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, Schonburger and Siegerrebe wine grapes of up to four vintages from two East Anglian vineyards were analysed for volatile flavour components, using stir-bar sorptive extraction-gas chromatography-mass spectrometry. The analytical flavour profiles 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 flavour profiles, 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)-beta-damascenone contents probably had the greatest flavour (aromatic fruity) impact on Schonburger and Siegerrebe juices and Huxelrebe and Ortega juices, respectively. Copyright (C) 2008 John Wiley & Sons, Ltd.