EVOLUTION OF THE AROMATIC POTENTIAL DURING RIPENING OF SYRAH GRAPES ...

730 Pages·2010·27.53 MB·English

EVOLUTION OF THE AROMATIC POTENTIAL DURING RIPENING OF SYRAH
GRAPES EXPOSED TO DIFFERENT IRRIGATION STRATEGIES

P. Hernandez-Orte, N. Loscos, M.* Suarez, J. Cacho, y V. Ferreira
Laboratory for Aroma Analysis and Enology, Department of Analytical Chemistry, Faculty of
Sciences, University of Zaragoza. 50009. Spain.
*Habla Winery, Trujillo. Spain.

ABSTRACT
The aromatic compounds coming from grapes play a decisive role on the quality and
regional character of wines. The varietal aroma consists of free aroma compounds and bound
aromas or precursors. The different types and quantities of aromatic precursors in grapes are
the main source of aromas which differentiate the diverse varieties. It is known that these
precursors are synthesized during grape ripening. However, the effect of the irrigation
techniques during this process and the optimal moment for harvest are not accurately known.
In this work, the changes in the concentration of glycosidic precursors of Syrah grapes
exposed to different irrigation strategies were monitored during ripening in two consecutive
years. It has been found that ripening has a significant effect (p<0.05) on the concentration of
17-23 compounds out of 64 analyzed, while the irrigation affects the concentration of 4-26
compounds, depending on the year.

RESUMEN
Los compuestos aromáticos procedentes de las uvas juegan un papel decisivo en la calidad y
el carácter regional de los vinos. El aroma varietal esta formado por aromas libres y por
precursores. Los diferentes tipos y cantidades de precursores aromáticos en la uva son la
mayor fuente de los aromas que distinguen las distintas variedades. Estos precursores se van
sintetizando durante la maduración. El efecto del riego durante este proceso y cual es el
momento óptimo de la vendimia para conseguir una mayor concentración de estos
compuestos no se conoce con exactitud.
En este trabajo se han estudiado los cambios producidos en la concentración de precursores
glicosídicos en uvas de la variedad Shiraz sometidas a distintos aportes hídricos durante su
maduración en dos añadas consecutivas. La maduración afecta significativamente (p<0.05) a
la concentración de 17-33 compuestos de 64 analizados, mientras el riego lo hace a la
concentración de 4-26 compuestos, en función de la añada.

1. INTRODUCTION
The characteristic aroma of a wine is the result of the simultaneous action of a certain
number of compounds present in a combination of concentrations relatively specific of the
grape variety from which the wine has made.

It can be differentiate between aromatic varieties, such as Muscat, Riesling or
Gewürztraminer, whose musts present a characteristic aroma similar to that found in wines;
and non-aromatic or non-floral varieties, whose musts do not present a characteristic aroma.
In these last varieties, the varietal aroma is present as odorless precursors. Therefore, varietal
aroma consists of (1): odorous molecules or free aromas and precursors, which themselves
can be divided into non-volatile precursors (odorless) and volatile precursors. The different
types and quantities of aromatic precursors in grapes are the main source of aromas which
differentiate the diverse varieties.

Glycosidic precursors have been extensively studied after their discovery in the sixties.
These compounds are mainly monosacharides or disaccharides, and in all cases the aromatic
molecule is linked to a glucose molecule through a β-O-glycoside bound. Among the
aglycones, important wine aroma compounds have been identified, including terpenes,
norisoprenoids, C6 alcohols, benzenes, volatile phenols, vanillin derivatives, and lactones (2-
4). These aromas can be released by acid or enzymatic hydrolysis of the β-O-glycoside bound.
It is known that glycosidic precursors accumulate during grape ripening. Nevertheless, the
optimal moment for harvest and the effect of the irrigation to achieve a higher concentration
of these compounds are not accurately known. The information available in literature about
the evolution of the aroma compounds and their precursors during the developing of grapes
only concerns the changes in norisoprenoids, terpenes, and methoxypyrazines. A little
information is found about the evolution of the precursors of vanillin compounds, volatile
phenols, or lactones.

