Whey protein isolate-chitosan interactions: A calorimetric and spectroscopy study

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Hileia K S de Souza (Author) FEUP; Guangyue Y Bai (Author) Other; Maria do Pilar Goncalves (Author) FEUP; Margarida Bastos (Author) FCUP

Journal

Title: Thermochimica Acta

Vol. 495

Pages: 108-114

ISSN: 0040-6031

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 60 Citations

ISI Web of Science

Scopus - 63 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

CORDIS: Physical sciences

Other information

Authenticus ID: P-003-ECZ

DOI: 10.1016/j.tca.2009.06.008

Abstract (EN): Isothermal titration calorimetry (ITC) measurements were performed using solutions of whey protein isolate (WPI) and chitosan with different deacetylation degrees (DD), in acetate buffer solutions, pH 3-6. Turbidity measurements were performed in parallel in order to follow the changes in aggregation. so as to get deeper insight on the interaction mechanism. The viscosity-average molar mass of chitosan was obtained from intrinsic viscosity measurements, and the interaction enthalpies were derived at the studied pH values. Further, the denaturation process of alpha-lactalbumin and beta-lactoglobulin within WPI was characterized by differential scanning calorimetry (DSC). At pH 3, where both chitosan and the proteins are positively charged, a weak carbohydrate-protein interaction is observed. When the pH is raised to 6, where the protein charge is expected to be negative, a much stronger interaction takes place. The results are discussed with special emphasis on the effect of pH on the interactions observed in this complex system.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7