作　　者： ; ; ; ;

机构地区： 广东省农业科学院

出　　处： 《食品工业科技》 2013年第7期90-95,共6页

摘　　要： 以大豆分离蛋白(SPI)为研究对象,初步研究了超声促进大豆分离蛋白-糖接枝反应的机理。结果表明:与普通加热相比,当超声处理60min时,SPI的自由氨基含量由0.86mol/L增加到0.98mol/L;表面疏水性和表观巯基含量也有一定程度的增加,蛋白的肽链更加伸展,埋藏于分子内部的自由氨基不同程度的暴露,与糖分子接触的几率增加;同时,SPI分子中的α-螺旋和β-折叠明显减少,而无规则卷曲则明显增多,SPI分子由有序结构变得无序,蛋白的空间位阻降低,使蛋白与糖分子在激烈的振动中更加充分的接触,增加接枝反应的速率。 The mechanism of ultrasound promoting soy protein isolate（SPI）-saccharide graft reaction was studied by using soybean protein isolates as the research object. Compared with classical wet-heating, content of free amino acid increased from 0.86mol/L to 0.98mol/L when SPI was treated by ultrasonic for 60min. Surface hydrophobicity and content of apparent sulfhydryl content were also increased to a certain extent respectively.In this case, polypeptide chains of protein were more stretch,and part of free amino groups buried in the molecules inside were exposed.At the same time,c^-helix and [5-folding of SPI was significantly reduced while irregular coil was significantly increased,that showed ordered molecule structures become disordered and its steric hindrance reduced.The graft reaction of SPI-saccharide was accelerated because their more contacting led by intense vibration of ultrasound.

关 键 词： 超声处理 大豆分离蛋白 接枝反应 机制

领　　域： [轻工技术与工程] [轻工技术与工程]