The aims of this work are to study the changes in the glycosidic precursor composition of
some of the most important wine aromas during the ripening of Syrah grapes, as well as, to
study the effect of the irrigation on the synthesis of these compounds. With this work, it is
expected to determine with more accuracy the moment of the highest aromatic quality of
grapes to carry out harvest.

2. METHODS

Preparation and analysis of the precursor extract
Glycosidic precursors were extracted from Syrah grapes collected at three different ripening
times and one at over-ripening during 2008 vintage, and at two ripening times and one at
over-ripening during 2009 vintage. Sampling has carried out in a vineyard split in two parts;
each one of them underwent a different irrigation strategy (“up” and “down”). “Down”
samples had a higher water supply (50-60 mm), since they were submitted to an additional
irrigation process at mid-veraison.
Three replicates of 200 g were collected in each part at every time. Grapes were stored
frozen in the winery until their analysis. 100 g of grapes from each sample were destemmed
and homogenised, and then juice and skins were separated by centrifugation and filtration.
The precursors coming from must were extracted using LiChrolut EN resins. After
percolating the sample, resins were first washed with water to remove highly polar
compounds and then with dichloromethane to remove free aroma compounds.
After drying the cartridge, the precursors were eluted with ethyl acetate. The ethyl acetate
extract was evaporated under vacuum to dryness, then reconstituted in the hydrolysis tampon
following the procedure reported by Loscos et al. (5). The released aroma compounds were
extracted by SPE using LiChrolut EN and determined by GC-MS (5). Data were treated using
analysis of the variance (ANOVA) to determine the existence of significant differences
between samples. Factors were ripening and irrigation procedure.

3. RESULTS AND DISCUSSION

In both years, the amount of rainwater collected during ripening was very similar, less than
25 mm (data from the National Institute of Meteorology). So, the hydric conditions were
similar in both years. On the other hand, the average temperatures were significantly different.
In 2008, the average temperature was 26.36ºC, while in 2009 the average has higher, 29.6ºC.
This fact involved a higher over-ripening in 2009, even with a loss in the berry weight.
In 2008, the ºBrix values (average of 3 replicates) were the following: “up” (23.2, 23.8, and
25) and “down” (21.6, 21.6, and 25.2). In 2009, the values were: “up” (24.5, 26.4, and 28.1)
and “down” (23, 26.2, and 28.3). In 2008, 11 days passed between the first and the last
sampling, while in 2009, the difference was only 6 days. The fast accumulation of sugar in
2009 forced to harvest 20 days before than in 2008.
Regarding the glycosidic precursors, as can be seen in Table 1, the behavior is quite
different depending on the year. In 2008, only 17 compounds presented significant differences
for the ripening factor, while in 2009 differences were found in the double of compounds, 34.
Moreover, only 10 compounds had significant differences in both years. Differences are even
higher if the irrigation factor is considered.

Table 1. Significant differences (p<0.05) of the aroma compounds released from precursors coming from Syrah grapes
harvest in 2008 and 2009, depending on the factors: ripening, irrigation, and their interaction.

