A flower reveals its secrets to science

Head Space is a technique developed in the 1970s originally to clone the natural fragrance of certain flowers, from which no oil can be extracted by traditional methods. It can now be performed on all types of flowers.The flower is placed inside a container adapted to its shape to avoid any risk of damage to the flower.  A micro captor, filled with an absorbent substance is used to soak up the perfumed air around the flower, the “Head Space”, for a period ranging from half an hour to sometimes several hours according the species.Illustration from Rose, Rosa, Rosae, International Perfume Museum, Grasse.

The perfume, 1 to 150 micrograms, absorbed by pre concentration of the air around the flower, can be recuperated by extraction, using the appropriate solvent.  The different molecules are separated by gas chromatography and identified according to their molecular weight by mass spectrometry

This technique analyzes a flower’s olfactive cycle. Analytical chromatography shows that during the course of a day, a flower can put out 400 different olfactive molecules. So a choice has to be made among this multitude of molecules of the ones which will reproduce the flower’s fragrance best. Once the choice has been made, all the molecules must be blended together to create the fragrance that will be closest to nature.