Abstract
Shear softening and thixotropic properties of wheat flour doughs are demonstrated in dynamic testing with a constant stress rheometer. This behaviour appears beyond the strictly linear domain (strain amplitude γ0 ≥ 0.2%),G′,G″ and |η*| decreasing with γ0, the strain response to a sine stress wave yet retaining a sinusoidal shape. It is also shown thatG′ recovers progressively in function of rest time. In this domain, as well as in the strictly linear domain, the Cox-Merz rule did not apply butη(γ) and |η *(ω))| may be superimposed by using a shift factor, its value decreasing in the former domain when γ0 increases. Beyond a strain amplitude of about 10–20%, the strain response is progressively distorted and the shear softening effects become irreversible following rest.
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Berland, S., Launay, B. Shear softening and thixotropic properties of wheat flour doughs in dynamic testing at high shear strain. Rheola Acta 34, 622–625 (1995). https://doi.org/10.1007/BF00712321
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DOI: https://doi.org/10.1007/BF00712321