2008 2009
Ripening Irrigation Interaction Ripening Irrigation Interaction
Terpenes
α-terpinolene 0,0007 0,0017
(Z)-linalool oxide <0.0001 <0.0001
(E)-linalool oxide 0,0002 0,0002
Linalool 0.0307 0.0006
α-Terpineol 0,0006 0,0496 0,0451
β-citronellol 0.0501
Geraniol 0.0006
Linalool acetate* 0.0001 0.0061 0,0001 0,0018
Terpinen-4-ol* 0,0004 0,0248
δ-terpineol* 0,0002 0,0059
Neric acid* 0,0004 0,0001
Nerol oxide* 0.0358
Norisoprenoids
β-damascenone 0,0004 <0.0001
β-ionone <0.0001 0,0005 0,0402
Vitispirane A* 0.0364 0.0304 0,0468 0,0121
Vitispirane B* 0.0462 0,0467 0,0151
Riesling acetal*
TDN* 0,0199
TPB* 0,0005 <0.0001
3-Oxo-β-ionone* 0.050 <0.0001 0,0001 <0.0001
Actinidols* <0.0001 0,0001 <0.0001
Norisoprenoid 1* 0.0023 0,0008 <0.0001
Benzenes
Benzaldehyde 0.0388 0,0124
Phenylacetaldehyde <0.0001 0,0319
Benzyl alcohol <0.0001 <0.0001 0,0099
β-phenylethanol 0,0005 <0.0001 0,0079
2-phenoxyethanol 0.055 0,0001
Benzoic acid
Phenylacetic acid 0,0277 0,0031
Volatile phenols
Guaiacol <0.0001 <0.0001
4-ethylguaiacol 0,01 0,01
eugenol 0,0014
4-vinylguaiacol 0,0001
2,6-dimethoxyphenol 0,0134
(E)-isoeugenol 0,0071 0,0013 0,0003
4-vinylphenol 0,0373 0,0085 0,0019
4-allyl-2,6-dimethoxyphenol 0,0002 0,0229
Dihydromethyl-eugenol*
Vanillin compounds
Vanillin
Methyl vanillate 0.0149 0,0001
Ethyl vanillate 0,0003 0,0109
Acetovanillone 0,0002
Zingerone 0,0001
Syringaldehyde 0,0413
Acetosyringone 0,0684 0,0471 0,0001
Homovanillyl alcohol* 0,02
Miscellaneus
(Z)-3-Hexen-1-ol <0.0001 0.0106 0,0089
(E)-2-Hexen-1-ol 0,0009 0,0135
Ethyl decanoate 0.0342 0.0396
3-methylbutyric acid 0.0185 0,0103
2-methylbutyric acid 0.0357 0,0134 <0.0001
2ethylhexanoic acid <0.0001 0.0217 0,0386
Pantolactone 0.0049 0,0336 0,0005
*Data are the relative areas.
In 2008, only 5 compounds presented p values < 0.05, while in 2009 the number of
compounds was 25, of which only Vitispiranes A and B presented significant differences in
both years.

The evolutions of the impact compounds or the sum of the main groups of compounds in
table 1 depending on the irrigation during ripening are plotted in figures 1, 2, 3, 4, and 5 for
both years.
Linalool -2009
Linalool -2008 0.30
0.90 g) 0.25 down
centration (ug/kg) 00000.....1346750505 dupown ncentration (ug/k 0000....01125050 up
n o
Co 0.00 C 0.00
8-Sep 10-Sep 15-Sep 19.sep 25/26aug 28/27aug .31aug

a-terpineol-2009
a-tepineol -2008 down
up 5.0
4.0 down
g/kg) 3.0 ug/kg) 4.0 up
entration (u 12..00 centration ( 123...000
c n
n o
Co 0.0 C 0.0
8-Sep 10-Sep 15-Sep 19.sep 25/26aug 28/27aug .31aug

Sum of terpenes conc -2009
Sum of terpenes conc -2008
30
g/kg) 2350 duopwn ug/kg) 2205 duopwn
n (u 20 on ( 15
ntratio 1105 entrati 10
ce 5 nc 5
n o
Co 0 C 0
8-Sep 10-Sep 15-Sep 19.sep 25/26aug 28/27aug .31aug

Sum of terpenes area -2009
Sum of terpenes area -2008
70
70
elative area x 1000 123456000000 duopwn Relative area x 1000 123456000000 duopwn
R 0 0
8-Sep 10-Sep 15-Sep 19.sep 25/26aug 28/27aug .31aug

Figure 1. Evolution of the released terpenes during ripening of the Syrah grapes harvest in 2008 and 2009 with two
different irrigation strategies (“down” more irrigation than “up”)

As the figure 1 shows, the behavior is quite different depending on the year and even the
evolution of the amount of terpenes is different depending on the irrigation strategy in the
same year. In 2008, linalool increased significantly during ripening and decreased during
over-ripening for the most irrigated grapes, while it remained more or less constant during
ripening and increased during over-ripening for the less irrigated grapes. On the other hand,
the variations between both types of irrigation were lower in 2009, increasing the
concentration of this compound during ripening in both cases. The sum of terpenes in
concentration (α-terpinolene, linalool oxides, linalool, α-terpineol, β-citronellol, and geraniol)
increased during ripening in both years and the higher values were found with less irrigation.
In 2009, the sum of terpenes in area (linalool acetate, terpinen-4-ol, δ-terpineol, neric acid,
and nerol oxide) followed the same evolution, but in 2008 a higher concentration of terpenes
was found with more irrigation.

