Determination of typical features of Ruché wine aroma by headspace solid phase microextraction coupled to bidimensional chromatography – time-of-flight mass spectrometry and chemometric data exploration

Ruché is a red wine produced from a native grape variety in Piedmont, a region situated in north-western Italy. This wine is attracting growing interest among customers because of its peculiar bouquet. In this study, the analysis of volatile organic compounds (VOCs) was conducted using headspace solid phase microextraction (HS-SPME) coupled to bidimensional chromatography and time-of-flight mass spectrometry (GCxGC-ToFMS, high resolution), resulting in the identification of over one hundred compounds. The extensive set of experimental data was investigated by means of advanced chemometric techniques. The most relevant VOCs detected in this study are 2-phenylethanol and its acetate, along with usual and some unusual terpenoids such as bergamotene. Appreciable concentrations of off-odor molecules, including octanoic acid and ethyl-guaiacol, were also detected; nevertheless, they are considered as peculiar components of the whole complex bouquet of Ruché. Chemometric analysis was employed to characterize the set of typical Ruché wines, and to identify anomalous samples, whose differentiation may be linked to specific wine practices or accidental pollution or improper wine storage. This study may provide a valuable indication for wine producers seeking to optimise their product, and it serves as a foundation for further investigation about specific winemaking techniques and evolution with aging.