Carotenoids are responsible for the colour of a great number of both vegetable and animal foods, such as carrots, orange juice, tomato, salmon and egg yolk. It has been known for many years that some of these compounds, such as alpha and beta-carotene, as well as beta-cryptoxanthin, are provitamins A. However, recent studies have shown the antioxidant properties of these compounds and their efficiency in the prevention of certain human diseases, such as atherosclerosis or cancer. Because of all this, the interest in these compounds has increased substantially from a nutritional point of view.