Carotenoids are terpenoid pigments very widespread in nature, there are more than 700. They are industrially used as highly safe colorants of food and cosmetic preparations. Beta-carotene is the dietary precursor of vitamin A. In developed countries we eat between 1 and 1,5 mg/day beta-carotene and in some third world countries this figure is below 0.5 mg/day. Carotenoid metabolites also play a role in aroma: the flavour of many plant products, such as tomato and saffron, is due to volatile derivatives of the xanthophyll oxidative metabolism.