抄録
Humans perceive taste, odor, and food texture during mastication. In particular, food texture is an important quality indicator in determining the palatability of food. Hence, food developers require an evaluation method for food texture. Mechanoreceptors in the periodontal ligament contribute to the delicate perception of texture and are roughly divided into two types of response characteristics: fast adaptation, and slow adaptation. To measure and evaluate food texture, a magnetic texture sensor is designed to imitate the characteristics of such mechanoreceptors and the structure of teeth. The magnetic texture sensor mainly consists of a probe, a linear slider, a spring, and a circuit board. The probe is made by a 3D printer, and any shape can be formed on the probe tip for the measurement of various food. The probe also contains a permanent magnet. Both ends of the spring are fixed to the probe and the circuit board. The linear slider limits the oneaxis displacement of the probe, and the bearing balls on the inner surface of the linear slider make the smooth displacement of the probe. The circuit board has two types of sensor elements, magnetoresistive elements, and an inductor. Magnetoresistive sensors and inductors measure the displacement and velocity of the permanent magnets in the probe as changes in magnetic field strength and magnetic flux density, which correspond to the receiving characteristics of slow-adapting and fast-adapting mechanoreceptors, respectively. This paper firstly describes the structure and measurement characteristics of the magnetic texture sensor and shows an example of measuring food. Furthermore, the method of estimating the texture evaluation value from the measured data using Gaussian process regression is described, and the estimation result using commercially available foods is also introduced.
