ANALYTICAL STRATEGY BY COUPLING HEADSPACE GAS-CHROMATOGRAPHY, ATOMIC-EMISSION SPECTROMETRIC DETECTION AND MASS-SPECTROMETRY APPLICATION TO SULFUR-COMPOUNDS FROM GARLIC

Numerous sulfur-containing molecules are present in garlic cloves, alliine being the most important. The characteristic aroma of garlic is obtained after the reaction of the enzyme alliinase which converts alliine into allicine. This very unstable molecule is rapidly converted into a series of numerous other odorous sulfur-containing molecules. This complex mixture of volatile compounds was analysed using GC-atomic emission spectrometric detection and GC-MS after introduction with a headspace device. The analysed products were non-peeled and peeled whole garlic cloves, peeled and crushed garlic cloves and garlic juice obtained by crushing the cloves. A comparison was made between the heating times of the headspace device (5 and 45 min). The two-stage analytical strategy used for this kind of analysis is described: (i) location of the sulfur-containing compounds from the specific sulfur chromatograms obtained by monitoring the sulfur atomic emission line with an atomic emission spectrometer coupled to a gas chromatograph and (ii) structural analysis of the located and selected compounds by mass spectrometry after transposing the chromatographic method to GC-MS.