Chlorophyll as food additive

Chlorophyll is the well known green pigment of plants. Higher plants and green algae contain chlorophyll A and chlorophyll B in the approx ration of 3:1. Chlorophyll C is found together with chlorophyll A in many types of marine algae.

Because of the light and acid sensitivity of there magnesium-chelated porphyrin structures, chlorophylls are the least useful food colours, The green colour is easily destroyed under even the mildest processing conditions.

Natural chlorophylls for the food colorant market have been extracted from an assortment of green leaves, but usually land plants such as several pasture grasses lucerne, and nettles. The choice of raw material must take into account high-yield producton, availability and convenience of harvesting and dying, chlorophyll comet facility of extraction, and desirability of low chlorophyllase activity. 

Chlorophyll extracts are not permitted for food use in the United States. However they may be added to foods in the form of green vegetables. In such cases, they are classified as food ingredients.
Chlorophyll as food additive