Anthocyanins are water-soluble vacuolar pigments that may appear red, purple, or blue according to pH. They belong to a parent class of molecules called flavonoids synthesized via the phenylpropanoid pathway. Anthocyanins occur in all tissues of higher plants, including leaves, stems, roots, flowers, and fruits. Anthoxanthins are their clear, white to yellow counterparts occurring in plants. Anthocyanins are derivatives of anthocyanidins which include pendant sugars.

Anthocyanins are powerful antioxidants in vitro. This antioxidant property may be conserved even after the plant which produced the anthocyanin is consumed by another organism, possibly explaining why fruits and vegetables with colorful skins and pulp are considered nutritious. Research continues to be underway as to the potential range of health benefits from anthocyanins.