Cereal Chem 51:151 - 162. | VIEW
Stress Relaxation in Wheat Flour Doughs Following a Finite Period of Shearing. I. Qualitative Study.
B. Launay and J. Bure. Copyright 1974 by the American Association of Cereal Chemists, Inc.
The possibility of studying, with a classical cone and plate rheometer, the stress relaxation following shearing of finite and variable extent is shown. The half-relaxation time is the parameter chosen to evaluate the speed of stress relaxation; this time varies little with the extent of shearing, but is essentially dependent on the stress in the dough at the beginning of the relaxation. The effects on stress relaxation of the following factors are reviewed: flour type, dough-water content, mixing time, presence of sulfite or N-ethylmaleimide, and dough temperature; results are compared with those obtained by others. The curves representing the variation of the half-relaxation time in terms of the initial stress are similar to hyperbolas. It is suggested that the phenomenon of rapid stress relaxation can best be described as the rupture of a three dimensional network which is at least partly constituted by secondary forces connecting the different chains.