Capturing the pepper character in Shiraz

Transcription

1 Capturing the pepper character in Shiraz Leigh Francis Tracey Siebert Sheridan Barter Markus Herderich Mark Solomon Gerard Logan (University of Auckland)

2 Gas chromatography-mass spectrometry

3

4 (-)-Rotundone O Identity confirmed with reference Cyperus compound rotundus, (Symrise) nut grass weed 1 H and 13 C NMR, ORD GC-MS-O, co-injections Quantification using SIDA O By GC-MS-O, rotundone was established as the principal aroma impact compound for pepper aroma in grapes and wine. D D D D D Wood, C.; Siebert, T. E.; Parker, M. et al. J. Agric. Food Chem. 28, 56, Siebert, T. E. et al. J. Agric. Food Chem. 28, 56,

5 How potent is rotundone? aroma detection threshold 8 ng/l in water 16 ng/l in red wine 2 to 25% of the panellists were anosmic to rotundone Wood, C.; Siebert, T. E.; Parker, M. et al. J. Agric. Food Chem. 28, 56,

6 Number of panellists Aroma detection threshold of the black pepper compound Rotundone, in red wine, is 16 ng/l > 4 Concentration (ng/l)

7 Adelaide Hills Clarendon Hills Coonawarra Geelong Grampians Macedon Ranges McLaren Vale Yarra Valley Adelaide Hills/Yarra Mornington Peninsula Tasmania Yarra Valley Barossa Valley Goulburn Valley Rutherglen Canberra District Frankland River Rotundone (ng/l) Rotundone in Australian wines AWRI TR #18 (June 29) Region/Variety

8 Adelaide Hills Clarendon Hills Coonawarra Geelong Grampians Macedon Ranges McLaren Vale Yarra Valley Canberra District Great Southern New Zealand Hawke s Bay Rotundone (ng/l) Rotundone in other commercially available Shiraz wines Region

9 Sensory attribute intensities: Margaret River and Barossa Shiraz Astringency * Acidity* Hotness Colour intensity* Brown colour* Overall fruit* Dark fruit* Sweet 2 Red berries Viscosity* 1 Jammy fruit* MR BV Wood fl. Vanilla Chocolate fl.* Woody Vanilla fl.* Red berries fl. Dark fruit fl. Pepper* Overall fruit fl.*

10 Barossa Valley Shiraz Margaret River Shiraz Compound concentration concentration (µg/l) b OAV c (µg/l) + OAV acetic acid ethyl lactate ethyl acetate methyl butanol methyl butanol 415 < methyl propanol 2675 < phenyl ethanol methionol hexanoic acid ocatanoic acid methylbutyl acetate methylbutanoic acid butyric acid ethyl octanoate ethyl hexanoate methylbutanoic acid cis-oak lactone ethyl butanoate vanillin <1 ethyl-2-methyl propanoate dimethyl sulfide ethyl 3-methyl butanoate ethylphenol <1 eugenol ethyl 2-methyl butanoate guaiacol linalool <1 sotolon <1 methanethiol <1 β-damascenone hydrogen sulfide.6 < rotundone.1 < Mayr, C.M., Geue, J.P., Holt, H.E., Pearson, W.P., Jeffery, D.W., Francis, I.L Journal of Agricultural and Food Chemistry 62 (2):

11 Rotundone (ng/l) Rotundone variability across vintages: Canberra District Shiraz/Viogner wines - same winery and style Vintage

12 Rotundone is only present in the skin Skin: rotundone Seeds: not detected Pulp: not detected Photograph by Eric Wilkes

13 Rotundone (ng/kg of berries) Rotundone increases during late stage ripening Adelaide Hills Shiraz berries during ripening AH AH Veraison Midway Harvest Ripening timepoint

14 Rotundone (ng/kg of berries) Rotundone (ng/kg of berries) Rotundone increases during late stage ripening Adelaide Hills Shiraz berries during ripening AH AH 2626 NZ Hawke's Bay Syrah berries during ripening 7 Har 6 29 NZ ME 5 21 NZ CR 4 3 Ver Mid 2 1 Veraison Midway Harvest Ripening timepoint Sampling point (weeks) Vine management may impact rotundone concentration

