Multi-scale NMR and MRI approaches to characterize starchy products

- This review collates briefly the research on the use of TD-NMR and MRµI in starchy products.
- Real-time quantitative measurements are promising to monitor starch processing.
- Composition, starch source and water availability in starch mixtures have been discussed.
- Development of 2D TD-NMR enhanced the information on multi-scale dynamics.
- Water transport diffusion kinetics can be measured in starchy products using MRµI technique.

This review deals with the use of Nuclear Magnetic Resonance techniques to monitor the behavior of starch as well as the migration and distribution of water during the processing or storage of starchy matrices. The aim is to emphasize the potentials of NMR techniques for the quantitative characterization of water transfers in starch-water systems on different length scales. Relaxation and self-diffusion experiments using low-field NMR spectrometry provided important information on the relationship between water dynamics and the microscopic organization of starch granules at various temperatures and water contents. Some works dealt with the botanical origin of starch but also the impact of possible additives. Indeed, the investigation on model starch-based systems was recently expanded to more complex real systems, including dough, bread, cakes, spaghetti and lasagna. Two-dimensional (2D) cross correlation methods have also been developed to elucidate chemical and diffusional proton exchange phenomena, and to improve the interpretation of results obtained in 1D. Finally, magnetic resonance micro-imaging methods were developed to study or to quantify water intake into starch-based matrices.