Improving the Stability and Bioaccessibility of Vitamin D3 in the Structure of Nanoniosomes Designed by Different Surfactants

Due to the high nutritional value of vitamin D3 and its instability in various environmental and processing conditions, the need to preserve it through techniques such as capsulation during nutrification is felt. In this study, vitamin D3 was encapsulated in the structure of niosomes based on various surfactants (Span 60, Tween 20, and 80) and cholesterol with ratios (80:20 and 60:40 w/w) using by thin layer hydration-sonication method. It was found that the niosomes prepared with tween 20 and 80 with a surfactant to cholesterol ratio (80:20 w/w) had the lowest mean particle size distribution, lowest polydispersity index, and the highest zeta potential magnitude. Also, these samples had high encapsulation efficiency and their sizes were in the nanoscale. The stability of vitamin D3 was determined during 1 month at refrigerator condition for nanoniosomes samples based on tween 20 and 80 with a surfactant to cholesterol ratio (80:20 w/w). The results showed that tween 20 based nanoniosomes were more stable than tween 80 based samples during 1 month storage. Also, the bioaccessibility of vitamin D3 after complete digestion was evaluated under simulated gastrointestinal conditions. Based on this, it was found that the bioaccessibility of vitamin D3 in the free form is 58%, which the design of nanoniosomes based on tween significantly improved its bioaccessibility (P<0.05). The highest bioaccessibility of vitamin D3 was obtained for tween 20 nanoniosomes at ratio 80:20 of surfactant to cholesterol.