Influence of the extraction process on the rheological and structural properties of agars

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Ana M. M. Sousa (Author) FEUP; João Borges (Author) FCUP; Fernando Silva (Author) FCUP; Maria P. Gonçalves (Author) FEUP

Journal

Title: Carbohydrate Polymers

Vol. 96

Pages: 163-171

ISSN: 0144-8617

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 32 Citations

ISI Web of Science

Scopus - 37 Citations

Scientific classification

FOS: Engineering and technology

Other information

Authenticus ID: P-004-ZSQ

DOI: 10.1016/j.carbpol.2013.03.070

Abstract (EN): Agars obtained by traditional hot-water (TWE) and microwave-assisted (MAE) extractions were compared in terms of their rheological and physicochemical properties and molecular self-association in solutions of low (0.05%, w/w) and high (1.5%, w/w) polymer concentrations. At low concentration, thin gelled layers were imaged by AFM. Slow or rapid cooling of the solutions influenced structure formation. In each case, TWE and MAE agar structures were different and apparently larger for MAE. At high concentration, progressive structural reinforcement was seen; while TWE agar showed a more open and irregular 3D network, MAE agar gel imaged by cryoSEM was denser and fairly uniform. The rheological (higher thermal stability and consistency) and mechanical (higher gel strength) behaviors of MAE agar seemed consistent with a positive effect of molecular mass and 3,6-anhydro-alpha-L-galactose content. MAE produced non-degraded agar comparable with commercial ones and if properly monitored, could be a promising alternative to TWE.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9