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Carotene analysis

Aalbersberg, William G.L. (1992) Carotene analysis. [Conference Proceedings]

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Vitamin A deficiency is one of the major public health nutrition problems in many developing countries (including atoll nations in the South Pacific) (WHO, 1982). Its main manifestation is xerophthalmia, which may lead to irreversible blindness. The major source of vitamin A in most developing countries is carotenoids, which occur in very high levels in a number of green leaves (Tee, 1988). Recent epidemiological evidence and experimental studies indicate that carotenoids may also be associated with reduced risk of certain types of cancer. This is likely to be related to the antioxidant properties of the extended polyene system in these compounds (Tee, 1988). There are several carotenes that have pro-vitamin A activity (Table 1). Their common feature is the β-ionene ring. Beta-carotene, having two such rings, has roughly twice the activity as the other carotenoids. These compounds are transformed into retinol (vitamin A) by enzyme action in the liver and intestine. Of the above carotenoids the four that normally occur in fruits and vegetables, in order of relative amounts, are beta-carotene, cryptoxanthin, alpha-carotene, and gamma-carotene. The efficiency of absorption and conversion of beta-carotene is such that ingestion of 6 mg results in formation of 1 mg of retinol. The other three have half this activity.

Item Type: Conference Proceedings
Subjects: Q Science > QD Chemistry
Divisions: Faculty of Science, Technology and Environment (FSTE) > Institute of Applied Science
Depositing User: Ms Niumai Kavoa
Date Deposited: 13 Aug 1992 00:43
Last Modified: 13 Aug 2012 00:43

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