Is your olive oil really 100% olive oil? The question is more important than it probably seems. In recent years, counterfeit oils have become big business; One European Union anti-fraud trafficker said that the profits from counterfeit olive oil are “comparable to cocaine trafficking, with none of the risks.” Olive oil is often cut with less expensive vegetable oil and disguised with chlorophyll and beta carotene to look genuine, and fakes are surprisingly difficult to detect.

One new research project that hopes to change that. Scientists from ETH Zurich have created tiny magnetic DNA particles that can be encapsulated in silica, and mixed in with the oil. The DNA can store tons of information such as the oil’s source and quality. They particles are small and cheap to produce, with a cost of about $.02 per bottle, according to R&D Magazine. Since they contain small pieces of iron oxide, they can be easily separated from the oil with a magnet, and then “read” rather easily via a process called PCR. As R&D Magazine noted, the method also “made it possible to detect adulteration: if the concentration of nano-particles does not match the original value, other oil—presumably substandard—must have been added.”

While the idea of DNA in your olive might not sound appealing, the particles are supposedly safe to eat, and the silica coating prevents the DNA from being absorbed into the body. Silica and iron oxide additives are already present in foods like ketchup and orange juice. In one trial, the researchers heated and cooled the oil, and the particles and DNA remained intact.

The technology was described in a study published in the journal ACS Nano.