Soft materials deformation, flow, and lubrication between compliant substrates: impact on flow behavior, mouthfeel, stability, and flavor.

Foods are rationally designed to be semifluids or soft solids for optimal stabilization of the multiple phases they contain and to provide favorable textural properties. Although rheology provides a guide to physical stability and initial texture perception, measurements on intact foods do not enable predictions of the organoleptic properties experienced during oral processing. Oral processing includes lubrication between compliant oral substrates, and studies into soft lubrication/tribology are providing new insights into the physical processes experienced by soft foods in the mouth. We provide a review of the key rheological considerations for food product stability and texture, and we delve into how rheology and soft tribology, with consideration for oral physiology and saliva, are providing new insights into texture, mouthfeel, taste, and aroma.