Abstract
The effects of intake volume on bolus migration velocity were investigated by preparing model samples in which solid samples were dispersed in starch, guar gum, xanthan gum and water. The migration characteristics of the bolus in the pharyngeal region during deglutition were assessed and measured using a combination of the ultrasonic pulsed Doppler technique, swallowing contrast studies, sensory characteristics and mechanical characteristic values. The effects of increase and decrease of the bolus volume on mastication and deglutition were investigated. In both cases of 5 times and 30 times of mastication, the maximum migration velocity of the bolus water added and starch paste added samples tended to increase in accordance with increase of intake volume. These samples were easily affected by intake volume. However, guar gum added and xanthan gum paste added samples were not affected by the intake volume and maintained approximately the same migration velocity. Regarding the transit time, in the case of liquid-like boluses, transit time tended to lengthen as intake volume increased, whereas, in the case of viscous and solid-like boluses, they were hardly affected by increase of the intake volume and maintained approximately the same transit speed. These findings suggest that there is a high possibility that the effects of intake volume of solid dispersion pastes are associated with the mechanical characteristic values of added paste.
