Aromatic Characterisation of by GC-MS/MS and Validation of Stable Isotopic Ratio Analysis of the Major Volatile Compounds.

Among the grapes, is a winegrape variety characterised by a high content of free and glycosylated monoterpenoids, which gives wines very intense notes of ripe fruit and flowers. The aromatic bouquet of is strongly influenced by the high concentration of linalool, geraniol, linalool oxides, limonene, α-terpineol, citronellol, hotrienol, diendiols, -8-hydroxy linalool, geranic acid and myrcene, that give citrus, rose, and peach notes. Except for quali-quantitative analysis, no investigations regarding the isotopic values of the target volatile compounds in grapes and wines are documented in the literature.

Insights into the stable isotope ratio variability of hybrid grape varieties: a preliminary study.

Background: Official stable isotope databases, based on the analysis of (D/H) , (D/H) , δ C and δ O of wine, are an indispensable tool for establishing the limits beyond which the mislabeling or the addition of sugar and/or water in wine production can be detected. The present study investigates, for the first time, whether the use of hybrid varieties instead of European Vitis vinifera for wine production can have an impact on the stable isotope ratios.

Results: The analyses were performed by isotope ratio mass spectrometry and site-specific natural isotope fractionation by nuclear magnetic resonance, in accordance with the official methods of the International Organization of Grapes and Wine.

Development of a fast gas chromatography-tandem mass spectrometry method for volatile aromatic compound analysis in oenological products.

Aroma plays an important role in food quality, and knowledge of volatile composition is essential to support technological choices during industrial transformation processes. In this study, an innovative GC-MS/MS method useful for fast analysis of the broad aroma profile of oenological products was developed. Fifty volatile compounds of oenological interest belonging to the main chemical classes (acetates, acids, alcohols, aldehydes, esters, ketones, phenols, terpenes, and thiols) were identified and quantified in a single chromatographic run taking only 15 minutes.

Induction of Terpene Biosynthesis in Berries of Microvine Transformed with Alleles.

Terpenoids, especially monoterpenes, are major aroma-impact compounds in grape and wine. Previous studies highlighted a key regulatory role for grapevine 1-deoxy-D-xylulose 5-phosphate synthase 1 (VvDXS1), the first enzyme of the methylerythritol phosphate pathway for isoprenoid precursor biosynthesis. Here, the parallel analysis of genotype and terpene concentration in a germplasm collection demonstrated that sequence has a very high predictive value for the accumulation of monoterpenes and also has an influence on sesquiterpene levels.

Characterization and differentiation of monovarietal grape pomace distillate from native varieties of Galicia.

Monovarietal grape pomace distillates (orujo) of six native varieties of Vitis vinifera L. from Galicia (Albarino, Treixadura, Godello, Loureira, Dona Branca, and Torrontes) have been thoroughly analyzed considering esters, alcohols, major aldehydes, monoterpenes, sesquiterpenes, norisoprenoids, and diterpenes. Albarino and Loureira distillates showed similar profiles of terpenic compounds, with the Loureira products having higher contents of monoterpenols.

The 1-deoxy-D: -xylulose 5-phosphate synthase gene co-localizes with a major QTL affecting monoterpene content in grapevine.

Muscat flavor is a relevant trait both in winemaking and in fresh grape consumption. From a chemical point of view, it is strongly related to the accumulation of monoterpenes in berries. However, knowledge of the genetic mechanisms underlying its regulation is still limited.

Concurrent quantification of light and heavy sulphur volatiles in wine by headspace solid-phase microextraction coupled with gas chromatography/mass spectrometry.

A new method based on headspace solid-phase microextraction coupled with gas chromatography/mass spectrometry (HS-SPME-GC/MS) to analyse 13 light and heavy volatile sulphur compounds in the same run was established. For the successful application of the procedure, various adsorption process parameters were optimised. In particular the nature of the adsorptive phase, the temperature, the ionic strength of the sample solutions and the equilibration time were considered.