Food texture and its effect on ingestion, mastication and swallowing

The oral processing of most semisolid and solid foods can be summarized in terms of two opposing mechanical influences: forces that fracture food particles versus those that make them adhere to each other. During either the ingestion of food into the mouth or the early stages of mastication, the aim of processing solid food particles is usually to fracture them. However, later on towards swallowing, adhesion is desirable in order to try to form a sticky food bolus that could clear the mouth of isolated food fragments. Neither of these tendencies is actually a function of any particular force (or stress) or displacement (or strain) on food particles, but is instead controlled by energy. Food particles can adhere not only to each other but to the mouth's surfaces. This produces friction. While this is essential for the tongue to grip food particles and move them around the mouth, it also adds to the work that mouthparts must do during processing and may affect sensory perception of food quality. Successful processing of foods in the mouth requires a considerable amount of neural feedback from sensory receptors. We focus here on recent evidence about these sensory receptors with an attempt to reinterpret their role in terms of textural perception.