A new open-access publication by Mustapha and collaborators has been published in the journal Food Hydrocolloids, describing how he used various ssNMR measurements to probe alginate hydrogel structure and (re)hydration. Alginates can be cross-linked with calcium to form hydrogels, which are used in many different types of applications. This includes their use in slow-release drug delivery as well as food/nutritional applications. In this new paper, Mustapha shows how 1H, 2H and 13C ssNMR measurements can be used to see how these hydrogels are structured, but especially also how they are hydrated by the aqueous solvent. A key feature of the work is the use of 1H MAS NMR to detect the water molecules in the hydrogel macropores as well as those waters directly interacting with the alginate. The two types of water molecules form distinct ‘pools’ in the hydrogel, which can be nicely distinguished by their different molecular motion. The latter is detected via different relaxation measurements, in these NMR experiments.
To read more:
El Hariri El Nokab, M..; Lasorsa, A.; Sebakhy, K. O.; Picchioni, F.; van der Wel, P. C. A. Solid-State NMR Spectroscopy Insights for Resolving Different Water Pools in Alginate Hydrogels. Food Hydrocolloids 2022, 107500.