QENS investigation of the dynamics of starch saccharides.
We present here quasi-elastic neutron scattering results on D20 hydrated samples of amylose, one of the main saccharide components of starch. Two different sample hydrations (h = 0.5 and 1.0 g D2O (g dry amylose)-1 have been investigated in the temperature range 170 to 350 K. Below 260 K only an elastic contribution is present in the spectra, while a quasi-elastic component shows up above this temperature. The elastic incoherent structure factor (EISF) associated with this component changes considerably with increasing temperature. For the sample with hydration h = 0.5 the confinement volume increases by a factor of four in going from 300 to 350 K, and the proportion of hydrogen involved in the confined diffusion motion increases as well from 30 to 55%. Similar effects are observed at the higher hydration investigated. The observed dynamics can be associated with the known plasticising role of water in polysaccharides.
Di Bari
M
M
Dipartimento di Fisica, Università di Parma, Parma, Italy.
Deriu
A
A
Albanese
G
G
Cavatorta
F
F
D000688:Amylose / Q000737:chemistry*; D002627:Chemistry, Physical / Q000379:methods*; D004058:Diffusion; D004548:Elasticity; D006859:Hydrogen / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry; D012542:Scattering, Radiation; D013053:Spectrophotometry / Q000379:methods; D013213:Starch / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry
D011134:Polysaccharides; D014867:Water; D006859:Hydrogen; D013213:Starch; D000688:Amylose