Download Environmental and Viticultural Practice Effects on the Phenolic

Stefanos Koundouras
Aristotle University of Thessaloniki
Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture,
Laboratory of Viticulture
541 24 Thessaloniki, Greece
11th International Terroir Congress
Willamette Valley, Oregon
July 10-14, 2016
Presentation Layout
1
Localization and sensory properties
2
Evolution pattern during berry development
3
4
Environmental factors affecting phenolic
composition
Vineyard factors affecting phenolic
composition
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Presentation Layout
1
Localization and sensory properties
2
Evolution pattern during berry development
3
4
Environmental factors affecting phenolic
composition
Vineyard factors affecting phenolic
composition
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Classification of Compounds
• Grape-derived secondary metabolites are the
principal sources of wine color and flavor.
• Aroma compounds – esters, thiols, terpenes,
norisoprenoids ...
• Phenolic Compounds
– Anthocyanins determine the color of red wines but
they are tasteless or indistinctly flavored (Vidal et al.
2004).
– Proanthocyanidins are responsible for the bitter and
astringent sensation of red wines (react with saliva
proteins)
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Anthocyanins
• Anthocyanins are glycosides of anthocyanidins
• In Vitis vinifera varieties, the most common 3-O-glucoside
derivatives of anthocyanidins are delphinidin-3-O-glucoside,
cyanidin-3-O-glucoside, petunidin-3-O-glucoside, peonidin-3O-glucoside, and malvidin-3-O-glucoside
• Dominant anthocyanin in all varieties is malvidin-3-Oglucoside
Anthocyanidin
cyanidin
delphinidin
petunidin
peonidin
malvidin
R1
OH
OH
OH
OH
OH
R2
OH
OH
OH
OH
OH
R3
H
H
H
H
H
R4
OH
OH
OH
OH
OH
R5
OH
OH
OMe
OMe
OMe
R6
OH
OH
OH
OH
OH
R7
H
OH
OH
H
OMe
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
• Anthocyanin profile is genetically driven
Kotseridis et al. (2012) J. Agric. Food Chem.
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Proanthocyanidins
•
•
•
•
Polymeric flavan-3-ols or Condensed Tannins
Usually soluble but very large tannins may precipitate
Major antioxidants of red wines
Four subunits in grapes
(+)-catechin (C)
(-)- epicatechin (EC)
(-)- epigallocatechin (EGC)
(-)- epicatechin-3-gallate (ECG)
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Tannin Composition of Skins and Seeds
• Skin tannin content is lower than seeds
• Skin tannins are generally longer (higher DP) than seeds
and contain low levels of free monomers and oligomers
• Skin proanthocyanidins are usually composed of C, EC and
EGC (prodelphinidin) with EC as major extension unit
• Seeds contain gallate esters (ECG), have similar amounts
of C and EC as extension units and lower proportion of EGC
seeds
skins
Kyraleou et al. (2016) Food Chem.
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Astringency
• Positively related with proanthocyanidin concentration
• Mostly determined by polymer size, the larger molecules
being more astringent than the smaller ones
Sun et al. (2013) J. Agric. Food Chem.
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Astringency
• Astringency could decrease at high mDP since large
molecules become either less soluble or too bulky to
bind with proteins (Sun et al. 2013)
• Tannin binding to cell wall material increases with
tannin concentration and mDP (Bindon et al. 2014)
Bindon et al. (2014)
Cabernet-Sauvignon grapes
at ripeness (26 obrix)
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Astringency
• Increases with the degree of galloylation (presence of
ECG subunits)
• Decreases in the presence of prodelphinidins
(proanthocyanidins with subunits constituted of EGC)
(Vidal et al. 2003)
ECG
EGC
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Astringency
• Seed extracts are perceived more astringent than those
from skins
Extracts:
seeds
15 g/L freeze-dried seed or
skin powder
skins
was dissolved into model
wine solution
(10% ethanol,
tartaric acid 5 g/L
pH 3.2)
Kyraleou et al. (2016) Food Chem.
cv. Syrah
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Presentation Layout
1
Localization and sensory properties
2
Evolution pattern during berry development
3
4
Environmental factors affecting phenolic
composition
Vineyard factors affecting phenolic
composition
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Anthocyanin evolution pattern
• Accumulation of anthocyanins commences at veraison and
increases until harvest
• Some authors have observed a decline just before harvest or
during over-ripening
Maximum accumulation of
anthocyanins (and esters)
of Syrah berries occurred
18-24 days after veraison
Kyraleou et al. (2016) J. Sci. Food Agric.
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Proanthocyanidin evolution pattern
• Biosynthesis of tannins occurs
after anthesis, reaching a
maximum at (or shortly after)
veraison (Ollé et al. 2011)
2011
• Tannins were found to change
little (Harbertson et al. 2002) or
decline from veraison to harvest
(Kyraleou et al. 2015)
2012
Kyraleou et al. (2015) 19th GiESCO Symposium
cv. Syrah
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Proanthocyanidin Size
2011
2012
• The degree of
polymerization of
seed tannins follows a
decreasing trend during
ripening
• The degree of
polymerization of skin
tannins is reported to
increase with ripening
cv. Syrah, North. Greece (unpublished data)
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Presentation Layout
1
Localization and sensory properties
2
Evolution pattern during berry development
3
4
Environmental factors affecting phenolic
composition
Vineyard factors affecting phenolic
composition
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of soil type on anthocyanins
•
•
More spatially structured
than must components
Generally coincide well with
soil variability
Warmer vintage
2010
Milder vintage
2011
Central Greece, cv. Agiorgitiko
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of light on anthocyanins
• High light incidence on grapes was observed to
generally promote anthocyanin accumulation in the skins
• The specific anthocyanin biosynthetic gene encoding UDP
glucose: flavonoid-3-O-glucosyltransferase (UFGT) was
particularly enhanced under increased light exposure in
grapes (Matus et al. 2009)
Matus et al. (2009) J. Exp. Bot.
cv. Cabernet Sauvignon
Leaf removal
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Interaction between
light intensity and temperature
• Under warm climate conditions, grape exposure may
cause lower pigmentation in red grapes (Bergqvist et al.
