Carrot, carotene

Carotene and lycopene are polyenes occurring in tomatoes and carrots. Carotene is a natural source of vitamin A. Cengage Leaming/Charles D. Winters... 

An alkene, sometimes called an olefin, is a hydrocarbon that contains a carbon-carbon double bond. An alkyne is a hydrocarbon that contains a carbon-carbon biple bond. Alkenes occur abundantly in nature, but alkynes are much more rare. Ethylene, for instance, is a plant hormone that induces ripening in fruit, and a-pinene is the major component of turpentine. Life itself would be impossible without such polyalkenes as /3-carotene, a compound that contains 11 double bonds. An orange pigment responsible for the color of carrots, -carotene is a valuable dietary source of vitamin A and is thought to offer some protection against certain types of cancer. 

Wagner LA, Warthesen JJ. 1995. Stability of spray-dried encapsulated carrot carotenes. J Food Sci... 

Carotenoids are natural pigments characterized by a tail to tail linkage between two C20 units and an extended conjugated system of double bonds They are the most widely dis tributed of the substances that give color to our world and occur m flowers fruits plants insects and animals It has been estimated that biosynthesis from acetate produces approximately a hundred million tons of carotenoids per year The most familiar carotenoids are lycopene and (3 carotene pigments found m numerous plants and easily isolable from npe tomatoes and carrots respectively... 

Carotin, n. carotene, (formerly) carotin. Garotte, /. carrot. 

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. 

An excellent case in point is the coloration of the American lobster, Homarus americanus. The pigment associated with the typical greenish-brown outer layer of the lobster shell is the carotenoid, astaxanthin (Figure A), an oxygenated derivative of p-carotene, also known as the molecule that imparts the orange color to carrots. 

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. 

Alkenes with many double bonds in a row are colored. Some plant pigments are alkenes of this kind. One example is )S-carotene, which gives carrots their distinctive orange color. Animals break down )S-carotene into vitamin A, which is essential for vision. Xanthin molecules, relatives of j6-carotene that contain oxygen atoms, occur in com, orange juice, and shellfish. The xanthin below makes the flamingo pink. 

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). 

Carrot root Carotenes, mainly 3-carotene Dietary supplement... 

The first reports of genetic manipulation of a crop plant were using the carrot. The introduction of crt genes from Erwinia herbicola by a group from Amoco (Ausich etal, 1991 Hauptmann etal.,1991) resulted in elevated levels of P-carotene. 

Falconer, M.E. et ah. Carotene oxidation and off-flavor development in dehydrated carrot, J. Sci. Food Agric., 15, 857, 1964. 

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. 

Carrots were also the main sonrces of a-carotene, whereas tomatoes and tomato prodncts were the major sources of lycopene. Lutein was mainly provided by peas in the Republic of Ireland and United Kingdom. Spinach was found to serve as the major source in other countries. Lutein and zeaxanthin xanthophylls are found in a wide variety of fruits and vegetables, particularly green leafy vegetables, but also in some animal products such as egg yolks. In all countries, P-cryptoxanthin was obtained primarily from citrus fruits. 

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-... 

Among thermal processes, canning caused the largest trans-to-cis isomerization of provitamin A carotenoids, increasing the total cis isomers by 39% for sweet potatoes, 33% for carrots, 19% for collards, 18% for tomatoes, and 10% for peaches 13-di-P-carotene was the isomer formed in highest amonnts. ... 

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." ... 

Losses of 45 to 48% in the P-carotene contents and formation of cis isomers were also verified by pasteurization of carrot juice at 110 and 120°C for 30 sec. No significant effects on trans-to-cis isomerization of a- and P-carotene isomers were observed after acidification and heating of carrot juice at 105°C for 25 sec. In addition, an increase of only 3% in the cis isomers of provitamin A carotenoids was observed after orange juice pasteurization. " ... 

Extensive carrot blanching (100°C for 60 min) cansed losses of 26 to 29% in total p-carotene content, along with increased IS-CM-P-carotene contents up to 10% after pasteurization 95°C, P = 3) and to 14% after sterilization 121°C, F = 5). ° However, unheated juices produced from carrots blanched at 80°C for 10 min were devoid of cis isomers, and further pasteurization or sterilization processes formed only IS-di -P-carotene, at 2 and 5%, respectively. ... 

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