Identification and Quantification of a Marker Compound for 'Pepper' Aroma and Flavor in Shiraz Grape Berries by Combination of Chemometrics and Gas Chromatography-Mass Spectrometry
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- 作者：Mango Parker ; Alan P. Pollnitz ; Daniel Cozzolino ; I. Leigh Francis ; Markus J. Herderich
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2007
- 出版时间：July 25, 2007
- 年：2007
- 卷：55
- 期：15
- 页码：5948 - 5955
- 全文大小：92K
- 年卷期：v.55,no.15(July 25, 2007)
- ISSN：1520-5118
文摘
'Black pepper' aroma and flavor is important to some Australian Shiraz red wine styles but the aromacompounds involved have yet to be identified, and no objective analytical method to assess 'pepper'grape aromas is available to date. Samples of potentially 'spicy'/'peppery' grapes were obtained fromvineyards in South Australia and Victoria over two vintages. The important sensory attributes of thegrapes, including the aroma descriptor 'pepper', were rated by a sensory panel. The sensory studyrevealed a strong correlation between the intensity of 'pepper' aroma and the intensity of 'pepper'flavor perceived on the palate. The grape homogenates were analyzed by static headspace GC-MSusing a cool inlet system. Vectors obtained by analysis of over 13 000 individual mass spectra pergrape sample were then subjected to multivariate analyses. Both principal component analysis andpartial least-squares regression were used to develop multivariate models based on mass spectraand aroma descriptors to explain the intensity of the rating of the 'pepper' character. Correspondingdifferences in mass spectra and aroma were observed among vineyards and from the same vineyardsin different years. Additional optimization of the methodology enabled selection of a single region ofthe GC-MS chromatogram that allowed prediction of 'pepper' aroma intensity with a correlationcoefficient >0.98 and led to the identification of 
-ylangene, a tricyclic sesquiterpene. To assess thepotential of -ylangene as a marker for this sensory characteristic, a method for -ylangene analysisof grapes and wine using HS-SPME-GC-MS was developed. Although not a significant aromacompound by itself, -ylangene was a satisfactory marker for the 'pepper' aroma in grapes and wine,and its concentration showed similar discrimination between 'peppery' vineyards and vintages asthat obtained using the multivariate models. Despite its presence in grapes, we could not detect-ylangene in wine.
-ylangene, a tricyclic sesquiterpene. To assess thepotential of -ylangene as a marker for this sensory characteristic, a method for -ylangene analysisof grapes and wine using HS-SPME-GC-MS was developed. Although not a significant aromacompound by itself, -ylangene was a satisfactory marker for the 'pepper' aroma in grapes and wine,and its concentration showed similar discrimination between 'peppery' vineyards and vintages asthat obtained using the multivariate models. Despite its presence in grapes, we could not detect-ylangene in wine.