Betalainic and nutritional profiles of pigment-enriched red beet root (Beta vulgaris L.) dried extracts

Red beet root (Beta vulgaris L) colourants (betalains) are available either as concentrates produced by evaporating beet juice under vacuum, or as powders made by spray-drying a concentrate. The degradation of the pigments is dependent upon temperature, duration of heat treatment, pH and water activity of a product. Recently, a new proprietary method of large-scale chromatographic purification of red beet root extract has been discovered and developed that allows the production of more concentrated betalain formulations. In order to trace the betalainic compositions of the new products in comparison to the currently in-use spray-, air- and freeze-dried concentrates, a chromatographic study on betalains and their degradation derivatives analysed by LC-DAD-ESI-MS/MS was performed. Additionally, nutritional characterisation of the extracts was accomplished. Besides the most prominent betanin/isobetanin, elevated levels of neobetanin, which previously had been frequently detected in red beet roots, were also observed in the product prepared by the new method. The principal betanin/isobetanin pigments measured spectrophotometrically, comprised a major portion of the total betalain content (41%), the highest concentration of betalains reported in industrial products to date. The presence of other decarboxylated and dehydrogenated betanin derivatives in the new products is also discussed. (C) 2010 Elsevier Ltd. All rights reserved.