carotene (redirected from alpha carotene)

carotene (kâr`ətēn'), long-chained, unsaturated hydrocarbon found as a pigment in many higher plants, particularly carrots, sweet potatoes, and leafy vegetables. Carotene is thought to assist in trapping light energy for photosynthesis or to aid in chemical reduction. It is important in animal biology as the main dietary source of vitamin A (see vitamin), which is produced by splitting one molecule of carotene into two molecules of vitamin A. Carotene that is thus converted is called provitamin A. This reaction occurs in either the liver or intestinal wall. The absorption of dietary carotene is dependent on the action of bile. Its absorption is less efficient than that of vitamin A. High intake of dietary carotene is being studied for its disease prevention potential. Carotenes are the simplest of a group of natural pigments called carotenoids, of which there are more than 600.

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carotene

Any of several organic compounds widely distributed in plants and animals. They are pigments that give orange, yellow, or sometimes red colours to, for example, dandelions, apricots, carrots, sweet potatoes, butter, egg yolks, canary feathers, and lobster shells. Carotenes are converted in the body into vitamin A, but, unlike the vitamin, they are not toxic even at high doses. Carotene has an antioxidant effect and is therefore used in pharmaceuticals and as a food and feed additive, as well as to colour margarine and butter.

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carotene, carotin

any of four orange-red isomers of an unsaturated hydrocarbon present in many plants (β-carotene is the orange pigment of carrots) and converted to vitamin A in the liver. Formula: C₄₀H₅₆