Lamellar structure change of waxy corn starch during gelatinization by time-resolved synchrotron SAXS
Lamellar structure change of waxy corn starch during gelatinization by time-resolved synchrotron SAXS
复制标题
利用时间分辨同步加速器 SAXS 观察蜡质玉米淀粉糊化过程中层状结构的变化
DOI：
10.1016/j.foodhyd.2016.07.024
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发表时间：
2017-01-01
影响因子：
10.7
通讯作者：
Liu, Xingxun
中科院分区：
文献类型：
--
作者：
Kuang, Qirong;Xu, Jinchuan;Liu, Xingxun
利用同步辐射小角和广角X射线散射（SAXS/WAXS）原位实验研究了淀粉糊化过程中片层结构的变化。以糯玉米淀粉为模型材料，排除直链淀粉的影响。基于一维线性相关函数，得到了层片晶区（d（c））、非晶区（d（a））的厚度和长周期距离（d（ac））。SAXS和WAXS结果揭示了糊化的多阶段性。首先，由于水渗透到结晶区域中，结晶层厚度优选增加。然后，非晶层的厚度显著增加，而晶态层的厚度减小。接下来，无定形薄片的厚度开始减小，可能是由于淀粉分子从薄片中异相。最后，无定形片层的厚度迅速减小，形成了比片层更大尺度的分形凝胶，随着温度的进一步升高，分形凝胶的厚度逐渐减小，这与淀粉分子链的浓度有关。该体系揭示了糯玉米淀粉的糊化机理，为淀粉无定形材料的加工提供了理论依据。(C)2016爱思唯尔有限公司版权所有
In situ experiment of synchrotron small- and wide-angle X-ray scattering (SAXS/WAXS) was used to study the lamellar structure change of starch during gelatinization. Waxy corn starch was used as a model material to exclude the effect of amylose. The thicknesses of crystalline (d(c)), amorphous (d(a)) regions of the lamella and the long period distance (d(ac)) were obtained based on a 1D linear correlation function. The SAXS and WAXS results reveal the multi-stage of gelatinization. Firstly, a preferable increase in the thickness of crystalline lamellae occurs because of the water penetration into the crystalline region. Then, the thickness of amorphous lamellae has a significant increase while that of crystalline lamellae decreases. Next, the thickness of amorphous lamellae starts to decrease probably due to the out-phasing of starch molecules from the lamellae. Finally, the thickness of amorphous lamellae decreases rapidly, with the formation of fractal gel on a larger scale (than that of the lamellae), which gradually decreases as the temperature further increases and is related to the concentration of starch molecular chains. This work system reveals the gelatinization mechanism of waxy corn starch and would be useful in starch amorphous materials processing. (C) 2016 Elsevier Ltd. All rights reserved.