2009_Book_FoodChemistry

20.2 Wine 925
Fig. 20.7. Monoterpenes in wines from the grape cultivar “White Riesling” and in wines from other grape cultivars
which are also sold as “Riesling” (according to Rapp et al., 1985). A: White Riesling (Rheinpfalz), B: White
Riesling (France), C: Welschriesling (Austria), D: Welschriesling (Italy), E: Laski Rizling (Yugoslavia), F: Hunter
Valley Riesling (Australia), G: Emerald Riesling (USA). Monoterpenes: 1 trans-furan linalool oxide, 2 cis-furan
linalool oxide, 3 neroloxide, 4 linalool, 5 hotrienol, 6 α-terpineol, 7 not identified, 8 trans-pyran linalool oxide,
9 cis-pyran linalool oxide, 10 3,7-dimethylocta-1,5-trans-dien-3,7-diol, 11 3,7-dimethyl-1-octen-3,7-diol
Table 20.24. Aroma defects in wine
Aroma defect Key aroma substances Cause
Mousy note
2-Ethyl-3,4,5,6-tetrahydropyridine,
2-acetyl-3,4,5,6-tetrahydropyridine,
2-acetyl-1,2,5,6-tetrahydropyridine
Strawberry note 4-Hydroxy-2,5-dimethyl-3(2H)-furanone
(HD3F): >1500 µg/l
Medicine note 4-Vinylphenol +
4-vinylguaiacol: >800 µg/l
Medicinal, woody,
smoky, horse sweat
Kerosine/petrol note
4-Ethylphenol +
4-ethylguaiacol: >400 µg/l
1,1,6-Trimethyl-1,2-dihydro-naphthaline
(TDN): >300 µg/l
Lactic acid bacteria in combination
with yeasts
of the genus Brettanomyces
Characteristic of the cultivar
Climate, microbiological processes
Climate, microbiological processes
Southern climate, excessively high
carotinoid concentration in Riesling
“Boeckser” Hydrogen sulfide Fermentation
Cork taste/musty note 2,4,6-Trichloroanisole, geosmin,
2-methylisoborneol, 1-octen-3-one,
4,5-dichloroguaiacol, chlorovanillin
Contamination during wine storage
Untypical aging note
(naphthaline note, fox
note, hybrid note)
2-Aminoacetophenone: >0.5µg/l
Stress reaction of the vine
The so-called “boeckser” is caused by the smell
of hydrogen sulfide. The very unpleasant, rotten
and yeasty “boeckser” (= mercaptan) odor is
most objectionable and lingers for a long time.
It is due to ethylthiol, which can be removed
by activated charcoal. The volatile sulfur compounds
originate from sulfite which is reduced
to H 2 S by yeast, later reacting with ethanol to
form ethylthiol. Additional wine taste defects are
the odd and disagreeable cork tastes which is
due to the formation of the odorants listed in Table
20.24 and 2,4,6-trichloroanisole. Above con-