Limitations in the use of some synthetic food colourants have renewed interest in the use of plant pigments for this purpose. One possibility is the use of anthocyanins, which are of widespread occurrence in plants and are responsible for almost all the red, blue and purple colours found in nature.
Studies evaluating the utility of anthocyanins as food colours are based primarily on extracts from the mart of grapes after wine-making. In addition to a large number of different anthocyanins, these extracts contain several other phenolic substances, especially tannins. This complex composition makes the analyses tedious, and raises questions regarding their use as a food additive.
Another source of anthocyanins for food colouring could be elderberry, Sumhucu.s nigra L, a small tree growing freely in the northern hemisphere with fruits which are an extremely good source of anthocyanins of a more simple composition and with few other phenolic substances.
The use of high-performance liquid chromatography (HPLC) for the separation of anthocyanins has been reviewed by FrancisI. Especially, the development of reversed-phase columns has greatly improved the separation performance of anthocyanins by HPLC. To our knowledge no work dealing with the anthocyanins of elderberry has previously been reported.
In this paper we describe an analytical HPLC technique based on a reversedphase separation with linear-gradient elution which enables the resolution of the four anthocyanins in elderberry, their chalcone forms, and their common aglycone. The chalcone form and the aglycone are both intermediates of the degradation pathway of anthocyanins* and are therefore of interest in stability and metabolic studies of the anthocyanins.