Enhanced lutein stability under UV-Light and high temperature by loading it into alginate-chitosan complex
Shulan Xiao, Dong Uk Ahn
Abstract
Lutein is one of the carotenoids found in various fruits, green leafy vegetables, and egg yolk. Lutein has multiple functions, including preventing age-related macular degeneration in the human body. However, lutein is susceptible to high temperature, light, and oxygen. The objective of this study was to produce lutein-loaded polysaccharide complexes to increase the stability of lutein. The physical and chemical properties of lutein-polysaccharide complexes were characterized. The entrapment efficiency (EE%) and loading capacity (LC%) of ltuein, and the lutein's stability to high temperatures and UV light were tested. The results showed that the lutein-loaded complexes had greater than 98% entrapment efficiency and 35% loading capacity. The AL/CS complexes showed significantly higher thermal (70 °C, 3 h) and UV-light stabilities than the free lutein. The SEM, FTIR, and XRD results suggested that the lutein-loaded AL/CS complexes had a flake-like structure, and lutein was inserted into the AL/CS complexes as amorphous forms. The main forces that incorporated and stabilized lutein inside the AL/CS complexes were the hydrophobic environments caused by the neutralization of net charge on the alginate and chitosan and the intermolecular hydrogen bonds between lutein, alginate, and chitosan.