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Biologische Systeme und Medizin Poster: Mi., 14:00–16:30 M-P196
Investigation of Native Starch Granules using Synchrotron Radiation Microdiffraction
Henrik Till Lemke 1 , Jean-Luc Putaux 2 , Andreas Blennow 3 , Manfred
Burghammer 5 , Ingo Grotkopp 4 , Klaas Kölln 4 , Martin Müller 4 , Christian
Riekel 5
1 Niels Bohr Institute, Copenhagen – 2 CERMAV-CNRS, Grenoble, France – 3 Royal
Veterinary and Agricultural University, Copenhagen – 4 Institut für Experimentelle
und Angewandte Physik, Universität Kiel – 5 European Synchrotron Radiation Facility,
Grenoble, France
The hierarchical structure of single starch granules was investigated using scanning
X-ray microdiffraction. Combined small- and wide-angle scattering experiments at the
1 µm level allowed spatially resolved investigation of the amylopectin microstructure
and the lamellar superstructure at multiple length scales in fully hydrated potato granules
of 50-100 µm diameter. The obtained fiber diffraction patterns showed changes
in both orientation and intensity of characteristic reflections, which could be modeled
by a ellipsoidal alignment of the lamellar structures around an eccentric origin. Investigation
of starch granules from plants with selectively altered enzyme distribution in
starch synthesis showed significant changes in crystallinity and lamellar distance. A
kinetic study of the hydration process in dried starch granules suggests different time
constants for the hydration of crystalline and amorphous regions.