Rheological and calcium equilibrium changes during the ripening of Cheddar cheese

The small deformation rheological properties and the calcium (Ca) equilibrium of Cheddar cheese were investigated as a function of ripening time. The proportion of insoluble Ca as a percentage of the total Ca decreased from ∼72 to 57% between 3 days and 9 months; most changes occurred within the first 4 weeks. During ripening, the storage modulus (G′) of the cheese increased at low temperature, but decreased rapidly at high temperature. At temperatures >40 °C, the loss tangent increased to reach a maximum at a temperature of ∼70 °C in young cheese and there was a steady decline in this temperature during ripening. The maximum loss tangent values increased substantially during the first 4 weeks and then showed little change. Changes in the insoluble Ca content significantly correlated with pH 4.6 soluble nitrogen (pH 4.6 SN). Partial correlation analysis indicated that the insoluble Ca content was more significantly correlated with the rheological properties than was pH 4.6 SN.