Copper chlorophyllin

Potassium sodium copper chlorophyllin (chiorophyllin—copper complex)—A green-black powder obtained from chlorophyll by replacing the methyl and phytyl ester groups with alkaH and replacing the magnesium with copper. The source of the chlorophyll is dehydrated alfalfa. 

Hydrolysis of chlorophyll using sodium hydroxide produces the moderately water-soluble sodium salts of chlorophyllin, phytol and methanol (145). The magnesium ia chlorophyllin may be replaced by copper. The sodium copper chlorophyllin salt is heat stable, and is ideal for coloring foods where heat is iavolved, such as ia canning (146). 

In a clinical trial performed in China, the administration of 300 mg/day of copper chlorophyllin to humans who had detectable levels of serum aflatoxin due to unavoidable food contamination resnlted in a 50% reduction of median urinary levels of aflatoxin-DNA adducts. If health benefits from consuming natural chlorophylls were confirmed, it wonld be easy to add green leafy vegetables to a daily diet to obtain the benefit. Since leafy vegetables contain usually up to 200 mg chloro-phylls/100 g fresh weight, the intake of approximately 1 to 2 cups of raw spinach/day... 

Commercially produced metal-substituted chlorophylls such as copper chlorophylls and copper chlorophyllins that can be obtained by chemical modification of natural chlorophylls have better stability, solubility, and tinctorial strength, but they cannot be considered natural food colorants and will be discussed later. 

Commercial food grade water-soluble Cu-chlorophyllin is the most notable among these preparations. Copper chlorophyllins are produced from crude natural chlorophyll extracts followed by the hydrolysis of the phytyl and methyl esters, cleavage of the cyclopentanone (E) ring in dilute alkali, and the replacement of magnesium by copper. ... 

Chemical analysis revealed that commercial food grade copper chlorophyllin is not a single, pure compound, but is a complex mixture of structurally distinct porphyrins, chlorin, and non-chlorin compounds with variable numbers of mono-, di-, and tri- carboxylic acid that may be present as either sodium or potassium salts. Although the composition of different chlorophyllin mixtures may vary, two compounds are commonly found in commercial chlorophyllin mixtures trisodium Cu (II) chlorin Cg and disodium Cu (II) chlorin which differ in the number of... 

It must be remembered that copper chlorophylls and copper chlorophyllins are chemically modified natural extracts and therefore should not be called natural. 

Fermzzi, M.G. and Schwartz, S.J., Thermal degradation of commercial grade sodium copper chlorophyllin, J. Agric. Food Chem., 53, 7098, 2005. 

U.S. Eood and Drug Administration, Listing of color additives exempt from certification sodium copper chlorophyllin, 21CER Part 73, 67 Fed. Reg. 35429, May 20, 2002. 

Sodium copper chlorophyllin, approved by the FDA as a color additive in citrus-based dry beverage mixes, should have a ratio of absorbance (SoretQ band) not less than 3.4 and not more than 3.9. In Europe, purity criteria of the food additives E141[i] and E141[ii], which are copper complexes of chlorophyll and chlorophyllin, respectively, are set out in the EC color specifications that include identification and spectrophotometric assay tests. ... 

Purity levels of commercial preparations have also been estimated based on their Cu contents and compared with the theoretical values expected for fuUy coppered chlorophyllin based on the two major compounds Cu(ll) chlorin e4 (disodium salt) and Cu(ll) chlorin e6 (trisodium salt). The expected theoretical content of copper in a pure Cu chlorophyllin complex is 9.2%, which has never been found in commercial preparations. The sodium copper chlorophyllin from Sigma-Aldrich (St. Louis, MO) has a 4.5% copper content, specified by the manufacturer with respect... 

Fig. 2.137. Left electrophoregram of chlorophyll pigments in fresh extra virgin olive oil, added with copper chlorophyllin (1) chlorophyllin B (2) pheophytin B (3) pheophytin B(4) chlorophyllin A (5) pheophytin A (6) pheophytin A (7) copper chlorophyllin. Right electrophoregram of chlorophyll pigments in extra virgin olive oil, with a long shelf-life, added with copper chlorophyllin (1) chlorophyllin B (2) chlorophyllin derivatives (3) chlorophyllin A (4) copper chlorophyllin. Reprinted with permission from L. Del Giovine et al. [308].

