十聚甘油单油酸酯-酪蛋白酸钠复合物的构建与对柠檬醛的稳定作用

Preparation of Decaglycerol Monooleate-sodium Caseinate Complex and Stabilization for Citral

摘要:

通过自组装方法制备了十聚甘油单油酸酯（DGMO）与酪蛋白酸钠（NaCas）的复合物，以粒径、PDI和Zeta-电位为评价指标，探究了两者质量比对NaCas-DGMO复合物的影响，并通过荧光光谱、紫外-可见分光光度计、傅里叶红外光谱对复合物进行表征，同时考察了NaCas-DGMO复合物的pH值、盐离子耐受性及米糠油水包油乳液乳化性质。结果表明：NaCas与DGMO质量比1:2、80 ℃反应1 h能获得稳定复合物，粒径为238.10 nm，PDI为0.27；浊度实验表明NaCas-DGMO复合物能稳定存在，荧光光谱和FT-IR表明NaCas与DGMO通过疏水相互作用结合，同时两者相互作用导致NaCas的表面疏水性增强（319.46增至596.45）；NaCas-DGMO复合物更耐酸和盐离子变化；NaCas-DGMO复合物具有优异的稳定水包油（O/W）乳液性质，能在油滴表面形成稳定的界面层，防止油滴凝聚。构建的O/W乳液包封柠檬醛后具有很好稳定性，粒径为208~225 nm，PDI为0.18~0.27，储存28 d柠檬醛保留率达78.83%，能实现对柠檬醛的有效保护。因此，NaCas-DGMO复合物不仅能有效稳定O/W乳液，更能将O/W乳液应用于脂溶性活性物质的良好递送载体。

Abstract:

Decaglycerol monooleate (DGMO)-sodium caseinate (NaCas) complex was prepared by the self-assembly method. The particle size, polydispersity index (PDI), and zeta potential were used as indexes to investigate the effect of mass ratio of NaCas-to-DGMO on the complex. Furthermore, fluorescence spectroscopy, UV-Vis spectrophotometry, and Fourier transform infrared spectroscopy (FTIR) were used to characterize the NaCas-DGMO complex. The properties of the NaCas-DGMO complex, such as stability against pH and salts, and emulsifying property of soybean oil-in-water (O/W) emulsion, were also investigated. A stable complex with a particle size of 238.10 nm and a PDI of 0.27 was obtained with a NaCas-DGMO mass ratio of 1:2 and 80 ℃ for one hour. The fluorescence and FT-IR spectra showed that the NaCas-DGMO complex could exist stably, and hydrophobic interaction promoted the formation of the NaCas-DGMO complex, which enhanced the surface hydrophobicity of NaCas (319.46 to 596.45). The NaCas-DGMO complex had better stability against acid and salts, and showed the ability to improve the dispersity of NaCas. The NaCas-DGMO complex had excellent properties of stable O/W emulsions, which could form a stable interfacial layer on the surface of oil droplets to prevent them from coagulating. The constructed O/W emulsion had better stability after encapsulation of citral with a particle size of 208~225 nm and PDI of 0.18~0.27. The citral retention rate was 78.83% after storage for 28 days, which could effectively protect the citral. Therefore, the NaCas-DGMO complex could stabilize O/W emulsions and be used as a good delivery system for lipophilic bioactive compounds.