Direct Analysis of Odors Emitted by Freshly CutAllium Using Combined High-performance Liquid Chromatography and Mass Spectrometry

Abstract

Allium odors were re-examined to determine whether or not they contain degradation compounds of thiosulfinates. Garlic (Allium sativum), leek (Allium porrum) and onion (Allium cepa) were investigated using cryotrapping and direct injection of aqueous solutions of the samples into a high-performance liquid chromatograph (HPLC), with a diode-array detector, coupled to a maw spectrometer (MS). Various commercial systems which couple HPLC to tandem MS, but using different ionization systems, were compared. Best results were obtained with atmospheric pressure chemical ionization although degradation of certain thiosulfinates was observed. Depending on the HPLC/MS interface, thiosulfinates formed dimers in variable quantity and this reaction could be used to differentiate isomeric 1-propenyl and 2-propenyl thiosulfinates. Some unresolved isomers were identified by their fragment ions. No disulfides or other rearrangement products were observed and it was concluded that Allium odors contain only thiopropanal S-oxide and thiosulfinates as sulfur volatiles.

Chemical constituents and antimicrobial activity of a traditional herbal medicine containing garlic and black cumin

“…In order to confirm the identity of the isolated allicin, the major antibacterial compound in garlic, the extracts were then analyzed by LC-MS and then had been isolated by preparative HPLC. The electrospray mass spectral fragmentation of allicin was found to be similar with published values (Calvey et al, 1994;Ferary et al,1996). γ -Glutamyl-Sallylcysteine was also identified from its (M+H) + ion and the MS 2 fragmentation pattern thereafter.…”

Observation of allicin‐cysteine complex by reactive desorption electrospray ionization mass spectrometry for garlic

“…10,11 Now HPLC/UV and HPLC/ MS methods are generally applied for the analysis of constituents of garlic with suitable sampling methods. [12][13][14] However, as far as we know, direct analysis of crude garlic has not been reported previously.…”

Comparative study of extraction techniques for determination of garlic flavor components by gas chromatography?mass spectrometry

“…Steam distillation (SD), solvent extraction, and supercritical fluid extraction (SFE) have usually been employed for isolation and extraction of garlic flavors [2,10,11,14,15]. Recently, active studies on Allium flavors were reported by Auger and Ferary and their co-workers; they employed several different isolation methods such as extraction, trapping on Tenax, cold trapping, headspace solid-phase microextraction (HS-SPME) and hyphenated chromatographic procedures [12,13,14,19,20,21]. According to their reports, Allium odors contain only thiopropanal S-oxide and thiosulfinates as sulfur volatiles [21].…”

“…Recently, active studies on Allium flavors were reported by Auger and Ferary and their co-workers; they employed several different isolation methods such as extraction, trapping on Tenax, cold trapping, headspace solid-phase microextraction (HS-SPME) and hyphenated chromatographic procedures [12,13,14,19,20,21]. According to their reports, Allium odors contain only thiopropanal S-oxide and thiosulfinates as sulfur volatiles [21]. In addition, they claimed that gas chromatography-mass spectrometry (GC-MS) did not seem to be a suitable method for the analysis of true garlic flavor as it gave many artifacts [12,20].…”

“…In addition, they claimed that gas chromatography-mass spectrometry (GC-MS) did not seem to be a suitable method for the analysis of true garlic flavor as it gave many artifacts [12,20]. As a preferable alternative they proposed high-performance liquid chromatography (HPLC) after cryo-trapping or high performance ion-pair chromatography for labile substances such as allicin and alliin [12,20,21]. Bocchini et al also employed HPLC for determination of allicin [22].…”