Selected Natural Colorants in Foods and Beverages

Four major categories of food colorants are reviewed, i.e., carotenoids, anthocyanins, the products of enzymatic browning and substances formed by non-enzymatic browning. Topics covered within each class are structure, biosynthesis, occurrence, stability, effects of food processing and physiological properties. Much is known concerning the structures and formation of carotenoids, anthocyanins and theaflavins while the structures of thearubigins and products of non-enzymatic browning largely remain to be elucidated. There is a lack of knowledge concerning the uptake, distribution, bioavailability and bioactivity of food colorants in the human body.