导　　师： 曾新安

学科专业： 082202

授予学位： 硕士

作　　者： ;

机构地区： 华南理工大学

摘　　要： 本文以磷脂为处理对象，以脉冲电场（Pulsed electric field,简称PEF）为处理手段，采用马尔文粒度分析仪、表面张力仪、电导率仪、紫外分光光度计、丙二醛（MDA）试剂盒、气相色谱及拉曼光谱分析了PEF处理前后磷脂理化性质的变化。从磷脂分散体系粒径、表面ξ-电位及其溶液表面张力、电导率以及动力学常数、氧化指数、 MDA含量、脂肪酸组成、分子构象多个角度，探索了PEF影响其分散体系稳定性的情况。 实验结果表明：PEF处理场强及脉冲数都不同程度地影响了磷脂分散体系颗粒粒径大小及其分布；随着PEF处理场强及脉冲数的增大，磷脂平均粒径减小、粒度分布向粒径减小的方向移动；随着处理后静置时间的延长，磷脂平均粒径增大，粒径分布区间向粒径增大的方向移动。其中在场强为70kV//cm条件下，平均粒径减为203nm，相比对照样减少了67/%。 对于浓度为2、5、10g//L的磷脂溶液，在脉冲电场处理下磷脂溶液的表面张力值呈现出相似的变化规律：随着脉冲电场场强的增加，表面张力逐渐下降，在60kV//cm时浓度2、5g//L其表面张力最小分别为47.396、47.210mN//m，而50kV//cm下10g//L的磷脂分散体表面张力为39.472mN//m。其ξ-电位绝对值随着脉冲场强增大呈现先增大随后下降的趋势。 电场对不同浓度磷脂分散体的电导率作用表明，经电场处理之后，电导率升高，随着静置时间的延长，其电导率逐渐减小，且在0-50min内变化最大，其变化规律符合一级反应规律，拟合凝聚动力学方程，随着施加场强强度的增加，其凝聚动力学常数出现不同的变化规律，在2g//L浓度下，先减小后增大，而在5g//L和10g//L的分散体系中，随着场强的增大动力学常数增大，经60kV//cm处理后磷脂分散体凝聚动力学常数最大。 对磷脂氧化稳定性及脂肪酸组成研究表明，经 Effects of pulsed electric field /(PEF/) treatments on the stability of phosphatidesdispersion were studied in this paper. Various physical and chemical properties of treatedphosphatides dispersion, concering particle size distribution, ξ-potential, surface tension,conductivity as well as the kinetics constants of coalescence，oxidative index, MDA contents,fatty acid composition and molecular conformation,were analzed by dynamic light scattering/(DLS/), Wilhelmy measuring plate, Zetasizer /(ZS/),conductivity meter, UV spectrophotometer/(UV/), GC, Raman spectrum /(Raman/). Detail research contents are as following. The results showed that the partical mean size was significantly reduced and sizedistribution of powder phosphatides shifted towards smaller size direction with the increase ofelectric field strength and number of applied pulses. The mean particle size was reduced by67/%from594.4nm /(contrast/) to203nm at a filed intensity of70kV//cm. The surface tension value of solution with different concentration after being treateddecreased with increasing electric field strength. The absolute value of ξ-potential firstlyincreased when the filed intensity ranges from0-20kV//cm, and then decreased if the filedintensity increased further. The conductivity of solution with different concentration after being treated increasedwith increasing electric field strength while conductivity decreased with increasing keepingtime after PEF treatment.The changes of conductivity were decreased sharply between0and50min, and these change law fitted to coacervation dynamics equation. The kinetics constantsof coalescence changed with changing electric field strength and different concentration and itdecreased first and then increased at concentration of2g//L while increased with increasingelectric field strength with concentration of5g//L、10g//L. There no obvious oxidation showed from phospholipid oxidation stability and fatty acidcomposition of the phospholipid. The conformation changes of phospholipid molecular

关 键 词： 脉冲电场 磷脂 稳定性 构象

领　　域： [理学] [理学] [理学] [理学]