Color stability of commercial anthocyanin-based extracts in relation to the phenolic composition. Protective effects by intra and intermolecular copigmentation

Anthocyanin extracts are increasingly used as food ingredients. A current c hallenge is to maintain their color properties. The stability of some color ants has been studied in sugar and non-sugar drink models at three pH value s (3, 4, and 5) under thermal and light conditions simulating rapid food ag ing. At a given pH, color stability mainly depends on the structures of ant hocyanins and of colorless phenolic compounds. Colorants rich in acylated a nthocyanins (purple carrot, red radish, and red. cabbage) display great sta bility due to intramolecular copigmentation. The protection of red chromoph ore is higher for diacylated anthocyanins in red radish and red cabbage. Fo r colorants without acylated anthocyanins (grape-marc, elderberry, black cu rrant, and chokeberry), intermolecular copigmentation plays a key role in c olor protection. Colorants rich in flavonols and with the highest copigment /pigment ratio show a remarkable stability. By contrast, catechins appear t o have a negative effect on red colorants, quickly turning yellowish in dri nk models. This effect is more pronounced when the pH is increased. Finally , color does not seem to be greatly influenced by the addition of sugar.