Abstract
A description of a magnetic microrheometer for the measurement of dynamic viscoelasticity of soft gel is given. The complex compliance of the thick white of the hen's egg for various storage time at 25°C was measured over the frequency range from 20 to 0.01 Hz.
Frequency-storage time superposition of the storage and loss compliance data could be achieved in the high frequency region when a shift factor was used on the vertical axis. With increasing the storage time, the loss tangent curve shift toward higher frequencies, the magnitude of the storage compliance increases, and the maximum in the loss compliance becomes broader in shape. The thick white samples exhibited a substantial secondary loss mechanism at very low frequencies. The low-frequency loss is evident in the newly laid egg, and its magnitude increases rapidly with increasing the storage time. The rate of this egg thinning depends on the temperature at which the egg is kept.
The magnitude of the loss tangent at a low frequency can be used as a measure of egg thinning. These results can be interpreted as indicating the variable structure of the thick white gel composing of ovomuchin during the storage.
