超声波预处理对玉米醇溶蛋白结构及其Pickering乳液稳定性的影响

Ultrasonic pretreatment improves the stability of zein and Pickering emulsion

为探究超声波预处理在反溶剂法制备玉米醇溶纳米颗粒(zein nanoparticle,ZNP)过程中的作用,并将ZNP通过静电作用与亚麻籽胶(flaxseed gum,FSG)结合形成复合颗粒,探究其对Pickering乳液稳定性的影响,对不同超声波处理条件对ZNP的内源荧光性、二级结构、粒径和电位的影响进行分析。结果表明,超声波预处理玉米醇溶蛋白的乙醇水溶液,可以显著降低ZNP的平均粒径,并提高ZNP的电位绝对值。在较低超声功率密度(230 W/cm2)下,粒径随着处理时间延长而进一步减少,电位绝对值增加,即稳定性提升。但当超声功率密度增加至460 W/cm2时,ZNP的粒径开始缓慢增大,电位绝对值降低。将经超声波预处理的ZNP与FSG按质量比1∶1均质混合,通过表面疏水性分析发现:由超声波预处理的ZNP可以与更多的FSG结合,提高亲水性,分析其原因可能是ZNP表面电位升高,促进了更多FSG结合在ZNP的表面,有效地抵御乳液中液滴的聚集及破裂。通过对热稳定性的研究发现,超声波预处理可以显著提升Pickering乳液的稳定性。该研究结果可为超声波预处理在ZNP及Pickering乳液制备过程中的应用提供一定的基础依据,并为制备更高效、热稳定的Pickering粒子提供一种新型绿色的途径。

In order to explore the roles of ultrasonic pretreatment in the preparation of zein nanoparticles(ZNP)by anti-solvent method,the formation of composite particles by ZNP and flaxseed gum(FSG),and the impact on the stability of the Pickering emulsion,the intrinsic fluorescence,secondary structure,particle size and potential of ZNP were analyzed.The results show that ultrasonic pretreatment of zein ethanol solution can significantly reduce the average particle size of ZNP and increase the absolute value of ZNP potential.It was also found that the particle size of ZNP further decreased with the increasing ultrasound time at lower ultrasonic power density(230 W/cm 2),the absolute value of the potential increased,that is,the stability increased.However,when the ultrasonic power density up to 460 W/cm 2,the particle size of ZNP increased slowly,and the absolute value of potential decreased.Then,ZNP pretreated by ultrasound were mixed with FSG by mass ratio of 1∶1,which stated ultrasound treatment make ZNP combine more FSG by surface hydrophilicity analysis.The surface potential of the ZNP was increased,which promoted more FSG to bind to the surface of the ZNP,resisting the aggregation and breakage of droplets in the emulsion.At the same time,through the study of thermal stability,it was confirmed that ultrasonic pretreatment can significantly improve the stability of Pickering emulsion.Therefore,the results of this study can provide a certain basis for the application of ultrasonic pretreatment in the preparation of ZNP and Pickering emulsion,and provide a new green way for the preparation of Pickering particles with higher efficiency and thermal stability.