Flow Behavior of Native Corn and Potato Starch Granules in Aqueous Suspensions
| Autor: | Nasibeh Y. Sinaki, Martin G. Scanlon |
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| Rok vydání: | 2016 |
| Předmět: |
Dilatant
Materials science Starch Rheometer Relative viscosity Biophysics Bioengineering 02 engineering and technology 01 natural sciences Applied Microbiology and Biotechnology Analytical Chemistry Physics::Fluid Dynamics Viscosity chemistry.chemical_compound 0103 physical sciences Composite material Potato starch 010304 chemical physics Granule (cell biology) food and beverages 021001 nanoscience & nanotechnology Condensed Matter::Soft Condensed Matter chemistry 0210 nano-technology Shear flow Food Science |
| Zdroj: | Food Biophysics. 11:345-353 |
| ISSN: | 1557-1866 1557-1858 |
| Popis: | The flow behavior of native corn and potato starch granule suspensions prepared in a concentrated sucrose solution has been investigated. Measurements were performed using a rotational rheometer with a concentric cylinder geometry. Starch suspensions were dilute to semi-concentrated (1 % to 25 % by volume). Shear and dynamic viscosity were measured by shear flow and dynamic oscillatory testing at 20, 50 and 80 °C. The starch suspensions exhibited essentially Newtonian behavior at all solid contents, although at higher solid volume fractions there was evidence of slight shear thickening. The relative viscosity of suspensions increased with increasing starch granule content, and the data conformed well to Maron-Pierce’s equation. An increase in maximum packing fraction and gravitational depletion of the starch granules with increasing temperature resulted in lower relative viscosities at higher temperatures. Also, the relative viscosities of potato starch granule suspensions with bigger, more oval and anisometric particles were lower than those of corn starch suspensions where granules were closer to sphericity but were angular in shape. Oscillatory shear testing results showed the presence of viscoelastic properties at intermediate solid volume fractions at low frequencies; in addition, the relative shear viscosity was higher than the relative dynamic viscosity, probably due to the formation of shear-induced structures during the shear flow test. |
| Databáze: | OpenAIRE |
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