BslA-stabilized emulsion droplets with designed microstructure.
BslA-stabilized emulsion droplets with designed microstructure.
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DOI：
10.1098/rsfs.2016.0124
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发表时间：
2017-08-06
期刊：
影响因子：
4.4
通讯作者：
MacPhee CE
中科院分区：
文献类型：
--
作者：
Bromley KM;MacPhee CE
乳液是食品、药品、农用化学品和个人护理产品中许多现代配方的核心成分。由于分散相和连续相之间的界面张力，这些制剂中的液滴限于球形。控制乳液液滴形态和稳定非球形液滴的能力将能够改变乳液性质，例如稳定性、基底结合、递送速率和流变性。控制液滴微结构的一种方法是在液滴周围施加弹性膜以防止其松弛成球体。我们以前已经表明，BslA，由细菌属芽孢杆菌产生的界面蛋白，当暴露于油或空气-水界面时形成弹性膜。在这里，我们强调BslA稳定各向异性乳液液滴的能力。首先，我们表明，BslA是能够逮捕动态乳化过程，导致不同形态的乳液取决于所应用的条件和乳化技术。然后，我们表明，冷冻乳液液滴可以操纵诱导部分聚结。部分聚结的液滴的结构在熔融后保留，但仅当连续相中存在足够的游离BslA时。复制的保真度可以通过调节溶液中游离BslA的量来调节，这表明冷冻BslA稳定的液滴破坏了BslA膜。最后，我们使用BslA的能力，以保持乳液液滴的结构完整性，在整个熔化过程中，设计具有选定的形状和大小的乳液液滴。
Emulsions are a central component of many modern formulations in food, pharmaceuticals, agrichemicals and personal care products. The droplets in these formulations are limited to being spherical as a consequence of the interfacial tension between the dispersed phase and continuous phase. The ability to control emulsion droplet morphology and stabilize non-spherical droplets would enable the modification of emulsion properties such as stability, substrate binding, delivery rate and rheology. One way of controlling droplet microstructure is to apply an elastic film around the droplet to prevent it from relaxing into a sphere. We have previously shown that BslA, an interfacial protein produced by the bacterial genus Bacillus, forms an elastic film when exposed to an oil- or air–water interface. Here, we highlight BslA's ability to stabilize anisotropic emulsion droplets. First, we show that BslA is capable of arresting dynamic emulsification processes leading to emulsions with variable morphologies depending on the conditions and emulsification technique applied. We then show that frozen emulsion droplets can be manipulated to induce partial coalescence. The structure of the partially coalesced droplets is retained after melting, but only when there is sufficient free BslA in the continuous phase. That the fidelity of replication can be tuned by adjusting the amount of free BslA in solution suggests that freezing BslA-stabilized droplets disrupts the BslA film. Finally, we use BslA's ability to preserve emulsion droplet structural integrity throughout the melting process to design emulsion droplets with a chosen shape and size.