Thermodynamic characteristics of copigmentation reaction of acylated anthocyanin isolated from blue flowers of Scutellaria baicalensis Georgi with copigments

Anthocyanin extracts are increasingly used as food colorants. So far, anthocyanins have not been broadly used in foods and beverages, since they are not as stable as synthetic dyes. Copigmentation between anthocyanins and copigments is the main colour-stabilizing mechanism. The process of copigmentation between isolated acylated anthocyanin and rutin, QSA or baicalin has been observed using UV-vis spectrophotometry. The thermodynamic parameters were correlated to the structure and position of the substituents in the interacting molecules. The acylated anthocyanin was isolated from cultivars of Scutellaria baicalensis Georgi flowers and purified by column chromatography by our own method and has been identified by 1H-/13C-NMR spectroscopy and electrospray mass spectrometry as delphinidin-3-O-(6-O-malonyl)-(beta)-D-glucopyranosyl-5-O-(beta)-Dglucopyranoside.