Melanin: A promising source of functional food ingredient

Melanin as a natural pigment widely exists in animals, plants, fungi and bacteria. In vivo and in vitro tests have proven that melanin has a variety of health-promoting effects, such as antioxidant and immunomodulatory activities, hypoglycemic and hypolipidemic effect, liver and gastrointestinal tract protection effect. Melanin can be extracted from animal and plant by-products or produced by microbial fermentation, involving five extraction and purification methods, with their own positive and negative aspects. Melanin can be added to a variety of foods as natural colorant and preservative, with high safety and almost no toxicity. This article focuses on melanin's source classification, health benefits, extraction technology and applications in food products to explore the potential of it as a functional food ingredient.