A notable impact of lipid matrices on cholesterol bioaccessibility from phytosterols-loaded nanostructured lipid carriers during in vitro intestinal digestion

Abstract

Encapsulation of phytosterols in nanostructured lipid carriers (NLCs) is an effective approach to improve their physicochemical properties, but the interaction of phytosterols in NLCs with cholesterol can be affected by lipid matrices. The objective of this study was to screen a desired phytosterols-loaded NLC (PS-NLC) formulation to reduce the absorption of intestinal cholesterol. A series of formulations were prepared using amphipathic glycerol monostearate (GMS) as the solid lipid fraction to increase lipid compatibity with phytosterols. All formulations showed a lowering effect on cholesterol bioaccessibility through in vitro intestinal digestion. And the PS-NLCs with medium chain triglycerides (MCT) as the liquid lipid showed significantly higher inhibition of cholesterol bioaccessibility (accessible fraction for intestinal absorption) than the formulations with long chain triglycerides (LCT), which could due to the solubilization of cholesterol by hydrolysis products of LCT, suggesting a notable impact of lipid type on cholesterol bioaccessibility. Furthermore, the analysis of distribution of phytosterols and cholesterol revealed a cocrystallization mechanism occurred during in vitro digestion. This study provides a certain reference for designing phytosterol-ingredient agents with a better hypocholesterolemic effect in water-dispersible functional foods.