Identification, quantification, and method validation of anthocyanins

Nowadays, anthocyanins have gained attention in the scientific and industrial fields, due not only to their biological activities but also to their coloring properties. In this sense, the use of anthocyanins for developing new nutraceutical foods has been proposed, both to substitute synthetic additives and also as ingredients with added-value. These compounds appear naturally in several plant sources, such as fruits and flowers, being part of plant secondary metabolites. Then, the extraction of anthocyanins is usually carried out from vegetal matrices. As the range of application of these compounds increase, it is necessary to design efficient extraction methods, with better yields, and also to develop suitable analytical methods for the identification and quantification of anthocyanins. The aim of this study was to evaluate the current data about the identification and quantification techniques employed and also the validation process of such methods. Our results showed that anthocyanins have been identified by different methods, including Nuclear Magnetic Resonance and chromatographic-based techniques (e.g. High Performance Liquid Chromatography coupled to Diode Array Detector or Mass Spectroscopy). When validating methods, several issues have been described, but most reports showed positive results on validation parameters, suggesting that the current analytical technology offers a successful identification and quantification of anthocyanins, with the capability of being applied for both research and industrial purposes.