Table 1 shows typical food sources and amounts of carotenoids
present. In the case of lutein and zeaxanthin, they are also present
in high concentrations in egg yolks [2].
Due to the unsaturated
nature of the carotenoids they are subject to changes due
mainly to oxidation.
However, other factors such as temperature,
light and pH can also produce alterations that can influence the
color of foods as well as their nutritional value [9].