CA-p-Carotene

Cultivar and harvest year greatly influenced P-carotene contents of acerola fruits, reaching a difference of ca. 2.5 times in a comparison of the same acerola cultivar harvested at the same plantation during two consecutive harvest years. In addition, differences up to 3 times were found in a comparison of the p-carotene contents of two acerola cultivars (Table 4.2.1). ... 

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." ... 

Similar effects could be observed in oil-rich foods such as pahn fruits in which losses of dll-trans a- and al -trans p-carotene were found to be, respectively, ca. 23 and 44% after sterilization. In terms of relative composition after processing, all-trans a-carotene decreased from about 30 to 23% and aH-trans P-carotene from 65 to 27%, whereas the cis isomers increased as follows D-di -a-carotene from less than 1 to 10%, D-cd-P-carotene from 3 to 23%, and O-cd-P-carotene from less than 1 to 18%. ... 

Colorant containing annatto and Ca caseinate as carrier mixed with water to be added directly to cheese milk yielding uniform colored cheese mass Water-dispersible beadlet of p-carotene is mixed with oil to attein composition that remains stable even in presence of polyphosphates and with antioxidant action even in absence of ascorbic acid Blending carotenoid pigment and soybean fiber (wifii tomato juice) as effective ingredient for dispersion stability... 

The spontaneous isomerization of all-trans- carotenoids at room temperature is a slow process, and its rate depends on the solvent and the pigment structure. For example, the initial solutions of P-carotene in a mixture of tetrahydrofuran (THF), methanol, and acetonitrile containing ca. 95% of all -trans- and 5% of 9-cis- plus 13-co-isomers was transformed to 90% all-fra ns- p -ca rot ene and 9% of 9-cis- plus 13-cA-carotene after 24h of spontaneous isomerization at 25°C (Pesek et al. 

Matsufuji H, Nakamura H, Chino M, Takeda M (1998) Antioxidant activity of capsanthin and the fatty acid esters in paprika (Capsicum annuum). J Agric Food Chem 46 3468-3472 WaU MM, WaddeU CA, Bosland PW (2001) Variation in P-carotene and total carotenoid content in fruits of Capsicum. HortScience 36 746-749... 

A C30 column can be used to distinguish between all-trans -lutein and all-tra 5-zeaxanthin and their cis isomers (Updike and Schwartz, 2003), P-carotene and P-carotene cis isomers (Emenhiser et al., 1995), and lycopene and cA-lycopene isomers (Frohlich et al., 2007). C30 columns can allow the separation of isomers induced by heat processing (Figure 4.4) and induced in vivo (Figure 4.5). Extensive reviews on... 

Note that the ring planes of the chlorophyll molecules in Fig. 5 (A) were shown oriented mostly perpendicular to the membrane plane. This orientation appears to be similar to that in the PS-II chlorophyll a/b protein (LHC II), as determined by Kiihlbrandt and Wang and predicted by Haworth, Tapie, Amtzen and Breton on the basis of circular-dichroism measurements. The center-to-center distances between the porphyrin planes of the CA-Chl a molecules in the PS-I reaction center range from 8 to 15 A, which are comparable to those in PS tf and in the BChl-a protein complex as measured by Mathews, Fenna, Bolognesi and Olson (see Chapter 8, Section V). Some of the closely spaced chlorophyll-a molecules appear to form chains mnning between the stroma and lumen sides of photosystem I. Between 12 and 16 P-carotene molecules are thought to be present in the PS-I reaction center, but they have not been identified by X-ray crystallographic measurements. 

Figure 17 summarizes the 15-cf carotenoids identified in the RCs so far (see above for references). The 5-cis isomers of neurosporene, spheroidene and spirilloxanthin have been identified in the quinone-type RCs of purple bacteria, i.e., Rb. sphaeraides GIC, 2.4.1 and Rs. rubrum SI, respectively. 15-CA-y-carotene and 15-crx-chloro-bactene are found in the iron sulfur-type RC of a green sulfur bacterium, Cb. tepidum. l5 Cis-P-carotene have been identified in the quinone-type PS II RC of spinach, and also in the iron sulfur-type PS I RCs of a cyanobacterium, Sc. vulcanus and from spinach. 

Already in 1975 were anion radicals shown to exhibit strong NIR absorption at ca. 150 nm shorter wavelengths than cation radicals [118]. The radical anions of p-carotene (1) and lycopene (24) exhibited w,x in hexane solution at 880 nm and at 950 nm respectively. Subsequent studies resulted in similar conclusions. The wavelength maxima of the absorption bands were linearly dependent on the number of conjugated double bonds [151]. Hypsochromic shifts were observed in methanol relative to hexane solutions [118,151],... 

In contrast to the unsubstituted p end group, the e end group possesses an asymmetric carbon atom at position 6 and therefore, in the synthesis of compounds with this end group, the stereochemistry has to be considered. The most prominent carotene with the 8 end group is p,e-carotene (a-carotene) (127) which possesses the (6 R)-configuration. By analogy with the synthesis of p,p-carotene (2), the strategy Ci6 + Ca + Ci6 = C40 was used for the first synthesis of a-carotene (127) [75-77]. 

The Ci5-phosphonium salt 284, a key intermediate also in the industrial synthesis of vitamin A (29), is reacted in a double Wittig olefination with the Cio-dial (45) to give p,p-carotene (2) in an overall yield of ca. 80% [111,112], Alternatively also the Wittig reaction of retinal (33) with retinyltriphenylphosphonium salt (285) gives 2 in yields up to 85% [113,114],... 

In another approach to the technical synthesis of the apocarotenoids 286, 287 and 292 [118] the C25-aldehyde 12 -apo-p-caroten-12 -al (293) is the key intermediate. Several ways to synthesize this compound have been developed, applying the Wittig reaction to couple the building blocks. By the reaction of the Cas-aldehyde 293 with the protected Cs-phosphonium salt 294 the Cao-aldehyde is obtained [119,120], and this can be transformed by a base-catalysed aldol condensation with acetone (295) to give the Css-ketone citranaxanthin (292) [121]. Alternatively the C2s-aldehyde 293 can be reacted in a Horner-Emmons reaction with the Cs-phosphonate 296 to give 292 [122] Scheme 61). 

Jones, J.D., Hohn, T.H., and Leathers, T.D. 2004. Genetically modified strains of Fusarium sporotrichioides for production of lycopene and 3-carotene. Proceedings of Annual Meeting of Society of Industrial Microbiology, San Diego, CA, p. 91. 

Precautions Swallowing may cause night blindness. FDA permits limited use in foods. Synonyms cas 514-78-3 cantha p-carotene-4,4 -dione 4,4 -diketo-p-carotene... 

CAS 472-61-7 EINECS/ELINCS 207-451-4 Synonyms 3,3 -Dihydroxy-p,p-carotene-4,4 -dione 3,3 -Dihydroxy-4,4 -diketo-p-carotene Ovoester... 

CAS 7235-40-7 EINECS/ELINCS 230-636-6 Synonyms p-Carotene Food orange 5 Synthetic carotene Classification Carotenoid color Empirical C40H56 Toxicology TSCA listed Uses Colorant in cosmetics, pharmaceuticals Manuf./Distrib. Aldrich http //www.sigma-aldrich.com, Fluka http //www.sigma-aldrich.com, Sigma See aiso Carotene Cl 75130... 

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