Summary: | Carotenoids are biosynthesized by bacteria, algae, fungi, and plants, but not by animals, which must
obtain them from their food. These compounds are divided into two major classes based on their
structural elements; carotenes, constituted by carbon and hydrogen (e.g. b-carotene, a-carotene and
lycopene), and xanthophylls, constituted by carbon, hydrogen, and additionally oxygen (for example
lutein, b-cryptoxanthin, zeaxanthin, astaxanthin and fucoxanthin). Carotenoids have good effect on
human health, such as pro-vitamin A, antioxidant, anticancer, antiobesity effect and anabolic effect on
bone components. Currently, carotenoids are used commercially as feed additives, animal feed
supplements, natural food colorants, nutrient supplement and, more recently, as nutraceuticals for
cosmetic and pharmaceutical purposes. These compounds can be produced commercially by chemical
synthesis, fermentation or isolation from the small number of abundant natural sources. Furthermore,
commercial production of carotenoids from microorganisms competes mainly with synthetic
manufacture by chemical synthesis. However, most of the commercially used carotenoids (for example
β-carotene, astaxanthin and cantaxanthin) are produced by chemical synthesis.
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