Abstract
A sensory evaluation was conducted on 19 types of food material with different physical properties to clarify the smallest size recognizable as a particle (the recognition threshold value) by the mouth and the minimum particle size difference that could be distinguished. These characteristics were examined in relation to the physical properties of each type of material.
The recognition threshold value ranged from 51 μm for cellulose to 270 μm for domyoji flour. On the other hand, two particles differing in size by about 1.19 times were distinguishable for all the materials above a certain particle size (the smallest distinguishable particle size) that depended on the material. The smallest distinguishable particle size ranged from 124 μm for cellulose to 487 μm for buckwheat noodle. With all the materials except shiitake mushroom, the recognition threshold value was less than the smallest distinguishable particle size.
The recognition threshold value and the smallest distinguishable particle size were examined in relation to the physical properties of the materials. As a result, both values were small when the materials had a relatively solid structure and their particles absorbed a small amount of water slowly before saturation. For materials with these features, a particle was thought to be perceived even when the particle size could not be distinguished.
The recognition threshold value could be expressed by a multiple-regression equation involving seven physical properties with a high multiple-correlation coefficient (R = 0.93).