There have been only a few citations in the literature concerning the extraction and recovery of natural chlorophyll pigments. Chlorophylls, despite their high molecular weights, are soluble in pure CO2 (like pheophytin a at 500 bar and 55°C), or in the presence of an entrainer (like copper chlorophyllin at 60 bar and 20°C with 5% ethanol entrainer). The extraction of dried grass resulted in 1.56 wt.% yield of green components [79]. 

Fig. 10. Diameter of a PNIPAM gel containing copper chlorophyllin as a function of light intensity at 31.5°C...

Fig. la, h. Chemical structure of poly N-isopropylacrylamide (a) and of trisodium salt of copper chlorophyllin molecule (b). The chlorophyllin molecule has a double bond which can be covalently connected to the polymer networks... 

Chlorophyll. Chemically pure chlorophyll is difficult to prepare, since it occurs mixed with other colored substances such as carotenoids. Commercially it is solvent extracted from the dried leaves of various plants such as broccoli or spinach. Chlorophyll is water-iosoluble. It has none of the characteristics of a dye in that it has no aflinity for the usual libers such as cotton or wool. Chlorophyll is properly classified as a pigment tCI Natural Green 3 Cl 75810), As such. It finds use lor coloring soaps, waxes, inks. fats, or nils. Chlorophyll is an ester composed of an acidic pint, chlorophyllin, esterilied by an aliphatic alcohol known as phylol. Hydrolysis of chlorophyll using sodium hydroxide produces the moderately water-soluble sodium salts of chlorophyllin. phytol. and methanol. The magnesium in chlorophyllin may be replaced by copper. The sodium copper chlorophyllin salt is heat-stable, and is ideal for coloring foods where heat is involved, such as in canning. 

Sato, M., Fujimoto, I., Sakai, T., Aimoto,T., Kimura, R., and Murata, T. 1986. Effect of sodium copper chlorophyllin on lipid peroxidation. IX. On the antioxidative components in commercial preparations of sodium copper chlorophyllin. Chem. Pharm. Bull. 34 2428-2434. 

Potassium or sodium copper chlorophyllin Potassium or sodium chlorophyllin Color of porphyrin ADI 0-15... 

Copper Chlorophyll. Current efforts to improve the green color of processed foods include the use of copper complexes of chlorophyll derivatives. Copper complexes of pheophytin and pheophorbide are available commercially under the names copper chlorophyll and copper chlorophyllin, respectively. Their use in canned foods, soups, candy, and dairy products is permitted in most European countries under regulatory control of the European Economic Community (47). The Food and Agriculture Organization (FAO) of the United Nations (48) has certified their safe use in foods provided that no more than 200 ppm of free ionizable copper is present. Use of copper-containing chlorophyll derivatives in foods is not allowed in the United States under the Color Additive Amendment to the Food, Drug, and Cosmetic Act of 1938. 

Commercial production of the pigments in England was described by Humphrey (49). Chlorophyll is extracted from dried grass or alfalfa with acetone or chlorinated hydrocarbons. Sufficient water is added, depending on the moisture of the plant material, to aid in penetration of the solvent while avoiding activation of chlorophyllase enzyme. Pheophytin may be acid hydrolyzed before copper ion is added resulting in the formation of water soluble copper chlorophyllin. 

The stability of commercially prepared copper chlorophyllin in water was measured by Kearsley and Katsaboxakis (50). Color, measured spectrophotometrically, was approximately 80% reduced after 1 hour at 100°C. In samples stored at 7°C, rapid color loss at pH values lower than 4.0 was attributed to precipitation of the pigment. The color of blanched peas was improved after holding them in copper chlorophyllin solution, however, use of the pigment in canned foods is limited because of its instability at high temperatures. 

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