Yuan D B, Hu Y Q, Zeng T, Yin S W, Tang C H, Yang X Q
Research and Development Center of Food Proteins, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, Guangzhou 510640, PR China.
Food Funct. 2017 Jun 21;8(6):2220-2230. doi: 10.1039/c7fo00418d.
In this paper, we demonstrate the use of gliadin/chitosan complex particles (GCCPs) as particulate stabilizers of oil-in-water emulsions of natural oils and water. For this purpose, we fabricated GCCPs through a facile anti-solvent procedure and demonstrated their usage in the formation of Pickering emulsions and Pickering high internal phase emulsions (HIPEs). The GCCPs can be used to produce surfactant-free o/w Pickering emulsions and Pickering HIPEs; unfortunately these emulsions were labile to coalescence. NaCl addition and/or pH regulation, and the combination were used to modify the surface wettability of the complex particles to achieve stable emulsions. The microstructures, e.g., interfacial frameworks, GCCP partition between the continuous phase and interfacial region, and the state of the droplets, of Pickering emulsions were visualized by confocal laser scanning microscopy (CLSM), confirming that the inclusion of NaCl and slightly adjusting pH toward 4.0 and/or 5.0 benefited the adsorption and accumulation of colloid particles at the droplet surface to form an engineered interfacial structure, bridging droplets together through a percolating layer of colloidal particles at the oil/water interface. A schematic representation for the formation route of the emulsions is proposed to relate the physical performance and rheological property with the interfacial structures and aggregate behaviors in the Pickering system stabilized by the complex particles. Interestingly, direct freeze-drying of the emulsions transformed unstable Pickering emulsions into stable oil powders. This study opens a promising route based on Pickering HIPEs or oil powders to structure liquid oils into solid-like fats without artificial trans-fat, which outlines new directions for future fundamental research.
在本文中，我们展示了麦醇溶蛋白/壳聚糖复合颗粒（GCCPs）作为天然油与水的水包油乳液的颗粒稳定剂的用途。为此，我们通过简便的反溶剂法制备了GCCPs，并展示了它们在形成Pickering乳液和Pickering高内相乳液（HIPEs）中的应用。GCCPs可用于制备无表面活性剂的水包油Pickering乳液和Pickering HIPEs；不幸的是，这些乳液对聚结不稳定。添加NaCl和/或调节pH值，以及两者结合使用，来改变复合颗粒的表面润湿性以实现稳定的乳液。通过共聚焦激光扫描显微镜（CLSM）观察Pickering乳液的微观结构，例如界面框架、GCCP在连续相和界面区域之间的分配以及液滴状态，证实加入NaCl并将pH值略微调节至4.0和/或5.0有利于胶体颗粒在液滴表面的吸附和积累，从而形成一种工程化的界面结构，通过油/水界面处的胶体颗粒渗透层将液滴桥接在一起。提出了乳液形成途径的示意图，以将物理性能和流变性质与由复合颗粒稳定的Pickering体系中的界面结构和聚集行为联系起来。有趣的是，乳液的直接冷冻干燥将不稳定的Pickering乳液转变为稳定的油粉。这项研究基于Pickering HIPEs或油粉开辟了一条有前景的途径，可将液态油构建成无人工反式脂肪的类固体脂肪，为未来的基础研究勾勒了新的方向。
