Su filindeu, originating from the Sardinian town of Nuoro and meaning “threads of God,” is the world’s thinnest known pasta, with single strands measuring a mere 0.016 inches wide (400 microns). However, su filindeu has now slid into second place, overtaken by an unusual contender, so to speak, about 1,000 times thinner.
University College London (UCL) graduate chemistry student Beatrice Britton used flour and liquid to produce nanofibers about 15 millionths of an inch thick (372 nanometers) thinner than some wavelengths of light. While this “nanopasta” will never make it onto a restaurant’s menu (it would overcook in less than a second), the findings, published last month in the journal Nanoscale Advances, could have important implications in medical applications such as bandages, scaffolding for bone regeneration and tissue regrowth, and drug delivery.
“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,” said Adam Clancy, a UCL researcher who participated in the study, in a university statement. “It’s literally spaghetti but much smaller.”
The key ingredient in these nanofibers is starch, which most green plants produce to store extra glucose. While extracting and purifying starch from plant cells takes a lot of energy and water, the researchers argue that simply using starch-rich ingredients like flour is more environmentally friendly.
“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,” Clancy explained. “But purifying starch requires lots of processing. We’ve shown that a simpler way to make nanofibers using flour is possible.”
The team used electrospinning, a technique in which an electrical charge pulls a mixture of flour and liquid through the tip of a needle and onto a metal plate, acting as two ends of a battery circuit. However, starch-rich ingredients have components such as protein and cellulose that make it more difficult for the mixture to thread into fibers than if it were pure starch.
To overcome this, the researchers mixed the flour with formic acid instead of water to break down the starch’s spiral structure, whose components would otherwise be too big to form nanofibers. The formic acid evaporated before the fibers landed on the plate.
The resulting nanopasta’s individual fibers were too thin to capture with visible light cameras or conventional microscopes, so the researchers measured them with a scanning electron microscope—a type of microscope that scans the surface of objects with a beam of electrons. The fibers were woven into a 0.79-inch-wide (2 centimeters) mat, which is visible to the naked eye.
“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,” Clancy said.
Italians who have been arguing that pasta is good for the heart and soul for centuries won’t be surprised to learn that our favorite carb’s impact reaches beyond gastronomy and straight into the medical field.
