Comparative Study of Fresh and Fermented Bilberry Juices-State and Modification of the Coloring Pigments

ABSTRACT Rapid and direct methods for the determination of the coloring pigments were applied to fresh and fermented bilberry juices–Vaccinium myrtillius–as well as to their fractionation products isolated by preparative column chromatography. These methods were: bisulfite de‐colorization, chromatic indices and analytical column chromatography for the appreciation of the different pigment states. Results obtained from these experiments gave an estimation and comparison of the states and the forms of the coloring pigments and underlined the effects of the physicochemical treatments such as condensation or degradation of pigments during fermentation, preservation and experimental procedures.