Lintnerization of two amylose-free starches of A- and B-crystalline types, respectively

Waxy maize starch (WMS) and potato amylopectin starch (PAPS), representing amylose-free A- and B-crystalline granules, respectively, were subjected to hydrolysis in diluted hydrochloric acid (lintnerization). The solubilization rate of the granules was dependent on the temperature, but there were only small differences between the samples. The compositions of the lintners obtained at 29degreesC were also similar, though the sensitivity to enzymatic debranching was different. The degree of debranching increased significantly if pullulanase and isoamylase were used successively. Because some branches remained resistant to enzymatic attack, the degree of scattered branching was difficult to estimate. The amount and composition of beta-limit dextrins suggested, however, that both starches contained scattered branches. Long chains and the shortest chains in the amylopectin molecules were sensitive to lintnerization and therefore probably located outside the crystallites. The composition of the PAPS lintners was dependent on the temperature of the lintnerization, whereas that of WMS lintners was not. The composition of a lintner from normal potato starch was compared with PAPS, and it is concluded that the presence of amylose has a higher effect than the type of crystallinity on the lintnerization results.