The results of this study showed that addition of acetic acid can
affect functional properties of the PGWS and PGCS. In the presence
of acetic acid, these starches exhibited lower viscosity than what
was expected and produced softer and less cohesive gels with
higher degree of syneresis during storage. These changes were
enhanced with increasing the concentration of acetic acid. The
effects of acetic acid on these starches appeared on the morphological
features of the samples. These changes may be related to starch
degradation due to acetic acid addition. Comparing the two samples,
it was found that the PGWS exhibited higher water uptake
and apparent cold water viscosity and resulted in gels with higher
consistency and cohesiveness with less syneresis. Further studies
are required to confirm the effects of pregelatinization process
and acetic acid addition on molecular structure of these starches