Encapsulation of Lutein into Starch Nanoparticles to Improve Its Dispersity in Water and Enhance Stability of Chemical Oxidation

Lutein is a carotenoid and has important physiological and antioxidant activity, but its poor dispersity in water and ease of oxidation impede applications. In this paper, encapsulation of lutein into starch nanoparticles is achieved by preparing starch-lutein nanoparticles via nanoprecipitation. Lutein content in the nanoparticles reaches 13.2mg g(-1) when 90mg lutein is added into 50 mL 1% (w/v) starch paste. Starch-lutein nanoparticles provide preservation for lutein from chemical oxidation so that the lutein in starch-nanoparticles oxidizes with a speed only about 25% when compared to pure lutein. In addition, the dispersity of lutein in water was considerably improved, and the aqueous dispersion of the starch-lutein nanoparticles can remain stable for 30 days. X-ray diffraction analysis suggests that lutein might form a complex with amylose.