Inhibition of a-amylase activity by condensed tannins

• Type: Article in International Scientific Journal
• Date: 2010

Authors

Rui Gonçalves (Author) FCUP; Nuno Mateus (Author) FCUP; Victor de Freitas (Author) FCUP

Journal

Title: Food Chemistry

Vol. 125 No. 2

Pages: 665-672

ISSN: 0308-8146

Publisher: Elsevier

Indexing

Scopus

Scientific classification

FOS: Engineering and technology > Chemical engineering

CORDIS: Physical sciences > Chemistry > Biochemistry > Enzimology ; Physical sciences > Chemistry > Analytical chemistry > Spectrochemistry

Other information

Abstract (EN): The ability of grape seed procyanidins to inhibit a-amylase activity was studied using a colorimetric method. This ability was found to be related with the average degree of polymerisation of the tested procyanidins. These interactions were further evaluated by fluorescence quenching, dynamic light scattering (DLS) and nephelometry, in order to understand the mechanisms by which they occur. A relationship between aggregate formation and enzymatic inhibition was observed. The interaction between procyanidins and enzyme involves a specific interaction as inferred from the calculated apparent bimolecular quenching constant in the fluorescence assays. Further experiments involved the determination of the effect of carbohydrates on the enzymatic inhibition observed. It was shown that pectin and arabic gum inhibited the formation of insoluble aggregates but were unable to restore fluorescence and activity to the enzyme. This suggests that these carbohydrates resulted in a decrease in turbidity due to the formation of a ternary complex with protein/polyphenol.

Language: English

Type (Professor's evaluation): Scientific