Determination of specific volatile organic compounds synthesised during Tuber borchii fruit body development by solid-phase microextraction and gas chromatography/mass spectrometry.

Fruit body development is a particular phase of the Tuber life cycle, characterised by the aggregation of different types of hyphae, i.e., vegetative hyphal cells and highly specialised reproductive hyphae (asci). In order to identify the volatile organic compounds (VOCs) produced in different stages of the Tuber borchii ripening fruit body, solid-phase microextraction with gas chromatography and mass spectrometry was used. The volatile organic compounds were extracted using a DVB/CAR/PDMS 50/30 microm fiber placed for 10 min at room temperature in the truffle headspace. The results obtained reveal 49 compounds each of which was present only in a particular stage of maturation. 1-octen-3-ol, aromadendrene, alpha-farnesene and other terpenoid compounds were of particular interest, and their possible biological roles are discussed. The production of aromadendrene in the completely unripe fruit body suggests the existence of communication events in the early stage of ascomata formation between the fungus and the host plant. alpha-Farnesene could represent a chemotactic attractant to saprophytic organisms in order to disperse the fungal spores in the environment. The identification of the VOCs produced by truffles during their maturation could give information about the processes underlying this phase of Tuber life cycle. Copyright 2003 John Wiley & Sons, Ltd.