Roles of protein, starch and sugar in the texture of sorghum biscuits
Roles of protein, starch and sugar in the texture of sorghum biscuits
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DOI：
10.1016/j.lwt.2020.110323
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发表时间：
2021-01-01
影响因子：
6
通讯作者：
Taylor, John R. N.
中科院分区：
文献类型：
--
作者：
Adedara, Olumide A.;Taylor, John R. N.
这项研究调查了为什么尽管高粱面团中不含麸质，但由高粱粉制成的饼干却具有与小麦饼干相似的质地。电子显微镜显示，高粱饼干中的高粱谷醇溶蛋白蛋白体保持完整，因此不太可能对饼干的结构和质地做出贡献。偏光显微镜观察发现，高粱饼干中的淀粉颗粒没有糊化。增加面团含水量会增加高粱饼干的断裂强度和脆性。然而，增加面团中预糊化高粱粉的比例降低了高粱饼干的断裂强度，表明淀粉糊化削弱了饼干结构。相反，增加面团的蔗糖含量会增加高粱饼干的断裂强度和脆性。当蔗糖含量为 20%（以面粉为基础）时，高粱饼干的断裂强度和脆性与玛丽饼干和脆小麦饼干相似。 DSC和X射线衍射表明，高粱饼干和小麦饼干中的糖均处于玻璃态，偏光显微镜显示糖玻璃嵌入或包裹着高粱饼干粉颗粒。结论是，这种糖玻璃基质决定了高粱饼干的强度和粘着性。
This study investigated why biscuits made from sorghum flour have a similar texture to wheat biscuits despite the absence of gluten in sorghum dough. Electron microscopy revealed that the sorghum prolamin protein bodies remained intact in the sorghum biscuits and hence were unlikely to contribute to biscuit structure and texture. Polarized light microscopy showed that the starch granules in the sorghum biscuits were not gelatinized. Increasing dough water content increased the breaking strength and brittleness of sorghum biscuits. However, increasing the proportion of pre-gelatinized sorghum flour in the dough reduced the breaking strength of the sorghum biscuits, indicating that starch gelatinization weakened the biscuit structure. In contrast, increasing the sucrose content of the dough increased sorghum biscuit breaking strength and brittleness. At 20% sucrose (flour basis), the sorghum biscuits had similar breaking strength and brittleness to both Marie and sugar-snap wheat biscuits. DSC and X-ray diffractometry showed that the sugar in both the sorghum and wheat biscuits was in the glassy state and polarized light microscopy revealed that the sugar glass embedded or enveloped the sorghum biscuit flour particles. It is concluded that this sugar glass matrix is responsible for the strength and cohesiveness of the sorghum biscuits.