3.3. Changes on proteolysis of Ibores raw goat milk cheese induced
by HP treatment
Table 3 shows the nitrogen fractions and FAA measured in
control and HP-treated cheeses. At day 2 of analysis, SN/TN and
Polypeptide N significantly increased (P < 0.05) after HP treatment.
On the contrary, FAA levels were reduced in HP-treated cheeses.
The relation SN/TN has traditionally been evaluated as a “ripening
index” for cheese. The effect of HP treatment on SN/TN fraction
could be caused by an increase of the residual coagulant action and/
or milk proteinases activity (e.g., plasmin) by a destabilization of
casein micelles induced by HP (Huppertz, Fox, & Kelly, 2004;
Regnault, Dumay, & Cheftel, 2006), which could enhance their
sensibility to proteolytic enzymes. In addition, studies about the
effect of HP on enzymatic activity in ewe and goat cheese have