Nano pasta is very thin and not suitable for eating

The world's thinnest pasta? You might think we're in the realm of food. But that's not the case—ultrafine pasta, although made from flour like its thicker cousin, falls into the realm of nanotechnology. You can't eat pasta that's only 372 nanometers thick (1 nanometer = one billionth of a meter) because it will overcook so quickly that you can't remove it from the boiling water in time, as Gareth Williams of University College London explains explained.

Williams is a co-author of a new study published in the journal Nanoscale Advances. A research team led by Adam Clancy, lecturer in inorganic and materials chemistry, created the world's thinnest spaghetti not to revolutionize the pasta world, but because the ultra-fine strands known as nanofibers have applications in numerous medical and industrial fields. application.

fiber with potential

Especially in the medical field, nanofibers made from starch (the starch produced by most green plants can store excess glucose) have great potential: for example, they can be used in bandages to speed up wound healing (as porous nanofiber pads Allows water and moisture to penetrate into the wound). by, but keeping bacteria away), as a support for bone regeneration and drug administration.

The disadvantage, however, is that the starch must be extracted and purified from plant cells. This process requires a lot of energy and water. Researchers say there's a greener way: to produce nanofibers directly from starchy ingredients like flour, the base material of pasta.

1000 times thinner than the thinnest spaghetti

The research team was successful in this regard. How thin is the pasta it makes when you compare it to the next thinnest pasta: Sophie Lindeu (“God's Thread”), handmade in Nuoro, Sardinia, is said to be approximately 400 microns (0.4 mm) thick. That's about 1,000 times thicker than the new nano-pasta, which is invisible to the naked eye. They are even thinner than some wavelengths of visible light.

Made using electrospinning technology

The nanopasta is made using electrospinning technology, in which electrical charges are used to pull threads of flour and liquid through a needle tip. The needle containing the mixture and the metal plate to which the mixture is applied act like the two terminals of a battery. By applying an electric charge, the mixture flows out of the needle and completes the circuit by falling on the metal plate.

“To make pasta, a mixture of water and flour is pressed into metal holes,” Clancy explains. “In our study, we did the same thing, but instead of pressing, we pulled the flour mixture through an electric charge. It's really like spaghetti, only much smaller.”

Individual fibers in close-up: they are invisible to the naked eye. Image: Nanoscale Advances

Formic acid instead of water

However, electrospinning using starch components such as white flour is more difficult than using pure starch. This is because proteins and cellulose, etc., make the mixture tougher, preventing fibers from forming. The researchers used flour and formic acid instead of water, because formic acid breaks down the large coils that form starch. The interconnected helical layers are too large to be used as the building blocks of nanofibers.

By the way, cooking has the same effect on starch as formic acid – it breaks down the spiral layers, making the pasta easier to digest. The team then had to gently heat the mixture for several hours and then let it cool slowly to reach the right consistency.

Only visible under a scanning electron microscope

The new nanopasta forms a nanofiber mat about two centimeters wide. This is visible, but each individual strand is too thin to be clearly captured with a regular camera or microscope. Therefore, a special scanning electron microscope is used to measure the width of the threads.

The success of this study is significant because it demonstrates that nanofibers can be produced without energy-intensive starch purification steps. This makes the production method more sustainable. “Starch is a promising material because it is abundant and renewable,” Clancy noted. “It is the second largest source of biomass on Earth after cellulose, and it is biodegradable, meaning it can be broken down in the body. However, purifying starch requires a lot of processing. We have shown that it can be used with more Simple method to produce nanofibers from flour” (HR).

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