Apparent Viscosity and First Normal Stress of Starch Dispersions: Role of Continuous and Dispersed Phases, and Prediction with the Goddard-Miller model.

GENOVESE, DIEGO B.; RAO, M. ANDY

Applied Rheology

Vincentz Verlag

Año: 2003 vol. 13 p. 183 - 190

1430-6395

Apparent viscosity (ha) and first normal stress coefficient (y1) of six different concentrations of cross-linked waxy maize (CWM), 3.5-5.0% w/w, and tapioca, 2.8-4.0% w/w, starch dispersions (SDs) showed power law relationships with shear rate ( ) and increased with starch concentration. In both ha and y1, volume fraction of the granules (f) played a more important role than the amylose content of the continuous phase. Slope of curves increased mildly with starch concentration, while slope of curves was almost the same for CWM at all concentrations and 4.0% tapioca SDs. Values of ha and y1 predicted from dynamic rheological and apparent viscosity data based on the Goddard-Miller model were in reasonable agreement with experimental values.