Dispersed phase-mediated gelation in plant protein-stabilized nanoemulsions for improved functionality of foods

纳米乳液是由分散在连续相中的纳米液滴组成的。近年来，由于其极高的稳定性，水包油NE越来越多地被用于食品和饮料中。然而，使用的大多数NE是液体，凝胶NE的独特功能特性，如在较低的油浓度(具有减少卡路里的潜力)下的凝胶和较高的凝胶强度，一直是非常未被探索的。为了解决这一知识差距，并极大地扩大NE在食品中的适用性，我的团队开发了独特的方法，将液体乳剂转化为具有可调质地的凝胶NE。结果表明，在较低的含油体积分数下，具有排斥作用的纳米液滴可以转变为具有较高凝胶强度和凝胶性的吸引相互作用。我们还发现，蛋白质也可能发生排斥的NE凝胶化。然而，尽管它们的新颖性和我们在这一领域取得的进展，在NE凝胶能够成功地应用于食品工业之前，仍然存在许多挑战。例如，我们对以植物蛋白为基础的纳米乳液的胶体凝胶化的了解仍处于初级阶段。植物蛋白处于最近一场食品革命的前沿，用植物蛋白取代合成乳化剂和动物乳化剂的需求正在改变该行业的动态。因此，迫切需要更好地了解分散液滴在植物蛋白纳米乳液中的凝胶化作用。为了应对这些挑战，我的研究计划的长期目标是加强控制NE形成、稳定性和凝胶的结构-功能关系，目的是创造具有可调功能和促进健康特性的新型食物结构。在接下来的五年里，我的研究计划将以三个短期目标为指导。在目标1中，我们将开发一个关于纳米液滴大小、多分散性和紧密堆积之间的关系的基本知识库，以控制植物蛋白质为基础的NE凝胶。目标2将集中在一系列耗尽剂引起的吸引人的耗竭相互作用，以控制植物蛋白稳定的NE凝胶的质地和流变学。最后，在目标3中，我们将通过改变pH和离子强度来诱导植物蛋白稳定的油滴之间更具吸引力的相互作用，并在最低的油浓度下创建比任何其他方法更强的NE凝胶。总体而言，从这些高度可行和相关的目标产生的研究成果将为更好地了解植物蛋白稳定的NE基食品的结构形成机制提供更好的见解。新型去甲肾上腺素凝胶的成功应用及其在减脂食品中的应用有望显著改善加工食品的结构和促进健康的特性。当经过研究计划培训的HQP加入劳动力大军时，他们也将为加拿大提供实质性的竞争优势。

Nanoemulsions (NEs) consist of nanodroplets dispersed in a continuous phase. In recent years, compelled by their extremely high stability, oil-in-water NEs have increasingly been sought for their use in foods and beverages. However, most of the NEs used are liquid, and the unique functional properties of gelled NEs, such as gelation at a lower oil concentration (with a calorie reduction potential) and higher gel strength, have been vastly unexplored. To address this knowledge gap and vastly expand the applicability of NEs in food, my group has developed unique approaches to convert liquid emulsions into gelled NEs with tunable texture. We showed that nanodroplets with repulsive interactions could be transformed into attractive interactions with higher gel strength and gelation at lower oil volume fraction. We also discovered that repulsive NE gelation could also be possible with proteins. However, despite their novelty and our strides in this area, many challenges remain before the NE gels can be successfully used in the food industries. For example, our knowledge of colloidal gelation involving plant protein-based nanoemulsions is still in its infancy. Plant proteins are at the forefront of a recent food revolution, where demand for replacing synthetic and animal-derived emulsifiers with plant proteins are changing the dynamics of the industry. Therefore, there is an urgent need to better understand dispersed droplet mediated gelation in plant protein-based nanoemulsions. To address these challenges, the long-term goal of my research program is to enhance the structure-function relationship controlling NE formation, stability and gelation, with the aim of creating novel food structures with tunable functionality and health-promoting properties. Over the next five years, my research program will be guided by three short-term objectives. In objective 1, we will develop a fundamental knowledge base on the relationship between nanodroplet size, polydispersity and close-packing to control plant protein-based NE gelation. Objective 2 will focus on attractive depletion interactions induced by a range of depletants to control the texture and rheology of plant protein-stabilized NE gels. Finally, in objective 3, we will induce stronger attractive interactions among the plant protein-stabilized oil droplets by modifying pH and ionic strength and create strong NE gels at the lowest oil concentration than any other methods. Overall, research outputs stemming from these highly feasible and relevant objectives will provide greater insight into the mechanisms of structure formation in plant protein-stabilized NE-based foods. The successful utilization of novel NE gels and their application in reduced-fat foods are expected to lead to significant improvements in the structure and health-promoting properties of processed foods. When HQP trained in the research program join the workforce, they will also provide a substantial competitive edge to Canada.