Seasonal variation of flavour content of English vineyard grapes, determined by stir‐bar sorptive extraction–gas chromatography–mass spectrometry

Abstract

The juices (musts) of Huxelrebe, Madeleine Angevine 7672, Ortega, Schönburger and Siegerrebe wine grapes of up to four vintages from two East Anglian vineyards were analysed for volatile ½avour components, using stir-bar sorptive extraction-gas chromatography-mass spectrometry. The analytical ½avour pro¼les for each variety differed considerably from season to season, depending on ripeness (and in turn on seasonal weather and yield), as judged by sugar content. (E)-Anethole and estragole were most abundant in less ripe juices, although in all cases their concentrations were low. Likewise, C6 aldehydes hexanal and (E)-2-hexenal, as well as other carbonyl compounds, were more abundant in less ripe musts. Additionally, the aliphatic:aromatic ester ratio tended to be higher for riper musts, and higher concentrations of decanoic and dodecanoic acids tended to characterize riper juices. Aliphatic alcohols and terpenoids showed mixed trends. Despite the seasonal differences in ½avour pro¼les, it was deduced that very few variations of individual components were likely to have much organoleptic impact in themselves. Seasonal variations in linalool and (E)-b-damascenone contents probably had the greatest ½avour (aromatic fruity) impact on Schönburger and Siegerrebe juices and Huxelrebe and Ortega juices, respectively.

Analysis of Volatile Components of Varietal English Wines Using Stir Bar Sorptive Extraction/Gas Chromatography-Mass Spectrometry

“…Likewise, all of the remaining terpenoids/norisoprenoids identified (apart from (Z)-rose oxide and (E)-β-damascenone) were also below their OTVs in the wines of this study, but it is likely that they provide an important synergistic background odour contribution [26]. Recent examples include vineyard elevation [29], climatic or vintage variations [6,14,30], vine variety (cultivar) [5,15,[30][31][32] and the use of oak or oak products [9,10,13,[33][34][35]. To our knowledge, this is the first report of an SBSE/GC-MS based comparison of aroma profiles of 'unoaked' white wines with corresponding wines that have had a limited oak contact.…”

“…In this way, the GC peak areas of the extracted volatiles were generally much more similar for the two media. Hence, it was possible to monitor changes in volatile component composition caused by the alcoholic fermentation of real grape must to wine by direct comparison of data for wines in this work with data for the corresponding musts, as reported in our previous reports [5,6], and as outlined in Figure 1. Briefly, compared with the original musts, the wines were characterized by much higher overall levels of volatiles, especially with regard to ethyl alkanoate and acetate esters, fatty acids, 2-phenylethanol and β-damascenone, whereas certain alcohols, carbonyl compounds and some terpenoids were more abundant in the musts.…”

“…Such a technique is stir bar sorptive extraction (SBSE) [3]. SBSE has been used to extract volatile compounds from grape juice [4][5][6][7][8][9][10] and wine [9][10][11][12][13][14][15][16][17], including wines that have had prolonged contact with oak wood, such as maturation in oak casks [12,13], and also including liquid (solvent) desorption in one case [15], as opposed to the standard thermal desorption. Similarly, SBSE has been used to extract volatile compounds from grape juice and wines of grapes to which French oak extract was applied at the ripening stage (veraison) [9,10].…”

“…Samples of these wines were derived from the same musts as those used in previous studies [4][5][6]. In particular, we report here a comparison of aroma profiles of varietal wines (Huxelrebe, Ortega, Schönburger) fermented and aged in stainless steel tanks, and wines from the same must that were fermented and matured in secondhand oak casks.…”

Unraveling different chemical fingerprints between a champagne wine and its aerosols

“…The latter can be for example isomers of dihydrovomofiliol or Blumenol B and Annuionone G, contributing to the fruity aroma of several grape varieties and related wines such as Syrah (23), Chardonnay (24), and Melon (25). Convincingly, an alternative isomer also corresponds to a related odorant norisoprenoid structure (dihydromethyl jasmonate) found in old English grape varieties (26). A further relevant compound was also possibly identified at m/z 297.2435 as ricinoleic acid (Table S1).…”