A Targeted and an Untargeted Metabolomics Approach to the Volatile Aroma Profile of Young 'Marastina' Wines

This study investigated the detailed volatile aroma profile of young white wines of Marastina, Vitis Vinifera L., produced by spontaneous fermentation. The wines were produced from 10 vineyards located in two Dalmatian subregions (Northern Dalmatia and Central and Southern Dalmatia). Volatile compounds from the wine samples were isolated by solid-phase extraction (SPE) and analyzed by an untargeted approach using two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GCxGC/TOF-MS) and a targeted approach by gas chromatography-tandem mass spectrometry (GC-MS/MS). A comprehensive two-dimensional GCxGC analysis detailed the total volatile metabolites in the wines due to its excellent separation ability. More than 900 compounds were detected after untargeted profiling; 188 of them were identified or tentatively identified. A total of 56 volatile compounds were identified and quantified using GC-MS/MS analysis. The predominant classes in Marastina wines were acids, esters, and alcohols. The key odorants with odor activity values higher than one were beta-damascenone, ethyl caprylate, ethyl isovalerate, ethyl 2-methylbutyrate, ethyl caproate, isopentyl acetate, ethyl butyrate, and phenylacetaldehyde. The metabolomics approach can provide a large amount of information and can help to anticipate variation in wines or change winemaking procedures.

Automated summary

This study investigated the volatile aroma profile of Marastina white wines produced by spontaneous fermentation. A total of 900 compounds were detected, with 188 of them identified or tentatively identified. The predominant classes in Marastina wines were acids, esters, and alcohols. Key odorants included beta-damascenone, ethyl caprylate, ethyl isovalerate, ethyl 2-methylbutyrate, ethyl caproate, isopentyl acetate, ethyl butyrate, and phenylacetaldehyde. The metabolomics approach provides valuable information for predicting wine variations and improving winemaking procedures.