Chlorophyll food sources

The chlorophylls are a group of naturally occurring pigments produced in all photosynthetic plants including algae and some bacteria. Hendry24 estimated annual production at about 1,100,000,000 tons with about 75% being produced in aquatic, primarily marine, environments. Obviously as a source of raw material for food colorants, chlorophylls present no problem with supply. 

Magnesium is present in most foods but green plants are an important source since the chlorophyll molecule contains magnesium. 

Figure 6-14 Structure of Chlorophyll a. (Chlorophyll b differs in having a formyl group at carbon 3). Source Reprinted with permission from J.R. Whitaker, Principles ofEnzymology for the Food Sciences, 1972, by courtesy of Marcel Dekker, Inc.

The best source for Chi a is the cyanobacterium Spirulina platensis, which is available commercially. Chi a/b mixtures can be obtained from all green plants. All other Chls are less readily accessible, which limits their applications. Several Chi derivatives are used as dyes for food colorants (Cu-chlorophyllin) and cosmetics. The chlorophyll used for the latter is a complex mixture of degradation products. More recently, (B)Chl derivatives have gained increasing interest as photosensitizers in photodynamic therapy of cancer, these compounds include pigments in which the isocyclic ring is opened and/or the central metal has been removed or replaced (e.g., by Pd" " ) to increase phototoxcicity (12, 13). 

Apart from the derivatives of p-carotene, other pigments are the anthocyanins, the chlorophylls, cochineal, the betalaines, turmeric, caramel and riboflavin. In this account the historical background in brief, the chemistry of these pigments, their extraction from natural sources and their synthesis will be discussed. The present permitted natural substances and nature-identical synthetic materials (also described by the Food and Drugs Administration, the FDA, as colorants exempt from certification ) is quite small in number. Reference is also made to colourants no longer listed but which have an historical organic chemical significance such as for example brazilin and its relative haematoxylin. 

Chlorophylls Natural food and beverage colorants Aquatic plants and bacteria e.g., S. platensis and A. flos-aquae Anticancer activity, natural source of pigmentation Bhattacharya and Shivaprakash, 2005 Chernomorsky et al, 1999 de Oliveira Rangel-Yagui et oL, 2004 Donaldson, 2004 Egner et oL, 2001 Kay, 1991 Sarkar et al., 1994... 

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