The hydrolysis of S1-casein 9P and -casein A1
inMilk72 during
storage are shown in Fig 6.Both S1-casein 9P and -casein A1
decrease in an inverse sigmoidalmanner. Hydrolysis of casein by PL
can usually be described by an exponential decay function
(Newstead et al., 2006). In Milk72, a lag phase in the first 2e3
weeks storage preceded the exponential decay. This lag phase can
be attributed to the activation of PLG to active PL as shown in Fig. 4.
With increasing PL activity, the rate of hydrolysis increased.