  Texture is an important attribute in the quality assessment of processed food
products. Youngs modulus is an indirect measure of texture. During thermal
treatment of hygroscopic foods, parameters such as moisture content
significantly affect Youngs modulus. However, the sensitivity to these
parameters has not yet been quantified in terms of the stress strain behaviour.
We have built an experimentally validated model to address this gap. This paper
presents the stress strain behaviour and its sensitivity towards various
parameters. Experiments are conducted with potato samples for stress strain
behaviour, parametric sensitivity analysis, estimation of initial and critical
values of moisture content and Youngs modulus. We found that the Youngs modulus
and the ultimate strength vary by as much as 54 percent and 29 percent
depending on the rate of applied strain, indicating the need for test
standards. Further, we propose a model to predict the local Youngs moduli as a
function of moisture content, and a relationship between these and the
effective Youngs modulus. While model results agree well for drying, they
deviate by as much as 16 percent from experiments for frying, indicating the
necessity of incorporating additional physics. We expect this work to serve as
a crucial step towards the physics based prediction modelling of local and
effective Youngs moduli during thermal processing of food products.
