Direct measurement of biting pressures for crackers using a multiple-point sheet sensor

Abstract

A multiple-point sheet sensor was used to observe the distribution of surface pressure during the biting of crackers adjusted to various water activities. The textural characteristics were clearly reflected in the three-dimensional displays so obtained. Textural differences between samples were most evident in the first 0.3 s. The magnitude, position and duration of biting pressure varied among subjects. For all subjects, crisp crackers with low water activities showed a large pressure distribution with respect to both time and position. Samples with high water activities displayed a higher maximum force on the area under the incisors than samples with low water activities, and required more work per incision. These results are opposite to the rheometric data measured with a single-point sensor. Using this method, we could directly display textural differences due to the mechanical and geometrical properties of food, and could evaluate their changes in the oral cavity during biting.