Anthocyanins belong to the group of flavonoids. As water-soluble plant pigments, they give flowers and fruits their red, purple or blue coloration. For example, anthocyanins are responsible for the red foliage coloration in autumn. They are widespread in the plant kingdom, but are not found in animals, aquatic plants or microorganisms.
A precursor in the biosynthesis of anthocyanins is oligomeric proanthocyanidins (OPC).
There are about 250 known anthocyanins. Anthocyanins are used in the food industry to color jams, confectionery, ice cream and other foods.
Anthocyanins can be divided into the sugar-free anthocyanidins (aglycones) and the glucoside-bound sugar residues (glycosides).
The anthocyanidins are the color-giving component of the anthocyanins and have antioxidant effects.
Among the most abundant anthocyanidins in nature are:
- Aurantinidin
- Capensinidin
- Cyanidin
- Delphinidin
- Europinidine
- Fisetindin
- Guibourtindin
- Hirsutidin
- 6-hydroxydelphinidin
- Malvidin
- Pelargonidin
- Peonidin
- Petunidin
- Pulchelidin
- Quercetagetinidine
- Robinetinidin
- Rosinidin
Under laboratory conditions, anthocyanins exhibit potent antioxidant activity – protection against oxidative stress – that can far exceed that of vitamin C and vitamin E. However, the bioavailability when ingested with normal food is only circa 1%.Furthermore, anthocyanins can bind free radicals, helping to protect DNA, lipids and proteins from damage.
