School of Chemical Engineering , University of Birmingham , Edgbaston, Birmingham B15 2TT , U.K.
Cargill, R&D Centre Europe , Havenstraat 84 , B-1800 Vilvoorde , Belgium.
Langmuir. 2019 Nov 26;35(47):15137-15150. doi: 10.1021/acs.langmuir.9b01995. Epub 2019 Nov 14.
Although water-in-oil-in-water (W/O/W) double emulsions have been associated with a spectrum of potential applications in foods, their complex microstructure is significantly unstable. Pickering stabilization, reputed for superior and longer-term interfacial stabilization when compared to surfactant-stabilized systems, could provide the opportunity to enhance double-emulsion stability. The current work presents a systematic study on the impact of progressively adopting such a Pickering intervention onto one or both interfaces of W/O/W emulsions relevant to foods. A range of surfactants/emulsifiers and particles have been used at the W/O or O/W interface of the W/O/W microstructure and, where appropriate, cross-compared with the equivalent interfaces of simple emulsions (W/O and O/W, respectively). As the aqueous compartments of all investigated systems were not osmotically balanced (at the point of formulating/forming these), any advantages in terms of double-emulsion stability enhancement can be directly attributed to the employed particle stabilization. It is demonstrated that, although partial Pickering intervention can encourage stability (particularly if that is introduced at the inner W/O interface), only complete Pickering stabilization of the double microstructure can ensure that the oil globule size is maintained and the internal water phase is retained over a storage period of one month.
虽然油包水包油（W/O/W）双重乳液与食品中一系列潜在应用相关，但它们复杂的微观结构极不稳定。与表面活性剂稳定体系相比，Pickering 稳定化以优越和更长期的界面稳定性而闻名，它为增强双重乳液稳定性提供了机会。本研究系统地研究了逐步采用这种 Pickering 干预措施对食品相关 W/O/W 乳液的一个或两个界面的影响。在 W/O/W 微结构的 W/O 或 O/W 界面处使用了一系列表面活性剂/乳化剂和颗粒，并在适当情况下与简单乳液（分别为 W/O 和 O/W）的等效界面进行了交叉比较。由于所有研究体系的水相都没有渗透平衡（在形成这些体系的过程中），因此，在双重乳液稳定性增强方面的任何优势都可以直接归因于所采用的颗粒稳定化。结果表明，尽管部分 Pickering 干预可以促进稳定性（特别是如果在内部 W/O 界面引入），但只有完全 Pickering 稳定双重结构才能确保在一个月的储存期内保持油滴大小并保留内部水相。
