Physical and related sensory properties of a swallowable bolus.

Rheology and water content properties of cereal boluses collected just before swallowing were investigated. No specific physical markers for swallowing were found between subjects. Each subject had his own mastication strategy leading to food boluses with different rheological and water content properties. However, for most of the subjects, similar physical properties were found for food boluses obtained from consumption of different cereals. Results showed that the food boluses from different cereals exhibited gel-like properties being in a range from 14.1 kPa to 21.2 kPa (G'(1 Hz, 0.4%)), when swallowed. The food boluses had a static yield stress varying from 1.3 kPa to 4.3 kPa. Another interesting finding was that the water content of food boluses might be an important marker for swallowing since it was similar for different cereal food boluses (around 50%). This physical property might drive the fluid sensory perception, which could also be a sensory swallowing threshold.