When you investigate something, your method can distort your results. This is a problem in lots of research and a case in point is trying to analyse the molecules that make up the smell of garlic. Many analytical methods actually alter the molecules being investigated, for example if they are degraded by heat. For example, gas chromatography is unsuitable because of the high temperatures routinely employed. This is especially true for the heat-sensitive, reactive, volatile organic sulfur compounds from alliums, like garlic, ramsons and onion, and so it is difficult to be sure what you find is a true picture of what you are looking for.
On-line gas analysis in real time, using a particularly gentle, low temperature ionisation of molecules in the air, followed by high-resolution mass-spectrometry (SESI-Orbitrap MS), has been applied to crushed garlic, onions, ramsons and even human “garlic breath” for the first time at the RWTH Aachen University. As the molecules diffuse into the gas phase from the source, they are “breathed” into the analytical apparatus and analysed within seconds under very gentle conditions, avoiding extremes of temperature. This has revealed some very interesting food chemistry and you can read about it in the following publication in Food Chemistry (https://doi.org/10.1016/j.foodchem.2022.133804) 1.
Alan Slusarenko, 22.08.2022
(1) Mengers, H. G.; Schier, C.; Zimmermann, M.; C. H. Gruhlke, M.; Block, E.; Blank, L. M.; Slusarenko, A. J. Seeing the Smell of Garlic: Detection of Gas Phase Volatiles from Crushed Garlic (Allium Sativum), Onion (Allium Cepa), Ramsons (Allium Ursinum) and Human Garlic Breath Using SESI-Orbitrap MS. Food Chemistry 2022, 397, 133804. https://doi.org/10.1016/j.foodchem.2022.133804.