Analysis of Non-linearity and Large Deformation Behavior of Foods with Development of Trial Sealed and Displacement Changeable Type Rheometer for Dynamic Viscoelasticity.

利用现有的流变仪测定了鱼肉、蛋白白色泡沫、多糖凝胶和淀粉等食品和食品配料的流变特性，以澄清和定性食品的流变行为。同时制作了新的粘弹试验装置。该装置是可变位移的。为了防止测量时试样中的水分被蒸发，并使试样产生较大的变形，采用了密封锥板作为试验夹具。此外，该装置的驱动单元可以控制强制振动、匀速旋转和步进旋转。因此，可以测量动态粘弹性行为、稳态剪切粘度和RCP（升余弦脉冲）。温度控制和驱动单元与计算机相连。通过对几种食品的流变测试，发现：（1）食品间的应变-应力线性范围并不均匀，而是个体性的：（2）在大变形下，番茄酱、蛋黄酱等分散体系具有另一种松弛现象;（3）在很低的剪切速率区，人们对粘度的感觉可能会受到影响;（4）RCP是研究加热过程中溶胶-凝胶转变的非常有用的方法。

The rheological properties of foods and food staffs such as fish meets, foam of egg white, polysaccharide gels and starches were measured by existing rheological apparatus in order to clarify and pigeonhole the rheological behavior of foods. While newly trial viscoelastic apparatus were made up. The apparatus was displacement changeable. As the test fixture, sealed cone-and-plate was prepared to prevent the evapolation of water in sample while measuring and to give the large deformation. Furthermore, driving unit of the apparatus can be controlled the forced vibration, uniform velocity rotation and step rotation. Hence, dynamic viscoelastic behavior, steady shear viscosity and RCP(raised cosine pulse) can be measured. The temperature controlled and driving unit were connected with computer. The computed program was supported the many types measurement and spontaneous analysis.From the measurement of some foods by the new rheometer, it was found that ; "(1)" the linear rage of strain-stress was not uniform among foods but individual ; "(2)" under the large deformation, dispersion system such as ketchup and mayonnaise possessed the another relaxation phenomena ; "(3)" the human sense for viscosity might be influenced by very low shear rate region ; "(4)" RCP was very useful methods to investigate the sol-gel transition during heating.