In the benchtop spectroscopy laboratory of the Research Institute for Renewable Energies and the Faculty of Industrial Chemistry and Environmental Engineering of the Timișoara Polytechnic University, a series of experiments are carried out, that allow the identification of the chemical compounds responsible for the aroma of flowers/rose petals as well as the identification of these compounds in rose-flavored food or cosmetic products.
Roses have a special meaning for Timișoara because in the well-known Roses Park, more than 10,000 red, pink, white, yellow and purple roses bloom annually, grouped according to varieties. The Roses Park was inaugurated on July 19, 1891 and was designed by the renowned landscape architects Wilhelm Mühle and Wenceslas Franz Niemitz. After the visit of Emperor Franz Joseph on September 16, 1891, Timisoara became known as the "city of roses".
In order to carry out the experiments, a modern analysis technique is used, named gas chromatography coupled with mass spectrophotometry through the Headspace technique. The technique can be applied to investigate various types of evidence, from food and cosmetics to forensic evidence or meteorites. The analyzed samples were petals of native roses from Timișoara of different species, but also different products with this aroma, rose water, essential oil, fragrance oil and a food product, rose syrup.
The Headspace technique has the advantage of allowing the direct analysis of samples without additional stages of preparation, without using solvents, being a very efficient method that is environmentally friendly. During the analysis, the aroma compounds are separated, generating a chromatogram in which they can be visualized and then identified based on the mass spectrum and the database of chemical compounds available in the laboratory.
The determination is carried out with the help of the automatic system available; after preparing the samples, they are subjected to a heating process at different temperatures and the volatile compounds pass into the gas phase, the chemical composition being analyzed by the device. Rose fragrance is generally composed of at least 20 major constituents and many more minor constituents. Depending on the geographical area and geographical conditions, the aroma of roses has a specific chemical composition. For example, Damascus roses, grown mainly in Bulgaria, will have a different flavor component than those from Timișoara, and through this analysis technique the differences can be identified.
In addition, this technique used within the Faculty of Industrial Chemistry and Environmental Engineering of the Timișoara Polytechnic University allows the establishment of the provenance of flavors from natural or synthetic sources.