Copigment and Anthocyanin-Rich Fractions from Berries Using Cationic Exchange Chromatography

Anthocyanins, the largest group of hydrosoluble pigments found in nature, play vital roles in plant life and have several bioactivities with potential applications in the food and nutraceutical industries. Efficient extraction and fractionation methods are crucial for isolating these compounds from complex mixtures. Cation exchange chromatography has emerged as a promising approach for this purpose. The method is based on the ability of anthocyanins to adopt a positively charged structure (flavylium cation form) under acidic conditions. Synthetic membranes with negatively charged sulfonic acid groups are used to retain anthocyanins through ionic interactions while non-charged copigments are flushed out in the acid eluent due to their neutral charge under acidic conditions. The recovered anthocyanin fraction can be further purified and utilized as natural colorants or for their bioactive properties. The methodology has been validated for the structural characterization and bioactivity evaluation of anthocyanins from various berries. Although the technique shows promise, careful consideration of source materials and specific application requirements are essential for optimal results. Further research and development in this field will enhance the understanding and applicability of cation exchange chromatography for anthocyanin fractionation.