Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
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