Interview: Building functional foods on the nanoscale

Ian Norton talks to Phillip Broadwith about engineering the structure of foods to make them smarter and healthier 

What is the nature of your research? 

We’re interested in understanding and engineering the microstructures of ’soft solids’, which covers a wide variety of products from foods to skin creams, paints and pharmaceuticals. For foods, we try to use this microstructure approach to replace or reduce unhealthy components such as fat or salt, while maintaining taste and flavour performance that people expect when they eat that type of food. We’re also interested in what happens to foods once they go inside people. 

It’s a very interdisciplinary field that’s very challenging but also great fun - we need to understand biology, biochemistry, chemistry and process science, but we also collaborate with psychologists because it’s people’s perception of the taste, texture and flavour of a food that governs whether they’ll buy it or not! 

What sort of applications do ’soft solids’ have in food products? 

We do a lot of work with emulsions, gels and colloids, particularly from a processing point of view - one example would be lowering the fat content of margarine-type spreads. These are usually emulsions of water droplets in fat, but we looked at crystallising natural polysaccharides to build a structure, then added droplets of fat back into that. Because the fat is no longer structural, we can completely remove the unhealthy saturated fat and lower the overall fat content, making a 15 per cent fat spread (instead of around 34 per cent) with zero saturated fat that, when you taste it, behaves very much like the full fat version.  

We also have a programme looking at salt replacement - using microstructures to localise salt in specific regions that are perceived by the consumer - so you can reduce the salt level but maintain the salt impression. 

What are the big challenges in food chemistry? 

One aspect is the environmental impact of the food industry. There is massive wastage in food production and transport, and moving to a more localised production system could reduce that, especially if we develop products with controlled microstructures - for instance, why should we transport ice cream in big, refrigerated lorries rather than making the structure, transporting that and then freezing it, or even adding the water and freezing the whole thing closer to the consumer. I think we could start to see this sort of distributed manufacturing quite soon, combined with tailoring production much more closely to local demand, making smaller batches rather than large amounts which are then stored and run out of date and end up as waste. 

Secondly, we’re only just beginning to understand how food behaves inside people from a chemistry and chemical engineering perspective, and looking at how those interactions relate to release of energy and nutrients. Really getting inside that sort of performance could have massive impact on things like diabetes and obesity. For example, we’re doing some research on self-structuring materials based on natural polymers that perform in specific ways inside the body - they can slow down digestion and reduce the desire to eat as a way to prevent snacking. 

What can food scientists do to help tackle obesity? 

I believe that there’s no such thing as an unhealthy food, only an unhealthy diet, so policies like taxing fatty and salty foods are really opting out of the problem. People want to indulge in things like chocolate, so what we’re trying to do is make ’healthy indulgence’ foods that give that same sense of pleasure but are healthier at the same time - ideally at no extra cost to the consumer. Ideally we’d like to do the same for everyday foods, which is much more of a challenge. 

We also use only natural ingredients, for example from plants and seaweeds, rather than new chemical components - we’re looking at how to make new structures with currently accepted food materials. It makes the chemistry tougher, but I think the consumer demand that foods be based on natural ingredients is exactly right.