Air-, oven- and freeze-dried garlic bulbs were hydrodistilled and the resulting essential oils were analyzed by gas chromatography (GC) and GC/mass spectrometry (GC/MS). The highest yields were 0.6 and 0.5% (w/w) for freeze- and oven-dried samples, respectively. The essential oils were characterized by a high amount of sulfur compounds (84.3â98.9%) with diallyl trisulfide (37.3â45.9%), diallyl disulfide (17.5â35.6%) and methyl allyl trisulfide (7.7â10.4%) being the major components. Remarkable qualitative and quantitative differences between the investigated oils owing to the drying procedure were found and a set of marker components was established to differentiate between them.