热诱导-自组装大豆蛋白凝胶结构与功能特性构效关系研究

Study of the relationships between structure and functional properties of heating induction-self-assembly soy protein gels

中文关键词:  11S/7S蛋白比例  热处理  二硫键  流变学  凝胶强度  

英文关键词:11S/7S protein ratio  heat treatment  disulfide bond  rheology  gel strength

中文摘要:

      目的 研究不同11S/7S比例大豆蛋白热诱导凝胶结构与功能特性的关系。方法 配比不同11S/7S比例蛋白分散液, 在100℃下对其热诱导凝胶化, 对其蛋白二级结构、Zeta电位、粒径、表面疏水性、浊度、凝胶流变学、质构学指标进行分析。结果 随着11S/7S蛋白比例从0.5/1.0增加到3.0/1.0, 蛋白凝胶的粒径增大到原来的1.91倍、二硫键含量从3.463 μmol/g增大到6.551 μmol/g(1.81倍)、表面疏水性减少了1/5。二级结构中β-折叠增加、α-螺旋减少以及Zeta电位绝对值的增加均与11S所占比例呈正相关; 流变学频率扫描结果显示11S蛋白占比越高, 凝胶的储能模量G′值越高, 凝胶硬度也显著增加了43.2%。凝胶硬度与二硫键含量、表面疏水性的相关性系数绝对值分别是0.946和0.789。结论 大豆蛋白热诱导凝胶中, 11S蛋白比例增多, 更多的二硫键形成促进了蛋白结构发生重排, 疏水基团进一步掩埋形成紧密的凝胶网络结构。蛋白凝胶巯基及二硫键含量变化代表凝胶结构状态改变,二硫键含量越多, 凝胶网络结构越紧密。

英文摘要:

      Objective To study the relationship between the structure and functional properties of heat-induced gel with different 11S/7S ratios of of soybean protein. Methods The protein dispersions with different 11S/7S ratios were thermally induced gelation at 100℃, and the indexes inculding secondary structure, Zeta potential, particle size, surface hydrophobicity, turbidity, gel rheology and texture were analyzed. Results With the increase of 11S/7S protein ratio from 0.5/1.0 to 3.0/1.0, the particle size of protein gel increased to 1.91 times of the original, and the disulfide bond content increased from 3.463 μmol/g increase to 6.551 μmol/g (1.81 times), surface hydrophobicity reduced by 1/5. In the secondary structure, the increase of β-sheet, the decrease of α-helix and the increase of Zeta potential absolute value were all positively correlated with the proportion of 11s; rheological frequency scanning results showed that the higher the proportion of 11s protein, the higher the storage modulus G′ value of the gel. The gel strength also increased significantly by 43.2%. The absolute values of the correlation coefficients between gel strength and disulfide bond content and surface hydrophobicity were 0.946 and 0.789, respectively. Conclusion In the heat-induced gel of soybean protein, the proportion of 11S protein increases, the formation of more disulfide bonds promotes the rearrangement of protein structure, and the hydrophobic groups are further buried to form a tight gel network structure. The change of sulfhydryl group and disulfide bond content of protein gel represents the change of gel structure. The more disulfide bond content is, the tighter the gel network structure is.