Copper chlorophyll

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. 

Lipid-soluble food grade copper chlorophyll is manufactured similarly by extraction of adequate plant material, followed by replacement of magnesium by copper, and purihcation steps to remove carotenoids, waxes, sterols, oils, and other minor components that are co-extracted. Commercial copper chlorophylls may vary physically, ranging from viscous resins to fluid dilutions in edible oils as well as granulated forms and emulsions standardized with edible vegetable oil. Colors may vary... 

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

Scotter, M.J., Castle, L., and Roberts, D., Method development and HPLC analysis of retail foods and beverages for copper chlorophyll (E 141 [i]) and chlorophyllin (E 141[ii]) food colouring materials, FoodAddit. Contam., 22, 1163, 2005. 

Copper Chlorophyll (E141). This is made from chlorophyll it is more blue than natural chlorophyll. The chemical modification makes it much more stable to heat and light. It is a more useful material than natural chlorophyll. 

Capillary electrophoresis coupled with a laser-induced fluorescence (LIF) detector has also been applied for the analysis of copper chlorophyll in olive oils. Samples were... 

L. Del Giovine and F. Fabietti, Copper chlorophyll in olive oils identification and determination by LIF capillary electrophoresis. Food Contr. 16 (2005) 267-272. 

Natural chlorophyll (E140) is oil-soluble but water-dispersible forms are available copper chlorophylls (E141), effectively chemically modified natural extracts, are water-soluble... 

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. 

Chiorophyllin—copper complex, oil soluble—The chlorophyllin is obtained by extraction from a mixture of fescue and rye grasses. The chlorophyll is... 

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... 

Diets high in red meat and low in green vegetables have been associated with increased colon cancer risk and the opposite has been postulated for diets rich in green vegetables. A plausible explanation for an increased colon cancer risk is that dietary haem is metabolized in the gut to a factor that increases colonic cytotoxicity and hyperproliferation, which are considered important risk factors in the development of cancer. In this sense, it has been shown that spinach and isolated natural chlorophyll, but not sodium-copper chlorophyUin, prevented the proliferation of colonic cells and may therefore reduce colon cancer risk. It has been speculated that haem and chlorophylls, due to their hydrophobicity, form a complex, thus preventing the metabolism of haem. ... 

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. ... 

In contrast to the well-established methods for identifying and quantifying naturally occurring chlorophylls, very few reports concern quantitative analysis of chlorophyllin copper complexes in color additives and in foodstuffs. Analytical methods proposed are based on spectral properties, elemental analysis, chromatographic separation, and molecular structure elucidation or a combination of these procedures. 

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. ... 

Usually, HPLC analysis resolves four peaks identified by co-chromatography with authentic standards as copper pheophorbide a, Cn(II) chlorin e6, Cn(II) chlorin e4, Cu rhodin g7, and their degradation products, but a sum of other colored components can also be found, for example, native chlorophylls, pheophytins, pheophor-bides, and rodochlorins (free carboxyl forms of pheophorbides) besides epimers, allomers, and degradation products that have been only tentatively identified. 

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