Micro-mechanical model development for predicting the effect of microstructure on bulk behaviour of aerated soft solids.

Soft food systems are often used in confectionery products, such as emulsion or foam fillings, to provide consumers with an indulgent and unique experience. Traditionally, the mechanical and rheological properties of these systems are studied in combination with sensory evaluation to describe their in-mouth flow properties. However, oral processing of food is very complex and several multi-scale mechanisms take place at the same time in the mouth. This is especially noticeable when dealing with more complex systems, e.g. when hard particles (inclusions) are included within a semi solid system, or products with different micro- and macroscopic structure, e.g. aerated systems. This hinders predictions of the in-mouth behaviour of the food. Knowledge of this behaviour is crucial as it is directly linked to sensory perception. The aim is to develop models for predicting the coupled phenomena involving flow and fracture/damage phenomena to heat flow and phase change during the oral process as well as the ensuing complex interaction of the food pieces with the mouth surfaces (tongue-palate contact) as food turns into a 'bolus' on mastication and mixes with saliva. A multi-scale thermomechanical computational model needs to be developed for simulating the interaction between aerated fluid and solid structures (scales 10-2 m to 10-3 m) in the oral cavity.