The Effect of Refrigerated Storage on the Rheological Properties of Three Commercial Mozzarella Cheeses

Abstract

The linear and non-linear viscoelastic properties and the effect of refrigerated storage on the rheological properties of three commercial mozzarella cheeses was studied. The linearity of the rheological behavior of mozzarella cheese increases with temperature because of the ability for the cheese to flow easier at higher temperatures as well as the lack of yield stress at elevated temperatures. The generalized Maxwell model parameters obtained from the linear viscoelastic data were found to describe the linear relaxation dynamics of the mozzarella cheese satisfactorily. It is also shown that the damping function of mozzarella cheese, which is a measure of the degree of non-linearity, can be described by a generalized Zapas model. Although, the different commercial mozzarella cheeses do not exhibit linear viscoelastic differences at room temperature, they do show significant differences at 60°C. The effect of refrigerated storage on the linear viscoelastic properties is brand-dependent and indicates structural differences among cheese samples. Finally it is shown that the dynamic moduli decrease with longer refrigerated storage due to proteolysis activities and/or weakening of the casein matrix.