Electrospinning helps create protective coating around health-promoting food ingredients

So-called functional ingredients, such as probiotics, prebiotics, and stanols and sterols are increasingly being added to foods to boost the immune system or reduce cholesterol, for example.

However, protecting these sensitive materials as they pass through the upper gastro-intestinal tract and ensuring they are delivered safely to their target site within the body is no easy task, according to Dr Nick Tucker of the School of Engineering at the University of Lincoln.

Researchers have investigated a number of different methods for encapsulating the materials inside a protective casing, but many of these processes, such as spray-drying, are themselves too harsh, and can damage the structure of the molecules, or harm the bacteria.

So instead Tucker and his colleagues at the Research Institute of Food Science and Technology in Iran have been investigating the use of electrospinning to encapsulate the materials. In electrospinning, a solution is drawn through an electrically-charged hollow needle onto a grounded target. As the solution is drawn towards the target, it stretches out into an extremely fine fibre.

Unlike spray-drying, electrospinning can be done at room temperature, and is therefore far less harsh on the sensitive materials, Tucker said. “These bacteria are known to be able to survive [the electrospinning process],” he said.

In a paper in the journal Food Hydrocolloids, the researchers review the process and its potential for producing nanofibres suitable for use in foods. They hope to collaborate with industrial partners to develop electrospun nanofibres for food and other applications.

In the meantime, they are also investigating methods to increase the production rates of the nanoparticles, including charging the particles to higher voltages, Tucker said.

As well as functional foods, the researchers are also considering the impact the nanofibre encapsulation process might have on our taste buds, for example. “You could get an intense burst of flavour or odour,” said Tucker.