title: Water mobility within arabinoxylan and β-glucan films studied by NMR and dynamic vapour sorption.
abstract: BACKGROUND
  The main purpose of this research was to determine the impact of the structure and organisation of polysaccharides on the hydration properties of the cell walls of cereal grains. In order to remodel the lamellar assembly of arabinoxylan (AX) and (1 → 3)(1 → 4)-β-D-glucan (BG) within the endosperm cell walls, films were prepared and analysed using dynamic vapour sorption and time domain nuclear magnetic resonance spectroscopy.
  
  
  RESULTS
  The water diffusivities within the AX and BG films were measured at 20 °C by observing the water sorption kinetics within a mathematical model based on Fick's second law. The evolution of spin-spin relaxation times of water protons measured by increasing the temperature is explained by the additional contributions of motion of the protons of polysaccharides and/or rapid chemical exchanges of protons between water and hydroxyl groups of polysaccharides.
  
  
  CONCLUSIONS
  The difference between patterns of water behaviour within the AX and BG films can be related to the difference in their nanostructures. The smaller nanopores of the BG films cause their nanostructure to be more compact.
authors.affiliation: UR1268 Biopolymères, Interactions, Assemblages, INRA, Rue de la Géraudière, BP 71627, F-44316 Nantes, France.
authors.forename: Ruifeng
authors.initials: R
authors.lastname: Ying
authors.forename: Cécile
authors.initials: C
authors.lastname: Barron
authors.forename: Luc
authors.initials: L
authors.lastname: Saulnier
authors.forename: Corinne
authors.initials: C
authors.lastname: Rondeau-Mouro
mesh_terms: D002152:Calorimetry, Differential Scanning; D002473:Cell Wall / Q000737:chemistry*; D004058:Diffusion; D002523:Edible Grain / Q000737:chemistry*; D056625:Endosperm / Q000737:chemistry; D001467:Hordeum; D007700:Kinetics; D008954:Models, Biological; D008956:Models, Chemical; D019906:Nuclear Magnetic Resonance, Biomolecular; D016062:Porosity; D013696:Temperature; D044366:Transition Temperature; D014908:Triticum / Q000737:chemistry; D014783:Viscosity; D014867:Water / Q000032:analysis*; D014990:Xylans / Q000737:chemistry*; D047071:beta-Glucans / Q000737:chemistry*
chemical_list: D014990:Xylans; D047071:beta-Glucans; D014867:Water; C085118:arabinoxylan