Carotenoids are plant pigments that act as antioxidants, and are especially associated with eye health. Scientists at Purdue University studied yellow maize (corn) to better understand the bioavailability of the carotenoids therein.  They found that lutein and zeaxanthin were the major carotenoids, making up about 70% of total carotenoid content. They also found that bioavailability of different carotenoids varied according to the type of foods (breads, extruded corn puffs, porridge).
Journal of Agricultural and Food Chemistry. November 12, 2008; 56(21): 9918-26. Epub Oct 21, 2008.