Olive oil counterfeiters may be
thwarted by DNA particles, that are mixed into the liquid (Photo: Shutterstock)
Because DNA can be damaged by exposure to chemicals, light, and fluctuations in
temperature when outside of a living organism, the particles are first encased
in a protective silica coating. Iron oxide
nanoparticles are also added, which come into the picture later.
DNA particles can then be added to olive oil, with quite a small amount of them
being sufficient for the task at hand – according to ETH, "Just a few grams of
the new substance are enough to tag the entire olive oil production of Italy."
stores subsequently wanted to verify the authenticity of tagged oil, they could
use a magnet to retrieve some of the DNA particles from a sample of the liquid.
This is where the attached iron oxide comes in, as it's drawn to magnets.
DNA is then freed from its silica shell using a fluoride-based solution, and
analyzed via an inexpensive process known as polymerase chain reaction (PCR).
If the code of the sampled DNA matched the code that was recorded when the DNA
was added by the manufacturer, then the oil would be the genuine article.
Although it would be extremely difficult for counterfeiters to create DNA with
that same code, they might be tempted to instead just add a bit of the authentic
tagged oil to their own product, thereby mixing in some of its DNA. That
wouldn't work, either, however, as it's also possible to measure
the concentration of DNA particles in a sample – again, that amount would have
to match the value that was recorded by the original manufacturer.
particles reportedly don't alter the appearance or taste of the oil, and are
said to be harmless to ingest. Silica and iron oxide are essentially sand and
rust, and are already present in some commonly-consumed foods.
As for DNA, we eat it every time we eat plant or animal
products. That said, lead scientist Robert Grass thinks that the technology
might go over better with consumers if the synthetic
DNA were replaced with natural DNA, such as that of fruits or vegetables.
Application of the DNA particles would reportedly cost about 0.02 cents per
liter of oil. The tagging system could also be used on a wide variety of other
liquids, and has already been successfully tested on Bergamot essential oil,
which is used in perfumes. Scientists at Portugal's University of Aveiro are
working on a similar system, in which DNA "barcodes" can be added to both
liquids and dry goods.
paper on the ETH research was recently published in the journal ACS
Source: Gizmag URL: