ABSTRACT

There are two common tests for foods. One is a creep/recovery test to determine the yield stress of the food suspension, which is an indication that the material has structure. It is this structure that stabilizes the suspension. In this test a sample is subjected to a constant shearing stress and the amount that it deforms or flows is measured. The second commonly used test is an oscillatory test where the sample is vibrated at a controlled amplitude and frequency, and we measure the storage modulus (G’) and loss modulus (G”). The ratio of the loss to storage modulus, called tan delta, is a useful and sensitive rheological parameter for predicting the stability of suspensions. Both the storage modulus and the yield stress serve to quantify the amount of structure in a material.

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