Studies on rheological behaviour of canola and wheat

The modulus of elasticity, maximum compressive contact stress and the force relaxation behaviour of single wheat and canola (rapeseed) kernels at different moisture contents were determined. In the force relaxation experiments, the effect of different deformation rates and strain levels were examined. Results indicated that the modulus of elasticity and maximum compressive contact stress decreased linearly with increase in moisture content of the grains. A three-term Maxwell model was found to adequately describe the force relaxation behaviour of both grain kernels when compared with one- and two-term models. The optimum number of terms in the model was determined based on the criteria of maximum relative difference (≤5%). The moisture content was found to have a significant effect on stress relaxation behaviour of both grains.