Wine Chemistry and Biochemistry

(Steven Felgate) #1

8B Polyfunctional Thiol Compound 279


Ta b l e 8 B. 3 Assay of volatile thiols (ng/L) in Sauvignon blanc wines from the same Bordeaux
estate in several vintages (Tominaga et al. 1998a)


Compounds Compounds Samples
1992 1993 1994 1995


4-Methyl-4-sulfanylpentan-2-one 7(9) 45(50) 10(13) 44(55)
4-Methyl-4-sulfanylpentan-2-ol 46(0.8) 111(2) 25(0.5) 33(0.6)
3-Sulfanylhexan-1-ol 871(15) 1178(20) 600(10) 1686(28)
3-Sulfanylhexyl acetate 0(0) 0(0) 0.4(0.1) 2.8(0.7)
Entries in parentheses are the aromatic index of each compound: concentration/perception
threshold


3SH (ng/L) 4MSP (ng/L)

0

500

1000

1500

2000

2500

3000

3500

Gewurz. Tokay Riesling Muscat

4MSP

3SH

0

20

40

60

80

100

Fig. 8B.13SH and 4MSP concentrations in wines made from Alsace grape varieties (n=5)
(Tominaga et al. 2001)


Guth (1997) demonstrated the major olfactory impact of 4MSP in Scheurebe


wines, which may contain as much as 400 ng/L.


3SH is also present at concentrations well above its perception threshold in wines


made from Petit Manseng, Gros Manseng, Colombard, and botrytized S ́emillon


(Tominaga et al. 2000a) (Table 8B.4). This volatile thiol is present in small quan-


tities, but still above the perception threshold, in Melon de Bourgogne (Schnei-


der 2001) and Chardonnay wines (Tominaga, unpublished results). More recently,


these volatile thiols were identified in wines from the Canary Islands (Lopez


et al. 2003) and those made from Petite Arvine, a Swiss grape variety (Fretz


et al. 2005). Similarly, 3SHA is found in young dry white wines made from Petit


Manseng, Gros Manseng, and Colombard (Table 8B.4) (Tominaga et al. 2001).


The presence of 3SH was reported in red Cabernet and Merlot wines (Bouch-


illoux et al. 1998a; Kotseridis et al. 2000) and it is probably present in wine made


from other red grape varieties. However, after alcoholic fermentation, especially

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