Enhancement of Nutraceutical Bioavailability using Excipient Nanoemulsions: Role of Lipid Digestion Products on Bioaccessibility of Carotenoids and Phenolics from Mangoes.

The ability of excipient nanoemulsions to increase the bioaccessibility of different kinds of nutraceuticals (phenolics and carotenoids) in mangoes was studied. Oil-in-water excipient nanoemulsions containing small digestible lipid nanoparticles (d < 200 nm) were prepared using different oil phases: medium chain triglycerides (MCT) and long-chain triglycerides (LCT). These nanoemulsions were then mixed with pureed mango and passed through a simulated gastrointestinal tract (GIT): mouth, stomach, and small intestine. Carotenoid bioaccessibility decreased in the following order: LCT nanoemulsions > MCT nanoemulsions > buffer solution, which was attributed to differences in the solubilization capacity of the mixed micelles generated in the intestinal fluids. The digestion products of LCT formed mixed micelles with hydrophobic domains large enough to accommodate the carotenoids, whereas those of MCT did not. Excipient emulsions had much less effect on phenolic bioaccessibility, which may be because phenolics are smaller more polar molecules and are therefore more easily solubilized in aqueous intestinal fluids. These results highlight the potential of excipient nanoemulsions in boosting the bioavailability of lipophilic bioactive agents in fruits and vegetables.