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Resolution and analysis of total phenolic constituents of grape pigment
Author(s) -
Somers T. C.
Publication year - 1967
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740180505
Subject(s) - pigment , chemistry , chromatography , anthocyanin , tannin , polyphenol , elution , sephadex , proanthocyanidin , acetone , column chromatography , fraction (chemistry) , organic chemistry , food science , enzyme , antioxidant
Abstract A procedure for the analysis of plant phenolics is described which allows the quantitative isolation of the high‐molecular‐weight tannin fraction, the separation of acylated anthocyanins from other anthocyanins, and the further partial separation of the monomeric polyphenols by adsorptive partition within each zone. The system used is a column of Sephadex G‐25 gel prepared in an aqueous acetone medium at low pH and eluted with the same solvent. By this means, an extract of the pigment from a single berry of Vitis vinifera cv. Shiraz has been separated into three distinct pigment fractions, the first of which, a red tannin pigment, was excluded from the gel. The second and third bands contained acylated anthocyanin 3‐glucosides and anthocyanin 3‐glucosides respectively, the components of each band being eluted in order of their decreasing R F in normal paper chromatography. Other phenolics of corresponding R F were found in each of these latter fractions. Pigment composition, expressed in terms of the three fractions, was calculated by use of mean extinction values. The red tannin pigment is the major fraction of total extractable pigment in the grape, although it is only a minor contributor to total colour of extracts.