Anthocyanins in plants mainly have three functions, namely as absorbers of harmful radiation, as transport vehicles for monosaccharides and as osmotic adjusters during periods of drought and low temperatures. In general, anthocyanins are believed to increase the antioxidant response against biotic and abiotic stress factors.
Apart from their physiological roles in plants, anthocyanins are regarded as important components in human nutrition, which is supported by numerous studies that report a high positive correlation of fruit or vegetable pigment content and antioxidant capacities.