Volatiles playing an important role in South African Sauvignon blanc wines

[摘要] ENGLISH ABSTRACT: Sauvignon blanc wines have become progressively more important in the commercial market.Extensive research is being done in various countries to gain more understanding about thearoma compounds found in Sauvignon blanc wines and the interactions between them.Sauvignon blanc wines often have either have a green or tropical style. The green style iscaused by the methoxypyrazines while the volatile thiols are important contributing compoundsto the tropical style. Various international studies have focussed on measuring the chemicalcomposition of Sauvignon blanc wines. However, more research is required on South AfricanSauvignon blanc wines. Little is known of the volatile thiols content of South African Sauvignonblanc wines, although the methoxypyrazine content has been extensively reported on. Althoughmethoxypyrazines and volatile thiols are seen as the most important aroma compoundscontributing to Sauvignon blanc character, other compounds contribute as well. Esters,monoterpenes and phenols have been found to influence Sauvignon blanc aroma and interactwith the methoxypyrazines and volatile thiols. The complex interaction between the compoundsresponsible for the aroma of Sauvignon blanc wines are still not fully understood and furtherresearch is thus needed. The first part of the current study investigated the interaction betweena specific methoxypyrazine and volatile thiol. Five different concentrations of 2-isobutyl-3-methoxypyrazine (ibMP) and 3-mercaptohexan-1-ol (3MH) were spiked in dearomatize, neutralSauvignon blanc wine. The single compounds as well as every possible combination of therange of concentrations were evaluated using sensory descriptive analysis. It was found usingvarious statistical approaches that ibMP suppressed the tropical attributes associated with 3MHand that 3MH suppressed the green attributes that correlated with ibMP. The concentrations atwhich the suppression occurred and the degree of suppression was different for each attribute.The second part of the current study focussed on commercial South African Sauvignon blanc wines. Sensory descriptive analysis and chemical analysis were used to assess the wines andmeasure the volatile thiol and methoxypyrazine concentrations. The concentrations of volatilethiols and methoxypyrazines were found to be in line with international Sauvignon blanc wines.It was also shown for the first time that the mutually suppressive trend between the volatilethiols and methoxypyrazines can be seen in commercial Sauvignon blanc wines as well. Futurework is needed to fully understand the complex interaction between the various compounds inSauvignon blanc wines. Further research could focus on investigating the mechanism ofinteraction between the volatile thiols and methoxypyrazines as well as other aromacompounds.

[发布机构] Stellenbosch University