b-damascenone -2009 down
b-damascenone -2008 up
1.2
1.4
g) 1.2 down kg) 1
g/k 1.0 up ug/ 0.8
n (u 0.8 on ( 0.6
ntratio 00..46 entrati 0.4
ce 0.2 nc 0.2
n o
Co 0.0 C 0
8-Sep 10-Sep 15-Sep 19.sep 25/26aug 28/27aug .31aug

b-ionone -2009 down
b-ionone -2008 up
0.075
0.60
g/kg) 0.50 duopwn ug/kg) 0.06
n (u 0.40 on ( 0.045
centratio 000...123000 ncentrati 00.0.1053
n o
Co 0.00 C 0
8-Sep 10-Sep 15-Sep 19.sep 25/26aug 28/27aug .31aug

Sum of norisoprenoids area -2009
Sum of norisoprenoids area -2008
160 200
000 112400 duopwn down
x 1 100 00 160 up
Relative area 246800000 e area x 10 12800
8-Sep 10-Sep 15-Sep 19.sep v
ati 40
el
R
Figure 2. Evolution of the released norisoprenoids during ripening of0 the Syrah grapes harvest in 2008 and 2009 with two
different irrigation strategies (“down” more irrigation than “up”)

The norisoprenoids evolution can be seen in figure 2. The concentration of β-damascenone
is higher with less irrigation in both years, but the evolution is different depending on the
irrigation strategy, especially in 2009, when the concentration decreased during ripening with
more irrigation and increased with less irrigation. Regarding β-ionone, the results are more
inconsistent from year to year. As can be seen in figure 2, the sum of norisoprenoids in area
(all norisoprenoids except β-ionone and β-damascenone) decreases at first, then increases, and
after that decreases again. The lot with less irrigation accumulated higher concentration.
Guaiacol -2009
Guaiacol -2008
1.8
4.0 down
g) down kg) 1.5 up
g/k 3.0 up ug/ 1.2
ntration (u 12..00 entration ( 00..69
ce nc 0.3
n o
Co 0.0 C 0
8-Sep 10-Sep 15-Sep 19.sep 25/26aug 28/27aug .31aug

Eugenol -2009
Eugenol -2008
0.6
1.8 down
g/kg) 1.5 duopwn ug/kg) 00..45 up
n (u 1.2 on ( 0.3
ncentratio 000...369 oncentrati 00..12
Co 0.0 C 0
8-Sep 10-Sep 15-Sep 19.sep 25/26aug 28/27aug .31aug

Vinylphenols -2009
Vinylphenols -2008
50
70
g/kg) 5600 duopwn kg) 40 duopwn
n (u 40 ug/
atio 30 n ( 30
Concentr 12000 entratio 20
8-Sep 10-Sep 15-Sep 19.sep nc 10
o
C
Figure 3. Evolution of the released volatile phenols during ripening o0f the Syrah grapes harvest in 2008 and 2009 with two
different irrigation strategies (“down” more irrigation than “up”)

As for the volatile phenols, as shown in figure 3, they tend to increase during ripening,
being more abundant with more irrigation in 2008 and the opposite in 2009. In general, they
tend to decrease during over-ripening.

Vanillin compounds -2009 down
Vanillin compounds -2008 up
14
14
g) 12 down g) 12
on (ug/k 108 up n (ug/k 108
centrati 246 ntratio 46
Con 0 nce 2
8-Sep 10-Sep 15-Sep 19.sep Co
0
25/26aug 28/27aug .31aug

Figure 4. Evolution of the released vanillin compounds during ripening of the Syrah grapes harvest in 2008 and 2009 with
two different irrigation strategies (“down” more irrigation than “up”)

Figure 4 shows the different evolution of the sum of vanillin compounds depending on the
irrigation and the year.
(Z)-3-hexen-1-ol -2009
(Z)-3-hexen-1-ol -2008 down
up 1.5
3 down
n (ug/kg) 22 on (ug/kg) 01..92 up
entratio 11 centrati 00..36
c n
n o
Co 0 C 0
8-Sep 10-Sep 15-Sep 19.sep 25/26aug 28/27aug .31aug

Figure 5. Evolution of the released hexenols during ripening of the Syrah grapes harvest in 2008 and 2009 with two
different irrigation strategies (“down” more irrigation than “up”)

Z-3-hexen-ol (figure 5) decreases during ripening in 2008 and increases in 2008, but
decreases during over-ripening in both years. With respect to the irrigation, nothing can be
affirmed. The concentration reached for this compound in 2008 was two times higher than in
2009.

