NMR relaxation investigation of the native corn starch structure with plasticizers

The influences of starch, glycerol and water ratios on the structure, morphology and dynamics of starch polymer chains were investigated by NMR relaxation method. The 1HNMR CPMG echo decays and saturation recovery build-up curves were recorded and analyzed using the UPIN algorithm in order to get the spin-spin T2 and spin-lattice T1 relaxation times distributions. Significant differences between the CPMG curves were observed for native starch and the formulas in which water is added, whether these have or not glycerol in composition. For the formula which contains both plasticizers (water and glycerol), the CPMG curves decay slowly, indicating the presence of more mobile components.