ABSTRACT

The yield stress is one of the most important macroscopic properties of fats and fat-containing products because it is strongly correlated to sensory perception of hardness and spreadability, as well as to material stability. The apparent yield stress of a plastic solid is usually defined as the point at which, when the stress is increased, the deforming solid first begins to show liquidlike behavior [1]. Even though the concept of a yield stress has been incorporated into phenomenological rheologic models, the relationship between a material’s structure and its yield stress has not been established. In this chapter, we

develop a general model relating the structure of a fat crystal network to its yield stress and elastic modulus.