid digestion rate of Pickering emulsions was studied using an in vitro digestibility protocol. Emulsion properties during in vitro digestion were modulated according to the particle nature. Tween 80, CCrys and CNFs were able to inhibit lipid digestion. Chitosan-stabilized Pickering emulsions presented delayed lipid hydrolysis. Relevant aspects about the interfacial design of food Pickering emulsions were elucidated. Abstract: An in vitro digestibility protocol was used to elucidate the role of different emulsifying polysaccharides particles on the lipid digestion rate of oil-in-water Pickering emulsions. Emulsions stabilized by cellulose crystals (CCrys), cellulose nanofibers (CNFs), chitosan particles and a conventional emulsifier (Tween 80) were evaluated concerning microstructure, droplet size, zeta potential and free fatty acids released during digestion. After gastric step, the high positive charge of chitosan-stabilized emulsions favored the droplets disaggregation resulting in a mild effect of bridging flocculation by particles sharing and displacement of the size curve distribution toward lower size. After passing through the intestinal condition, these emulsions presented few droplets and chitosan aggregates with a monomodal size distribution and high mean droplet size ( D4, 3 = 197 ± 8 μm). On the other hand, Tween 80, CCrys and CNFs were able to inhibit lipid digestion and no changes on mean droplet size were observed following intestinal step. CNFs-stabilized emulsion showed the lowest lipid digestion, whereas the strong adherence of the CCrys particles onto the droplet interface became them resistant to displacement by surface-active components ( i.e. bile salts and lipase enzyme). On the other hand, a slow lipid hydrolysis could be observed in chitosan-stabilized emulsions promoted by competition between chitosan aggregates and intestinal fluids by the oil droplet interface. Studying the emulsions stabilized using different polysaccharides particles on gastrointestinal conditions we could elucidate important features for their potential application as control systems of lipid digestion rate, as well as, as delivery systems of lipophilic compounds.