Effect of freezing on the viscoelastic behaviour during the ripening of a commercial low-fat soft cheese

The effect of the freezing process (freezing at -25 degrees C, frozen storage at -25 degrees C during 33 days, and thawing at 6 degrees C) on the viscoelastic behaviour of a commercial low-fat soft cheese containing micro-particulated whey proteins as fat replacers at different ripening times (1, 21, 48, and 76 days) was studied. Frequency sweeps (0.01-10 Hz) at 20 degrees C in the linear viscoelastic region were performed. Frequency dependency of viscoelastic data was determined using power-law equations (G` = a omega(x), G '' = b omega(y)). Freezing process produced an increase in the maturation index, the viscous behaviour and a decrease in values of coefficient a. However, the decay rate of coefficient a during the studied ripening period was not influenced by this process. A negative correlation between a and maturation index was obtained. The results of this work indicated that the freezing process is a factor that contributes to the viscoelastic behaviour of the studied cheeses. (c) 2011 Elsevier Ltd. All rights reserved.