A proton NMR relaxation study of the gelatinisation and acid hydrolysis of native potato starch

The effect of acid hydrolysis (Lintnerisation) and the thermal gelatinisation on the dynamic state of starch and the microscopic distribution of water within native potato starch granules is investigated with proton NMR relaxometry. The NMR relaxation data show several dynamic states of the amylose and amylopectin chains and clearly identify the melting transition during thermal processing. The Lintnerisation process is found to follow first-order kinetics and to shift and broaden the melting transition. The unique value of NMR relaxometry for monitoring the processing response of starch granules is discussed.