Detection of Enocyanin in Cranberry Juice Cocktail by HPLC Anthocyanin Profile

Adulteration of cranberry juice products by enocyanin, a colorant from grapes, was detected by comparing HPLC chromatographic profiles of cranberry anthocyanins with those from enocyanin. Two peaks present in all enocyanin samples but not in cranberries were identified as delphinidin-3-glucoside and petunidin-3-glucoside. A group of unidentified pigments which eluted after the cranberry pigments was also present in enocyanin. It was possible by considering differences in the chromatograms to detect replacement of 5% or more of the expected amount of cranberry juice in cranberry juice cocktail by a solution of enocyanin. A CG-50 column was used to concentrate the pigments followed by chromatography on a polymer styrene column at pH 1.6. The method gives reliable results even on samples 18 months of age.