The breakdown ratio (G’BDr (%)¼ [(G’max G0
90 C)/
G0
90 C
100%]), an indirect measure of the thermal stability and
degree of disintegration of starch granules varied widely between
50.7% (WR6) and 97.4% (WR9). Keetels et al. (1996b) postulated that
breakdown of the amylopectin matrix inside the swollen starch
granules and disentanglement of branches during prolonged
heating would cause the granules to become less rigid. G’BDr
showed significant negative correlations with TG’ (r¼0.665) and
TG0
max (r¼0.810). Thus, it can be confirmed that breakdown ratio is
inversely proportional to swelling extent of starch granules.