Dr Caroline Giezenaar, Postdoctoral Fellow
At the Riddet Institute, I have the freedom to show initiative in my research and the support to develop useful skills for my future career. I am a project leader and I have been able to develop a strong network with both researchers and industry partners. This has been a steep learning curve but the skills I am developing will be very useful for my future career. I have a passion for research but I do like to see applicable results. I can see myself moving into industrial R&D where I can work on projects that are going to deliver products to the market to improve human health. The Riddet Institute collaboration with industry is a great pathway to get there.”
Dr Caroline Giezenaar completed her PhD at the University of Adelaide, Australia, in May 2018. Her research focused on the effects of ageing on whey protein digestion, metabolism and energy intake regulation, with the goal to optimise protein supplementation strategies for older malnourished adults. During her PhD, she published several articles in high-impact nutrition and geriatrics journals, and she received of multiple awards, including a research medal for academic excellence.
Caroline joined the Riddet Institute in September 2018, where she focusses on the digestion, absorption and metabolism of the amino acid tryptophan following ingestion of different protein sources. Tryptophan is a precursor for serotonin and melatonin, which regulate mood, sleep, and cognitive function. With her research, Caroline aims to investigate whether tryptophan-rich protein has the ability to increase brain serotonin and melatonin production.
Laura Payling, PhD Student
Laura started her PhD with the Riddet Institute just over 1 year ago. Laura is not new to industrial science and research having spent nearly 4 years working as a scientist in the Innovation Team at DuPont Industrial Biosciences in the UK. During that time, she worked on global research and development projects.
With a first class honours degree in animal sciences from the University of Reading, she has now transferred her skills to studying human nutrition. Her PhD is entitled ‘Dissecting the impacts of food structure on gastrointestinal microbial signalling networks to optimise nutrient uptake in human”. With experience in immunology, endocrinology, genetics, chemistry, physiology, nutrition, dairy production and practical work, Laura combines her scientific role with a love of horses, running and volunteering to support her peers and community.
Dr Debashree Roy, CoRE Associate Investigator
Dr Debashree Roy has a background in Agriculture and Food Technology from India. After completing her studies, she worked in industrial research and development overseas in UAE for three years, focusing on worldwide wheat grain protein quality and applications. Her keen interest in fundamental research, including food structure and digestion, drew her to pursue a PhD at the Riddet Institute in 2016.
Dr Roy first learned about the Institute through former students and online PhD opportunities. She was attracted by the strong emphasis on fundamental research, the chance to develop advanced research skills and learn from some of the best and renowned experts in the field.
With a background bridging agriculture, post-harvest systems, and food science, Dr Roy was eager to improve her understanding of how food structure influences human health after consumption. Her experience gave her a holistic view and shaped her current research focus.
Her PhD research investigated the structural changes in milk from different species during digestion. This work laid the foundation for her ongoing multidisciplinary research, which combines fundamental and applied science to develop innovative, structurally and nutritionally superior foods. She is currently leading various projects on these areas, some key ones include impact of food structure on elderly or infant nutrition, alternative proteins, and plant-based cheese development.
Dr Roy describes the Riddet student community as supportive and inclusive, making the long PhD journey enjoyable and memorable. Being part of a global network of scientists has broadened her professional horizons, opening doors to multidisciplinary collaborations, keynote speaking opportunities, and industry partnerships.
Balancing multiple projects taught Dr Roy the importance of time management, delegation, and clear communication to align teams toward shared goals.
Her future research ambitions include continued research to develop structurally and nutritionally superior future foods, either in the space of dairy or alternative proteins, and solving any ongoing challenges that the food industry faces. She also aims to blend fundamental research with entrepreneurship, inspiring the next generation on science and research impact for global food sustainability.
Dr Roy is currently a Research Officer at the Riddet Institute and co-founder of ANDFOODS, a startup dedicated to sustainable plant-based foods leveraging Riddet Institute’s breakthrough technologies.
Nick Smith, CoRE Associate Investigator
Dr Smith is passionate about science communication, especially translating complex mathematical models into accessible insights. He enjoys engaging with audiences, taking them from initial confusion— “You’re a mathematical modeler? Sounds complicated!”— to a moment of clarity where the concepts click.
Dr Nick Smith is a Senior Research Officer at the Riddet Institute’s Sustainable Nutrition Initiative® (SNi®), a program dedicated to providing evidence for the sustainable food system debate while ensuring that human nutrition remains central to sustainability.
Dr Smith holds degrees in mathematics from Swansea University (UK) and nutritional science from Massey University (NZ). His expertise lies in mathematical modelling of complex systems, particularly in human nutrition. His work at SNi® began with developing the DELTA Model®, which assesses global nutrient supply under various future scenarios. Over time, his research has expanded into nutrient trade modelling, national food system modelling, and dietary optimisation.
Dr Smith currently co-leads the Kai anamata mō Aotearoa Research programme, funded by the New Zealand government. This project explores future food system scenarios for the country and develops an interactive model for stakeholder use. He also contributes to various other aspects of SNi® research.
Before embarking on his research career, Dr Smith took a gap year working as a tour guide in Abel Tasman National Park, uncertain about his next steps. Initially unfamiliar with the Riddet Institute, he was drawn into research after conversations with its scientists, who helped him see how his background in infectious disease modelling could be applied to human gut microbiota and nutrition.
Dr Smith completed his PhD as a Riddet Institute PhD Fellow, based at AgResearch Ruakura in Hamilton. His doctoral research focused on using mathematical modelling to analyse metabolite exchange within the human gut microbiota. His models help infer complex interactions that are difficult or impossible to study experimentally.
One of the highlights of Dr Smith’s research journey has been the strong scientific community at the Riddet Institute. He has benefited from networking with leading scientists, attending international conferences, and collaborating across disciplines.
Dr Smith is passionate about science communication, especially translating complex mathematical models into accessible insights. He enjoys engaging with audiences, taking them from initial confusion— “You’re a mathematical modeler? Sounds complicated!”— to a moment of clarity where the concepts click.
With his deep expertise in food system sustainability, mathematical modelling, and human nutrition, Dr Smith continues to contribute significantly to the Riddet Institute’s research, helping shape future food system policies and strategies.
