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carotene
carotene The red and orange pigments of many plants, obvious in carrots, red palm oil, and yellow maize, but masked by chlorophyll in leaves. Three main types of carotene in foods are important as precursors of vitamin A: α‐, β‐ and γ‐carotene, which are also used as food colours. Plant foods contain a considerable number of other carotenes, most of which are not precursors of vitamin A.
Carotene is mostly converted into vitamin A (retinol) in the wall of the intestine, but some is absorbed unchanged. 6 μg of β‐carotene, and 12 μg of other provitamin A carotenoids, are nutritionally equivalent to 1 μg of preformed vitamin A. About 30% of the vitamin A in Western diets, and considerably more in diets in less‐developed countries, comes from carotene. In addition to their role as precursors of vitamin A, carotenes are antioxidant nutrients, and there is evidence that they provide protection against ischaemic heart disease and some forms of cancer. There is no evidence on which to base reference intakes of carotene other than as a precursor of vitamin A. |
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DAVID A. BENDER. "carotene." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. DAVID A. BENDER. "carotene." A Dictionary of Food and Nutrition. 2005. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O39-carotene.html DAVID A. BENDER. "carotene." A Dictionary of Food and Nutrition. 2005. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O39-carotene.html |
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carotene
carotene , 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." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. "carotene." The Columbia Encyclopedia, 6th ed.. 2008. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1E1-carotene.html "carotene." The Columbia Encyclopedia, 6th ed.. 2008. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-carotene.html |
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carotene
car·o·tene / ˈkarəˌtēn/ • n. Chem. an orange or red plant pigment found in carrots and many other plant structures. It is a terpenoid hydrocarbon with several isomers, of which one ( beta carotene) is important in the diet as a precursor of vitamin A. |
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"carotene." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. "carotene." The Oxford Pocket Dictionary of Current English. 2009. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O999-carotene.html "carotene." The Oxford Pocket Dictionary of Current English. 2009. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O999-carotene.html |
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carotene
carotene A member of a class of carotenoid pigments. Examples are β-carotene and lycopene, which colour carrot roots and ripe tomato fruits respectively. α- and β-carotene yield vitamin A when they are broken down during animal digestion; β-carotene has antioxidant properties.
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"carotene." A Dictionary of Biology. 2004. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. "carotene." A Dictionary of Biology. 2004. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O6-carotene.html "carotene." A Dictionary of Biology. 2004. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O6-carotene.html |
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carotene
carotene (ka-rŏ-teen) n. a yellow, orange, red, or brown plant pigment; one of the carotenoids. The most important form, β-carotene, is an antioxidant and can be converted in the body to retinol (vitamin A).
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"carotene." A Dictionary of Nursing. 2008. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. "carotene." A Dictionary of Nursing. 2008. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O62-carotene.html "carotene." A Dictionary of Nursing. 2008. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O62-carotene.html |
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carotene
carotene One of a group of hydrocarbon carotenoids.
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MICHAEL ALLABY. "carotene." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "carotene." A Dictionary of Plant Sciences. 1998. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O7-carotene.html MICHAEL ALLABY. "carotene." A Dictionary of Plant Sciences. 1998. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O7-carotene.html |
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carotene
carotene One of a group of hydrocarbon carotenoids.
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MICHAEL ALLABY. "carotene." A Dictionary of Zoology. 1999. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "carotene." A Dictionary of Zoology. 1999. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O8-carotene.html MICHAEL ALLABY. "carotene." A Dictionary of Zoology. 1999. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O8-carotene.html |
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carotene
carotene See carotenoid.
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MICHAEL ALLABY. "carotene." A Dictionary of Ecology. 2004. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. MICHAEL ALLABY. "carotene." A Dictionary of Ecology. 2004. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O14-carotene.html MICHAEL ALLABY. "carotene." A Dictionary of Ecology. 2004. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O14-carotene.html |
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carotene
carotene
•diamantine • dentine • Benedictine
•Christine, pristine, Sistine
•Springsteen • tontine • protein
•Justine • libertine • mangosteen
•brigantine • Augustine • nicotine
•galantine • guillotine • carotene
•quarantine • astatine • travertine
•brilliantine • ethene • polythene
•hypersthene • olivine • Slovene
•go-between • fanzine
•benzene, benzine
•bombazine • organzine
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"carotene." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. 11 Feb. 2012 <http://www.encyclopedia.com>. "carotene." Oxford Dictionary of Rhymes. 2007. Encyclopedia.com. (February 11, 2012). http://www.encyclopedia.com/doc/1O233-carotene.html "carotene." Oxford Dictionary of Rhymes. 2007. Retrieved February 11, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O233-carotene.html |
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