Flavour characterization of red wines by descriptive analysis and ESI mass spectrometry

Direct infusion electrospray ionization mass spectrometry (ESI-MS) is a new technique that allows for the identification of volatile and non-volatile compounds in foods and beverages, without the need for extraction, isolation and prior chromatographic separation of the sample constituents. The objective of this research was to explore the potential of ESI-MS to identify the acid and phenolic compounds in red wines important for the beverage flavour profile. Thus, descriptive flavour data from red wines elaborated with Vitis labrusca, hybrid and Vitis vinifera grapes was initially generated by a trained panel (n1 = 12 panellists; n2 = 6 repetitions) and subsequently correlated with ESI-MS data collected in the negative ion mode. Considerable variation concerning several acid and polyphenolic compounds identified in the samples was observed amongst the wines. The Principal Component Analysis (PCA) and correlation analyses of the data showed that the succinic acid contents were good predictors of sourness (r = 0.63, p = 0.05). A negative correlation was also observed between grape flavour and the carbonic acid contents (r = −0.76, p = 0.02), amongst other findings. Overall, the results indicated ESI-MS fingerprinting as a fast and reliable technique with potential use in wineries for quality control.