The microscopic images of the samples are shown in Fig. 1. The
absence of intact starch granules in the PG samples indicates the
fully gelatinization of both samples during heating and drying over
the drum driers. Similar findings have been reported for other PG
cereal starches (Anastasiades et al., 2002; Majzoobi et al., 2011;
Yan & Zhengbiao, 2010). Addition of acetic acid however, altered
the smooth surface of PG starch to a more uneven structure and
the effect increased with increasing the concentration of acetic acid.
Similar effects have been observed for native and cross-linked
wheat starches and PG maize and wheat starch in the presence of
some other organic acids (Majzoobi et al., 2012, 2014a). These
changes may have some effect on functional properties of the samples
which need further investigations.