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Titre :
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Rheological behavior of cross-linked waxy maize starch dispersions during and after heating
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Auteurs :
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J. Tattiyakul ;
M. Rao
|
|
Type de document :
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article/chapitre/communication
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|
Année de publication :
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2000
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|
Format :
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p. 215-222
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Langues:
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= Anglais
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Catégories :
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PHYSIQUE ETAT DE LA MATIERE
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Mots-clés:
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AMIDON DE MAIS
;
DISPERSION
;
RHEOLOGIE
;
CHAUFFAGE
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Résumé :
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A model was developed to describe the complex viscosity versus temperature ( -T) data on 5% (w w) cross-linked waxy maize (CWM) starch dispersions (STDs) obtained over the frequency range ( ) 1.26-31.38 rad s and temperature range 55-95°C. The 5% CWM starch dispersions had an onset gelatinization temperature at 60°C with a peak complex viscosity ( ) of 6.9 Pa s at 64°C. The lowest post-gelatinization complex viscosity ( ) was about 0.85 at 80°C. The complex viscosity was related to the apparent viscosity using a Modified Cox-Merz rule. Flow tests on gelatinized 5% CWM STDs showed that the sample exhibited a combined time-dependent shear-thickening (antithixotropic) and time-dependent shear-thinning (thixotropic) behavior. The antithixotropic behavior, that appears to have resulted from a shear-induced structure formation, predominated when the level of shear stress imposed on the sample was less than 120-150 Pa.
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Source :
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Carbohydrate polymers, vol.43
|
