Impact of a Water-Soluble Gallic Acid-Based Dendrimer on the Color-Stabilizing Mechanisms of Anthocyanins

• Type: Article in International Scientific Journal
• Date: 2019

Authors

Luis Cruz (Author) FCUP; Baslio, N (Author) Other; Mendoza, J (Author) Other; Nuno Mateus (Author) FCUP; Victor de Freitas (Author) FCUP; Tawara, MH (Author) Other; Correa, J (Author) Other; Fernandez Megia, E (Author) Other

Journal

Title: Chemistry - A European Journal

Vol. 25

ISSN: 0947-6539

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 17 Citations

Scopus - 17 Citations

Other information

Authenticus ID: P-00Q-Z5V

DOI: 10.1002/chem.201901912

Abstract (EN): The interaction of two anthocyanins with a water-soluble polyanionic dendrimer was studied through UV/Vis, stopped-flow, and NMR spectroscopy. Cyanidin-3-glucoside (cy3glc) revealed a stronger interaction than malvidin-3-glucoside (mv3glc) at pH 1 according to their apparent association constants. A higher color increased was also obtained for cy3glc at pH 3.5 as a result of this stronger interaction. A high-frequency chemical shift of the cy3glc aromatic protons suggest the formation of ionic pairs. The interaction parameters (K approximate to 700 m(-1), n approximate to 295) indicated the binding of approximately two anthocyanin molecules by each sulfate group. The equilibrium and rate constants of cy3glc in the presence of dendrimer showed an increased stability of the flavylium cation and a higher protection of this species from hydration (pK '(a) and pK(h) increased almost one pH unit). The tuning and color stabilization of anthocyanins by using this dendrimer allow novel applications as colorimetric sensors for food packaging.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11