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Updated: Aug 15, 2026

Atomic Scale Structural Studies of Macromolecular Assemblies by Solid-state Nuclear Magnetic Resonance Spectroscopy
Published on: September 17, 2017
Molecular characterization around a glassy transition of starch using (1)H cross-relaxation nuclear magnetic
Y Vodovotz1, L C Dickinson, P Chinachoti
1Department of Food Science and Technology, The Ohio State University, 2121 Fyffe Road, Columbus, Ohio 43210-1097, USA. vodovotz.1@osu.edu
Abstract:
The aim of this work was to characterize the glassy-rubbery transition in starch gels using molecular (NMR) techniques. Proton cross-relaxation ((1)H CR) NMR spectra of gelatinized starch ( approximately 50% mc) were obtained by cooling stepwise from 20 to -30 degrees C. A significant line broadening was observed in the CR spectra between 0 and -10 degrees C. Deconvolution of the spectra into its component curves (broad and narrow) yielded a peak amplitude, width at half-height, and peak area for each curve. Between 0 and -10 degrees C (temperatures around T(g)), a significant line width change in the broad component (rigid solid) was apparent. These observed qualitative changes may be evidence of a glassy-rubbery transition at a molecular (short-range) level which are strengthened by a similar transition temperature range found previously with (13)C CP-MAS and DMA tan delta(T) measurements. However, the increase in the relative quantity of rigid protons observed by (1)H CR NMR spectra could also be attributed to ice. The (1)H CR NMR method showed its potential application for probing solid components in gels using a simple and economical NMR spectrometer, without the need for a solid-state instrument.
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