Carminic acid

Two colorimetric methods are recommended for boron analysis. One is the curcumin method, where the sample is acidified and evaporated after addition of curcumin reagent. A red product called rosocyanine remains it is dissolved in 95 wt % ethanol and measured photometrically. Nitrate concentrations >20 mg/L interfere with this method. Another colorimetric method is based upon the reaction between boron and carminic acid in concentrated sulfuric acid to form a bluish-red or blue product. Boron concentrations can also be deterrnined by atomic absorption spectroscopy with a nitrous oxide—acetjiene flame or graphite furnace. Atomic emission with an argon plasma source can also be used for boron measurement. 

C-Glycosyl compounds have a carbon atom ia place of the exocycHc oxygen atom of the acetal group and, therefore, are branched cycHc ethers. An example is the naturally occurring anthroquiaone dye, carminic acid [1260-17-9] (Cl Natural Red 4). 

Cochineal Extract. Cochineal extract (Cl Natural Red 4, Cl No. 75470 EEC No. E 120) is the concentrated solution obtained after removing the alcohol from an aqueous-alcohoHc extract of cochineal, which is the dried bodies of the female insect Coccus cacti Dactylopius coccus costd) a variety of field louse. The coloring principle of the extract is beHeved to be carminic acid [1260-17-9] (40), an hydroxyanthraquinone linked to a glucose unit, comprising approximately 10% of cochineal and 2—4% of its extract. 

Carmine [1390-65-4] is the aluminum or calcium-aluminum lake on an aluminum hydroxide substrate of the coloring principle (again, chiefly carminic acid) obtained by the aqueous extraction of cochineal. Carmine is normally 50% or more carminic acid. 

Ger. Pat. 927,305 (May 5, 1955), F. Rath. Natural dyes like norbixki, crocetki, and carminic acid are discussed from an appHcations standpokit. 

Kermisic Acid. Many accounts claim that kermisic acid [476-35-7] (Cl Natural Red 3 Cl 75460) is the oldest dyestuff ever recorded (23). The name kermes is derived from an Armenian word meaning Httle worm for which the later Latin equivalent was vermiculus, the basis of the Knglish word Vermillion. The dye was obtained from an oriental shield louse, K. ilicis which infest the holm o5kQuercus ilex and the shmb oak. coccifera. The dye produces a brilliant scarlet color with an alum mordant. Although expensive, it was cheaper than its rival Tyrian Purple. It was in great demand until the sixteenth century when it was displaced by carminic acid. 

Although carminic acid had been known since 1818 (28), it was not obtained in a pure form until 1858 (29). The stmcture was finally estabhshed as (5) (30-33). 

Later studies (35—37) showed that the original assignment of (5) was not quite correct. The actual stmctural formula of carminic acid is (6) (38). 

Carmine [1390-65-4] is the trade name for the aluminum lake of the red anthraquinone dye carminic acid obtained from the cochineal bug. The dye is obtained from the powdery form of cochineal by extraction with hot water, the extracts treated with aluminum salts, and the dye precipitated from the solution by the addition of ethanol. This water-soluble bright red dye is used for coloring shrimp, pork sausages, pharmaceuticals, and cosmetics. It is the only animal-derived dye approved as a colorant for foods and other products. 

Carminic acid (7-a-D-glucopyranosyl-9,10-dihydro-3,5,6,8-tetrahydroxy-l-methyl-9,10-dioxo-2-anthracene carboxylic acid. Neutral Red 4 Cl 75470) [1260-17-9] M 492.4, m... 

Carminic acid is orange in acidic media (pH 3), red in nearly neutral media (pH 5.5), and purple at pH 7. It forms complexes with metals such as tin and aluminum to make brilliant red pigments. Carmine is easily bleached by sulfur dioxide. 

Carminic acid is related to another dye molecule, alizarin. 

A similar effect can be observed in anthaquinones, mainly for the presence of an hydroxyl group. The ionization of hydroxyl groups under basic conditions also undergoes a bathochromic shift. Alizarin has two absorption bands in the vis region, simated at 567 and 609 nm carminic acid has a visible absorption maximum at around 500 nm and kermesic acid at 498 mn. 

The same resin was used for the purification via downstream processing of carminic acid, the natural colorant extracted from cochineal. By a direct adsorption method, a crude extract was applied on the polymeric bed gel and the adsorption kinetics studied using elution with hydrochloric acid and ethanol. The desorbed pure carminic acid concentrated under vacuum yielded a final product that complied with Codex Alimentarius requirements and FAO/OMS norms. 

Cabrera, R. and Fernandez Lahore, H.M., Downstream processing of carminic acid from raw cochineal, in Proceedings of 4th International Congress on Pigments in Food, Hohenheim, Germany, Carle, R. et al., Eds., Shaker Verlag, Aachen, 2006, 203. 

