The color of anthocyanins and anthocyanidins results from excitation of molecule by visible light. At pH values lower than 3, the anthocyanidin appears as the red flavylium cation, and at pH values higher than 6 it is preset as the blue quinonoidal base form.
The richest sources of anthocyanidins to the diet are red wine and fruit, particularly berries. Foods can have one or a variety of anthocyanidins and the concentration is influenced by environmental conditions, ripeness, cultivar, cultivation site, processing and storage.
Only three types of anthocyanidins have been identified in plant tissues. Pelargonidin, cyanidin and delphinidin are wide spread in nature with cyanidin the most common.
Cyanidin is the anthocyanidin found in red cabbage, pelargonidin occurs in radishes and red-seeded varieties of bean and delphinidin occurs in aubergines.
Anthocyanidins are less water soluble than their corresponding glycosides (anthocyanins) and they are not found free in nature.
Freezing may be the best method of preserving anthocyanidins in foods so as the consumption can continue throughout the year even when particular foods such as berries are not in season.
What is anthocyanidin?