Solid-phase extraction (SPE)—a comparison of 16 materials for the purification of anthocyanins fromaronia melanocarpa var Nero

Abstract

There is an increasing interest in anthocyanins, not only as natural food colourants but also for pharmaceutical products due to their antioxidative potential. Common extraction procedures of anthocyanins from plant material are non-selective and yield pigment solutions with large amounts of by-products such as sugars, sugar alcohols, organic acids, amino acids and proteins. Some of these impurities may accelerate anthocyanin degradation or cause problems in further processing steps such as spray drying. In order to obtain a highly concentrated and purified anthocyanin pigment from black chokeberry (Aronia melanocarpa var Nero), juices and skin extracts were purified by solid-phase extraction (SPE). Sixteen solid-phase materials were tested on a laboratory scale, whereby the anthocyanin and sugar content of collected fractions were determined to represent elution profiles. Among these, reversed-phase silica gels and macroreticular non-ionic acrylic polymer adsorbents such as Serdolit PAD IV or Amberlite XAD-7 turned out to be most suitable. SPE was investigated with these materials in an enlarged scale, improving elution gradient and column purification. Amberlite XAD-7 was successfully applied in a 36-litre-scale separation. © 1998 Society of Chemical Industry.