Screening of Volatile Compounds in Mate (Ilex paraguariensis) Tea—Brazilian Chimarrão Type—By HS-SPDE and Hydrodistillation Coupled to GC-MS
The volatile fraction of mate (Ilex paraguariensis) tea—specifically Brazilian chimarrão type, which has an odor profile comprising distinctive fresh, green, grass, and herbal notes—was investigated. Hydrodistillation in a Clevenger apparatus was employed in order to extract volatiles from the tea matrix. Headspace–solid-phase dynamic extraction (HS-SPDE) was employed to extract the volatiles from two types of infusions of this tea—a simple single infusion and a traditional preparation of consecutive infusions. Volatiles were analyzed by gas chromatography–flame ionization detection/mass spectrometry (GC-FID/MS). In total, 85 compounds were either identified or tentatively identified and semi-quantified. Semi-quantification comprised peak area integration of all the peaks (including the unidentified ones) in the chromatogram. Results obtained by hydrodistillation and by HS-SPDE were distinct, covering mostly different ranges of volatility and showing only 15 compounds in common. The identified compounds had their respective average and minimum odor thresholds and odor characteristics compiled from the literature. Several major compounds considered as key odorants in other mate tea products were not detected or only present at low levels in the samples of this research. Approximately half of the odorants identified in these samples were commonly reported in different mate tea types; the remaining 41 molecules—predominantly terpenoids (isoprenoids)—could be listed as specific to the Brazilian chimarrão type and are suggested to underlie its typical freshness.