INVESTIGADORES
BERLI Claudio Luis Alberto
artículos
Título:
Connection between rheological parameters and colloidal interactions of a soy proteins suspension
Autor/es:
CLAUDIO L. A. BERLI, JULIO A. DEIBER, MARÍA C. AÑON
Revista:
FOOD HYDROCOLLOIDS
Editorial:
Elsevier Science
Referencias:
Año: 1999 vol. 13 p. 507 - 515
ISSN:
0268-005X
Resumen:
The viscosity of a 9.1% (w/w) aqueous suspension of soy proteins at pH 7.5, which constitutes a colloidal dispersion of negatively charged
and hydrated particles, is analyzed in relation to colloidal interactions. An experimental study is carried out through the classical shear rate
rheometry, in the range 20508C. Viscosity data at different temperatures and shear rates are superimposed onto a master plot, which shows
the characteristic shear-thinning behavior of colloidal suspensions. A microstructural model for the low shear limit viscosity is derived to
establish a quantitative relationship between the viscosity and the interparticle forces in the suspension. Apart from the electrical forces, the
hydration repulsive force must be considered in the calculation of the proteinprotein interaction energy, in order to achieve a satisfactory
prediction of the high viscosity values obtained experimentally. It is also observed that the relaxation time associated to small shear
deformations differs from the characteristic relaxation time of the steady shear flow. The theoretical analysis carried out in this work
explains the effect of colloidal interactions on rheological parameters of the soy protein suspension.8C. Viscosity data at different temperatures and shear rates are superimposed onto a master plot, which shows
the characteristic shear-thinning behavior of colloidal suspensions. A microstructural model for the low shear limit viscosity is derived to
establish a quantitative relationship between the viscosity and the interparticle forces in the suspension. Apart from the electrical forces, the
hydration repulsive force must be considered in the calculation of the proteinprotein interaction energy, in order to achieve a satisfactory
prediction of the high viscosity values obtained experimentally. It is also observed that the relaxation time associated to small shear
deformations differs from the characteristic relaxation time of the steady shear flow. The theoretical analysis carried out in this work
explains the effect of colloidal interactions on rheological parameters of the soy protein suspension.