Nanoemulsion Delivery Systems for Oil-soluble Vitamins: Influence of Carrier Oil Type on Lipid Digestion and Vitamin D3 Bioaccessibility
Bengu Ozturka,b,e, Sanem Arginc, Mustafa Ozilgenc, David Julian McClementsa,d 
aDepartment of Food Science, University of Massachusetts, Chenoweth Laboratory, Amherst, MA, USA bDepartment of Chemical Engineering, Yeditepe University, Kayisdagi, Istanbul, Turkey cDepartment of Food Engineering, Yeditepe University, Kayisdagi, Istanbul, Turkey
d Production of Bioproducts for Industrial Applications Research Group, Department of Biochemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203 Jeddah 21589 Saudi Arabia e Food Institute, TÜBITAK Marmara Research Center, P.O. Box 21, 41470 Gebze, Kocaeli, Turkey 

The influence of carrier oil type on the bioaccessibility of vitamin D3 encapsulated within oil-in-water nanoemulsions prepared using a natural surfactant (quillaja saponin) was studied using a simulated gastrointestinal tract (GIT) model: mouth; stomach; small intestine. The rate of free fatty acid release during lipid digestion decreased in the following order: medium chain triglycerides (MCT) > corn oil ≈ fish oil > orange oil > mineral oil. Conversely, the measured bioaccessibility of vitamin D3 decreased in the following order: corn oil fish oil > orange oil > mineral oil > MCT. These results show that carrier oil type has a considerable impact on lipid digestion and vitamin bioaccessibility, which was attributed to differences in the release of bioactives from lipid droplets, and their solubilization in mixed micelles. Nanoemulsions prepared using long chain triglycerides (corn or fish oil) were most effective at increasing vitamin bioaccessibility.