Résumé
Grape anthocyanins from rosé wine pomace and grape skins were fractionated by multilayer coil countercurrent chromatography (MLCCC). Tert-butyl methyl ether/n-butanol/acetonitrile/water acidified with trifluoroacetic acid (2/2/x/5) was chosen as the solvent system because of its demonstrated efficiency in separating anthocyanins. A method combining MLCCC and step gradient elution has been developed. This method enabled the fractionation of anthocyanins as series of glucosides, and the corresponding acetylated, coumaroylated, and caffeoylated derivatives. The different anthocyanins were identified on the basis of their UV spectra, their elution time on reversed-phase HPLC as well as by mass spectrometry. A polar-colored fraction free of anthocyanin monomers and corresponding to the material remaining in the stationary phase after the completion of the gradient was recovered.