NAPIC: Colloidal performance of plant proteins – unravelling shear-hydration-surface activity synergies

One full scholarship is available in the School of Food Science and Nutrition in 2025/26. This scholarship is open to Home fee rated and International applicants and covers UK tuition fees plus a maintenance grant (&pound;19,237 in 2024/25) for full-time study. Please note that international applicants would have to pay the difference between Home and International student tuition fees.<br /> <br /> This fully funded PhD place provides an exciting opportunity to pursue postgraduate research in a range of fields relating to Food Science, Physical Chemistry and Material Science with an industry partner.

<p paraeid="{bcd58e17-5810-49c1-9ce6-96cd1168166b}{201}" paraid="1080181221">There is an increasing motivation to employ plant proteins as emulsifiers and foaming agents in a wide range of food and beverage applications.  This is due to pressing demands of animal protein-linked sustainability concerns, increased consumer interest in veganism as well as interests in the food industry to reduce E-numbered ingredients in products, such as some classic low molecular weight surfactants (LMWS) that are still deemed essential.  One of the key disadvantages of plant proteins as surface active agents is their size – of both the constituent protein molecules but more importantly the aggregates in which the proteins are almost always part of, which are complex and multimeric.  These aggregates are often so large that they impart cloudiness or even sediment out of solution, in other words have poor ‘solubility’ – Nature has designed these protein aggregates as a protein/nitrogen stores deliberately not to be so easily dissolved, dispersed or digested.  Not surprisingly, this poor solubility also impairs the rate and extent to which they can adsorb to oil-water or air-water interfaces and therefore their ability to compete with the superior emulsifying and foaming properties of either synthetic (or semi-synthetic) LMWS and widely used animal proteins (e.g., milk or meat proteins).  </p> <p paraeid="{400b7605-22f1-47f0-9a13-c076ad031023}{46}" paraid="1745373973">Various fractionation procedures are traditionally used to try and isolate the parts of plant storage proteins that have the best performance, but these procedures are multi-step, high energy and involve additional chemical reagents, making this not economically viable, sustainable or even desirable from the point of view of ‘ultra processed’ food and the environmental footprint. However, what has been largely unexplored is how purely physically processing, particularly as a function of their state of hydration, can bring about improvements in the functional performance of plant proteins at fluid-fluid interfaces. This type of processing is far more desirable but the interplay between protein aggregate size, hydration and shear forces (mixing, blending, homogenization, extrusion, etc.) is poorly understood.   </p> <p paraeid="{400b7605-22f1-47f0-9a13-c076ad031023}{156}" paraid="1617360497">This PhD within the National Alternative Protein Innovation Centre (NAPIC) will therefore address a number of key fundamental questions: (1) how do shear forces influence protein aggregation; (2) how does hydration combined with shear effect protein aggregate size and structure across length scales from Angstroms to microns; (3) how do (1) and (2) affect plant protein performance at fluid-fluid interfaces.  To answer these fundamental questions, knowledge of the nanomechanical properties of plant protein particles in the bulk and at the interface will be vitally important. Currently this knowledge is sparse because the experimental techniques necessary are limited, but this PhD will be highly interdisciplinary and combine cutting edge techniques ranging from super resolution microscopy, rheo-scattering (rheology combined with in situ real time particle scattering) to methods of protein monolayer compression, expansion interfacial rheology and imaging. In this way we aim to create a radically new understanding of the relationship between the properties of plant protein concentrates and their collective behaviour at the interface and in the bulk.   </p> <ul> </ul> <p paraeid="{0f7fa43e-e4f6-4457-a37a-fbc55722409e}{52}" paraid="2112586821">Specifically, the project will employ the Biofluidic Microscope (BFM), that uniquely combines Atomic Force Microscopy (AFM), Fluidic Force Microscopy (FluidFM), and Ultra-Fast Confocal Imaging.  The BFM therefore has the ability to measure interactions between plant protein assemblies of targeted hydration and surface characteristics over protein length scales covering several orders of magnitude.  This will be further complemented by in operando X-ray analytical facilities to characterise the protein systems in solution and/or gel state under stress/shear conditions. By employing serial small- and wide-angle X-ray scattering (SAXS/WAXS), we will also capture real-time images to show the dynamics of protein structural features at the Angstrom scale.  This will reveal the evolution of protein size, shape and aggregation state as a function of shear history and hydration at the nanoscale.  </p> <p paraeid="{0f7fa43e-e4f6-4457-a37a-fbc55722409e}{160}" paraid="1266434538">Using one or two specific plant proteins as examples, the project will build a multiscale, multidimensional tool that will allow industry to fine tune the functional performance (bulk and adsorption properties) of these and other plant protein concentrates via the appropriate combinations of shear and hydration  </p> <p paraeid="{0f7fa43e-e4f6-4457-a37a-fbc55722409e}{208}" paraid="726319699">In addition to the bulk of the experimental work carried out at Leeds, there will be also an exciting opportunity for the student to do a short placement at an industry R&D facility. The PhD student will get excellent opportunities to do placements with our industrial partners and the wider community in UK and abroad within NAPIC – please see the website for partners of NAPIC: <a aria-label="Link https://napic.ac.uk/partners/" href="https://napic.ac.uk/partners/" id="menurm75" rel="noreferrer noopener" target="_blank" title="https://napic.ac.uk/partners/">https://napic.ac.uk/partners</a>.</p> <p paraeid="{6d93a545-c271-413b-a72c-f30f9d25d956}{33}" paraid="1554547130"><strong>Information about the award</strong></p> <ul> <li paraeid="{6d93a545-c271-413b-a72c-f30f9d25d956}{33}" paraid="1554547130">We are offering 1 full-time PhD scholarship in the School of Food Science and Nutrition for one candiate, covering a maintenance grant of £19,237 per year and UK tuition fees for three and a half years, subject to satisfactory academic progress. <strong>Please note that international applicants are welcome to apply but would need to cover the difference between UK and International tuition fees. The maintenance stipend is paid monthly and cannot be used to pay your fees. You can read more about research degree fees <a href="https://www.leeds.ac.uk/research-fees/doc/research-degrees-fees">here</a>.</strong></li> </ul> <p paraeid="{6d93a545-c271-413b-a72c-f30f9d25d956}{33}" paraid="1554547130"><strong>Duration of the award</strong></p> <ul> <li paraeid="{6d93a545-c271-413b-a72c-f30f9d25d956}{33}" paraid="1554547130">Full-time (3.5 years).  The award will be made for one year in the first instance and renewable for a further period of up to three years, subject to satisfactory academic progress.</li> </ul> <p><strong>Other conditions</strong></p> <ul> <li>Applicants must not have already been awarded or be currently studying for a doctoral degree.</li> <li>Awards must be taken up by 1 October 2025.</li> <li>Applicants must live within a reasonable distance of the University of Leeds whilst in receipt of this scholarship.</li> </ul>

