A team of researchers from University College London, UK, created the world’s thinnest spaghetti, according to a study published in Nanoscale Advances. The spaghetti — about 200 times thinner than air — is not a new food, but it can have multiple applications in medicine and industry.
The authors suggested multiple applications, including bandages to promote healing because the starch fibers are highly porous and allow water and moisture in but keeping bacteria out; as well as scaffolding for bone regeneration and drug delivery. “Nanofibers, such as those made of starch, show potential for use in wound dressings as they are very porous. In addition, nanofibers are being explored for use as a scaffold to regrow tissue, as they mimic the extra-cellular matrix – a network of proteins and other molecules that cells build to support themselves,” said Professor Gareth Williams (UCL School of Pharmacy).
The idea of using thin fibers is not new, but previous versions require high amounts of energy and water to extract starch from plant cells. A more environmentally friendly method is to make nanofibers directly from a starch-rich ingredient like flour, which is the basis for pasta.
In the new study, the UCL team describe how they made spaghetti measuring 372 nanometres (billionths of a metre) using a technique called electrospinning. The process involves pulling threads of flour and liquid through the tip of a needle by an electric charge. “To make spaghetti, you push a mixture of water and flour through metal holes. In our study, we did the same except we pulled our flour mixture through with an electrical charge. It’s literally spaghetti but much smaller,” said Dr Adam Clancy (UCL Chemistry).
By comparison, the thinnest pasta made by hand— called su filindeu — is estimated to be about 400 microns wide – 1,000 times wider than the new creation. Incredibly, at 372 nanometres, the new fibers are narrower than some wavelengths of light. Each individual strand is too narrow to be captured by light camera or microscope, so their widths were measured with a scanning electron microscope. “I don’t think it’s useful as pasta, sadly, as it would overcook in less than a second, before you could take it out of the pan,” joked Professor Williams.
“Starch is a promising material to use as it is abundant and renewable – it is the second largest source of biomass on Earth, behind cellulose – and it is biodegradable, meaning it can be broken down in the body. But purifying starch requires lots of processing. We’ve shown that a simpler way to make nanofibers using flour is possible. The next step would be to investigate the properties of this product. We would want to know, for instance, how quickly it disintegrates, how it interacts with cells, and if you could produce it at scale,” said Dr Clancy.
In electrospinning, the needle and the metal plate containing the starchy mixture are placed at opposite ends of a battery. Applying an electrical charge makes the mixture close the circuit by streaming out of the needle on to the metal plate. Using a starch-rich ingredient such as white flour is harder than using pure starch, because impurities present – the protein and cellulose – make the mixture more viscous and unable to form fibres.
To reduce this issue, the team used flour and formic acid instead of water, as this acid breaks up the giant stacks of spirals that make up starch. This solves the problem of using layers of helices that are too big to make nanofibers. Out of curiosity, cooking has the same effect on the starch as the formic acid – it breaks up the layers of helices, making the pasta digestible.
Britton B, Zhang F, Anthony DB, Reyes CIDL, Pawlus M, Williams GR, Clancy AJ. Nanopasta: electrospinning nanofibers of white flour. Nanoscale Adv. 2024 Oct 30;6(24):6129-6133. doi: 10.1039/d4na00601a.