Chlorophyll degradation in processed foods and senescent plant tissues

Green colour losses in processed and minimally processed fruit and vegetable products are associated with decreases in the quality of such products. Chlorophyll, the pigment responsible for the characteristic green colour of several fruit and vegetables, can degrade to undesirable grey-brown compounds such as pheophorbide and pheophytin. This degradation is mediated by acid and the enzyme chlorophyllase. Pheophorbide can be further metabolized to colourless compounds in metabolically active tissue. This article summarizes the accepted mechanism of chlorophyll degradation in fruit and vegetables, and extends it to include the degradation of pheophorbides into colourless compounds. Strategies for the control of chlorophyll degradation in food products are also discussed.