Fortifying foods with vitamins and other bio-active compounds has become common practice in Europe; you just have to look at the ingredients panel on a packet of sliced bread or a cornflakes box. This is often achieved by coating – or encapsulating – certain molecules and compounds in order to conceal their bad taste or smell and protect them during processing.
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However, encapsulating certain unstable bio-active molecules has consistently been a major hurdle for the functional food sector. “What the industry needs is a way of treating certain compounds in a manner that ensures their stability, protects them during food processing and then releases these compounds at the right time, either during food processing or in the gastrointestinal tract,” explains project coordinator Iris Joye, who is currently building on her successful research as assistant professor at the University of Guelph in Canada.
Rising to the challenge
Joye was able to focus on this challenge thanks to an EU-funded Marie Curie International Outgoing Fellowship, which took her from the University of Leuven in Belgium to the University of Massachusetts in the US. Supported by world-leading cereal science and encapsulation experts, she began by investigating the potential of emulsions to encapsulate oxidising agents for bread-making, but soon discovered that protein nanoparticles were more promising.
“The grant was flexible enough that it enabled me to change track,” she says. “We found that emulsion-based systems were not that convenient to work with as they tended to be unstable during bread-making steps, such as mixing and heating. Protein nanoparticles, on the other hand, were an effective way of encapsulating bio-active molecules and protecting unstable compounds during food processing.”
A major challenge for food-makers has been how to effectively encapsulate hydrophilic molecules such as certain polyphenols and vitamin C – which dissolve in water – as these tend to break down easily during food processing. “Protein-based delivery systems are very versatile and we found them to be promising for encapsulating and protecting both hydrophobic [insoluble in water] and hydrophilic molecules,” says Joye. “Obtaining more insight into the interactions between proteins and these molecules is the key to the development of economically viable delivery systems.”
This new method of encapsulation promises to make it possible to add bio-active compounds to food products, such as cereal products, more effectively. The compounds are then released into the gut at the right moment for maximum quality and nutritional benefit.
A bright future
While the protein-based encapsulation systems developed by Joye have recorded positive results, no one really knows what is going on at the molecular level. Understanding what molecular changes are happening and how these chemical interactions can be controlled is one of the focuses of Joye’s current work at the University of Guelph. “The commercial side is still in its infancy,” she says. “If successful, patents will certainly be applied for, and collaborations with industrial partners sought. However, the incredibly small size of these particles means that a thorough toxicity assessment will be needed first.”
In addition to uncovering the encapsulating potential of nano-sized protein particles, the Marie Curie grant has also enabled Joye to build up an extensive international network of fellow young scientists who are also just launching their academic careers. “This has been invaluable to me,” she says. “Through working in another scientific environment and setting, this project has transformed me into a critical and more self-aware scientist and it certainly inspired me by exposing me to totally different research cultures.”
It is great that the outgoing researchers come back to the EU and share their knowledge and expertise, as this helps to build up international collaborations, she adds. “The grant has definitely served as a propelling force behind my selection for faculty positions both in Belgium and in Canada.”
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Project acronym: EMULSIFOOD