Analysis and identification of volatile aroma compounds of the garlic-scented mushroom Mycetinis scorodonius

Fruiting bodies of Mycetinis scorodonius, a mushroom with an intense garlic flavor, were cultivated under laboratory conditions. Focusing on sulfur compounds, volatile organic compounds of the freeze-dried fruiting bodies were analyzed for the first time by means of headspace solid-phase micro extraction and GC–MS/MS-olfactometry. Nine sulfur compounds were identified, including primarily methanethiol, methyl dithioformate, 2,3,5-trithiahexane, dimethyl trithiocarbonate and 2,4,5,7-tetrathiaoctane. For the first time, methyl dithioformate was detected in Mycetinis species. Only four aroma compounds were found in a dichloromethane extract, which were also quantitated. For comparison, the garlic-scented plant Tulbaghia violacea was extracted due to the presence of the thiosulfinate marasmicin. Measurements of liquid Mycetinis and T. violacea extracts by UHPLC-MS and GC–MS/MS-O indicated the presence of the aroma precursor marasmicin in the fungal extract. GC–MS/MS measurements of a pure HPLC marasmicin fraction revealed the thermal degradation products of marasmicin.