Structural and mechanical characterization of k/i-hybrid carrageenan gels in potassium salt using Fourier Transform rheology

• Tipo: Artigo em Revista Científica Internacional
• Data: 2009

Autores

Loic Hilliou (Autor) FEUP; Manfred Wilhelm (Autor) Outra; Mikio Yamanoi (Autor) Outra; Maria P. Gonçalves (Autor) FEUP

Revista

Título: Food Hydrocolloids

Vol. 23 Nº 8

Páginas: 2322-2330

ISSN: 0268-005X

Editora: Elsevier

Indexação

ISI Web of Knowledge - 20 Citações

ISI Web of Science

Scopus - 27 Citações

Classificação Científica

FOS: Ciências exactas e naturais

CORDIS: Ciências Físicas

Outras Informações

ID Authenticus: P-003-DX3

DOI: 10.1016/j.foodhyd.2009.06.008

Abstract (EN): The mechanical and structural properties of κ/ι-hybrid carrageenan gels obtained at various concentrations in the presence of 0.1 m KCl were studied with Fourier Transform rheology (FTR) and cryoSEM imaging. FTR data show that gels formed at concentration below 1.25 wt% exhibit a strain hardening behavior. The strain hardening is characterized by a quadratic increase of the scaled third harmonic with the strain and a third harmonic phase angle of zero degree. Both features are weakly depending on the concentration and conform to predictions from a strain hardening model devised for fractal colloidal gels. However, the phase angle of the third harmonic reveals that κ/ι-hybrid carrageenan gels obtained at higher concentrations show shear thinning behavior. Colloidal gel models used to extract structural information from the concentration scaling of gel equilibrium shear modulus G0 and the strain dependence of FTR parameters suggest that κ/ι-hybrid carrageenan gels are built from aggregating rod-like strands (with fractal dimension x = 1.13) which essentially stretch under increasing strain. The mechanically relevant structural parameters fairly match the gel fractal dimension (d = 1.66) obtained from the cryoSEM analysis. © 2009 Elsevier Ltd. All rights reserved.

Idioma: Inglês

Tipo (Avaliação Docente): Científica