HEADSPACE SOLID-PHASE MICROEXTRACTION ANALYSIS OF VOLATILE ORGANIC SULFUR-COMPOUNDS IN BLACK-AND-WHITE TRUFFLE AROMA

Headspace solid-phase microextraction (HS-SPME) combined with gas chro matography-ion trap mass spectrometry (GC-ITMS) has been shown to be a powerful technique for detection of volatile organic sulfur compounds (sulfur VOCs) in aromas of white truffles (Tuber magnatum Pico) and b lack Perigord truffles (Tuber melanosporum). For both species all of t he compounds previously identified during several studies were detecte d in single analyses, and in the case of white truffles three new sulf ur compounds were identified: dimethyl di- and trisulfide and 1,2,4-tr ithiolane. Comparison with traditional headspace Tenax adsorption/deso rption CC-MS analyses of the aromas showed that the HS-SPME technique is less suited for quantitative analyses, especially because the polyd imethylsiloxane fiber coating used in the SPME device strongly discrim inates more polar and very volatile compounds. With the Tenax adsorpti on analysis two new sulfur compounds were identified in black truffle aroma: 1-(methylthio)propane and 1-(methylthio)-1-propene, The predomi nant sulfur compounds are dimethyl sulfide and bis(methylthio)methane in white truffle aroma and dimethyl sulfide in black truffle aroma. On evaporation of the sulfur compounds from cuttings of black truffle a distinct mushroom odor appeared that is ascribed to the considerable c ontents of 1-octen-3-ol and other C-8 compounds, characteristic for mu shroom aroma, that are present in the black truffle aroma.