Structural changes during starch pasting using simultaneous Rapid Visco Analysis and small-angle neutron scattering
Structural changes during starch pasting using simultaneous Rapid Visco Analysis and small-angle neutron scattering
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DOI：
10.1016/j.carbpol.2012.01.066
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发表时间：
2012-04-15
影响因子：
11.2
通讯作者：
Gilbert, Elliot P.
中科院分区：
文献类型：
--
作者：
Doutch, James;Bason, Mark;Gilbert, Elliot P.
快速粘度分析（RVA）是广泛用于确定淀粉浆料的粘度特性的工业范围的方法，其使得能够提取关于糊化特性的信息;然而，对于在标准方案期间发生的结构变化知之甚少。对商业RVA仪器进行了修改，以允许中子束通过其加热块和桨组件，从而能够同时测量各种商业淀粉上的SANS和RVA。在标准的13分钟RVA过程中，在0.018-0.2 A（-1）的q范围内，以1分钟的间隔进行SANS测量。在每种淀粉中，观察到众所周知的层状结构，直到粘度开始显著增加的点。在这个阶段，层状结构瞬间转变;散射图案表明形成了大规模结构，没有明显的半结晶性质，其空间排列可以用分形凝胶来分析。在假设它们是球状的情况下，该凝胶的基本构建块在所有测试的淀粉中似乎具有约1 nm的尺寸。所形成的聚集体的尺寸是几倍大，并且发现在实验的时间过程中变化。(C)2012爱思唯尔有限公司保留所有权利。
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. (C) 2012 Elsevier Ltd. All rights reserved.