Publications (2)0 Total impact
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ABSTRACT: There have been well over 600 carotenoids described in nature with the vast majority having colors ranging from pale yellow to deep red . We find them not only in our fruits and vegetables, but in the flowers and foliage decorating our environment. In addition, many animal species contain visible coloration due to the ingestion of carotenoid-containing plant material. The pinkish tone of many fish species, some of the color in the skin and plumage of birds, and even the yellow color in the fat associated with meat products represents the transfer of carotenoids from plants to animals. The human is not exempt from this process, for we absorb numerous carotenoids from our diet, and then deposit them in our tissues . Figure 1 represents the structures of the most common carotenoids found in humans, with relative levels depending on regional differences in diet. It should be noted that some of the naturally occurring carotenoids are found in the cis-configuration, which can significantly alter their physical properties and may impact on their biological properties. An example of this phenomenon relates to β-carotene. In our usual plant sources of β-carotene, the predominant isomeric form is the all-trans-β-carotene. In some algal sources, such as Dunaliella, there is a 50:50 mixture of the all-trans-β-carotene and 9-cis-β-carotene . The latter isomer is much more soluble, presumably due to an inability to form tightly structured crystals. This change in solubility has been suggested as one reason for differences in the biological properties of these two isomers .07/2011: pages 45-57;
Article: beta-carotene: friend or foe?[show abstract] [hide abstract]
ABSTRACT: This symposium focused on the research which documents benefit and toxicity in beta-carotene supplementation. Reflecting on past and current studies, the panel of experts discussed: (1) the potential harm of a high intake of beta-carotene on selected populations, (2) biochemical antioxidant/prooxidant mechanisms of beta-carotene at the cellular level, (3) potential benefits of other carotenoids and antioxidants, and (4) future directions for research in beta-carotene and other antioxidants.Fundamental and Applied Toxicology 01/1998; 40(2):163-74.