Vane Yield Stress of Starch Dispersions

Authors


Direct inquiries to author Rao (E-mail: mar2@cornell.edu).

Abstract

ABSTRACT: Yield stresses of 5% (wt/wt) cross-linked waxy maize, tapioca, and Amioca starch dispersions (SDs) were measured with the vane method at different rotational speeds (N). The static (σ0S) and dynamic (σ0d) yield stress values of each SD were measured before and after breaking down its structure under continuous shear, respectively. The difference (σ0S - σ0d) was associated with the stress required to break the internal bonds (σb). Values of total yield stress (σ00S) and σb, and shear rate were related by power law relationships. The contribution of viscous and network stresses were estimated from an energy balance model. Textural characteristics of the SDs were analyzed in a texture map.

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