15 Rotundone (ng/kg) Rotundone (ng/kg) Clone and crop load 18 NZ Hawke's Bay Syrah Clones NZ Hawke's Bay Syrah Crop Load Chave 47 MS Clone 1 1% 5% 1%

16 Rotundone (ng/kg) Rotundone (ng/kg) Leaf removal NZ Hawke's Bay Syrah 211 Leaf removal 5 NZ Hawke's Bay Syrah 211 Leaf removal timing % LR 1% LR 1% LR+SH Leaf removal & shade 17-Nov-1 11-Dec-1 1-Jan-11 Leaf removal date

17 Trunk Circumference: 163mm LLN: 2.73 Gaps: 1.5%

18 Trunk Circumference: 129mm LLN:.795 Gaps: 29%

19 Rotundone (ng/kg) Vigour 2 NZ Hawke's Bay Syrah - Vigour high 21 high 211 low 21 low B14 R14 B25 R11 B25 R19 Vineyard block and row

20 Rotundone (ng/l) (ng/l) Rotundone extraction during winemaking Adelaide Hills Shiraz commercial fermentation ` Tank Tank Tank Time from inoculation (days) Fermentation (Day)

21 Rotundone (ng/l) Rotundone extraction from berries during winemaking NZ Hawke's Bay Syrah commercial fermentation OT2 OT4 OT6 OT Time from inoculation (days)

22 Rotundone (ng/l) Can yeast affect rotundone levels during fermentation? Fermentation in defined juice medium Control AWRI Yeast S. bayanus

23 Rotundone (ng/l) Rotundone in French Pyrenees wines Olivier Geffroy, IFV Sud-Ouest 211 Duras microvinification at 5 levels of maturity Theoretical optimum picking date at day 45 after veraison 211 Graciano ng/l 211 Gamay ng/l 211 Pineau d'aunis 66-2 ng/l 28 Duras 95 ng/l 212 Duras 26 ng/l days IFV viticulture trials: Irrigation / Elicitor / crop load ng/l ng/l Control 37 ng/l 27 ng/l Leaf removal 12 ng/l 12 ng/l

24 Variability across the vineyard Nathan Scarlett, RWG; Rob Bramley, CSIRO 212 Rotundone concentration in grapes 177 vines sampled ng/kg 214: 6-15 ng/kg Scarlett, N.J., Bramley, R.G.V., Siebert, T.E Within-vineyard variation in the 'pepper' compound rotundone is spatially structured and related to variation in the land underlying the vineyard. Australian Journal of Grape and Wine Research.

25 Mean January temperature is associated with rotundone concentration in wines Relationship between mean January temperature and the mean rotundone concentration in Shiraz wine samples from eight selected Australian wine regions. Plotted from the data of Jeffery et al. (29) and the Australian Bureau of Meteorology. The equation to the dotted line is y = x (R 2 =.44, P =.75). Within vineyard variation in the pepper compound rotundone is spatially structured and related to variation in the land underlying the vineyard Australian Journal of Grape and Wine Research Scarlett, Bramley and Siebert Volume 2, Issue 2, pages , 16 APR 214 DOI: /ajgw

26 Conclusions Viticultural parameters affected rotundone levels: Picking date, clone, vigour, leaf removal & crop load Rotundone is a very stable compound, easily extracted from skins Why does rotundone occur in Shiraz more often than other varieties? Is temperature during berry development a major influence?

27 The AWRI, a member of the Wine Innovation Cluster in Adelaide, research is financially supported by Australia's grape growers and winemakers through their investment body the Grape and Wine Research and Development Corporation, with matching funds from the Australian Government. Acknowledgements Rob Bramley, CSIRO Darryl Catlin, Winemaker, and the winery and laboratory staff of Shaw and Smith Wines Frank van de Loo, Mt Majura Vineyard Jim Lumbers, Lerida Estate and Lumbers Consulting Dr Ayalsew Zerihun, Curtin University of Technology Nathan Scarlett, Dan Buckle, Damien Sheehan (Mt Langi Ghiran), Allen and Andrea Hart (Treasury), Inca Pearce, Martin Wirper (Orlando), Sue Hodder (Wynns Coonawarra Estate) Symrise, Germany AWRI Mango Parker, Claudia Wood, Dimitra Capone Flavour & Sensory Teams Radka Kolouchova The University of Auckland & EIT Hawke s Bay Mission Estate Wines Craggy Range Vineyards