Visualization of Changes in Taste of Food during Chewing Process

Recently, food production technologies using a 3D food printer have been developed. A taste sensor is expected to be used for food design in such food production. In this study, as the first step toward food design, we attempted to visualize the changes in the taste of food during the chewing process using a model food of a monaka (a traditional Japanese sweet with a wafer coating) with a three-layer structure composed of three ingredients: a salty gel, mashed potato, and the wafer. The temporal changes in the six taste qualities of the model food, namely, saltiness, sweetness, umami, bitterness, sourness, and astringency, were analyzed. Sensory tests using the temporal dominance of sensation (TDS) method were performed at the same time. The difference in the release of chemicals associated with the tastes of the three ingredients with the number of times that they were mashed as a simulation of chewing was analyzed. We found that texture and bitterness were dominant in the wafer, saltiness was dominant in the salty gel, and umami was dominant in the mashed potato. The results of the sensory tests using the TDS method and those of the measurement using the taste sensor were in good agreement: the saltiness of the salty gel and mashed potato was perceived in the initial and middle stages of the chewing process, whereas the umami of the mashed potato was perceived from the middle stage onwards. Moreover, the texture of the wafer was perceived in the initial stage, whereas its bitterness and texture were perceived in the final stage. These findings indicate the possibility of visualizing the release of chemicals associated with taste along with the breakdown of food in the mouth using a taste sensor.