A study carried out by researchers at the Alexander Fleming Research Centre in Athens, published in the journal PLOS ONE, has unveiled that humans have the potential to smell and differentiate between ordinary odorant molecules and deuterated organic fragrant molecules.
Fragrance chemist Luca Turin and colleagues are of the view that Turin's controversial theory of olfaction is strongly supported by the findings. The theory says that the vibrations of odorant molecules can be sensed by smell receptors.
The study has for the first time evidence that most people can easily identify the differing smells. A notably high number of hydrogen atoms were replaced by deuterium in the molecules and the difference was detectable by smelling.
It is a belief since long that smell sense of humans is dependent on the shapes of molecules that they sniff in the air. But, the same has proved to be a mere public perception as deuteration of odorants hardly makes any difference in the shape of the molecules. However, these may largely change their vibrational frequencies.
"If you look from the standpoint of an alternative theory - that what determines the smell of a molecule is the vibrations - the sulphur-hydrogen mystery becomes absolutely clear", said Dr. Turin.