|
The chemical analyses
presented in this report are the results of 10 years of experimentation
with tartrate stabilization of wines using membranes (TSM), a system based on
electrodialysis. These experiments were conducted on many types of wines,
in France and elsewhere.
Treatment rate and evaluation of the
main analytic parameters during Tartrate Stabilization using Membranes
(TSM).
Treatment rate
Deionisation kinetic: impact on mineral
content
The following table
demonstrates the effect of varying the degree of reduction to the wine’s
conductivity on the concentrate of other constituents.
|
Conductivity
reduction (in %)
|
0
|
10
|
17
|
20
|
25
|
30
|
|
Tartaric acid g/l
|
2.60
|
2.20
|
1.80
|
1.80
|
1.60
|
1.40
|
|
Lactic acid g/l
|
1.40
|
1.40
|
1.40
|
1.40
|
1.40
|
1.40
|
|
Potassium
(K) g/l
|
1690
|
1440
|
1280
|
1190
|
1100
|
990
|
|
Calcium
(Ca) mg/l
|
68
|
69
|
67
|
67
|
68
|
67
|
|
Sodium
(Na) mg/l
|
21.7
|
20.0
|
18.9
|
18.5
|
17.9
|
16.9
|
Table 1: Variation of the
mineral content during deionisation from 0% to 30%.
Evolution of the main analytic
parameters
The following table
demonstrates the effect of varying the degree of conductivity reduction on
a wine’s general characteristics. These are the results from a test run in
Languedoc Roussillon on 12000 hl of wine.
Treatment rate
|
Alcohol
(% vol)
|
V.A.
(g/l)
|
Total A.
(g/l)
|
pH
|
Free SO2
(mg/l)
|
Total SO2
(mg/l)
|
Iron
(mg/l)
|
CO2
(mg/l)
|
DO420
|
DO520
|
|
10-14%
|
0
|
-0.01
|
0
|
-0.01
|
-1
|
-3
|
-0.01
|
-30
|
+0.003
|
+0.001
|
|
15-19%
|
-0.05
|
-0.05
|
-0.06
|
-0.07
|
-8
|
-21
|
-0.45
|
-65
|
0
|
+0.004
|
|
>= 20%
|
-0.07
|
-0.01
|
-0.08
|
-0.11
|
-10
|
-21
|
-0.8
|
-100
|
+0.008
|
+0.003
|
Table 2: Evolution of the
analytic parameters after TSM for white wines (20% of treated wines)
|
Treatment rate
|
Alcohol
(% vol)
|
V.A.
(g/l)
|
Total A.
(g/l)
|
pH
|
Free SO2
(mg/l)
|
Total SO2
(mg/l)
|
Iron
(mg/l)
|
CO2
(mg/l)
|
DO420
|
DO520
|
|
10-14%
|
-0.04
|
-0.01
|
-0.15
|
-0.08
|
-6
|
-14
|
-0.9
|
-53
|
+0.012
|
+0.06
|
|
15-19%
|
-0.05
|
-0.02
|
-0.05
|
-.010
|
-5
|
-12
|
-0.5
|
-90
|
+0.009
|
+0.058
|
|
>= 20%
|
-0.04
|
-0.06
|
-0.05
|
-0.15
|
-5
|
-9
|
-1.0
|
-57
|
+0.017
|
+0.08
|
Table 3: Evolution of the
analytic parameters after TSM for
rosé wines ( 22% of treated wines)
|
Treatment rate
|
Alcohol
(% vol)
|
V.A.
(g/l)
|
Total A.
(g/l)
|
pH
|
SO2 free
(mg/l)
|
SO2 total
(mg/l)
|
Iron
(mg/l)
|
CO2
(mg/l)
|
DO420
|
DO520
|
|
10-14%
|
-0.08
|
-0.05
|
0
|
-0.12
|
-4
|
-9
|
-0.9
|
-44
|
+0.10
|
+0.47
|
|
15-19%
|
-0.04
|
-0.04
|
-0.01
|
-0.14
|
-4
|
-8
|
-1.4
|
-20
|
+0.006
|
+0.47
|
|
>= 20%
|
-0.08
|
-0.06
|
-0.08
|
-0.15
|
-4
|
-12
|
-0.04
|
-70
|
+0.04
|
+0.15
|
Table
4: Evolution
of the analytic parameters after TSM for red wines (IPT <50: 48% of
treated wines)
|
Treatment rate
|
Alcohol
(% vol)
|
V.A.
(g/l)
|
Total A.
(g/l)
|
pH
|
Free SO2
(mg/l)
|
Total
SO2
(mg/l)
|
Iron
(mg/l)
|
CO2
(mg/l)
|
DO420
|
DO520
|
|
> 10%
|
-0.06
|
-0.03
|
-0.5
|
-0.08
|
-2
|
-14
|
-0.05
|
+20
|
+0.0006
|
+0.26
|
|
10-14%
|
-0.03
|
-0.04
|
-0.03
|
-0.14
|
-5
|
-15
|
-1.5
|
-150
|
+0.18
|
+0.20
|
Table 5: Evolution of the
analytic parameters after TSM for red wines (IPT >50: 10% of treated
wines)
These analyses show that
three main characteristics: pH, volatile acidity, and alcohol percent
remain within the variation limits allowed legally. These are:
¨ A reduction of the pH less than 0.3: it is generally
limited to 0.1 and always lower than 0.15.
