Variations of Mechanical Properties in Egg White during Gel-to-Glasslike Transition

Simultaneous measurements of weight, volume and mechanical properties have been performed during the gel-to-glasslike transition of heat-treated egg-white gel. Change in the elastic stiffness occurred in three steps: in the initial stage, it remained almost constant, then increased exponentially, and lastly, saturation was attained. The saturation point almost coincided with the characteristic time at which the rates of decrease of the weight and volume changed. In addition, from the time dependence of the differentiated values, the close correlation between the elastic stiffness and weight was revealed. It was also found that the loss of free water induces an increase of about a thousardfold in elastic stiffness of gels during transition.