The primary colouring substances found in fruits are Anthocyanins, Tanins, Lycopenes and Carotenes.
Anthocyanins are water soluble pigments that are odourless and near tasteless. They appear as red, purple or blue depending on the pH of their surroundings, and it is these molecules that give colour to many plants and their fruits. Anthocyanins are increasingly being used to replace artificial colours in many food products. When used as an additive in foods, Anthocyanins are given the E-number E163.
Tannins are astringent polyphenolic compounds produced naturally by many plants, and the name covers a wide range of different molecules. Tannins are present in fruits including Apples, Grapes and many berries, along with tea, wine and beer and many non-food plant products; the name derives from Tannenbaum, an old German word meaning Fir Tree, as tannins from wood were used to tan leathers. Tannins are also used as an additive for both colour and their astringent taste, and are given the E-number E181.
Lycopene is an orange-red coloured pigment found in a number of red fruits and vegetables, particularly tomatoes from which the name is derived (from Lycopersicum, the species name for tomatoes). Lycopene belongs to the Carotene chemical family. It may be used as a colouring additive in foods and is given the E-number E160d.
Carotenes are orange-red coloured pigment found in several fruits and vegetables such as Mango and Carrot.
As with most of the colouring components found in fruits, Carotenes are also used as food colouring and are given the E-number E160a.