Anthocyanins in foods

Abstract

The colors of fruits and vegetables, particularly pink, red, mauve, blue, and violet, are caused by the combination of the glycosides of the six basic anthocyanidins. The amounts and chemical nature of the anthocyanins themselves have a strong influence on the color and storage stability in foods. This review describes the existing analytical methods and suggests some improvements in such techniques to provide information about anthocyanin composition and their degradation in foods. Being electron deficient, the flavylium nuclei of anthocyanins are highly susceptible to attack by nucleophylic reagents. The instability of anthocyanins in food products can pose problems of considerable economic importance. Condensation of anthocyanins with other polyphenols produces polymeric compounds which may or may not distort the typical color of the product. This review integrates several aspects and focuses attention on certain unanswered areas of research. The potential use of naturally occurring anthocyanins as food colorants is also discussed in the context of legal restrictions being imposed on synthetic food dyes.