A differential thermal analysis of the gelatinization and retrogradation of wheat starches with different amylopectin chain lengths

This paper reports on the influence of amylopectin chain length distributions on the gelatinization and retrogradation of starch. Wheat starch samples with different amylopectin chain length distributions were isolated, and the gelatinization and retrogradation phenomena of the samples were studied with differential scanning calorimetry (DSC). Wheat starch containing longer side chains of amylopectin (LCA) in higher ratios exhibited a sharper and deeper peak at higher temperatures in the heating DSC curve than did starch with low ratios. The retrogradation of starch was advanced with LCA. Although the re-gelatinization temperatures for retrograded starch varied slightly, the peak depth and enthalpy for re-gelatinization were higher with high ratios of LCA. For retrograded starch, each ordered region of amylopectin was not very different, however, more number of ordered regions was formed as the ratio of LCA of amylopectin increased.