Abstract
The brain blood flow of chewing various flavors of gumi-jelly was analyzed in order to clarify the effect of taste of the food on brain blood flow during chewing. Ten healthy subjects (5 males, 5 females, ages 22 to 34, average age 24.8) were asked to chew three types of gumi-jelly with three different flavors (normal, sweet, bitter) on their habitual chewing side for 20 seconds and the bilateral brain blood flow were recorded using near-infrared spectroscopy (NIRO-300®, Hamamatsu Photonics) . The measuring probe was placed so that the distance between the irradiation part and the receptive part was to be 4 cm, and was placed on the bilateral sides by pushing away the hair in an area related to cortical masticatory area and thus would mostly react to opening and closing movement. First the brain blood flow of prior to, during and after chewing gumi-jelly were investigated. Next the amount of change in blood flow were compared among the three types of gumi-jelly. The brain blood flow increased during chewing gumi-jelly, started to decrease after chewing and returned to its original state. The amount of change in brain blood flow was smallest when chewing bitter gumi-jelly, increased with chewing sweet gumi-jelly and was largest when chewing normal taste, and significant differences were found among the different flavors. From these results it was concluded that brain blood flow increased by masticatory movement and that the difference in flavor affected increase and decrease in the amount of brain blood flow.
