多模式频率超声波调控玉米醇溶蛋白-壳聚糖复合凝聚层的自组装及包埋白藜芦醇机制研究

Ultrasonic technology has been proven effective at preparing protein-polysaccharide complex coacervation and improving encapsulation properties for active ingredients. The mechanism of ultrasonic influence on encapsulation properties of protein-polysaccharide complex coacervation is a hot research area of ultrasonic sonochemistry, protein biochemistry and polysaccharide biochemistry. In this project, zein-chitosan complex coacervation will be prepared to encapsulate resveratrol by multi-frequency ultrasonication. The phase behaviors and thermodynamic stability of zein-chitosan complex coacervation will be studied. The influence of multi-frequency ultrasound on particle size distribution, electrophoretic properties, turbidity and thermal stability of zein-chitosan complex coacervation will be studied systematically. Spectroscopic techniques such as near-UV circular dichroism, infrared spectroscopy, fluorescence spectroscopy, as well as scanning electron microscopy and atomic force microscopy will be employed to study the effects of multi-frequency ultrasound on the tertiary structure and surface microstructure of zein-chitosan complex coacervation. The relationships between physicochemical properties, surface microstructure, morphology of zein-chitosan complex coacervation and the encapsulation efficiency and release performance of resveratrol will also be studied. The ultimate goal was to clarify the mechanisms of muti-frequency ultrasound induced zein-chitosan complex coacervation self-assembly and the related influence on encapsulation of resveratrol. This project will help elucidating the mechanisms and help on future establishment of encapsulation methods of protein-polysaccharide complex coacervation using ultrasound.

超声波能够大规模应用于蛋白质-多糖复合凝聚层制备及显著改善其对生物活性成分包埋特性，相关机制一直是国际超声化学和蛋白质/多糖生物化学研究的热点问题。本项目拟以玉米醇溶蛋白和壳聚糖制备复合凝聚层并对白藜芦醇进行包埋，经多模式频率超声波处理，建立蛋白质-多糖自组装动力学和热力学相分离模型，系统研究超声波对玉米醇溶蛋白和壳聚糖复合凝聚层粒径分布、电荷分布、表观粘度和热力学等功能特性的影响。借助近紫外圆二色谱、红外光谱、荧光光谱和冷冻扫描电镜、原子力显微镜等技术研究超声波对复合凝聚层高级结构和表面微观结构的影响；再结合白藜芦醇包埋效率和释放性能及包埋物稳定性等宏观特征和复合凝聚层表面微观结构、形貌特征等微观信息，研究多模式频率超声波对蛋白质-多糖自组装及包埋白藜芦醇行为的影响机制。本项目涉及科学问题的解决有助于超声波强化蛋白质-多糖复合凝聚层包埋技术方法的建立及科学问题的阐述。

蛋白质与多糖相互作用可以自组装形成负载生物活性物质的良好载体。但是其制备方法存在着均一性差、稳定性差、对活性物质的负载效率低的不足。超声波能够应用于蛋白质-多糖复合物的制备并显著改善其对生物活性成分包埋特性。本项目利用多模式频率超声波调控玉米醇溶蛋白-阿拉伯胶、玉米醇溶蛋白-壳聚糖的自组装并对白藜芦醇进行包埋；利用多模式频率超声波制备酪蛋白磷酸肽-壳聚糖纳米颗粒并用于包埋槲皮素。.研究发现，超声波处理可以显著减小玉米醇溶蛋白-多糖复合物的粒径、提高对白藜芦醇的包埋率和负载量。对于最佳质量比为5:1的玉米醇溶蛋白/壳聚糖复合物，超声波处理使复合物粒径降低了31.29nm，包埋率和负载量分别达到72.13%和6.01%；对于最佳质量比为1:1的玉米醇溶蛋白/阿拉伯胶复合物，超声波处理使复合物粒径降低了44.69nm，Zeta电位绝对值增加了5.16mV，包埋率和负载量分别提高至74.20%和3.71%。蛋白磷酸肽-壳聚糖-槲皮素（Qu）纳米颗粒经超声处理后，Qu的包埋率提高了9.49%，颗粒粒径减小了119.11nm，Qu在水中的溶解量从30.98提高至35.50μg/mL。.通过对复合物的功能特性和结构特征的研究表明，超声波的空化作用改变了复合物中蛋白质的构象和二级结构，增加了多酚物质与生物大分子之间的氢键相互作用，提高了复合物的热稳定性。超声处理引起酪蛋白磷酸肽分子结构的展开并暴露出更多的相互作用位点，增强了与壳聚糖的静电结合，同时提高了与槲皮素之间的相互作用力。模拟体外消化研究表明，超声制备的载体对生物活性成分有着较好的保护作用，并可起到缓释和延长作用时间的效果。本项目为拓展生物活性物质载体的制备及有效包埋提供了新的制备思路。.通过上述研究，课题组在Food Chemistry等权威期刊发表高水平SCI收录论文9篇，申请发明专利5件，授权国家发明专利1件，培养硕士研究生4名，有4项成果获得了江苏省科学技术进步奖等科研奖励。