超高压均质处理大豆分离蛋白-磷脂复合物的理化性质研究  

Physicochemical Properties of Soy Protein Isolate-phospholipid Complex Treated by Ultrahigh Pressure Homogenization

作　　者：郑环宇[1,2,3] 孙美馨 张林 闫国森 朱秀清 韩建春[1,2,3] Zheng Huanyu;Sun Meixin;Zhang Lin;Yan Guosen;Zhu Xiuqing;Han Jianchun(College of Food,Northeast Agricultural University,Harbin 150030,China;Heilongjiang Green Food Science Research Institute,Harbin 150028,China;National Research Center of Soybean Engineering and Technology,Harbin 150028,China)

机构地区：[1]东北农业大学食品学院,哈尔滨150030 [2]黑龙江省绿色食品科学研究院,哈尔滨150028 [3]国家大豆工程技术研究中心,哈尔滨150028

出　　处：《大豆科技》2019年第3期14-21,共8页Soybean Science & Technology

基　　金：国家863项目“大宗食品品质改良蛋白配料制备关键技术研究与开发(2013AA102208)”;国家自然科学基金面上项目“多酚调控大豆蛋白乳液结构及其营养输送特性研究(31871809)”

摘　　要：以大豆分离蛋白-磷脂复合体系为研究对象,通过巯基含量测定和圆二色谱表征复合体系构象变化,并对体系乳化性、乳化稳定性和表面疏水性进行测定、采用扫描电子显微镜和SDS-PAGE凝胶电泳等技术手段解析了超高压均质处理对复合体系中大豆分离蛋白二级结构和理化(功能)性质影响。其结果表明,超高压均质-磷脂复合改性可以改进大豆分离蛋白的结构和性质,超高压均质处理后,SPI中所含有的暴露巯基和总巯基数量显著降低(P<0.05),体系引入磷脂后,可以减少巯基的氧化,使巯基含量显著上升(P<0.05)。SPI经过高压均质处理,其疏水基团外露,提高了其疏水性。通过圆二色性光谱可研析出,SPI经超高压均质处理后,其所含α-螺旋总量增加,β-折叠总量减少,无规则卷曲结构总量增加,且其空间稳定性下降,加入磷脂后,球蛋白结构稳定化。SDS-PAGE凝胶电泳图谱则表明,高压均质后,图谱条带发生颜色变化,加入磷脂亚基成分含量也发生改变。通过扫描电镜观察,高压均质后的SPI由球状结构变为片状,与磷脂结合得到的USPI-PLW片状结构变得小而薄,光滑且均匀。Soy protein isolate-phospholipid composite system was used as the research object.The conformations changes of the composite system were characterized by sulfhydryl content determination and circular dichroism.The emulsification,emulsion stability and surface hydrophobicity of the system were determined.By using scanning electron microscopy and SDS-PAGE gel electrophoresis,the effects of ultra-high pressure homogenization treatment on the secondary structure changes and physicochemical(functional)properties of soy protein isolate in the composite system were analyzed.The results showed that the ultra-high pressure homogenate-phospholipid complex modification could improve the structural properties of soy protein isolate.After ultra-high pressure homogenization treatment,the number of exposed sulfhydryl groups and total sulfhydryl groups contained in SPI was significantly decreased(P<0.05).After the phospholipids,the oxidation of the sulfhydryl groups can be reduced,and the sulfhydryl content was significantly increased(P<0.05).The SPI was subjected to high pressure homogenization treatment,and its hydrophobic group was exposed to improve its hydrophobicity.Circular dichroism spectroscopy results showed that the total amount ofα-helix increased,the total amount ofβ-sheet decreased,the total amount of random coil structure increased,and its spatial stability decreased after the SPI was treated by ultra-high pressure homogenization.After the addition of the phospholipid,the globulin structure was stabilized.SDS-PAGE gel electrophoresis showed that high pressure homogenization could cause dissociation polymerization of SPI,which made the band of the spectrum deeper and the content of phospholipid subunits changed.The results of scanning electron microscopy showed that the SPI after high pressure homogenization changed from a spherical structure to a sheet shape,and the USPI-PLW sheet structure obtained by combining with phospholipids became small,thin,smooth and uniform.

关 键 词：超高压均质 磷脂 大豆分离蛋白 结构性质 

分 类 号：TS214.2[轻工技术与工程—粮食、油脂及植物蛋白工程]