Rheological Characteristics of Halberd Wheat Starch
The non-Newtonian behavior and dynamic viscoelasticity of Halberd wheat starch (23.0% amylose content) pastes were determined with a rheogoniometer. The flow curves, at 25°C, of Halberd starch pastes showed plastic behavior at concentrations of more than 4.0%. The shear viscosity of the starch paste...
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Published in | Die Stärke Vol. 61; no. 5; pp. 275 - 281 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
Weinheim
Wiley-VCH Verlag
01.05.2009
WILEY-VCH Verlag WILEY‐VCH Verlag Wiley |
Subjects | |
Online Access | Get full text |
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Summary: | The non-Newtonian behavior and dynamic viscoelasticity of Halberd wheat starch (23.0% amylose content) pastes were determined with a rheogoniometer. The flow curves, at 25°C, of Halberd starch pastes showed plastic behavior at concentrations of more than 4.0%. The shear viscosity of the starch pastes decreased gradually with an increase in temperature at concentrations less than 4.0%, but remained constant at a concentration of 5.0%. The storage modulus of the starch pastes increased with increasing concentration and remained high during increase in temperature up to 80°C. Almost the same storage modulus was observed upon addition of urea (4.0 M) to the paste at low temperature (0°C), and the modulus stayed at a large value with increase in temperature up to 60°C, which was estimated to be a transition temperature; then it decreased rapidly with further temperature increase. A transition temperature of 60°C was also observed in the dynamic viscosity. A very large storage modulus and dynamic viscosity were observed in alkaline solution (0.05 M NaOH) at low temperature (0°C), both quantities decreased slightly with increase in temperature up to 25°C, which was estimated to be a transition temperature, then decreased rapidly with further increase in temperature. A possible intermolecular hydrogen bonding between amylose and amylopectin molecules is proposed. |
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Bibliography: | http://dx.doi.org/10.1002/star.200800073 ark:/67375/WNG-7P0GX8Q6-9 ArticleID:STAR200800073 istex:5AF61C57FB8DC8F4889ABA80CBAB0F15B6EC06A5 |
ISSN: | 0038-9056 1521-379X |
DOI: | 10.1002/star.200800073 |