Physicochemical properties of soy protein: effects of subunit composition.
Physicochemical properties of soy protein: effects of subunit composition.
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DOI：
10.1021/jf201077b
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发表时间：
2011-08
影响因子：
6.1
通讯作者：
Guangyan Qi;K. Venkateshan;Xiaoqun Mo;Lu Zhang;X. Sun
中科院分区：
文献类型：
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作者：
Guangyan Qi;K. Venkateshan;Xiaoqun Mo;Lu Zhang;X. Sun
大豆蛋白弹性体（SPE）在其天然状态下表现出弹性、可延展性和粘性等特性，作为小麦面筋的替代品具有巨大潜力。本研究的目的是更好地理解大豆蛋白亚基（多肽）对SPE功能特性的作用。根据伴大豆球蛋白（7S）和大豆球蛋白（11S）球蛋白的不同溶解性，在不同pH值下提取蛋白质，制备了六种具有不同亚基组成的大豆蛋白样品。含有大量由α'和α亚基形成的高分子量聚集体的大豆蛋白，在动态弹性和粘性模量方面比其他大豆蛋白样品表现出更强的粘弹性固体行为。电泳结果显示，这些聚集体主要通过二硫键稳定，这也导致了更高的变性焓（通过差示扫描量热法表征）以及通过透射电子显微镜观察到的更大尺寸的蛋白质聚集体。此外，通过扫描电子显微镜观察到，最具粘弹性的大豆蛋白样品的蛋白质颗粒表面平整光滑，而其他样品的颗粒表面粗糙且多孔。据推测，α'和α形成聚集体的能力以及大豆蛋白中由此产生的适当的蛋白质 - 蛋白质相互作用是对SPE连续网络的关键贡献。
Soy protein elastomer (SPE) exhibits elastic, extensible, and sticky properties in its native state and displays great potential as an alternative to wheat gluten. The objective of this study was to better understand the roles of soy protein subunits (polypeptides) contributing to the functional properties of SPE. Six soy protein samples with different subunit compositions were prepared by extracting the proteins at various pH values on the basis of the different solubilities of conglycinin (7S) and glycinin (11S) globulins. Soy protein containing a large amount of high molecular weight aggregates formed from α' and α subunits exhibited stronger viscoelastic solid behavior than other soy protein samples in terms of dynamic elastic and viscous modules. Electrophoresis results revealed that these aggregates are mainly stabilized through disulfide bonds, which also contributed to higher denaturation enthalpy as characterized by DSC and larger size protein aggregates observed by TEM. Besides, the most viscoelastic soy protein sample exhibited flat and smooth surfaces of the protein particles as observed by SEM, whereas other samples had rough and porous particle surfaces. It was proposed that the ability of α' and α to form aggregates and the resultant proper protein-protein interaction in soy proteins are the critical contributions to the continuous network of SPE.