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

许多食品乳剂，如醋汁和奶油，都是由悬浮在水中的微小油滴组成的。乳化剂是防止油和水分离的重要成分。例如牛奶蛋白和芥末粉。最近，由于降低卡路里和节省食品加工成本的潜力，由颗粒而不是乳化剂保持稳定的乳剂引起了越来越多的兴趣。这种方法也被用于稳定由悬浮在油中的微小水滴组成的乳液，即所谓的油包水（W/O）乳液，这种乳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基于颗粒的稳定剂在非食品应用中的应用，如防晒霜和原油，因为这些颗粒具有很长的保质期。在食品中，尽管人们正在探索许多类型的颗粒（例如，以淀粉或蛋白质为基础的颗粒），但基于科学文献中知识的缺乏，脂肪晶体的情况并非如此。因此，有一个很好的机会来加深关于脂肪晶体如何作为乳剂稳定剂的知识基础，这是与许多加工食品中存在的脂肪特别相关的。为了解决这个问题，我提出了以下四个目标，以极大地推进关于脂肪晶体如何与W/O乳液中分散的水滴表面相互作用的基础知识基础。目标1将建立支持脂肪晶体稳定水乳状液的科学，重点关注以微小颗粒或薄膜形式存在的晶体的能力，以帮助提高乳液的稳定性。这一过程可以通过添加不同的食品乳化剂来控制。目标2将探索脂肪晶体颗粒或薄膜的能力，通过调整它们与水滴的相互作用来改变乳液的质地和流变性，也在乳化剂的存在下。同样，目标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，以可控地破坏和释放作为货物掺入乳液水滴中的生物活性成分。Aim 4将进一步创新，揭示脂肪晶体稳定的W/O乳剂在实验室规模消化系统中的表现。解决这些问题将有助于开发具有更长的保质期，更低的热量负荷和新的质地，以促进摄入的食品乳剂。我的实验室积极参与了所有4个目标的早期阶段，并就这些主题发表了初步论文，这一事实支持了拟议研究的可行性。基于这四个目标的高度相关的研究将使人们更加了解W/O乳剂中界面脂肪结晶的机制，这是目前缺乏的知识，并有望为开发具有促进健康特性的食品乳剂提供重大见解。

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.