This study aimed to elucidate the effects of food bolus volume on tongue movement at the initiation of swallowing using ultrasonography. Four healthy women were asked to consume 3-and 6-mL spoon-served different food samples (hard gel, soft gel, sol and water) in one swallow each and in their natural manner of eating. An ultrasound probe was positioned under each person's chin to produce coronal images of the tongue. The up-down movement of the dorsal surface of the tongue was observed in the M-mode. The grooving depth for 6 mL of gels and water was greater than that for 3 mL. The duration of grooving for 6 mL of gels was longer than that for 3 mL. The velocity of descending and ascending grooving was not significantly different between the volumes for each food sample, and the velocity of descending grooving was greater than that of ascending grooving. PRACTICAL APPLICATIONSUltrasonography, using a medical ultrasound instrument, is an effective method for observing tongue movement during the oral phase of swallowing. The M-mode can visualize the kinematics of the dorsal surface of the tongue and bolus passing from the tongue to the pharynx at the initiation of swallowing. Different kinematics of tongue movement can be observed for different volumes of food bolus, mechanical properties and individuals. This technique can be used for designing the texture of food materials for the elderly and infants who experience aspiration or suffocation by food.

To determine an effective method to evaluate the texture of cucumbers, human-bite measurement using a multiple-point sheet sensor and instrumental tests using wedge probes with various angles and a cylindrical probe were conducted. To detect small differences in texture, cross-sectional slices taken from the middle part of a cucumber fruit were served at 4 or 22C. The 60°-wedge probe that could completely divide samples like human incisors performed best compared with sharper wedges or cylindrical probe that partly broke the tissue. The human-bite force for cucumber slices of 4C was significantly lower than that of 22C. Breaking force and energy with the wedges of 60 and 30°in the compression test and those for flesh puncture test demonstrated a similar temperature effect. A faster compression speed close to the human-bite speed (20 mm/s) was necessary to detect the significant temperature effects. PRACTICAL APPLICATIONSThe texture of cucumber was analyzed more precisely using a wedge probe with an angle of 60°inserted into sectional slices of the samples similar to the action of human front teeth that completely cut off the section. A cylindrical probe could insert only part of the cucumber tissues and a blade or a sharper wedge probe partially broke the slices to the depth which the probe reached. Faster test speed (>10 mm/s) close to the average speed of human bite is preferred to detect temperature effects on fracture force. If there are some differences in breaking properties of cucumbers, the proposed conditions of compression test with a 60°wedge at 20 mm/s will detect delicate differences as those due to serving temperature were small. 1982; Thompson et al. 1982Thompson et al. , 1992McFeeters and Lovdal 1987;Horie et al. 2004;Sakurai et al. 2005;Suojala-Ahlfors 2005;Sakata et al. 2008). Another method to measure the bs_bs_banner A journal to advance the fundamental understanding of food texture and sensory perception Journal of Texture Studies

The purpose of this study was to investigate the effects of mechanical properties of foods on tongue movement at initiation of swallowing. Five healthy adult volunteers freely ate four types of food (3 ml of hard gel, soft gel, sol and liquid). A probe was placed under the chin and the coronal section of the tongue was observed. Displacement of the dorsal surface of the tongue from the under surface of the chin was recorded against time using M-mode ultrasound imaging. We analyzed up-down movement of the tongue with the grooving depth, and the velocities of descending and ascending of grooving. The results obtained were as follows. 1) The grooving depth differed significantly among the foods; the sol showed the maximum and water exhibited the minimum. 2) Mechanical properties significantly affected the velocity of descending grooving, which was greatest for the sol. 3) The velocity of descending grooving was greater than that of ascending grooving for all the food samples. The results suggested that tongue movement at the initiation of swallowing changes according to the mechanical properties of foods.