The milk samples were warmed at 39.0 C in a temperature-controlled
water bath with gentle agitation for 30 min prior to rheological
experiments. ThepHvalues of the milk samples were adjusted to
6.5, 6.0, 5.8 and 5.6 using 1:4 diluted lactic acid and/or 1 M sodium
hydroxide solutions. Samples were incubated for a further 15 min
and the pH checked and readjusted if necessary.