4. CONCLUSIONS

The results of this study suggest continuing monitoring the concentration of the glycosidic
precursors during the next seasons to be able to determine the influence of the different
factors in the synthesis of these compounds, since it has been found that the evolution during
ripening varies very differently depending on the year and the amount of irrigation water.

5. REFERENCES

1. Ribéreau-Gayon, P., Dubourdieu, D., Donèche, B., Lonvaud, A., Varietal aroma. In
Handbook of enology. Vol 2: The Chemistry of Wine. Stabilization and Treatments, Ribéreau-
Gayon, P., Ed. Jonh Wiley & Sons: Chichester, England, 2000; Vol. 2, pp 205-230.
2. Williams, P. J.; Strauss, C. R.; Wilson, B.; Massywestropp, R. A., Use of C reversed-
18
phase liquid-chromatography for the isolation of monoterpene glycosides and nor-isoprenoid
precursors from grape juice and wines. Journal Of Chromatography 1982, 235, (2), 471-480.
3. Wirth, J.; Guo, W. F.; Baumes, R.; Gunata, Z., Volatile compounds released by
enzymatic hydrolysis of glycoconjugates of leaves and grape berries from Vitis vinifera
Muscat of Alexandria and Shiraz cultivars. Journal Of Agricultural And Food Chemistry
2001, 49, (6), 2917-2923.
4. Schneider, R.; Razungles, A.; Augier, C.; Baumes, R., Monoterpenic and
norisoprenoidic glycoconjugates of Vitis vinifera L. cv. Melon B. as precursors of odorants in
Muscadet wines. Journal Of Chromatography A 2001, 936, (1-2), 145-157.
5. Loscos, N.; Hernandez-Orte, P.; Cacho, J.; Ferreira, V., Release and formation of
varietal aroma compounds during alcoholic fermentation from nonfloral grape odorless flavor
precursors fractions. J. Agric. Food Chem. 2007, 55, (16), 6674-6684.
TRADTIONAL GRAPE RPODUCTS OF THRACIAN REGION AND LOCAL
PRODUCTION FORM IN TURKEY

Mehmet GÜLCÜ1

1Ministry of Agriculture and Rural Affairs, Viticultural Research Institute,
Tekirdağ/Turkey
[email protected]

ABSTRACT

Grapes harvested from Thracian Vineyards are utilized by marketing to vine factories,
table grape varieties by transporting to İstanbul market and rest in family as fresh berry or
processed products such as pekmez (grape molasses), bulama (solid molasses), hardaliye
(grape juice flavored and protected with mustard) and salamura yaprak (brined leaf).
Despite lowest protein level, the main traditional food Pekmez, is a good diet food with its
high carbonhydrate and mineral content. “Bulama” is a solid molasses produced by
bleaching the settling juice and foam added likid molasses with airing. “Hardaliye” is
grape juice flavored with mustard is an alcohol free beverage produced by lactic acid
fermentation of grinded mustard seed added grape must. Brined leaf is the main ingredient
of Turkish traditional meal „‟Sarma‟‟. Yapıncak grape variety leaves are most used as
brined leaf in Thracian Region.
Molasses, Bulama, Hardaliye and Brined leaf of Thracian Region and production
technics is surveyed in this study.

