The Dynamic Characteristics of Gelled Food Materials against Small Impact Force

Abstract

The dynamic mechanical characteristics against small impact force of konjak were measured in this study. Konjak is one of the popular and healthy Japanese foods and is the Gunma prefectural specialty. There are many studies discussing the sensory characteristics of food materials, however few of them measure the characteristics quantitatively and accurately. If it has been done, the detail of sensory properties will be able to be discussed. We have done the experience and shown the characteristics. Konjak is flexible and slimy food material. We thought konjak is like rubbers and it can be measured the response against small impact force. To measure the precise dynamic mechanical force, the levitation mass method (LMM) is used. In LMM, a pneumatic linear bearing is used to reduce friction to almost zero, and an optical interferometer is used. The acceleration, velocity, position, and inertial force of the mass are calculated from the measured time-varying frequency due to Doppler Effect, which can be calculated by using the zero-crossing fitting method (ZFM). LMM had been used to only measure the dynamic forces acting on the mass before, but we utilized it to test the mechanical characteristics of food materials. Konjak has the characteristics of viscoelasticity. We have revealed the quantitative and logical characteristics of konjak.

Impact force measurement of a spherical body dropping onto a water surface

“…In the LMM, a mass levitated by an aerostatic linear bearing is used, and the laser Doppler interferometer is used for measuring the velocity. We have precisely calibrated force transducers (8) , tested materials (9,10) , and examined the structures (11) using LMM. A method to measure the impact force of a spherical body dropping onto the water surface has been proposed by modifying the LMM (12) .…”