One‐Dimensional Nuclear Magnetic Resonance Studies of Starch and Starch Products

Abstract

Abstract The use of one‐dimensional Nuclear Magnetic Resonance (NMR) spectroscopy as applied to structural studies of starch, starch products and glycogen is reviewed. Proton, carbon‐13 and phosphorus‐31 NMR spectra of a range of starches and starch products are described. These spectra, particularly carbon‐13 NMR spectra, permit one to obtain structural information regarding these molecules. From the proton NMR spectra, which can be obtained with greater sensitivity, it is possible to determine the DP (degree of polymerization, the average number of glucose units per molecule) and the degree of branching (the proportion of glucose units which are (1→6) linked) without recourse to chemical or enzymatic methods. Moreover, the anomer distribution of the reducing sugars can be determined by 1 H or 13 C NMR. Finally, some examples of the application of NMR to follow the time course of enzymatic digestion and sugar anomerization are discussed, as is the solid‐state NMR of starch and glycogen. The phosphorus‐31 NMR spectra provide information about the nature of the phosphate groups in potato starch.