INTRODUCTION

Viticulture is one of the most important activity among other agricultural activities. This
agricultural activity affects directly social and commercial life of the area. So it is a culture.
Grapes can usually be classified as table grape, wine/must grape and dried grape. Becides
these common classification styles, local traditional products have also been developed.
These products, known in different names and they were earlier as viticulture and have
been consumed by people for centuries. Particularly in late years according to the demand
for natural products increase of interest on traditional products has been seen (Gülcü et al.
2009).
Thrace, gateway of Turkey to Europe, also has an important position with its agricultural
potential. Vineyards of the local cities (Tekirdağ, Edirne and Kırklareli) constitutes % 0,87
of the total cultivated agricultural lands. According to the data of the Local Agricultural
Departments, vineyard are of the region in 2006 was 9321 ha and grape production in the
same year was 80.000 - 100.000 tons.(Semerci 2006, Kiracı et al 2007)
Wine grape production is common in the Tekirdağ and these grapes are marketed to wine
factories. On the other hand grapes produced in small family enterprises (<2000 m2
vineyard) are used to supply the consumption of the family as form of fresh grape, pekmez
and bulama. Grape production of Kırklareli and Edirne consists of table grape growth and
produced grapes are marketed in the local markets or used for the production fresh grape,
molasses and hardaliye (Durgut and Arın 2005, Kiracı et al 2007).
In this study the production methods of the traditional grape products of Thrace Region
including pekmez (grape molasses), bulama (solid molasses), hardaliye (grape juice
flavored with mustard) and salamura yaprak (brined leaf) were examined.

TRADTIONAL GRAPE RPODUCTS AND OF THRACIAN REGION

Pekmez (Grape molasses)
Although containing lower level of protein pekmez is a good diet food that can be
consumed by person at any age with its higher carbonhydrate and mineral content. The
sugar in the pekmez are in the form of glucose and fruktose and they don‟t need to be
decomposed in the digestive system. These sugars can diffused into blood easly without
consuming energy and thus produces energy for human body rapidly (Taneli 1990). All
fruit containing lower level of sugar can be used to produce pekmez but today the
production of pekmez from grape is common (Batu 2006).
Pekmez in Thrace region is produced generally from grape but production from sugar
cane is also seen in Kırklareli. Home made molasses produced by using local production
methods is consumed by family members or marketed in the local markets.
Classical method is also used in the production of pekmez. First of all grapes were
crashed by human power to obtain must. This must is boiled in the oven for a while and
then by adding pekmez earth "kestirme" process (acid reduction) is applied. This earthl is
collected from different locations of the region, crumbled, sieved and used by appliying to
grapes before squeezing or after boiling the must in the oven. Pekmez earth contains 50-
90% CaCO and the amount added to must varies due to acidity level of must. 1-5 kg
3
pekmez earth is generally used for 100 liter must. After kestirme process must is kept for
one night to cool and deposition of residues. The liquid must is absorbed with tube after
the duration period. This liquid must is boiled in open boilers in the higher temperatured
oven for a while and thickened. During boiling this must is mixed and foams were taken
out by spoon. While boiling continues must and foams starts to redden. Colour becomes
darker and bubbling decreases. When a small amount of pekmez is taken by spoon and
dropped on to plate and stayed like bead or when last drops dropped by the two sided of
the spoon on to plate it can be understood that pekmez is ready and no need to be boiled.
Due to boiling in the oper boilers these molasses are darker.

Bulama (Solid molasses)
Bulama (solid molasses) varies from region to region in the point of production method
and variety of production materials. Bulama is a solid molasses colouring light yellow to
light brown. This product, produced in Thrace for years, is nowadays produced by grape
growers at home conditions to sell on the local market. Tekirdağ is the main city on region
that producing bulama mostly. Bulama is commonly produced from grape and grape
molasses but sugar cane bulama is also available on the market. Çöğen (Gypsophila L. )
roots were boiled and this çöğen juice is added to bulama to open the colour and hardening
of molasses.
Bulama is produced in Tekirdağ in this way; firstly pekmez earth was added to must and
boiled in 70-80 ºC for for acid reduction. Çöğen roots and 20 lt water is boiled for 10-15
min in another boiler. This water is throw away because it is bitter. 30-40 lt water is added
to çöğen and boiled till half of the water evaporate. This process repeated 3 times. Then 30
lt must, 15 lt çöven, 2 kg sucrose are boiled till it becomes like pekmez. Çöğen foams was
prepared in another pot and added to this pekmez. Pekmez is mixed with wood spoon and