Progress of Research on Melanin in Foods and Their Materials

Melanin in food and its raw materials has been widely studied in recent years. Each kind of melanin has many types, various formation mechanisms and complicated structures. Black animal, fungus, plant food or raw materials generally contain a certain amount of melanin. Artificial melanin caramel pigment is widely used in variously processed beverages and foods. Research results indicates that, edible melanin has antioxidant activity, anticancer ability, antimicrobial capacity, anti-inflammation, hypotensive or hypolipemia function, metal ion chelation and beneficial effect on intestines and stomach system. The melanin derived from the oxidation of polyphenols has the property of liver protection and immune function adjustment. With the human diet, a certain amount of melanin is taken into the body every day, but there is no research evidence of toxicity of melanin or artificial caramel pigment in various foods or beverages and their raw materials. Therefore, this paper systematically discusses the formation, structural composition and characteristics, content, various important functional characteristics and edible safety of three kinds of melanin (including natural biosynthesis, Maillard reaction and synthetic caramel) commonly used in some foods and their raw materials to provide reference for the development and utilization of various melanins or artificial melanins in foods and their raw materials.