<p>Formal applications for research degree study should be made online through the <a href="https://www.leeds.ac.uk/research-applying/doc/applying-research-degrees">University's website</a>. You will need to create a login ID with a username and PIN.</p> <ul> <li>For ‘Application type’ please select ‘Research Degrees – Research Postgraduate’.</li> <li>The admission year for this project is 2025/26 Academic Year.</li> <li>For ‘Planned Course of Study’ please select ‘PhD Food Science and Nutrition Full-time’.</li> <li>For ‘Proposed Start Date of Research’ please select 1 October 2025.</li> <li><strong>In the research information section, you must state clearly that the project you wish to be considered for is ‘NAPIC: Colloidal performance of plant proteins –  unravelling shear-hydration-surface activity synergies’ and name <a href="https://environment.leeds.ac.uk/food-nutrition/staff/7143/professor-brent-s-murray">Professor Brent Murray</a> as your proposed supervisor. If you do not do this, your application may not be considered.</strong></li> </ul> <p>If English is not your first language, you must provide evidence that you meet the University's minimum English language requirements (below).</p> <p><em>As an international research-intensive university, we welcome students from all walks of life and from across the world. We foster an inclusive environment where all can flourish and prosper, and we are proud of our strong commitment to student education. Across all Faculties we are dedicated to diversifying our community and we welcome the unique contributions that individuals can bring, and particularly encourage applications from, but not limited to Black, Asian, people who belong to a minority ethnic community, people who identify as LGBT+ and people with disabilities. Applicants will always be selected based on merit and ability.</em></p>

Applicants to this scholarship in the School of Food Science and Nutrition are expected to hold a bachelor degree in a relevant subject (2.1 or above or equivalent) or a good honours degree together with a Masters degree. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the Postgraduate Research Admissions team prior to making an application.

The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.5 overall with at least 6.0 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid. Some schools and faculties have a higher requirement.

<p>For further information please contact Prof Brent Murray (<a href="mailto:b.s.murray@leeds.ac.uk">b.s.murray@leeds.ac.uk</a>). </p>