Citrus fruit carotenoids

Carotenoids and prostate cancer — Numerous epidemiological studies including prospective cohort and case-control studies have demonstrated the protective roles of lycopene, tomatoes, and tomato-derived products on prostate cancer risk other carotenoids showed no effects. " In two studies based on correlations between plasma levels or dietary intake of various carotenoids and prostate cancer risk, lycopene appeared inversely associated with prostate cancer but no association was reported for a-carotene, P-carotene, lutein, zeaxanthin, or p-cryptoxanthin. - Nevertheless, a protective role of all these carotenoids (provided by tomatoes, pumpkin, spinach, watermelon, and citrus fruits) against prostate cancer was recently reported by Jian et al. ... 

Kato, M. et al.. Accumulation of carotenoids and expression of carotenoid biosynthetic genes during maturation in citrus fruit. Plant Physiol. 134, 82, 2004. Cunningham, F.X. Jr. and Gantt, E., One ring or two Determination of ring number in carotenoids by lycopene epsilon-cyclases, Ptvc. Natl. Acad. Sci. USA 98, 2905, 2001. 

Kato, M., H. Matsumoto et al. (2006). The role of carotenoid cleavage dioxygenases in the regulation of carotenoid profiles during maturation in citrus fruit. J. Exp. Bot. 57(10) 2153-2164. 

Another study employed an ODS column and different mobile phase composition for the measurement of carotenoids in orange juice. Citrus fruits were hand-squeezed and the juice was filtered. Aliquots of 5 ml of juice were extracted with ethyl acetate (3 X 50 ml) containing 0.004 per cent butyl hydroxytoluene (BHT). The organic phase was dried with 50 g of anhydrous sodium sulphate and the aqueous phase was mixed with 50 ml of mehanol and 100 ml of 1 M NaCl, extracted with 75 and 25 ml of ethyl acetate. The ethyl acetate fractions were combined, evaporated to dryness at 40°C and redissolved in the mobile phase. Extracts were analysed in an ODS column (250 X 4.6 mm i.d. particle size 5 jian). The mobile phase consisted of ACN-methanol-l,2-dichloroethane (60 35 5, v/v) containing 0.1 per cent BHT, 0.1 per cent triethylamine and 0.05 M of ammonium acetate. The column was not thermostated and the flow rate was 1 ml/min. Pigments were detected... 

The first fully comprehensive coupling of NP and RP, where the previously described difficulties related to solvents immiscibility were overcome, was developed by Dugo et al. and applied to the analyses of oxygen heterocyclic components of lemon essential oils [22], Based on the configuration described in this work, other applications were developed for the analysis of carotenoids in citrus samples [48], citrus fruit extracts [29], pharmaceutical products [29], and triglycerides in fats and... 

Botanically speaking, citrus is a hesperidium, a berry with a leathery aromatic rind and a fleshy interior divided into sections. As shown by the cross section shown in Fig. 6.1, the exo carp or peel consists of an outer layer called the flavedo which contains oil glands and pigments and a white spongy inner layer called the albedo. The fleshy interior or endocarp of the fruit consists of wedge-shaped sections (segments) filled with multiple fluid-filled sacs or vesicles. These juice sacs constitute the edible portion of a citrus fruit. The cytoplasm contents provide the primary source of the citrus juice. The juice consists primarily of water, sugars, pectins, lipids, terpenes, amino acids, phenolics, carotenoids and minerals. 

Among the several vitamins in this classification, only vitamin A is present in appreciable quantity as carotenoid provitamin A in citrus (38). No vitamin D has ever been reported in citrus nor any plant vitamin D precursors, such as ergosterol. Several of the sterols present in citrus fruits are reported (39, 40, 41), but they are not related to vitamin D. 

Chemi cals, parti cularly 2-(4-chlorophenylthi o)-triethyl amine (CPTA) and some related compounds have been applied postharvest to citrus fruit to enhance carotenoid synthesis (22 26, 151,... 

The relationship between dietary carotenoids and risk of lung cancer has been determined in a pooled analysis of seven cohort studies (studies with the asterisk in Table 7). The results (42) indicate that /3-carotene was not associated with lung cancer, that smoking was the strongest risk factor for lung cancer, and /3-cryptoxantin (contained in citrus fruit) may modestly reduce the risk. 

The structure of a number of important xanthophylls as they relate to the structure of P-carotene is given in Figure 6-22. Carotenoids may occur in foods as relatively simple mixtures of only a few compounds or as very complex mixtures of large numbers of carotenoids. The simplest mixtures usually exist in animal products because the animal organism has a limited ability to absorb and deposit carotenoids. Some of the most complex mixtures are found in citrus fruits. 

Triterpenoid Carotenoids. Two novel triterpenoid xanthophylls from Streptococcus faecium have been identified " as 4,4 -diapo-7, 8 -dihydro-i/, / -caroten-4-al (16) and 4,4 -diapo-i/, A-caroten-4-al (17). Two other C30 carotenoids, jS-citraurinene 8 -apo-/S-caroten-3-ol (18)] and /8-citrauroP [8 -apo-/3-carotene-3,8 -diol (19)], both isolated from citrus fruits, are likely to be derived from C40 carotenoids. Spectroscopic data were presented for both compounds. 

Reviews.—Reviews published during the year include articles on the chemistry and biochemistry of carotenoids of higher plants/ algae, and citrus fruits," a detailed discussion of bacterial C30 carotenoids, and a short account of carotenoids in the food industry. A review of the chemistry of polyene compounds includes carotenoids and retinoids the chemistry of the latter group, especially of vitamin A itself, has also been reviewed. Two articles on ionones, irones, and damascones include an evaluation of these compounds as degraded carotenoids . 

Carotenoids Carotenoids are a class of natural fat-soluble pigments found principally in plants, algae, and photosynthetic bacteria. They are responsible for many of the red, orange, and yellow hues of plant leaves, fruits, and flowers, as well as the colors of some birds, insects, fish, and crustaceans. Some familiar examples of carotenoid coloration are the oranges of carrots and citrus fruits, the reds of peppers and tomatoes, and the pinks of flamingoes and salmon." From the... 

Unlike the fat-soluble carotenoids and vitamin E, which watch over cell membranes (also full of fat), water-soluble vitamin C is like the U.S. Coast Guard, navigating through our waterways and protecting the bloodstream and the inner areas of our cells. Citrus fruits such... 

In addition to these flavones and flavanones, many varieties of citrus fruits contain anthocyanin pigment. This does not appear to have been identified, but that in blood oranges has been studied by Matlack (1931), Carrante (1941), and Patane (1948). The color of pink grapefruit and Indian pummelo is due to lycopene, a carotenoid (Matlack, 1934, 1935). 

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