¨ A reduction of the volatile acidity way below
0.12 g/l: it is generally equal to the analytical precision.
¨ A reduction of the alcohol percent lower than
0.1%vol
Tables 2, 3, 4, and 5
are taken from the bibliographic reference 2
Stability for coloring substances and
polyphenolic structure
Table 6 shows analyses
done by INRA of Pech Rouge (for AOC Corbières Rouges).
Analytical criteria
|
Reference wine
|
Wine treated by cooling
method
|
Wine treated by TSM
|
|
Total Polyphenols
|
225
|
212
|
224
|
|
Absorbance at 280 nm
|
45
|
43,2
|
44,5
|
|
Coloring Intensity
|
6.26
|
6.07
|
6.26
|
|
Tint
|
0,77
|
0,74
|
0,76
|
|
Total Anthocyanes (mg/l)
|
332
|
304
|
326
|
|
Combined Anthocyanes (mg/l)
|
147
|
130
|
143
|
Polymérized Pigments Index
|
56
|
55
|
57
|
|
Procyanidines (mg/l)
|
2816
|
2763
|
2807
|
|
HCl Index
|
21
|
22
|
24
|
|
Gelatin Index
|
59
|
61
|
60
|
|
Ethanol Index
|
17
|
10
|
13
|
Table 6 :Comparison of
color and structure parameters
Tartrate
stabilization by membrane systems does not impact the color and structure
of the wine. The cooling stabilization process leads to losses of tannins and anthocyanises.
stability for aminated compounds
Tables 7, 8, and 9
present the results of trials
conducted on wines from various regions in Europe.
|
|
A.O.C. Médoc
|
A.O.C. Beaujolais
|
|
|
Reference wine
|
Cold Stabilization
|
TSM
|
Reference wine
|
Cold Stabilization
|
TSM
|
Treatment rate
|
|
|
12%
|
|
|
18%
|
Amino Acids mg/l
|
1495
|
1317
|
1462
|
514
|
522
|
553
|
Table 7: Results of trials
on red wines in the Bordeaux and
Beaujolais regions in 1996
|
|
A.O.C. Sylvaner
|
A.O.C. Muskateller
|
A.O.C. Riesling
|
|
|
Reference wine
|
TSM
|
Reference wine
|
TSM
|
Reference wine
|
TSM
|
Treatment rate
|
|
15%
|
|
24%
|
|
11%
|
Amino Acids mg/l
|
363
|
406
|
1104
|
980
|
572
|
587
|
Table 8: Results of trials
on white wines in Germany in1998
|
|
A.O.C. Champagne
|
|
|
Reference wine
|
Cold
Stabilization
|
TSM
|
Treatment rate
|
|
|
20%
|
Amino Acids mg/l
|
732
|
757
|
717
|
Table 9 :Results of trials
on AOC Champagne wines in 1998
These results on
high-quality wines from various regions, and different treatment rates,
illustrate a perfect conservation of the amino acid content after
stabilization by membranes. This
criteria not affected by TSM.
Preservation of sensory qualities
Each
trial included, a sensory evaluation. The sensory evaluation were performed
by professional organizations, with panels composed of trained tasters
familiar with the regional characteristics of the treated wines.
These sensory evaluations showed no
noticeable differences between the reference wines and the wines stabilized
by membranes. The panel members
did not observe significant differences between wine samples collected
before and after membrane stabilization.
In some cases, differences may be discerned between samples of wine
stabilized by the cooling method and those stabilized by membranes:
electrodialysis. This suggests that preserves the polyphenol structure of
wines.
CONCLUSION
Tartrate
stabilization of wines by membranes is a gentle removal technique that
preserves the main characteristics of the wine. The industry, including the
winemakers, management, and the regulator are familiar with the small
degrees of variation in the wine’s characteristics, and consider them
acceptable.
Changes to important parameters such as alcohol content, pH, total
acidity, and volatile acidity are generally less than those caused by the
cold stabilization method.
Other
parameters such as amino acids, structure, and color are preserved: the
overall quality of the wine is therefore preserved.
This method is compatible with the traditional
production of wines. The implementation of mobile units makes this system
available even to the small wineries. It is clearly a method that meets the
requirements of quality insurance and tractability for food production,
while continuing its traditions.
Bibliographic references :
Moutounet M. , Escudier J.L,
Saint-Pierre B., 1994, in Les acquisitions récentes dans les traitements
physiques du vin, B. Donèche éd., Tec et Doc, Lavoisier, Paris
(2) Biau G.,
Siodlack A, Conception, réalisation et utilisation d’une unité industrielle
de stabilisation tartrique, Revue française d’œnologie, 162, pp 18-20,
(1997)
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