During the storage time the concentration of pH
4.6-soluble peptides increased from 2.74 ± 0.05 mM to
6.96 ± 0.12 mM, 15.9 ± 0.3 mM and 27.7 ± 0.2 mM in case of
1 pkat mL1
, 10 pkat mL1 and 100 pkat mL1 added enzyme. These
increases of free peptides are equivalent to the unheated peptidase
containing milk samples. This fact is a further evidence for the heat-
resistance of the peptidase against UHT treatments.