Grant: Discovery Grants Program - Individual

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.