2001; Spayd et al. 2002)
• Cooling the highly exposed fruit increased the level of
anthocyanins
Bergqvist et al. (2001) Am. J. Vitic. Enol.
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of light and temperature on anthocyanins:
Cultivar effect
• the response of skin anthocyanins to the combined
effects of light and temperature is probably cultivardependent (related to anthocyanin profile)
Leaf removal intensity
positively affected the
concentration of
anthocyanins in Merlot
and Cabernet-Sauvignon
but not Sangiovese
Leaf removal
FR full removal
LR lateral shoot removal
ND non defoliated
Kotseridis et al. (2012)
J. Agric. Food Chem.
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of light on proanthocyanidins
• Sunlight exposure increased the accumulation of
proanthocyanidins in Shiraz skins (Downey et al. 2004).
• Sunlight exposure was reported to enhance the
transcription of the specific proanthocyanidin
biosynthesis genes in the skins (Fujita et al. 2007).
Downey et al. (2004) Aust. J. Grape Wine Res.
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of light on proanthocyanidins
Seed flavan-3-ols were higher
in shaded grapes
(mainly as a result of the reduction
in catechin and epicatechin
amount)
Non defoliated
Kotseridis et al. (2012) J. Agric. Food. Chem.
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Presentation Layout
1
Localization and sensory properties
2
Evolution pattern during berry development
3
4
Environmental factors affecting phenolic
composition
Vineyard factors affecting phenolic
composition
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Grape and wine phenolic content has been
related to many agronomical factors :
•
•
•
•
•
rootstocks (Koundouras et al. 2009)
training systems (Kyraleou et al. 2015)
nutrition (Delgado et al. 2004)
irrigation (Kyraleou et al. 2016)
summer pruning techniques (Kotseridis et al. 2012)
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of rootstock on flavonoids
•
Rootstock genotype affected total flavan-3-ol monomers in
seed tissue.
Koundouras et al. (2009) J. Agric. Food Chem.
cv. Cabernet-Sauvignon
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of training system on flavonoids
•
Lyre trellis resulted in an improvement of
anthocyanin composition of Xinomavro grapes,
compared to two VSP systems
Kyraleou et al. (2015) J. Int. Sci. Vigne Vin
cv. Xinomavro
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
•
•
Royat (double cordon) grape skins were richer in C &
EC while seed flavanol monomers were higher in
single Guyot.
Grapes of Royat vines had a higher proanthocyanidin
mDP in both skins and seeds.
Kyraleou et al. (2015) J. Int. Sci. Vigne Vin
cv. Xinomavro
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of irrigation on skin flavonoids
anthocyanins
•
non irrigated
Increasing trend of skin
flavonoids with water restriction
(Roby et al. 2004, Casassa et
al. 2015)
non irrigated
tannins
Kyraleou et al. (2015) 19th GiESCO Symposium
cv. Syrah
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of water conditions on flavonoid
biosynthesis
•
Under moderate water restriction, all genes encoding
enzymes in the phenyl-propanoid pathway were upregulated
flavanons
flavonols
proanthocyanidins
anthocyanins
Samplings 2011
Panagi et al. (2013) Hellenic Hort. Congress
cv. Syrah
Samplings 2012
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of irrigation on seed flavonoids
•
•
Some studies show increased concentration of seed
flavanols with water deficiency (Chacón et al. 2009,
Casassa et al. 2015)
Other authors found higher levels of polyphenols in the
seeds of irrigated vines (Kennedy et al. 2000, Koundouras
et al. 2009)
Full irrigated
Koundouras et al. (2009) J. Agric. Food Chem.
cv. Cabernet Sauvignon
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of irrigation on
proanthocyanidin structure
2011
seeds
2012
non irrigated
• Irrigation exerted a small
influence on seed tannin
polymerization
• Water deficit increased
skin tannin
polymerization
throughout berry ripening
skins
non irrigated
cv. Syrah, North. Greece (unpublished data)
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Effect of irrigation on
tannin sensory properties
• Lower astringency of seed extracts of non irrigated vines as
perceived by sensory analysis
• Probably related to the lower tannin content of seeds under
reduced water availability reported in several studies
Non irrigated
Kyraleou et al. (2016) Food Chem.
cv. Syrah
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Conclusions
•
Considerable research has been conducted on the
impact of environmental and cultural practice on grape
phenolics, mostly anthocyanins
•
Additional knowledge is required to elucidate the
dependence of polymeric flavonoids, as well as of their
structural and sensory properties on viticultural factors
•
Irrigation and microclimate manipulation are
highlighted as the most important tools influencing grape
phenolic potential
•
The influence of other vineyard factors such as
rootstocks, row orientation or training systems remain
relatively less studied.
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture
Many thanks to…
Laboratory of Enology - Food Science & Human Nutrition Dept
Agricultural University of Athens
Maria Kyraleou
PhD
Stamatina Kallithraka
Assistant Prof.
Laboratory of Viticulture - School of Agriculture
Aristotle University of Thessaloniki
Nikolaos Theodorou
PhD candidate
Yorgos Kotseridis
Assistant Prof.
Thank you
for your attention!
Aristotle University of Thessaloniki • Faculty of Agriculture, Forestry and Natural Environment
School of Agriculture • Laboratory of Viticulture