Carotenoids beta-carotene

The structures of four of the synthetic carotenoids (beta-carotene, canthaxanthin, beta-apo-8 -carotenol, beta-apo-8 -carotenoic acid) are shown in Fig. 8.2. By virtue of their conjugated double bond structure, they are susceptible to oxidation but formulations with antioxidants were developed to minimize oxidation. Carotenoids are classified as oil soluble but most foods require water soluble colorants thus three approaches were used to provide water dispersible preparations. These included formulation of colloidal suspensions, emulsification of oily solutions, and dispersion in suitable colloids. The Hoffman-LaRoche firm pioneered the development of synthetic carotenoid colorants and they obviously chose candidates with better technological properties. For example, the red canthaxanthin is similar in color to lycopene but much more stable. Carotenoid colorants are appropriate for a wide variety of foods.10 Regulations differ in other countries but the only synthetic carotenoids allowed in foods in the US are beta-carotene, canthaxanthin, and beta-8-carotenol. 

Carotenoids (beta-carotene, lycopene, etc.) Flavonoids (quercetin, rutin, catechin, etc.) Lipoic acid Melatonin... 

In spite of the protective effect of several antioxidant enzymes and metal-binding proteins, free radicals are still widely prevalent. Thus, Ames et al. (A 10) estimated that in each rat cell there are 100,000 radical hits each day, while in every human cells there are 10,000/day. Importantly, there are numerous natural free radical scavengers/chain breakers, the most notable being vitamins C andE, various carotenoids (beta-carotene, lycopene, etc.), flavonoids (rutin, quercetin, catechin, etc.), uric acid, and bilirubin, among others (Table 2). 

Nutrient Content high in protein, prebiotic fiber, antioxidant A-C-E vitamins, B vitamins, dietary minerals Phytochemical Content high in carotenoids (beta-carotene), polyphenols (anthocyanins)... 

High Phytochemical Content carotenoids (beta-carotene) polyphenols (anthocyanins, particularly pelargonidin, and ellagic acid and ellagitannins in the strawberry achenes, delphinidin and cyanidin glycosides and rutinosides, quercetin, hydroxycinnamic acids, proanthocyanidins)... 

High Phytochemical Content carotenoids (beta-carotene, beta-cryp-toxanthin) polyphenols (hesperidin, anthocyanins—cyanidin and xanthone glycosides, quercetin, gallic acid, gallotannins, rhamnetin, proanthocyanidins, resveratrol, ellagic acid, ellagitannins)... 

Figure 6. Kumquats are rich in flavonoids (flavanones and dihydrochalcones), carotenoids (beta carotene) and phenolic acids (cinnamic acids). These dietary polyphenols actually exhibit a dual effect through indirect neuroprotection against oxidative stress and indirect protection through suppression of gha-mediated inflammation.

Annatto is a colored pigment that is extracted from the Central and South American plant Bixa orellana. The color comes from the resinous outer covering of the seeds of the plant, which is composed of the carotenoid pigments bixin and norbixin and their esters. The central portion of those molecules is the same as that of the molecule beta-carotene, and the yellow-orange color of annatto comes from the same physical chemistry origins as the orange color of beta-carotene. 

Beta-carotene is used in foods to provide color (margarine would look as white as vegetable shortening without it). Another similar molecule, annatto, is used in cheeses. Another famous carotenoid dye, saffron, is used to color rice and other foods. 

The dye molecule in saffron is the carotenoid beta-gentiobiose crocetin. It is related to beta-carotene, and you can see the relationship in the center of the molecule. That center portion is the carotenoid pigment crocetin ... 

It is well known that excessive intake of P-carotene may lead to carotenodermia (yellow skin), and it is undoubtedly the case that some carotenoid is directly lost via the skin or through photo-oxidation in the skin. As far as is known the carotenoids are not cytotoxic or genotoxic even at concentrations up to 10 times the normal plasma concentration which may cause carotenodermia. However, they are associated with amenorrhoea in girls who may be consuming bizarre diets and, in long-term supplementation studies, with an increase in lung cancer (The Alpha-tocopherol, Beta-carotene Cancer Prevention Study Group, 1994). 

Carotenoid and tocopherol concentrations in plasma, peripheral blood mononuclear cells and red blood cells after long-term beta-carotene supplementation in men. Am J Clin Nutr 63(4) 553-8. 

Micozzi M s, BROWN E D, TAYLOR and WOLFE E (1988) Carotenodermia in men with elevated carotenoid intake from foods and beta-carotene supplements. Am J Clin Nutr. 49(6) 1330-31. 

Lafferty, J., Truscott, T.C., and Land, E.J., Electron transfer reactions involving chlorophylls a and b and carotenoids, J. Chem. Soc. Farad. Trans., lA, 2760, 1978. Burri, B.J., Clifford, A.J., and Dixon, Z.R., Beta-carotene depletion and oxidative damage in women, in Natural Antioxidants and Anticarcinogens in Nutrition, Health and Disease, Kumulainen, J.T. and Salonen, J.T., Eds., Royal Society of Chemistry, Stockholm, 1999, 231. 

