Volitional Control of Chewing Frequency Affects Food Oral Processing and Texture Perception

Although varieties in chewing patterns are essential for the transformation of food in mouth and thereby its sensorial perception, there are few reports that show the effect of chewing frequency on food oral processing and its properties.

The current study tested whether consciously controlled chewing frequency influences the oral processing of habitually consumed foods and their sensory analysis.

Chewing behaviour was analysed during the mastication of mushed potato samples by 20 participants in two separate test sessions, in which they were instructed to chew the sample in their habitual manner (free chewing test) or follow a preprogrammed video animation displayed on a screen, wich guided them to maintain a constant chewing frequency (F-const chewing test). Electromyography recording, sensory tests and rheological analysis of bolus properties were performed.

Oral processing in the F-const chewing test required longer chewing time due to the elongation of chewing cycle time, rather than an increased number of chews. The contribution of jaw muscle activity to chewing effort changed resulting in greater activity of temporalis muscle in the F-const chewing test. During volitional control of chewing frequency, the texture perception with respect to cohesiveness, adhesiveness and moisture scoring differed from that observed in habitual chewing, despite the similar physical properties of the bolus. These variabilities resulted in higher acceptability of the food sample.

Since this study clearly shows how control of chewing frequency led to changes in oral processing of food and its sensorial properties, nutritionists can employ the findings to optimise the dietary recommendations decreasing eating rate and increasing palatability of the target products.