For the unheated milk sample, the consistency coefficient of the
concentrate at 35% total solids was similar to the heated sample at
pH 6.7; however, at 45% total solids the consistency coefficient for
the concentrate from the unheated milk was markedly lower than
those of the heated milk samples. This is largely consistent with the
results of Snoeren et al. (1982) who showed that the viscosity of
concentrates from heated milk increased markedly above about
43% total solids, whereas those from unheated milk increased
markedly above about 49% total solids. From these experiments, the
milk samples in all subsequent experiments were concentrated to
35% total solids as this was easier to attain using rotary evaporation,
and the samples at these concentrations showed a marked difference
in their consistency coefficients.