Holick, C.N. et al., Dietary carotenoids, serum beta-carotene, and retinol and risk of lung cancer in the alpha-tocopherol, beta-carotene cohort study, Am. J. Epidemiol., 156, 536, 2002. 

Lindqvist, A. and Andersson, S., Biochemical properties of purified recombinant human beta-carotene 15,15-monooxygenase, J. Biol. Chem., 277, 23942, 2002. Krinsky, N.I., Cornwell, D.G., and Oncley, J.I., The transport of vitamin A and carotenoids in human plasma. Arch. Biochem. Biophys., 73, 233, 1958. 

Liebler, D.C. et al.. Antioxidant actions of beta-carotene in liposomal and microsomal membranes role of carotenoid-membrane incorporation and alfa-tocopherol, Arch. Biochem. Biophys., 338, 244, 1997. 

Isaacson, T. et al., Cloning of tangerine from tomato reveals a carotenoid isomerase essential for the production of beta-carotene and xanthophylls in plants, Plant Cell 14, 333, 2002. 

Hausmann, A. and Sandmann, G., A single five-step desaturase is involved in the carotenoid biosynthesis pathway to beta-carotene and torulene in Neurospora crassa, Eungal Genet. Biol. 30, 147, 2000. 

Ducrenx, L.J. et al.. Metabolic engineering of high carotenoid potato tnbers containing enhanced levels of beta-carotene and lutein, J. Exp. Bot. 56, 81, 2005. 

Ye, X. et al.. Engineering the provitamin A (beta-carotene) biosynthetic pathway into (carotenoid-free) rice endosperm. Science 287, 303, 2000. 

Orange carotenoid protein Conserved hypothetical protein (sir 1964) ft- OCP N terminal domain OCP C-terminal domain Hypothetical protein Hypothetical protein D- Beta carotene ketolase homolog Hydrolase... 

Castelli, F., S. Caruso, and N. Giuffrida. 1999. Different effects of two structurally similar carotenoids, lutein and beta-carotene, on the thermotropic behaviour of phosphatidylcholine liposomes. Calorimetric evidence of their hindered transport through biomembranes. Thermochim. Acta 327 125-131. 

Gabrielska, J. and W.I. Gruszecki. 1996. Zeaxanthin (dihydroxy-beta-carotene) but not beta-carotene rigidities lipid membranes A 1H-NMR study of carotenoid-egg phosphatidylcholine liposomes. Biochim. Biophys. Acta 1285 167-174. 

The interaction of carotenoids with cigarette smoke has become a subject of interest since the results of the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study Group 1994 (ATBC) and CARET (Omenn et al. 1996) studies were released. P-Carotene has been hypothesized to promote lung carcinogenesis by acting as a prooxidant in the smoke-exposed lung. Thus, the autoxidation of P-carotene in the presence of cigarette smoke was studied in model systems (toluene) (Baker et al. 1999). The major product was identified as 4-nitro-P-carotene, but apocarotenals and P-carotene epoxides were also encountered. 

Baker, D. L. et al. (1999). Reactions of beta-carotene with cigarette smoke oxidants. Identification of carotenoid oxidation products and evaluation of the prooxidant antioxidant effect. Chem. Res. Toxicol. 12(6) 535-543. Bonnie, T. Y. P. and Y. M. Choo (1999). Oxidation and thermal degradation of carotenoids. J. Oil Palm Res. 11(1) 62-78. 

Kanasawud, P. and J. C. Crouzet (1990a). Mechanism of formation of volatile compounds by thermal degradation of carotenoids in aqueous medium. 1. Beta-carotene degradation. J. Agric. Food Chem. 38(1) 237-243. 

Zurcher, M. et al. (1997). Oxidation of carotenoids-I. Dihydrooxepin derivatives as products of oxidation of canthaxanthin and beta,beta-carotene. Tet. Lett. 38(45) 7853-7856. 

Johnson, E. J. and E. Norkus (1995). Contribution of beta-carotene from beta-carotene enriched formulas to individual and total serum carotenoids in term infants. FASEB J. 9(4 Pt 3) 1869. 

V. Tyssandier, N. Cardinault, C. Caris-Veyrat, M.-J. Amiot, R Grolier, C. Bouteloup, V. Azais-Braesco, and R Borel, Vegetable-home lutein, lycopene, and beta-carotene compete for incorporation into cylomi-crons, with no adverse effect on the medium term (3-wk) plasma status of carotenoids in humans, Am. J. Clin. Nutr. 75 (2002) 526-534. 

M. van Lieshout, C. E. West, and R. B. van Breemen, Isotopic tracer techniques for studying the bioavailability and bioefficacy of dietary carotenoids, particularly beta-carotene, in humans A review, Am. J. Clin. Nutr. 77 (2003) 12-28. 

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