| Autor: |
Douglas Clowes, James Doutch, Elliot P. Gilbert, Ferdi Franceschini, Mark Bason, Kevin James |
| Rok vydání: |
2012 |
| Předmět: |
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| Zdroj: |
Carbohydrate Polymers. 88:1061-1071 |
| ISSN: |
0144-8617 |
| DOI: |
10.1016/j.carbpol.2012.01.066 |
| Popis: |
Rapid Visco Analysis (RVA) is an industry-wide method extensively used for determining the viscous properties of starch slurries enabling information to be extracted on pasting properties; however little is known about structural changes that occur during standard protocols. A commercial RVA instrument was modified to allow the passage of a neutron beam through its heating block and paddle assembly to enable the simultaneous measurement of SANS and RVA on a variety of commercial starches. SANS measurements were made at 1 min intervals throughout a standard 13 min RVA process across a q range of 0.018–0.2 A−1. In each of the starches, the well-known lamellar structure was observed up to the point at which the viscosity began to increase markedly. At this stage, the lamellar structure transformed instantaneously; the scattering patterns are indicative of the formation of a large scale structure with no apparent semi-crystalline properties and whose spatial arrangement may be analysed in terms of a fractal-like gel. The basic building blocks of this gel, under the assumption that they are spheroidal, appear to have dimensions of approximately 1 nm across all the starches tested. The sizes of the aggregates formed are several times larger and were found to vary across the time course of the experiment. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect