Determination of volatile organic compounds in four <i>Tuber</i> species, and discrimination of truffles on the basis of their identity, geographic origin and maturity

Truffles (genus <i>Tuber</i>, Ascomycota) are famous for their unique organoleptic characteristics and high commercial value. Their distinctive aroma depends on the relative content of volatile organic compounds (VOCs), and constitutes a principal factor for assessing ascomata quality. In this study, we investigated VOCs composition among mature ascomata of four molecularly identified <i>Tuber</i> species (i.e. <i>T. aestivum</i>, <i>T. bituminatum</i>, <i>T. borchii</i> and <i>T. magnatum</i>) originating from various regions of Greece. Profiles of volatiles from semi-mature <i>T. magnatum</i> samples were also assessed to evaluate the influence of the ascomata maturity stage on VOCs production. SPME-GC-MS analysis revealed the existence of ten chemical classes and 36 VOCs, as well as intra- and interspecific variation in VOCs profiles. Alcohols were found to be abundant in <i>T. aestivum</i> (<i>2</i>-butanol and <i>1</i>-octen-<i>3</i>-ol), ethers and ketones in <i>T. bituminatum</i> (<i>1</i>-methoxy-<i>3</i>-methyl-benzene and <i>2</i>-butanone), hydrocarbons in <i>T. borchii</i> (<i>1,3</i>-pentadiene) and organosulfur compounds in <i>T. magnatum (2,4</i>-dithiapentane). Information about VOCs in <i>T. bituminatum</i> is provided for the first time. Furthermore, principal component analysis distinguished the four <i>Tuber</i> species examined, while it also discriminated among <i>T. aestivum</i> samples of various geographic origins. Finally, quantitative modifications in VOCs profiles were associated to the maturity stage of <i>T. magnatum</i> ascomata.