Wine Chemistry and Biochemistry

8B Polyfunctional Thiol Compound 289

0

100

200

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400

0246810

0

0.5

1

1.5

2

2.5

nmol/L

days

S-3-(hexan-1-ol)-

L-cysteine

de

graded

3-mercaptohexan-1-ol

released

Pimaricin – ( )

Pimaricin + ( )

Fig. 8B.10Release of 3SH during alcoholic fermentation from a model medium to which syn-
thesizedS-3-(hexan-1-ol)-L-cysteine was added in the absence () and presence ( ) of pimaricin
(Tominaga et al. 1998c)

0

5

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15

20

0123456

0

50

100

150

200

3SH produced(nM) P-3SH metabolized (nM)

days

Fig. 8B.11Production of 3SH and degradation of its precursor (P-3MH) during alcoholic fermen-
tation of a Sauvignon blanc juice in practical conditions

factors such as yeast strains and species must composition and fermentation con-

ditions. The yeast genes and enzymes involved in these reactions are to day better

known (Howell et al. 2005; Thibon et al. 2008b).

The ability ofSaccharomyces cerevisiaestrains to enhance Sauvignon blanc

aroma is variable (Murat et al. 2001c). Some strains produce Sauvignon blanc wines

with higher quantities of volatile thiolsand more pronounced varietal character.

SomeSaccharomyces bayanusvar.uvarumyeast strains can also present a high

aptitude to reveal the volatile thiols from their natural precursor comparing with

Saccharomyces cerevisiaestrains. Those cryophilicS. bayanusvar.uvarumstrains

can be besides implicated in the spontaneous fermentation of various Sauvignon