2003 年 17 巻 3 号 p. 59-64
Physical properties of various foods in the mouth were measured during mastication. The masticatory pressure-displacement curves in the mouth reflect the physical properties of foods during mastication. The masticatory pressure-time curves were measured in the artificial first molar tooth embedded with the strain gage. While the displacement-time curves of the first molar tooth were deduced from the change in magnetic field of a small magnet fixed to the artificial molar tooth.
The masticatory pressure-displacement curves from beginning to the end of eating enable the rheological behavior of foods in the natural action of mastication including saliva. The first masticatory pressure-displacement curves were compared with the stress-strain curves measured by a compression machine with compression rate of 80% and a compression speed of 50mm/min.
The maximum pressure on the first bite of raw carrot, raw Japanese radish and cucumber almost agreed with that of the machine measurement. While, the maximum pressure on the first bite of bread, steamed fish paste were higher and that of peanut, cracker and rice cracker were smaller than that of machine measument.