Betalains: properties, sources, applications, and stability - a review

P>Consumers are increasingly avoiding foods containing synthetic colourants, which lead food industries to replace them by natural pigments, such as carotenoids, betalains, anthocyanins and carminic acid. Betalains are water-soluble nitrogen-containing pigments, composed of two structural groups: the red-violet betacyanins and the yellow-orange betaxanthins. This review synthesises the published literature on basic chemistry of betalains, their sources and chemical stability. Moreover, several works are mentioned which have demonstrated the potent antioxidant activity of betalains, which has been associated with protection against degenerative diseases.