3.5. Heat coagulation time
The pH-heat coagulation time (HCT) profiles of the MPI-C, MPIMD17,
MPI-CSS38 and MPI containing glucose (MPI-G) solutions
are given in Fig. 3. They all had similar shape and had maximum
HCT (HCTmax) at pH 6.8. The HCTmax of MPI-C solution was
38 min and decreased substantially on addition of glucose polymers
to HCTmax of 30, 26 and 18 min in the MPI-MD17, MPICSS38
and MPI-G solutions, respectively. The pH value of HCTmax
in all 4 solutions remained unchanged at pH 6.8. This result was
partially in agreement with Liang et al. (2014), who reported that
the HCTmax of 10% MPC (82% protein content) solutions shifted
from pH 7.0 to pH 6.8 for 10% glucose but was unaffected for
10% MD with a DE value of 18. It was noted that the pH-HCT pro-
files of the MPI-MD17 solution did not exhibit a HCTmin. Instead,
MPI-MD17 solution had the pH-HCT profile with very low HCT values
at the acidic side of the spectrum. Above the pH 6.8, HCT of the
MPI-MD17 decreased with increasing pH (Fig. 3). The pH-HCT patterns
(Fig. 3) in the present study have not been reported in the literature
previously for sterilisation of MPI-carbohydrate solutions,