3.2. Enzyme activities
The highest levels of plasmin activity were found in Pategras
cheeses on the manufacturing day (Fig. 1). At the beginning of the
storage, Cremoso and Reggianito cheeses had similar plasmin activities,
but then the levels decreased in Pategras and Cremoso,
reaching the lowest values in the latter of all cheeses (p < 0.05).
This inhibition of plasmin activity during ripening is probably
due to the environment conditions of Cremoso cheese, especially
pH (Watkinson et al., 2001).
Plasminogen activity did not vary significantly over time of
storage for all cheeses: no activation of the precursor was found
(Fig. 2). Despite a diminution in the activity of Cremoso cheeses was
noticed at the beginning of ripening, it was not significative
(p > 0.05). The lowest values for plasminogen were recorded in
Pategras cheeses, which agrees with the highest values found in
this cheese type for plasmin, and suggests that plasminogen activation
may have proceeded during milk processing/cheese manufacture,
i.e., before ripening. Activation of plasminogen during
Pategras cheese making is probably due to curd washing. Indeed,
other authors attributed high hydrolysis of b-caseins in Gouda
cheeses to the enhanced activation of plasminogen caused by curd