Improving the functionality of fat crystal-stabilized water-in-oil emulsions

许多食品乳状液，如调味汁和奶油，都是由悬浮在水中的微小油滴组成的。乳化剂是帮助防止油和水分离的重要成分。例如牛奶蛋白和芥末粉。最近，由于它们具有降低卡路里的潜力，并为食品加工商节省了成本，由颗粒而不是乳化剂保持稳定的乳液受到了越来越多的关注。这种方法也一直在稳定由悬浮在油中的微小水滴组成的乳状液，即所谓的油包水(W/O)乳状液，这种乳状液存在于黄油和人造黄油等产品中。人们一直致力于开发和了解微粒稳定剂在防晒霜和原油等非食品应用中的应用，因为这些微粒具有非常长的保质期。在食品中，尽管人们正在探索许多类型的颗粒(例如，基于淀粉或蛋白质)，但基于科学文献中知识的匮乏，脂肪晶体的情况并非如此。因此，有一个很好的机会来深化关于脂肪晶体作为乳状液稳定剂的知识基础，这一点特别相关，因为脂肪存在于许多加工食品中。为了解决这个问题，我提出了以下四个目标，以极大地推进关于W/O乳剂中脂肪晶体如何与分散的水滴表面相互作用的潜在知识基础。目标1将建立以脂肪晶体稳定W/O乳状液的科学基础，重点关注以微小颗粒或薄膜形式存在的晶体帮助提高乳状液稳定性的能力。通过添加不同的食品乳化剂可以很好地控制这一过程。目标2将探索脂肪晶体颗粒或薄膜通过调节它们与水滴的相互作用来改变乳状液纹理和流变学的能力，也是在乳化剂存在的情况下。同样，AIM 3将解决不同乳化剂如何促进或干扰脂肪晶体和水滴如何相互作用，以可控的方式破坏稳定并释放作为货物加入乳化液水滴中的生物活性成分。目标4将进一步创新，揭示脂肪晶体稳定的W/O乳剂在实验室规模的消化系统中的行为。解决这些目标将有助于开发更长保质期、更低卡路里负荷和新质地的食品乳液，以便于摄取。我的实验室积极参与了所有四个目标的早期阶段，并发表了关于这些主题的初步论文，这一事实支持了拟议研究的可行性。由这4个目标引发的高度相关的研究将提供对W/O乳状液中界面脂肪结晶机制的更多认识--这是目前缺乏的知识，有望为开发具有促进健康特性的食品乳状液提供巨大的见解。

Many food emulsions such as vinaigrette and cream consist of tiny oil droplets suspended in water. Emulsifiers are important ingredients that help prevent the oil and water from separating. Examples include milk protein and mustard powder. Recently, spurred by their potential for calorie reduction and costs savings to food processors, emulsions kept stable by particles rather than emulsifiers have seen rising interest. This approach has also been gaining traction to stabilize emulsions consisting of tiny water droplets suspended in oil, so-called water-in-oil (W/O) emulsions, which are present in products such as butter and margarine. There have been dedicated efforts to develop and understand particle-based stabilizers in non-food applications such as sunscreens and crude oil, because these particles impart a very long shelf life. In foods, though many types of particles are being explored (e.g., based on starch or protein), such is not the case with fat crystals based on the dearth of knowledge in the scientific literature. As a result, there exists a great opportunity to deepen the knowledge base regarding how fat crystals may behave as emulsion stabilizers, which is particularly relevant as fats are present in many processed foods. To address this, I propose the following four aims to greatly advance the underlying knowledge base regarding how fat crystals interact with the surface of dispersed water droplets in W/O emulsions. Aim 1 will establish the science underpinning the stabilization of W/O emulsions with fat crystals, focusing on the ability of crystals that exist as tiny particles or films to help increase emulsion stability. This process may be greatly controlled by adding different food emulsifiers. Aim 2 will explore the ability of fat crystal particles or films to change emulsion texture and rheology by tuning how they interact with water droplets, also in the presence of emulsifiers. Similarly, aim 3 will resolve how different emulsifiers promote or disturb how fat crystals and water droplets interact to controllably destabilize and release bioactive ingredients incorporated as cargo within emulsion aqueous droplets. Aim 4 will innovate further to reveal how fat crystal-stabilized W/O emulsions behave in a lab-scale digestive system. Addressing these aims will aid in the development of food emulsions with a longer shelf life, lower caloric load, and new textures to facilitate ingestion. The feasibility of the proposed research is supported by the fact that my lab is actively involved in the early stages of all 4 aims and has published initial papers on these topics. The highly-relevant research stemming from these 4 aims will provide greater awareness regarding the mechanisms of interfacial fat crystallization in W/O emulsions - knowledge that is currently lacking and that promises to yield great insights for the development of food emulsions with health-promoting properties.