Rheology of mozzarella cheese

The rheological properties of mozzarella cheese were studied by using a parallel plate, a sliding plate, an extensional and a capillary rheometer over a temperature range of 25–60 °C. While mozzarella cheese behaves as a semisolid at room temperature, it behaves mostly as a liquid at higher temperatures (typically greater than 40 °C). The rheological data obtained from the various pieces of rheometers were compared. Differences among the various data sets were observed and these were demonstrated to be due to the inherent changes to the material structure during testing and to the changes in the physical properties of the cheese at different temperatures. Mozzarella cheese is a viscoelastoplastic material at room temperature, which becomes viscoelastic at about 60 °C. Its yield stress gradually decreases with increase of temperature pointing to structural changes that occur at elevated temperatures. A Herchel–Buckley viscoplastic rheological model was found to describe adequately its rheology.