Impact of grape pectic polysaccharides on anthocyanins thermostability

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Fernandes, A (Author) Other; BrandAo, E (Author) Other; Raposo, F (Author) Other; Maricato, E (Author) Other; Joana Oliveira (Author) FCUP; Nuno Mateus (Author) FCUP; Coimbra, MA (Author) Other; Victor de Freitas (Author) FCUP

Journal

Title: Carbohydrate Polymers

Vol. 239

ISSN: 0144-8617

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 56 Citations

Scopus - 63 Citations

Other information

Authenticus ID: P-00S-08P

DOI: 10.1016/j.carbpol.2020.116240

Abstract (EN): The impact of grape pectic polysaccharides on malvidin-3-O-beta-D-glucoside thermostability was evaluated in model solutions. Pectic polysaccharides richer in homogalacturonan domains, with less neutral sidechains (chelator fraction) showed higher binding with malvidin-3-O-beta-D-glucoside, by H-1 NMR (K-a=505 M-1). Binding affinity with water soluble extract was estimated to be 10-fold lower, possibly due to the presence of neutral branched regions and more compacted structure, hampering the binding. Hydrophobic domains, such as rhamnogalacturonans-I domains in acid soluble polysaccharides, may participate in the formation of complexes with malvidin-3-O-beta-D-glucoside. The thermostability of anthocyanin-polysaccharides complexes was evaluated at different temperatures, assessing anthocyanins degradation by HPLC-DAD. Polysaccharides showed to improve anthocyanin thermostability, with chelator and acid extract having the highest impact at lowest temperatures. Electrostatic interactions, additionally stabilized by hydrophobic effect contribute to the anthocyanin-polysaccharides binding and to the consequent thermostabilization. The protection provided by grape pectic polysaccharides foresees innovative anthocyanin food products with improved thermostability and colour features.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 8