A Simple and Rapid Analytical Method of Grape Anthocyanin Pigments by Cellulose Thin-Layer Chromatography and Densitometry

Studies on Qualities of Grape Juice (Part 6)

Abstract

A simple and rapid analytical method of anthocyanin pigments in grapes and grape products was developed as follows. The pigments prepared by the basic lead acetate method were spotted on the cellulose thin-layers and separated by two dimensional chromatography. The individual pigments were identified by their locations on chromatogram and other qualitative tests, and determined by densitometry at 530nm. (1) Nineteen of the known anthocyanin pigments were arrayed on the two dimensional thin-layer chromatogram (the first solvent system, isobutanol-acetic acid-water, 8:2:3; the second solvent system, acetic acid-hydrochloric acid-water, 15:3:82), according to the number of sugars, organic acids and substituted groups (hydroxyl and methoxyl) in the B rings. (2) A linear relationship existed between the amounts (0-50μg) of pigments (malvidin-3, 5-diglucoside and peonidin-3, 5-diglucoside) and their densitometric readings, respectively. (3) Twenty anthocyanins from Concord grape juice and six anthocyanins (3-monoglucoside pigments only) from Hiro Hambrug grapes were characterized by this method.