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Scientists from Russian city of Voronezh have developed so-called “electronic nose” – a device, which can distinguish natural ingredients (fruits and berries) from artificial flavours in dairy products by smell. This new device has finest olfaction due to a system of piezoelectric sensors, and special software helps the “nose” to distinguish and remember various smells.
Requirements to some food products are really strict – baby nutrition and diet products are considered to be of highest quality, thus making these products more expensive. Unfortunately, some dishonest food producers substitute costly natural fruit ingredients with cheap imitations, which often aren’t mentioned on product’s label. Evidence for presence of such substitutes is very hard to find, because tasty natural aromas are usually complex mixtures of highly volatile substances of various chemical origin, thus identifying it with common chemical methods can be a problem. The only solution to the moment was a professional advice from experts.
New Russian development offers quick and simple solution to described problem. Of course, it won’t make natural strawberry jam from red-colored strawberry-flavored apple puree, but it can distinguish one from another without any time-consuming sample preparation and identification of components. Said device works similar to human nose.
Most important part of the device is a number of several non-specific sensors. Sensors consist of quartz plates, coated with a specific substance. This substance adsorbs molecules of a smell of interest, and plates gain additional weight. Then a generator initiates oscillations of the plate, which now contains unknown molecules (usually oscillation frequency is about 8-10 MHz). Oscillation parameters will depend on plate’s weight – a perfect technique to make weighing scales for nano-amounts out of the plate. These weighing scales are able to tell how many object molecules one or another coating absorbs.
Combination of several sensors with various coatings results in a specific response on a given smell. Other smells won’t have any effect on the system, or their response would be totally different. All we have to do now is “teach” our system – make a database of certain response on a certain smell – and sensors will correctly identify smells (or gases) we are interested in.
All this makes counterfeits tremble. Scientists claim synthetic flavors smell completely different from natural fruits and berries, and Russian “electronic nose” allows telling whether delicious smell of yoghurt is natural or artificial.
Moreover, similar “electronic nose” can tell whether dairy products are fresh. Sometimes expiry date isn’t reached, but milk is obviously sour. Sometimes you cannot tell whether yoghurt is edible. In case this product is made for sick children or those on diet nutrition, one should be absolutely sure food is fresh. Russian development helps to avoid said problems, since it can say how fresh a product is due to a number of chemical transformations taking place in dairy food during its shelf life. Scientists claim they developed a system, much more sensible that human nose, which can warn about non-edible products, when their smell seems to be normal.
Kizilova Anna
