A NMR self-diffusion study of the porous structure of starch granules
Författare
Summary, in English
The equilibrium self-diffusion of water contained within the porous structure of three different types of starch, viz. corn, wheat and potato starch was investigated. The samples were exposed to humid air until they reached a certain water content, the value of which was determined from the <sup>1</sup>H NMR free induction decays. The water self-diffusion coefficient was determined by means of a pulsed-field-gradient stimulated-echo experiment. This experiment is susceptible to cross-relaxation effects, i.e. the transfer of longitudinal magnetization during the experiment; therefore, the cross-relaxation process was first quantified by means of Goldman-Shen-type experiments. The water self-diffusion could then be rationalized in terms of a distribution of diffusion coefficients, with an average value much reduced compared to bulk water. No dependence on the diffusion time in the range from 70 to 340 ms was observed, indicating that there are no impermeable barriers for the diffusion of water on a length scale of microns
Avdelning/ar
Publiceringsår
2002
Språk
Engelska
Sidor
47-51
Publikation/Tidskrift/Serie
Progress in Colloid & Polymer Science
Volym
120
Dokumenttyp
Konferensbidrag
Förlag
Springer
Ämne
- Physical Chemistry
Nyckelord
- corn starch
- porous structure
- nuclear magnetic resonance self-diffusion
- starch granules
- equilibrium self-diffusion
- potato starch
- pulsed-field-gradient stimulated-echo experiment
- cross-relaxation effects
- longitudinal magnetization
- plants
- Goldman-Shen-type experiments
- storage polysaccharide
- humid air
- water content
- <sup>1</sup>H nuclear magnetic resonance free induction decays
- water self-diffusion coefficient
- wheat starch
Conference name
Conference on Lipid and Polymer-Lipid Systems, 2002
Conference date
2002-10-01 - 2002-10-02
Conference place
Chia Laguna, Italy
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0340-255X
- CODEN: PCPSD7