Lecithin-Based Nano-emulsification Improves the Bioavailability of Conjugated Linoleic Acid

In this study, we investigated the effects of lecithin-based nano-emulsification on the heat stability and bioavailability of conjugated linoleic acid (CLA) in different free fatty acid (FFA) and triglyceride (TG) forms. CIA nano emulsion in TG form exhibited a small droplet size (70-120 nm) compared to CLA nano-emulsion in FFA form (230-260 nm). Nano-emulsification protected CIA isomers in TG form, but not in free form, against thermal decomposition during the heat treatment. The in-vitro bioavailability test using monolayers of Caco-2 human intestinal cells showed that nano emulsification increased the cellular uptake of CIA in both FFA and TG forms. More importantly, a rat feeding study showed that CIA content in small intestinal tissues or plasma was higher when CIA was emulsified, indicating an enhanced oral bioavailability of CIA by nano-emulsification. These results provide important information for development of nano-emulsion based delivery systems that improve thermal stability and bioavailability of CLA.