Activation energy measurements in rheological analysis of cheese

Activation energy of flow (Ea) between 30 and 44 °C was calculated from temperature sweeps of cheeses with contrasting characteristics to determine its usefulness in predicting rheological behavior upon heating. Cheddar, Colby, whole milk Mozzarella, low-moisture part-skim Mozzarella, Parmesan, soft goat, and Queso Fresco cheeses were heated from 22 to 70 °C, and Ea was calculated from the resulting Arrhenius plots. Protein and moisture content were highly correlated with Ea. The Ea values for goat cheese and Queso Fresco, which did not flow when heated, were between 30 and 60 kJ mol−1. Cheddar, Colby, and the Mozzarellas did flow upon heating, and their Ea values were between 100 and 150 kJ mol−1. Parmesan, the hardest cheese, flowed rapidly with heat and had an Ea > 180 kJ mol−1. Ea provides an objective means of quantitating the flow of cheese, and together with elastic modulus and viscous modulus provides a picture of the behavior of cheese as it is heated.