Wine Chemistry and Biochemistry

114 M. Ugliano

Linalool

oxides

Linalool α-

Terpineol

Citronellol Geraniol Hotrienol 3-Oxo-α-

ionol

Vol

atile com

po

un

d

rele

ase

d

(μ

g/L)

R

esi

dua

l

gl

ycosi

d

es (

μ

g/L)

β-D-

Glucopyranosides

α-L-

Rhamnopyranosyl

glucopyranosides

α-L-

Arabinofuranosyl

glucopyranosides

β-D-Apiofuranosyl

glucopyranosides

Control S. cerevisiae S. bayanus

0

50

100

150

200

250

300

350

400

0

200

400

600

800

1000

1200

1400

1600

Control S. cerevisiae S. bayanus

ControlControl SS. cere. cerevvisiisiaae e SS. b. bayanuayanuss

Fig. 4.4Effect of alcoholic fermentation and yeast strain on the concentration of glycoside-derived
volatile compounds and of different classes of glycosidic precursors during the fermentation of a
model grape juice containing Muscat glycosides. The control refers to a non-fermented sample kept
under the same conditions utilized for fermentation, whichaccounts for acid catalysed hydrolysis
of glycosides (adapted from Ugliano 2006)

encoding for the production of an exoglucanase resulted in increased concentration

of monoterpenes after fermentations, suggesting that enzymatic activities not strictly

classified as glycosidases can play a role in the development of wine varietal flavor

during fermentation. Similar conclusions were reached by Daenen et al. (2007) in a

study on glucoside hydrolases inSaccharomycesandBrettanomycesbrewing yeasts.