Physicochemical properties and stability of melanin from black tea leaves

Yu Zou*, Kun Ma and Mixia Tian

Abstract

Melanin is a natural pigment with great development potential as a healthful food colorant. In this paper, melanin from black tea leaves was extraction and purification and its physicochemical properties and stability were investigated. The experimental results showed that melanin was insoluble in both water and common organic solvents. It dissolved only in alkali aqueous solution and precipitated acidic aqueous solution (pH < 3). Melanin was gradually oxidative bleached by oxidant and was stable to reducer. These physicochemical properties were very similar to those of the melanin reported in the previous studies. Melanin had good resistance to light decomposition and heating treatment. Therefore, melanin from black tea leaves could be further used as a natural food colorant.

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