EXTRACTIVE FRACTIONATION OF BETALAINES

A fractionation procedure, based on extraction with acidified ethanol, was developed for the separation of betalaine pigments in beet juice powder. Extraction of lyophilized fresh beet juice with boiling 95% ethanol and subsequent chilling of the extract to −25°C yielded two fractions: an orange precipitate containing betaxanthines and a yellow pigment obtained from the filtrate. Three additional extractions of the beet juice powder residue were carried out at room temperature with 95% ethanol containing 1.0, 0.6 and 0.4% HCl, respectively, and the resulting fractions were combined. This extract contained mainly the betacyanines. This procedure achieved rapid and satisfactory separation of the principal constituents of betalaine, comparable to other more complex methods. Fractions were analyzed by thin‐layer chromatography (TLC) on cellulose‐coated plates developed sequentially with solvent mixtures consisting of ethanol, isopropanol, water and HCl. Copyright © 1979, Wiley Blackwell. All rights reserved