All things are possible, it seems, when fundamental and applied physics are put to work solving the multidisciplinary science and technology challenges facing the food-manufacturing sector. Think new approaches for compelling product innovation, reduced costs as well as the scientific insights that will enable the food industry to reimagine best practice to ensure a more sustainable world. That, give or take a few embellishments, is the key take-away message from the Fourth IOP Physics in Food Manufacturing (PiFM) Conference in Leeds, UK, earlier this month.
“The PiFM conference is a unique forum, bringing together an unusually diverse range of academics and students with R&D scientists from the food-and-drink industry,” explained John Bows, R&D director at PepsiCo Global Snacks in Leicester, UK, and chair of the IOP PiFM group, which co-sponsored this year’s event along with the IOP’s Liquids and Complex Fluids Group. “We strive to educate physics academia on why food is so interesting [from a scientific perspective], while informing the food industry why they need physics,” he added.
In search of solutions
The meeting was the most international PiFM conference to date with speakers from Australia, China and Europe. Delegates who talked to Physics World commended the depth and breadth of the presentations – from the biomechanics of swallowing to new kinetic models of shear thickening to acoustic measurements in food processing (see box below). “It is good to know that there is a science cadre, by no means all physicists, who can address complex problems in the processing of the heterogeneous materials and almost all states of matter that make up foods,” noted Megan Povey, chair of the PiFM 2020 conference and a food physicist at the University of Leeds.
It appears that many of those complex problems land routinely on the desk of Martin Whitworth, technology lead for strategic knowledge development at Campden BRI, one of the world’s foremost food science and research centres, headquartered in the UK. In a call to arms to the assembled PiFM community, Whitworth showcased “a few industry problems perhaps amenable to physics solutions”. These included the need for enhanced diagnostic techniques to detect foreign bodies in food – especially impurities such as wood, plastic and glass fragments – as well as a requirement to evaluate the uniformity of thermally assisted high-pressure food processing (an emerging technique which uses pressures up to 600 MPa to reduce the thermal load of sterilization). Whitworth also highlighted the need to search for more stable and repeatable foaming capabilities in plant-based and vegan food products.
Our approach to physics must become far more inclusive if it is to make the contribution necessary to meet the tests we face as both a scientific and industrial community
Megan Povey
Given such wide-ranging demands for product and process innovation, it was disappointing that small and medium-sized enterprises (SMEs) were largely noticeable by their absence. “It is important for us, as a special interest group, to address this issue because the food industry is dominated by SMEs, both in terms of employment and turnover,” Povey acknowledged. One option for next year’s event is collaboration with other learned societies — such as the Society of Chemical Industry — or food industry bodies like the Food and Drink Federation.
The next generation
The conversation at the meeting also turned to careers and professional development, with the role of mentorship a prominent talking point in a lively panel debate featuring five early-career scientists from research and industry. “[As a student] you need senior people to champion you for funding, as well as giving you independence and the opportunity to strike out,” explained Zachary Glover, a PhD student at the University of Southern Denmark.
His point was amplified by panel chair Beccy Smith, head of the modelling and simulation group at Mondelēz International, who noted the importance of identifying the right mentor – someone who will give credit where it is due. “They’re easy to spot at conferences,” she added, “as they’ll always recognize the efforts of their co-workers and students first.” You are what you eat
While other panellists fretted about the near-term industrial relevance of their PhD research, it fell to a more experienced voice – Alessandro Gianfrancesco of Nestlé Product Technology Centre in the UK – to provide the necessary reassurance. “Your PhD is about the training, about tackling a complex problem, developing your research approach and how you present that research,” he said. “You cannot predict what will be useful in 20 years’ time, so just keep an open mind and keep on learning.”
For her part, Povey sees greater openness – individually and collectively – as the only way to go. “PiFM 2020 for me demonstrated the unifying power of physics in helping to understand the world,” she concluded. “The diversity of participants, in particular, is something that we must build on for the future. Our approach to physics must become far more inclusive if it is to make the contribution necessary to meet the tests we face as both a scientific and industrial community.”
Brief tasters from the PiFM 2020 conference and poster sessions
Of couscous and chocolate
A UK-Dutch team presented experimental findings that point to rheology-based design principles for industrial granulation — a ubiquitous operation in food manufacturing in which a small amount of liquid is incorporated into dry powers. Examples of the process include so-called “wet granulation”, in which a minimal amount of liquid is added to produce matt solid granules , for example in couscous and baby food. In “overwet” systems, a larger amount of liquid is added and the mixture turns into a flowing suspension, such as with liquid chocolate. The team’s experiments, using an industrially realistic model powder called Spheriglass, indicate the two regimes of granulation “may be amenable to a single, unified description”. Daniel Hodgson (University of Edinburgh) received the best student presentation prize for this work.
Targeted emulsions
Particle-stabilized emulsions, also known as Pickering emulsions (PEs), are attracting significant research interest as “biodegradable delivery vehicles” for a range of active compounds and micronutrients. Andrea Araiza-Calahorra and colleagues at the University of Leeds described the use of novel protein-based soft-gel particles as stabilizers in a new class of “gastric-stable” PEs. They used complementary techniques – among them static and dynamic light scattering, cryo-scanning electron microscopy and gel electrophoresis – to compare the behaviour of the PEs pre- and post-digestion. The studies provide new design principles for PE-based delivery systems for compounds that require targeted intestinal release. Andrea Araiza-Calahorra from the University of Leeds received the best student poster prize for this research.
Age-appropriate food and drink
A major reason why old people get ill is that they no longer salivate properly, to the point that they stop enjoying their food and in turn stop eating altogether. Marco Ramaioli, a senior scientist at INRAE in Paris, reported work that he and his colleagues have carried out to understand the biomechanics of swallowing to develop safer and more appropriate food and drinks for this group. Their mixed-methodology approach includes in vivo ultrasound observations, simplified fluid-mechanical analysis, novel biomimicking experiments and studies of the flow of a food bolus containing solid inclusions.
