The aim of this theses was to evaluate whether the species and the geographical origin of freeze-dried truffles could be differentiated according to their aromatic profiles based on volatile organic compounds (VOCs), and whether the simultaneous freeze-drying of large number of samples in a lyophilizer affects the aromatic profile of each sample. VOCs were evaluated on randomly selected truffle samples (54) of different species (Tuber aestivum, Tuber brumale, Tuber magnatum and Tuber melanosporum) using a combination of headspace solid-phase microextraction (HS-SPME) and gas chromatography coupled with mass spectrometry (GC-MS). The results demonstrate that the aroma of freeze-dried truffles of all species investigated was deeply modified as compared to the fresh truffles. The cross-validation, which was determined with linear discriminant analysis (LDA) of fresh and freeze-dried truffles used in the differentiation of species was > 80%, which indicates that individual species can be distinguished according to their aromatic profile. After freeze-drying, we were able to distinguish all the species tested (T. aestivum, T. brumale, T. magnatum and T. melanosporum). Cross-validation of distinguishing the geographical origin of fresh truffles amounted to 30%, while that of freeze-dried 41%. Despite the low cross-validation score, the results indicates possible differentiatiojn between geographical origin based on aromatic profile. The analysis confirmed that the simultaneous freeze drying of a large number of samples in the lyophilizer influences changes in the aromatic profile of truffles.
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