particles were further homogenized to reduce their particle size.
Fig. 5 shows the particle size distribution of the fine gel particle
suspensions prepared under the various homogenization conditions
and various salt concentrations. The size distribution of the
SPI and LMW-SPI coarse gel particles homogenized by the lowspeed
blender expressed as bold lines reasonably corresponds to
the microscopic observations under all added salt conditions
(Fig. 3). The results indicate that the large particles observed via the
microscope in the SPI suspensions were strongly coagulated aggregates
that were not be easily dissociated even by the high
dilution used for particle size analysis. On the other hand, according
to statistical correlation analysis performed, representative values
from the distributions of SPI and LMW-SPI coarse gel particles, that
is d3,2, d4,3 and d50 (Table 1) did not clearly correlate with either
surface hardness or elasticity of the SPI and LMW-SPI macrogels
obtained from texture tests (Fig. 1), suggesting that the size of SPI
gel particles does not necessarily depend on the texture properties
of the macrogels but does relate to the original structure of macrogel
networks, etc.
The particle size of SPI coarse and fine gel particle suspensions
was larger than that of LMW-SPI gel particle suspensions under all
salt conditions, particularly larger under conditions of no added salt
or NaCl added conditions (Fig. 5 and Table 1). The particle size of
LMW-SPI gel particle suspensions containing added CaCl2 and
MgCl2 was larger than that of the suspensions containing no added
salts and added NaCl, while it was rather smaller than that of all SPI
gel particle suspensions. For all suspensions, the size of fine gel
particles generally decreased in the order Blender < Blender þ High
speed blender < Blender þ Ultrasonicator < Blender þ Jet homogenizer.
Thus, the smallest gel particles were obtained via a
combination of homogenization processes: the juice blender