Isolation and characterization of melanic pigments derived from tea and tea polyphenols

The dark brown pigments derived from tea and tea polyphenols were studied. Physical and chemical properties revealed that pigments directly extracted from tea leaves and derived from tea polyphenols were similar to typical melanins. Further investigation showed that both melanic pigments possessed similar antioxidant capability, due to their chelating and scavenging properties. The inhibitory effect of melanic pigments, either from tea or tea polyphenols, was significantly stronger than that of non-treated tea polyphenols. According to these properties, we have extracted melanin from tea. In addition, oxidation of tea polyphenols also provided an alternative method to maximize the yields. The extracted melanin is an antioxidant, which interrupted free radical reactions at a step in the development chain by its scavenging properties and, at the step of initiation, by its ability to chelate metals.