Rheology of mozzarella cheese: Extrusion and rolling

A capillary rheometer was used to determine the processability and rheology of mozzarella cheese over the temperature range of 25–60 °C. End pressure corrections, which are corrections associated with the entry and exit of the mozzarella cheese in and out of the capillary die, were found to be significant. Surprisingly, wall slip was found to be insignificant up to shear stress values of 30 kPa. Capillary extrusion at low temperatures (<50 °C) resulted in extrudates that were distorted, while at higher temperatures (>50 °C), the extrudates were fairly smooth. Rolling experiments at 25 °C indicated that rolling can be used to shape mozzarella cheese (at a reduction ratio <2.1) without fracturing. Based on the extrusion and rolling experiments, mozzarella cheese can be described as a power law fluid with an index of about 0.24, while at higher temperatures (30 °C