The preliminary experiments suggested that the pH of milk
during heat treatments may impact on the rheological properties of
concentrates prepared from the heated milk samples. To examine
this in more detail, the differences between milk concentrates from
pH-adjusted heated and unheated milk samples were compared at
the pH to which they were adjusted. Reconstituted skim milk
samples at pH 6.5, 6.7, 6.9, and 7.1 were either unheated or heated
at 90 C for 30 min and then concentrated to 35% total solids. The
consistency coefficients and flow behaviour indices were determined
at temperatures of 20, 30 and 40 C.