Gamma- carotene

El 60 Carotenoids, Alpha-, Beta-, Gamma-carotene 192 E302 Calcium Ascorbate 660... 

The formation of the normally present cyclic carotenoids is Inhibited. The transformation of the acyclic lycopene to the monocyclic gamma-carotene Is partially inhibited and further cyclizatlon to the bicyclic beta-carotene is totally Inhibited. However, when the treatment of the entire tree which Is sprayed with 2,000 ppm MPTA Is conducted preharvest at the fully mature stage of fruit development [2], the carotenoid composition of the endocarp reflects a net synthesis of the cyclic pigments and differs from the pattern seen in the peel as shown in Table II. 

Spectral characteristics and configuration of some stereoisomeric carotenoids including prolycopene and pro-gamma-carotene. J. Am. Chem. Soc. 65 (1943) 1940—1951. (L. Zechmeister, A. L. LeRosen, W. A. Schroeder, A. Polgar, and Linus Pauling). 

In addition to the actual forms of vitamin A, related compounds, known as carotenes, are found in several fruits and vegetables. Carotene is also called (1) provitamin A, because it can be converted to vitamin A in the body and (2) precursor of vitamin A, because it precedes vitamin A. At least 10 of the carotenoids found in plants can be converted with varying efficiencies into vitamin A. Four of these carotenoids alpha-carotene, beta-carotene, gamma-carotene, and crypto-xanthine (the main carotenoid of corn)—are of particular importance due to their provitamin A activity. Of the four, beta-carotene (see Fig. V-25) has the highest vitamin A activity and provides about two-thirds of the vitamin A necessary for human nutrition. 

Cui, Y., Lu, Z., Bai, L., Shi, Z., Zhao, W.E., and Zhao, B. 2007. Beta-carotene induces apoptosis and up-regulates peroxisome proliferator-activated receptor gamma expression and reactive oxygen species production in MCF-7 cancer cells. EurJ Cancer 43 2590-2601. 

Rustan et al. (123) used an isocratic HPLC method for the determination of alpha-, gamma-, and delta-tocopherol, BHT, BHA, PG, OG, DG, NDGA, TBHQ, ascorbyl palmitate, and beta-carotene in foods. An RP18 column was used in experiments, and seven mobile phases based on various combinations of acetonitrile, methanol, water, and tetrahydrofuran were tested. Trials with carrot juice, dried milk formula for infants, and aperitif cakes showed that all 12 antioxidants could be determined by a single isocratic HPLC analysis. The optimum mobile phase... 

Sebastiao, K.I., Almeida-Muradian, L.B., Romanelli, M.F., Koseki, P.M. and Villavicencio, A.L.C.H. (2002) Effect of gamma-irradiation on the levels of total and cis/trans isomers of beta-carotene in dehydrated parsley. Radiation Physics and Chemistry 63(3-6), 333-335. 

Carotenes are relatively non-polar compounds which are soluble in lipophilic solvents. Most of the known natural carotenoids are oxygenated compounds, often termed xanthophylls, and may be classified as derivatives of the hydrocarbons lycopene or alpha-, or beta-carotene. Although alpha, beta, and gamma all have vitamin A activity in food products, only beta-carotene is used for calculating the vitamin A in vegetables. Carotenes are readily oxidised by light, air and many of the typical extraction solvents (or solvent impurities) including tetrahydrofuran (THF), chloroform, methylene chloride and hexane. 

Kontush, A, Spranger, T, Reich, A, Baum, K and Beisiegel, U (1999) Lipophilic antioxidants in blood plasma as markers of atherosclerosis the role of alpha-carotene and gamma-... 

Other new rapid screening technics included inhibition by drugs of the release of inorganic phosphate from baker s yeast upder irradiation and Inhibition of the reaction between irradiated oleic acid and carotene It was observed that gamma-irradiated mouse tissue homogenates or albu-men S undergo a chemiluminescent reaction and the inhibition of this reaction by radioprotective drugs was used for the evaluation of these. 

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