Antocyaniner

Antocyaniner, known in English as anthocyanins, are a class of water-soluble pigments in plants that belong to the flavonoid group of polyphenols. They are responsible for red, purple, and blue colors in fruits, vegetables, flowers, and leaves. Chemically, anthocyanins are glycosides of anthocyanidins, flavylium cations that commonly exist with various sugar residues and acyl groups.

They occur widely in nature and are especially abundant in berries (such as blueberries and blackberries), grapes, red cabbage, cherries, plums, and many other colorful fruits. In plant cells, anthocyanins are stored in the vacuoles, contributing to visible pigmentation in tissues.

Anthocyanidins include cyanidin, delphinidin, pelargonidin, peonidin, malvidin, and petunidin; the corresponding anthocyanins differ by sugar attachments or acylation. They are produced by the phenylpropanoid pathway, branching from flavonoid biosynthesis, and their color expression is highly pH dependent, typically shifting from red at acidic pH to blue at alkaline pH.

Functions in plants include attracting pollinators and seed dispersers, protection against UV radiation, and antioxidative roles that help stabilize reactive species in tissues.

Stability of anthocyanins is influenced by pH, temperature, light, and oxygen. Acylation and copigmentation can enhance stability. In humans, anthocyanins are absorbed to a limited extent in the small intestine, and are rapidly metabolized to various glucuronide or sulfate conjugates and microbial metabolites; bioavailability is generally low, and observed health effects are likely due to complex mixtures and metabolites rather than a single compound.

Anthocyanins are used as natural food colorants (E163 in the European Union). They are considered safe for most people when consumed as part of a normal diet, though supplements are not a substitute for medical treatment, and interactions with medications are not fully ruled out.