Measurement of the Effect of Accelerated Aging on the Aromatic Compounds of Gewürztraminer and Teroldego Wines, Using a SPE-GC-MS/MS Protocol

Abstract

Knowing in detail how the white and red wine aroma compounds behave under various storage conditions and especially at high temperature is important in order to understand the changes occurring to their sensorial character during the shelf life. The initial aim of this work was to develop and validate a fast, modern, robust, and comprehensive protocol for the quantification of 64 primary, secondary, and tertiary volatile compounds by using solid-phase extraction (SPE) cartridges in sample preparation and fast GC-MS/MS (gas chromatography-tandem mass spectrometry assay) in analysis. The protocol was applied to a study of the behavior of seven Gewürztraminer and seven Teroldego wines stored in anoxia at 50° C for 2.5 and 5 weeks. The results demonstrated a sharp decrease of the main linear terpenes linalool, geraniol, and nerol and the consequent increase of the cyclic ones, such as α-terpineol and 1,8-cineole; the increase of the C13-norisoprenoids 1,1,6,-trimethyl-1,2-dihydronapthalene (TDN), and β-damascenone and the C10 norisoprenoid safranal; the hydrolysis of acetates and linear esters; and the increase of some branched-chain esters. In red wines, a moderate increase was observed for some lactones. Some unwanted compounds, such as 2-aminoacetophenone (2-AAP), showed a notable increase in some Gewürztraminer wines, exceeding the olfactory threshold.

Flint glass bottles cause white wine aroma identity degradation

“…The wine science literature is rich in research results reporting the influence of shelf-life temperature conditions and of packaging oxygen level on varietal aromas ( 20 – 23 ). Here, we shed light on the influence of light and glass color on the most important and well-known wine aromatic volatile compounds.…”

“…On the other hand, for the wines produced from neutral and lightly aromatic grape cultivars, like Pinot gris and Chardonnay, terpenes play a paramount importance in their sensorial quality, and the winemakers’ main aim is to maintain their concentration. Terpenes are sensitive compounds, and their concentration is temperature, pH, oxygen, and time dependent ( 23 , 28 , 29 ). According to our results, we should add that light also plays an important role in their stability in wine.…”

“…The involvement of terpenoids in photodegradation was not unexpected because exposure to photochemical oxidation was found to be the major driver in long-term photochemical transformations, i.e., reaction times of several hours up to days, of terpene mixtures in secondary organic aerosols ( 37 ). In a small experiment, described in SI Appendix , where a wine was spiked with linalool, β-damascenone, and 4-vinyl-guaiacol at levels 3 to 50 times higher than the common concentrations in wines, it was hard to detect any of the degradation products described in the literature ( 23 , 38 – 43 ).…”

“…Several studies on wine accelerated aging at high temperature reported a loss of fruity and floral notes in young white wine, associated with the hydrolysis of the fermentative esters, and the increase of other compounds linked to the aging, such as TDN and vitispirane and other terpenoids, due to the hydrolysis of their precursors ( 31 , 46 , 47 ). Generally, at high temperatures (50 °C), their concentration initially increases due to glycoside hydrolysis and then decreases because of different rearrangements that lead to molecules such as α-terpineol, linalool oxides, and cyclic terpenes ( 23 , 48 , 49 ). Therefore, to have comparable results to our shelf-life experiment for the free monoterpenes, we need to store the wine at 50 °C.…”

Terroir Traceability in Grapes, Musts and Gewürztraminer Wines from the South Tyrol Wine Region

“…To assess the possible correlations between terroir ecological indicators and vineyard products' bio-fingerprints, oenological-chemical analyses were conducted on grapes, musts and wines using targeted procedures. The primary indicators of the more typical Gewürztraminer cultivar were examined, focusing mainly on volatile aromatic substances, mostly varietal [35][36][37]. The products of the complete transformation chain, from grapes to wine, were analysed to determine their composition, which varies due to the transformation of aroma precursors from yeast during alcoholic fermentation [38].…”