硫酸铵沉淀分离富硒大豆蛋白的初步研究  

Preliminary study on ammonium sulfate precipitation of selenium- enriched soybean protein isolate

作　　者：赵小莉[1] 付洋[1] 赵强[1] 宁方建 熊华[1] 

机构地区：[1]南昌大学食品科学与技术国家重点实验室,江西南昌330047

出　　处：《食品工业科技》2016年第13期92-95,100,共5页Science and Technology of Food Industry

基　　金：国家自然科学基金项目(31301436)

摘　　要：本文采用碱提酸沉法从天然富硒大豆中提取分离蛋白(SPI),再分别用质量分数为40%、60%、80%的硫酸铵溶液对其进行分级沉淀,比较研究分离得到的不同富硒SPI组分间的差异,以探讨硫酸铵分离富硒SPI的方法。结果表明:浓度为60%硫酸铵溶液分离得到的富硒SPI组分中总硒含量和可溶性蛋白含量最高;圆二色光谱和SDS-PAGE结果表明不同浓度硫酸铵溶液分离的富硒SPI组分的二级结构和亚基组成有明显不同;通过X-射线衍射分析和原子力显微观察,发现三种富硒蛋白组分的晶型和表面形态也区别较大。因此,硫酸铵法对于沉淀分离富硒SPI的差异组分,是一种有效的初筛方法,且以60%的硫酸铵浓度为较佳。In this study,soybean protein isolate（SPI） was extracted by alkali extraction and acid precipitation from natural selenium-enriched soybean,and SPI was sequentially precipitated by 40% ,60%, and 80% of ammonium sulfate to obtain three protein fractions,which were 40%-SPI ,60%-SPI, and 80%-SPI. In order to explore ways of selenium- enriched SPI fractionation by ammonium sulfate, the differences among the protein fractions were compared.The results showed that 60%--SPI had highest protein purity and selenium content.CD spectroscopy and SDS-PAGE results showed that the secondary structure and subunit composition were significantly different among the fractions.Through X-ray diffraction and atomic force microscopy, it found that crystal morphology and surface protein composition of the three fractions also varied widely. Therefore, ammonium sulfate salting precipitation was an effective primary screening method for separating selenium-enriched SPI with difference components, and 60% ammonium sulfate concentration was preferred.

关 键 词：大豆富硒蛋白 硫酸铵沉淀 二级结构 SDS-聚丙烯酰胺凝胶电泳 表面形态 

分 类 号：TS202.3[轻工技术与工程—食品科学]