Cochineals contain several compounds with antraquinonic structures the most important is carminic acid. An nncommon chemical featnre of carminic acid and its derivatives is the presence of a C-glncosidic bond (Fignre 5.2.2). 

Carminic acid is a water-solnble componnd, stable nnder conditions of light and heat. It shows a maximnm absorption at 518 mn in aqneous ammonia solutions and at 494 mn in dilnted hydrochloric acid. ° The cochineal color is-pH sensitive. In... 

Carmines are dehned as the lakes of carminic acid with various metals. The most used is carmine, the aluminium lake of carminic acid. Carmine is not soluble in water or oils and is also very stable under condition of light, heat, oxidation, and sulfur dioxide." ... 

Cochineal pigments are extracted from dried bodies of female insects with water or with ethanol the result is a red solution that is concentrated in order to obtain the 2 to 5% carminic acid concentration customary for commercial cochineal. For carmine lakes, the minimum content of carminic acid is 50%. An industrial procedure applied in Spain uses ammonium hydroxide as the extracting agent and phosphoric acid as the acidifying agent. For analytical purposes the extraction is carried out with 2 N HCl at 100°C. The chemical synthesis of carminic acid has also been reported and is the subject of European and United States patents. ... 

Cochineal, carminic acid, and carmines are approved as food colorants in the EU under code E 120, and their purity criteria are regulated.The amount of E 120 permitted in food ranges from 50 to 500 mg/kg. Carminic acid and carmine are considered very good food colorants due to their high stability and tinctorial properties. Solutions of carminic acid are yellow to orange, while carmines show various stable brilliant red hues. - ... 

AUevi, P et al.. Synthesis of carminic acid, the colourant principle of cochineal, J. Chem. Soc. Perkin Trans., 1, 575, 1998. 

ANALYSIS OF QUINONES FROM COCHINEAL INSECTS CARMINE AND CARMINIC ACID... 

Carmine extracted from cochineal insects is one of the most used natural colorings for beverages and other foods. Some representative articles refer to isolation and spectrometric analysis or the use of HPLC or capillary electrophoresis (CE) to separate and characterize all cochineal pigments. Its active ingredient, carminic acid, was quantified by rapid HPLC-DAD or fluorescence spectrometry. Carminic acid, used as an additive in milk beverages, was separated within 9 min using a high-efficiency CE separation at pH 10.0 after a previous polyamide column solid phase extraction (SPE), ... 

Samples with higher protein levels (yogurts), are initially treated with hydrochloric acid and after protein precipitation the supernatant is filtered and injected into the HPLC column. The separations performed with a LiChroCART RP18 column used a mixture of acetonitrile and formic acid as the mobile phase. A baseline quantification of the carminic acid was possible in the presence of other coloring agents, with excellent recuperation, selectivity, accuracy, and precision. ... 

Schwing-Weill, M.J. and Wechsler, S., Spectrophotometric study of carminic acid in solution application to its determination, Analysis, 14, 290, 1986. 

Lancaster, RE. and Lawrence, J.F., High-performance liquid chromatographic separation of carminic acid, and P-bixin, and a- and 13-norbixin, and the determination of carminic acid in foods, J. Chromatogr. A, 732, 394, 1996. 

Carvalho, P.R.N. and Collins, C.H., HPLC determination of carminic acid in foodstuffs and beverages using diode array and fluorescence detection, Chromatographia, 45, 63, 1997. 

A systematic study was carried out using in parallel 50 standard solutions for each concentration of three natural colorants (curcumin, carminic acid, and caramel as yellow, red, and brown, respectively). No false positive results for synthetics were obtained up to concentrations of 15 and 20 ng/ml for natural red and yellow colorants, respectively, or 110 ng/ml for natural brown colorant. The concentrations have to be high enough to prove that the screening method is able to accurately discriminate natural and synthetic colorants. To make a clear interpretation of the quantitative UV-Vis spectrum, linear regression analysis was used. Quantitative UV-Vis analysis of a dye ° can be calculated according to the following formula ... 

Carminic acid and carmine, cochineal E 120 Yes Female cochineal insect orange to red, pink to red ... 

The natural dye was extracted by immersion of fresh Morns nigra (black mulberry) in ethanol for several hours. The pure violet dye extract, a blend of p-carotene and Morus nigra, and a composite blend of chlorophyll A and B, carminic acid, trans-P-carotene, and Morus nigra extracts (hereafter called Mix) were deposited on Ti02. 

The adsorption spectra in the UV-visible range of the extracts exhibit different broad bands depending on the component of the mixtures photocurrent measurements show larger bands in comparison with those derived from adsorbed dyes. In particular, in the case of Mix, a bathochromic shift of about 40 nm was observed the proposed rationale is a band interruption between density states of Ti02 and the HOMO-LUMO in the dye. Moreover, the photocurrent response derives predominantly from the superposition of those of Morus nigra and carminic acid. 

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