reason for the different observations on age gelation of milk caused
by PL. If PL activity in the milk is high, the polypeptides could be
further degraded and inhibit the formation of a gel, before physical-
chemical changes will take place. Inmilk with only little residual PL
activity, physical-chemical changes induced by proteolysis could
occur prior to achieving a degree of proteolysis sufficient to cause a
gelation, which could be the case for observed sedimentation prior
to or instead of gelation (Kelly & Foley,1997; Newstead et al., 2006).
Thismay also explainwhy the degree of proteolysis and the onset of
gelation have not been directly correlated yet.