Evaluation of Stability and In-Vitro Bioaccessibility of Encapsulated Lutein via Microfluidic Technology

Abstract Objectives Inadequate intake of lutein was relevant to a higher risk of aging-related eye disease. Since lutein cannot be synthesized in body, it should be obtained from the food. However, lutein has been barely incorporated into food because it is prone to degradation and is poor bioaccessible in the gastrointestinal tract. Thus, this present study aimed to encapsulate lutein in staple food using excipient emulsions via a novel microfluidic technique and to assess the stability and bioaccessibility of lutein. Methods A combination of alginate and soy protein isolate was applied as food ingredients for fabricating structured encapsulation purposes and two types of oil (safflower oil (SO) and olive oil (OL)) were selected as a delivery vehicle for lutein. Two customized microfluidic devices (co-flow and combination-flow) were assembled to encapsulate lutein into food structures that mimic noodle, an Asian staple food. The extruded microfluidic noodle was created by the following: co-flow + SO, co-flow + OL, combination-flow + SO and combination-flow + OL. The stability of lutein from the microfluidic noodle was evaluated under 4°C storage for one week. The bioaccessibility of lutein was also investigated via a simulated in-vitro gastrointestinal model and lutein was detected by high-performance liquid chromatography. Results The successful encapsulation of lutein in noodle-like structures via microfluidic techniques was achieved at 86.0 ± 5.8% (mean ± SD). Although lutein's stability experienced a decreasing trend, the retention of lutein maintained above 60% up to one week's storage in all types of microfluidic noodle. However, two types of device did not result in a difference in lutein bioaccessibility (co-flow: 3.1 ± 0.5%, combination-flow: 3.6 ± 0.6%, mean ± SD) and SO and OL also showed no differences in lutein bioaccessibility (SO: 3.4 ± 0.8%, OL: 3.3 ± 0.4%, mean ± SD). Conclusions Lutein is successfully encapsulated in new noodle-like food products using excipient emulsions via a novel microfluidic technology and is relatively stable for up to one week's storage. However, findings from this study suggest that the types of oil and device do not affect the lutein bioaccessibility. Funding Sources National University of Singapore, Cross-Faculty Research Grant; Agency for Science, Technology and Research.