Carotene in carrot

Marx, M., M. Stuparic, A. Schieber et al. 2003. Effects of thermal processing on tran.v-f/.v-isomcrization of (3-carotene in carrot juices and carotene-containing preparations. Food Chem. 83 609-617. 

Hiranvarachat, B.. Suvarnakuta, P Etevahas-tin, S 2008. Isomerisation kinetics and antioxidant activities of p-carotene in carrots undergoing different drying techniques and conditions. FoodChem. 107 1538-1546. 

Why are some organic compounds colored while others aren t /3-Carotene, the pigment in carrots, is purple-orange, for instance, while cholesterol is colorless. The answer involves both the chemical structures of colored molecules and the way we perceive light. 

Beta-carotene is one of the orange dyes found in most green leaves and in carrots. When leaves lose their chlorophyll in the fall, carotene is one of the colors left over in the leaf. 

The range (p,g/100 fresh weight) of lycopene and P-carotene in selected tomato cultivars can be 20-62000 and 35-2200 respectively, and of P-carotene and a-carotene in selected carrot cultivars 1100-64000 and 530-36000 respectively. Some of the carotenoids may be present as fatty acid esters (Breithaupt and Bamedi, 2001). More extensive listings can be found (O Neill et al, 2001 van den Berg et al, 2000 Hart and Scott 1995). 

Daily consumption of various fruits, vegetables, and derived juices contributes to human intake of carotenoids. The estimation of carotenoid intakes has been made possible throngh publication of the qnalitative and qnantitative carotenoid contents of commonly consnmed foods. Average intake estimates in the United States are around 6.5 mg/day. In seven conntries in Enrope, the average total carotenoid intake based on the snm of the five carotenoids was approximately 14 mg/day. When dietary source of carotenoids were analyzed, carrots appeared as the major sonrces of p-carotene in all conntries except Spain, where spinach was the main contribntor. 

Torronen, R. et al.. Serum (3-carotene response to supplementation with raw carrots, carrot juice of purified (3-carotene in healthy non-smoking women, Nutr. Res., 16, 565, 1996. 

Among 19 cultivars of carrots, the contents of P-carotene varied from 46 to 103 pg/g and of a-carotene from 22 to 49 pg/g. Carrots of the cultivar Nantes grown in Brazil showed the lowest level and an unspecified cultivar from Spain had intermediate levels of both carotenes (Tables 4.2.1 and 4.2.2). The distribution of a- and p-carotene isomers in fresh carrots was investigated. Results reported included the absence of a- and P-carotene cis isomers in unspecified cultivars, 3% of 9-c -p-carotene and 3% of 9-c -a-carotene in cultivar Nantes, 9% of 9-... 

Canning at 121°C for 30 min was also responsible for the highest losses of carotenoids in carrot juice, reaching 60% for P- and a-carotene, whereas the lutein level decreased 50%, all accompanied by the formation of 13-c -p-carotene in the largest amount, followed by 13-cA-lutein and 15-cA-a-carotene. Canning (T x = 121°C, F = 5) of sweet com resulted in a decrease of lutein by 26% and zeaxanthin by 29%, accompanied by increased amounts of 13-cis- lutein, 13 -CM-lutein, and 13-c/i-zeaxanthin. ° The relative amounts of cis isomers of lutein, mainly the 13-cis, increased by 15% and of 13-di-zeaxanthin by 20% after com canning." ... 

Traditionally, carotenoid standards are prepared in each laboratory using the best sources of each individual carotenoid, for example, violaxanthin from spinach, antheraxanthin from potatoes, capsanthin and capsorubin from paprika, a- and P-carotene from carrots, and lycopene from tomatoes. 

Santos CA and Simon PW. 2002. QTL analyses reveal clustered loci for accumulation of major provitamin A carotenes and lycopene in carrot roots. Mol Genet Genomics 268 122-129. 

Carotenoids from fruits and vegetables can exist as protein-carotenoid complexes (as in the case of green leaf vegetables), crystals (as in carrots or tomatoes), or in oil solution (as in mango and papaya) (West and Castenmiller 1998). Carotenoids commonly found in human blood are lutein, zeaxanthin, (3-cryptoxantliin, lycopene, 13-carotene, and a-carotene. The content of some carotenoids in some fruits and vegetables is shown in Table 7.3. 

In systems where several carotenoids are involved, the absorption of each carotenoid is governed by interactions among them carotenoids compete for absorption (Furr and Clark 1997). For example, (3-carotene supplementation reduced absorption of dietary lutein and lycopene in humans (Micozzi and others 1992). Tyssandier and others (2002) found that the absorption of dietary lycopene was reduced when a portion of spinach or pills of lutein were additionally administered to the volunteers. Similarly, the absorption of dietary lutein was reduced by consumption of tomato puree or lycopene pills (Tyssandier and others 2002). Furusho and others (2000) demonstrated that liver retinol accumulation in Wistar rats was significantly reduced when a fixed amount of (3-carotene was replaced by a mixture of (3- and a-carotene, suggesting that each one of these carotenoids mutually inhibits the utilization of the other. The proportion of (3-and a-carotene in the mixture used in that study (Furusho and others 2000) simulated that of carrots. 

The antioxidant capacity retained in carrots washed with ASC could be attributed to retention of phenol and flavonoid compounds as well as carotene content (Ruiz-Cruz and others 2007). These results suggest that the use of sanitizers such as ASC is helpful in preserving the antioxidant capacity of carrots. Similar ORAC values were observed between different sanitizers and both water conditions, without significant changes. This is a clear example of a postharvest treatment maintaining the nutritional value of produce. 

DC030 Rhodes, B. B., and C. V. Hall. Effects of CPTA 2-(4-chlorophenyltio)-tri-ethylamine hydrochloride, temperature, and genotype on carotene synthesis in carrot leaves. Hortscience 1975 10 22. 

Figure 2.3 The orange-coloured pigment p-carotene (/ max 426, 451 and 483 nm), found in carrots...

After absorption of the blue-green colour from white light (carotene absorbs light of wavelength up to about 500 nm), the complementary colour (red-yellow) remains to be reflected and perceived by our eyes. P-Carotene, therefore, appears intensely orange coloured as the name implies, it is found in high concentrations in carrots. 

The solubility of P-carotene in supercritical fluids has been studied extensively [81 to 85], The extraction of P-carotene from a wide varieties of natural sources has also been described like alfalfa-leaf protein concentrates [86], carrots [34,87], sweet potatoes [88], and algae [89],... 

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... 

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