Linking sensory attributes to selected aroma compounds in South African Cabernet Sauvignon wines

[摘要] ENGLISH ABSTRACT: Cabernet Sauvignon is a widely planted red grape cultivar which produces worldwide, some ofthe finest and most expensive red wines. The typical aroma of Cabernet Sauvignon wines isoften described as either fruity and berry-like or vegetative, herbaceous and green; the latterdescriptors are often considered undesirable. High levels of 2-isobutyl-3-methoxypyrazine(ibMP), a powerful grape-derived compound, have been associated with greener notes inCabernet Sauvignon wines. Over the past two decades, extensive research has beenconducted worldwide to identify the active odorants that impact the aromatic profiles ofCabernet Sauvignon wines. These compounds are mostly higher alcohols, esters, C13-norisoprenoids, methoxypyrazines, sulphur compounds and certain terpenes. More recentstudies have endeavoured to establish a relationship between the sensory analysis andchemical composition of these wines as it could help to explain the impact of certain odorantson the perception of either fruity or herbaceous notes. Despite the interest shown by the SouthAfrican wine industry to improve the quality of Cabernet Sauvignon wines, no such study hasbeen conducted in South Africa yet.The first part of this study gives an overview of the major active aroma compounds whichhave been identified in Cabernet Sauvignon wines with a particular focus on volatile compoundsthat could exhibit either fruity berry notes or herbaceous/vegetative notes. Some of the findingsof studies conducted in Australia and the United States are also discussed.The second part of this study investigates the relationship between the volatile compositionand sensory properties in 13 mono-varietal Cabernet Sauvignon wines produced in SouthAfrica. The wines were selected to represent a broad range of fruity and herbaceous sensoryattributes and were assessed by descriptive analysis. A limited number of volatile compounds(33 in total) that could contribute to either fruity or herbaceous characters, as indicated in theliterature, were analysed using either headspace solid phase micro extraction (SPME) and gaschromatography–ion trap mass spectrometer detection (HS-SPME-GC-ion trap-MS analysis) orsolid phase extraction (SPE) and gas chromatography coupled with a triple quadrupole detector(SPE-GC-MS/MS analysis). The statistical treatment by multiple factor analysis (MFA) of bothcompositional data and sensory data showed that certain volatile compounds such as ß-damascenone, ß-ionone, dimethylsulphide (DMS) and ibMP predicted well some of the aromaattributes used to describe the selected wines.It was found that the analysis of ß-damascenone, ß-ionone, 3-mercaptohexyl acetate,dimethyl sulphide and ibMP could be of interest for winemakers wanting to explain certaintypical aroma descriptors characterising South African Cabernet Sauvignon wines.

[发布机构] Stellenbosch University