COMPARATIVE-STUDY BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY OF METHODS FOR THE EXTRACTION OF SULFUR-COMPOUNDS IN ALLIUM-CEPA L

The influence of two extraction processes on the composition and yield of organic sulfur compounds present in the bulb of Allium cepa L. was evaluated using gas chromatography-mass spectrometry. The direct extraction method with diethyl ether, using chopped and macerated plant tissue, yielded methyl propyl disulfide as the major component, with a mean concentration of 34.37-mu-g per 100 g of fresh tissue. Prior steam distillation followed by extraction of the distillate identified the same components with the exception of methyl propyl disulfide, as in direct extraction method. The major component of the steam distillate was dipropyl disulfide, with a mean concentration of 110.2-mu-g per 100 g of fresh tissue.