9-cis p-carotene

AiX-trans a-carotene, aH-trans ()-carotene, 9-cis P-carotene, 13-cis P-carotene... 

Astaxanthin, capsanthin, lutein, zeaxanthin, canthaxanthin, P-cryptoxanthin, echinenone, 15-cis-P-carotene, 13-cis- P-carotene, a-carotene, all-ircms P-carotene, 9-cis-P-carotene, 5-carotene, lycopene... 

All-trans p-carotene 13-cis p-Carotene 9-cis p-Carotene a-Carotene Lutein Lycopene... 

Figure 14a. c -Geometrical isomers of carotene related to Pearon s correlation coefficients for serum carotenoids and three adipose tissue carotenoids by diet P-carotene (2), 13 cis P-carotene (52) and 9 cis P-carotene (53). 

Interestingly, among thirteen carotenoids, the abdominal adipose tissue of these subjects had the highest carotenoid concentrations, followed by buttocks adipose tissue, and thigh adipose tissue with the lowest carotenoid concentrations. Especially, their concentrations of a-carotene (1), one trans and total cis type mixtures of P-earotene (2), dX -trans P-carotene (51), 13 cis P-carotene (52), and 5 cis lycopene (59) in the abdominal adipose tissue were signifreantly higher when compared to their eoncentrations in thigh adipose tissue. 

Some cultivars of sweet potatoes for human consumption are also good sources of P-carotene since their contents can achieve 218 pg/g as in cultivar Acadian (Table 4.2.1). Although separation of cis isomers was not carried out in the later study, small amounts of 13-c -p-carotene were found in fresh sweet potatoes of an unspecified cultivar, whereas no cis isomers of P-carotene were found in this fresh vegetable in other studies. ... 

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." ... 

In dark conditions, the spontaneous isomerization of carotenoids occurs in solution the rate is dependent on temperature, solvent, and carotenoid structure. In the case of P-carotene, 13-di-P-carotene was formed approximately three times faster than the 9-cis- isomer at room temperature and at 150°C. ... 

Mango puree was produced on a laboratory scale, mimicking typical operations in continuous and small-size batches, applying pasteurization between 85°C and 93°C up to 16 min (Vasquez-Caicedo et al. 2007). Although significant trans- to cis- isomerization of p-carotenc occurred, especially by the formation of 13-m-P-carotene, provitamin A (trans- + m-p-carotene) losses... 

Contrary to the carotenoid behavior during orange juice pasteurization, losses of 46%-54% in the all-trans-a- and all-trans-fi-carotene contents and the formation of m-isomers were also verified for the pasteurization of carrot juice at 110°C and at 120°C, both for 30 s (Chen et al. 1995). In addition, all cis- isomer levels increased, with 13-c -P-carotene and 15-d.v-a-carotene formed in the largest amount. Heating at 121°C for 30min caused further losses of 61% in al I-tran.v-a-carotene and 55% in all-trans-P-carotene (Chen et al. 1995). However, minor effects on the amounts of trans- and cis- isomers of a- and P-carotenes were observed after the acidification and the heating of carrot juice at 105°C for 25 s (Chen et al. 1995). 

Figure 4.4 Thermal processing induced isomerization of carrots, (a) Raw carrot and (b) thermally processed carrot. Peaks are tentatively identified as (1) all-froMs-lutein (2) 13-cis-a-carotene (3) a cis-ot-earotene isomer (4) 13 -cis-a-carotene (5) 15-cis-P-earotene (6) 13-cis-p-earotene, (7 and 8) cis-P-carotene isomers (9) aW-trans-Qt-earotene (10)9-cis-a-earotene (ll)all-fraMs-P-carotene and(12)9-cis-P-carotene. (Emenhiser et al., 1996).

All-trans-isomers of carotenoids in fresh and thermally processed materials are accompanied by small amounts of ds-isomers, called neocarotenoids. fS-Carotene is accompanied mainly by geometric isomers 9-cis, 13-cis- and 15,15 -cis-P-carotene. Lutein is accompanied mainly by 9-ds- and 9 -cis, 13-cis- and 13 -cis isomers less common are 15-cis and 15 -cis isomers. Neoxanthin is accompanied by 9-cis-, 9 -cis-, 13-cis- and 13 -cis isomers. Thermal processing can induce carotenoid trans to cis isomerisation. 

Four cis isomers of P-carotene (13,15-di-di-, 15-cis-, l3-cis-, and 9-cis-) and three of a-carotene (15-di-, 13-di-, and 9-cis-) were formed during heating of their respective dll-trans carotene crystals at 50,100, and 150°C. Isomerization catalyzed by heat was considered as a reversible first-order degradation reaction — a trans-to-cis conversion two- to three-fold slower than the backward (cis-to-trans) reaction (Table 4.2.6). The 9-cis- and 13-di- were the major P-carotene isomers formed and the 13 -cis- formed at a two- to three-fold faster rate than O-cw-P-carotene. In this system, a-carotene showed lower stability than P-carotene (Table 4.2.6). The activation energy (EJ was not reported since practically no degradation was observed... 

Losses from 21 to 23% in P-carotene, a-carotene, and lutein contents were observed during storage of carrot juice under light (1500 lux) at 25°C for 12 wk. The losses were accompanied by increased concentrations of the 13-cis isomer type of P-carotene, a-carotene, and lutein during dark storage, while the formation of 9-cw-P-carotene, 9-cii-a-carotene, and 13-cii-lutein was favored under light storage. ... 

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