大豆分离蛋白溶液/乳液酸化过程的微观流变学研究  

Studies on the Microrheology of Soybean Protein Isolate(SPI) Solution and Emulsion during Acid-induced Gelation Process

作　　者：叶晶 吕瑞鹤 苏春霞 冯有楠 李静[1] 杨楠[1,2,3] 方亚鹏[1,2,3] Ye Jing;Lii Ruihe;Su Chunxia;Feng Younan;Li Jing;Yang Nan;Fang Yapeng(Glyn O. Phillips Hydrocolloid Research Centre , Department of Bioengineering and Food Science , Hubei University of Technology, Wuhan 430068;Hubei Collaborative Innovation Centre for Industrial Fermentation, Hubei University of Technology, Wuhan 430068;Food Hydrocolloid International Science and Technology Cooperation Base of Hubei Province, Hubei University of Technology, Wuhan 430068)

机构地区：[1]菲利普斯亲水胶体研究中心生物工程与食品科学学院湖北工业大学,武汉430068 [2]工业发酵湖北省协同创新中心湖北工业大学,武汉430068 [3]湖北省食品胶体国际科技合作基地湖北工业大学,武汉430068

出　　处：《中国食品学报》2019年第3期23-34,共12页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家自然科学基金项目(31571797;31401649);湖北省教育厅重点项目(D20181403)

摘　　要：首次通过粒子示踪微流变学结合宏观流变学方法研究了大豆分离蛋白(SPI)溶液及其稳定的乳液酸化过程中微观/宏观流变学性质的变化。宏观流变学研究表明:酸化过程中,SPI溶液和乳液体系的黏弹模量均先增大后减小,SPI溶液经历了溶液(G″>G′)-凝胶(G′>G″)-解凝(G″>G′)的过程,而SPI乳液则一直存在一定的黏弹性结构,表现为G′>G″;微观流变学结果显示,示踪粒子在SPI溶液和乳液体系酸化过程中的均方位移(MSD)均先减小后增大,MSD的幂指数最终均小于1;酸化时间较长时,示踪粒子的连续位移均呈负相关性,且乳液强于溶液。上述结果说明SPI溶液酸化过程中,蛋白质先聚集后解聚,而酸化过程后期,体系仍存在一定的蛋白质聚集体;SPI乳液酸化过程中,体系在最初状态存在一定的乳滴聚集体,之后形成蛋白质和乳滴双重聚集体,体系的黏弹性更强,在酸化过程后期,体系仍存在较强的未完全解聚的乳滴和蛋白质的聚集体。本研究结果说明了微观流变学与宏观流变学的互补性。In this research, the microrheology and macrorheology of the soybean protein isolate(SPI) solution and the emulsion stabilized by SPI were first studied by particle tracking and bulk-rheology techniques. The macrorheology results show that the viscoelastic moduli of SPI solution and SPI emulsion increased first and then decreased during the acidification process. The SPI solution has gone through solution(G′>G″)-gel(G″>G′)-network decomposition(G″>G′) process, while the SPI emulsion has viscolastic structure with G′>G″ during the whole acidification process. The microrheology results show that the mean squared displacement(MSD) of the tracer particles embedded in the SPI solution and the SPI emulsion decreased first and then increased, and the power-law index of MSD was both smaller than 1 at the end of acidification. In the late stage of the acidification process, the successive displacement of the tracer particles is negatively correlated, and the correlation of the emulsion is stronger than that of the solution. The above results indicate that proteins first aggregate and then decompose in the acidification process of SPI solution, but in the late stage of acidification, a certain amount of protein aggregates still exist in the system. While in the acidification of SPI emulsion,the system has a certain amount of droplet aggregation in the initial state and then forms a double network structure of proteins and droplets with stronger viscoelasticity. But in the late stage of acidification, strong unresolved droplet and protein aggregates still exist. This research has reflected the complementarity of microrhology and macrorheology methods.

关 键 词：大豆分离蛋白 酸致凝胶 乳液 粒子示踪微流变学 

分 类 号：TS201.21[轻工技术与工程—食品科学]