大豆球蛋白自组装聚集及凝胶特性

研究了在低pH值、低离子强度下,分别加热诱导不同浓度11S(大豆球蛋白)和7S(大豆伴球蛋白)自组装纤维化聚集体的形成。通过平均粒径和Thioflavin T(硫磺素T)荧光光谱,对自组装纤维化聚集体的性质进行表征,并对其热致凝胶的流变学,硬度和微结构特性进行考察。结果表明:在低pH值、低离子强度的诱导条件下,蛋白浓度对自组装聚集的形成起着关键作用,随着诱导浓度的增大,蛋白的纤维化聚集越明显,7S比11S更容易形成纤维化聚集。在酸性环境下,大豆球蛋白的纤维化聚集程度越高,越有利于热致凝胶网络结构的形成。在相同的预处理条件下,11S自组装凝胶硬度强于7S。扫描电镜结果显示7S自组装凝胶的网络结构较11S致密,但有序性较11S低。

Research of Soybean Proteins Self-assembly Fibrils and Their Gelation Properties

The self-assembly fibrillar aggregations of soy glycinin and β-conglycinin at pH 2.0,85 ℃ with various protein concentrations were investigated using dynamic light scattering(DLS) and Thioflavin T fluorescence techniques.The heat-induced gelation properties including rheology,hardness and network structure of different fibrillar aggregations were characterized simultaneously.The results showed that protein concentration played an important role in the self-assembly aggregate formation at low pH and low ionic strength.The data suggested fibrillar aggregation progressively increased with the increasing of protein concentration.β-Conglycinin exhibited a higher ability to form thermally fibrillar aggregates than glycinin.The increasing degree of fibrillar aggregate was favorable for enhancing the network structure of heat-set gels.The hardness of glycinin fibril gel was stronger than that of β-conglycinin.Scanning electron microscopy observation indicated that the network of β-conglycinin fibril gel was more compact than glycinin,while the latter one was more in order.