Carotenoids

Natural dyes that occur primarily in plants.

Carotenoids belong to the secondary plant substances. They occur in many plants, but also in egg yolk and animals. There are around 800 different known carotenoids. The most common and best known is beta-carotene, a yellow vegetable dye found in carrots, peppers and tomatoes. Beta-carotene is converted to vitamin A in humans and is therefore also called provitamin A. It is authorised as a food dye (E160a).

Other carotenoids include lycopene (the red colour in tomatoes), lutein and zeaxanthin. Zeaxanthin is an essential component of the yellow spot (macular area) on the retina. An increased intake of zeaxanthin could prevent age-related macular degeneration, a condition that frequently leads to blindness.

Many carotenoids have an antioxidant effect. They are therefore said to help prevent cancer and degenerative diseases.

There are a number of projects that aim to increase the level of carotenoids in plants using genetic engineering methods. Examples are Golden Rice (production of beta-carotene/provitamin A to improve vitamin A levels), and potatoes enriched with zeaxanthin (to prevent age-related blindness). Researchers are also working on oilseed rape and mustard varieties with increased beta-carotene/provitamin A levels.