Public scandals, awareness of food safety of colorants and health promotion are factors that have prompted changes in the legislation of food additives worldwide. Furthermore, the substitution of synthetic with natural food colorants and the importance of finding new sources for natural food colorants have significantly increased.
In the first part of this work, the main aim was to characterize the phenolic composition of anthocyanin-rich plant-derived extracts, especially from blackberry, black chokeberry, sour cherry, black carrots, purple sweet potatoes, roselle and butterfly pea. The chemical composition of anthocyanins-rich extracts was obtained by TLC, UV spectra, HPLC-DAD, HPLC ESI-MSn and NMR analysis. In this way, their fingerprints were established in order to be used for routine analytical purposes as well as authenticity control. In the second part, the preparative isolation of anthocyanins by membrane chromatography and countercurrent chromatography was performed. Separation of anthocyanins by both chromatographic techniques was achieved in all cases and allowed isolation of anthocyanin pigments on a large scale in high purity and quantity. On the other hand, countercurrent chromatography, especially LSRCCC, HSCCC and HPCCC provided separation of polyphenols and isolation of individual compounds on a large scale, particularly anthocyanins, chlorogenic acids, quercetin glycosides and kaempferol glycosides.
