The objective of this study was to determine the effects of caprine casein in combination with arabinogalactan on the chemical stability of lutein in corn oil-in-water emulsion at 37°C for 96 h. Previous studies have reported an increase in the chemical stability of lutein-loaded oil-in-water emulsions prepared using bovine casein. However, the chemical degradation of lutein in corn oil-in-water emulsions stabilized by bovine casein increased by raising the temperature from 5 to 70°C. The concentration of lutein in oil-in-water emulsion stabilized by bovine casein was reduced by 12% at 37°C during the 96-h incubation as compared with the control. On the other hand, the ability of arabinogalactan, a condensation product of galactose and arabinose at 6:1 ratio, to form an inclusion complex with a guest molecule, can improve lutein application, bioavailability, and stability in foods. Corn oil-in-water emulsion (5% wt/wt) stabilized with bovine casein (0.5% wt/wt) or caprine casein (0.5% wt/wt), and arabinogalactan at a concentration of 0.25% (wt/wt) was prepared using a high-pressure homogenizer. The pH of the emulsions was adjusted to 7.0. The chemical stability of lutein was assessed by measuring the changes in lutein concentration in the emulsions during incubation at 37°C for 96 h using a spectrophotometric method. The chemical stability of lutein increased significantly (P < 0.05) in the caprine casein types I and II as compared with bovine casein. Microencapsulation of lutein with either caprine casein-arabinogalactan or bovine casein-arabinogalactan protected lutein in corn oil-in-water emulsions and significantly reduced (P < 0.05) the chemical degradation of lutein at 72 and 96 h of incubation at 37°C, compared with the treatments without arabinogalactan. This information will be useful for understanding the behavior of lutein emulsions in food products.