186 Technical Review June 2010
Total Page:16
File Type:pdf, Size:1020Kb
The Australian Wine A W R I Research Institute Technical Review No186 June 2010 Registered by Australia Post PP 531629/00034 Table of contents In this issue 1 AWRI notes 6 14th Australian Wine Industry Technical Conference – starts next month 6 Technical notes 8 Aroma detection threshold study of methanethiol in white and red wine 8 Reducing alcohol levels in wine 11 Studies involving precursors to the tropical wine odorant 3-mercaptohexan-1-ol 16 Current literature 21 AWRI publications 60 AWRI extension and roadshow calendar 66 Conference calendar 67 Editor: Michael Major, Michael Major Media All enquiries: Rae Blair; email [email protected] Copyright: Reprints and quotations of articles published herein are permitted on condition that full credit is given to both The Australian Wine Research Institute Technical Review and the author/s, and that the date of publication and issue number are stated. Acknowledgment: The production and distribution of Technical Review is partially financed by The Thomas Walter Hardy Trust Fund. ISSN 0816-0805 Cnr Hartley and Paratoo Rd PO Box 197 T +61 8 8303 6600 Published by The Australian Urrbrae Glen Osmond F +61 8 8303 6601 Wine Research Institute South Australia 5064 South Australia 5064 [email protected] ABN 83 007 558 296 Australia Australia www.awri.com.au Highlights this issue 14th Australian Wine Industry Technical Conference – starts next month .......................... 6 Aroma detection threshold study of methanethiol in white and red wine ............................ 8 Reducing alcohol levels in wine ..................................................................................................... 11 Studies involving precursors to the tropical wine odorant 3-mercaptohexan-1-ol ............ 16 June 2010 Technical Review No. 186 1 Photocopy requests Please supply a copy of the following papers from Technical Review No. 186 for the purpose of: □ Research □ Study □ Other The cost of each article is included in the square brackets. A service fee of $7.00 and appropriate overseas postage, copyright and GST costs might also apply. Please note photocopy requests for research and study purposes must be accompanied with a completed and signed copyright declaration form located on the back of this tear-out page. Current literature (circle the required papers) 186.01 [2.70] 186.02 [0.30] 186.03 [1.20] 186.04 [3.00] 186.05 [0.80] 186.06 [0.40] 186.07 [0.70] 186.08 [1.40] 186.09 [1.00] 186.10 [0.30] 186.11 [0.40] 186.12 [0.50] 186.13 [0.50] 186.14 [0.50] 186.15 [0.30] 186.16 [0.90] 186.17 [0.50] 186.18 [0.70] 186.19 [1.10] 186.20 [0.70] 186.21 [1.20] 186.22 [0.80] 186.23 [0.90] 186.24 [1.00] 186.25 [1.00] 186.26 [0.70] 186.27 [0.70] 186.28 [0.90] 186.29 [0.50] 186.30 [2.40] 186.31 [1.00] 186.32 [0.40] 186.33 [0.50] 186.34 [0.30] 186.35 [0.50] 186.36 [0.50] 186.37 [0.40] 186.38 [1.00] 186.39 [2.10] 186.40 [1.70] 186.41 [2.10] 186.42 [0.70] 186.43 [0.70] 186.44 [0.90] 186.45 [0.80] 186.46 [0.80] 186.47 [0.90] 186.48 [0.50] 186.49 [0.70] 186.50 [0.60] 186.51 [0.70] 186.52 [0.90] 186.53 [0.30] 186.54 [0.80] 186.55 [0.90] 186.56 [0.80] 186.57 [0.30] 186.58 [0.30] 186.59 [0.60] 186.60 [0.60] 186.61 [0.10] 186.62 [0.30] 186.63 [0.50] 186.64 [1.20] 186.65 [0.70] 186.66 [1.60] 186.67 [0.70] 186.68 [1.40] 186.69 [1.60] 186.70 [0.80] 186.71 [0.40] 186.72 [0.60] 186.73 [0.20] 186.74 [0.40] 186.75 [1.60] 186.76 [1.50] 186.77 [0.90] 186.78 [0.60] 186.79 [0.60] 186.80 [1.40] 186.81 [1.90] 186.82 [1.20] 186.83 [0.20] 186.84 [0.50] 186.85 [0.40] 186.86 [0.60] 186.87 [1.00] 186.88 [0.30] 186.89 [1.00] 186.90 [0.90] 186.91 [0.60] 186.92 [1.50] 186.93 [0.70] 186.94 [1.60] 186.95 [0.20] 186.96 [0.30] 186.97 [0.20] 186.98 [0.50] 186.99 [0.30] 186.100 [0.90] 186.101 [1.30] 186.102 [0.70] 186.103 [0.30] 186.104 [0.50] 186.105 [0.40] 186.106 [0.90] AWRI publications (circle the required papers) 1185 [0.50] 1186 [1.30] 1187 [0.60] 1188 [0.40] 1189 [0.20] 1190 [0.70] 1191 [0.80] 1192 [0.40] 1193 [0.50] 1194 [0.40] 1195 [0.30] 1196 [0.70] Translation requests (circle the required papers) A translation of any non-English articles within current literature is available upon request: 186.28 186.75 186.76 186.87 186.101 Payment details Cost of photocopies for all articles requested $.............. No. of Articles Postage (refer to square bracketed figures on previous page) 1-5 $A3.00 + Service Fee $7.00 6-10 $A8.00 + Postage (Overseas only - see chart opposite) $.............. 11-15 $A13.00 + Copyright ($5 per article) $.............. 16+ $A18.00 Include postage only if articles (Copyright fee is exempted for research and study purposes) need to be sent overseas Total $.............. Add 10% for GST (Australian residents only) $.............. TOTAL to be forwarded with request A$______ I enclose my cheque for $A ............ payable to The Australian Wine Research Institute or charge my: Visa [ ] Mastercard [ ] Card No. Cardholders Name ________________________________________ Expiry Date _____/_____ Signature ________________________________ Important note regarding payment of GST (Goods and Services Tax): 1) GST is payable by Australian residents only and does not apply to residents who live outside of Australia, and 2) A tax invoice will be forwarded with the articles requested, showing The Australian Wine Research Institute’s ABN, and the total amount paid (including GST). 3) Copyright does not apply to Australian wineries and grapegrowers who pay the Winegrapes Levy or Grape Research Levy Copyright declaration under section 49 (1) of the Copyright Act 1968 I declare that: (i) I require the copies for the purposes of research or study, and that I will not use them for any other purpose, and (ii) I have not previously been supplied with a copy by an authorised officer of the library. (iii) I acknowledge that I may be held personally liable for any breach of the Copyright Act with respect to a false or misleading declaration. Signed ____________________________ Date ____________________ NAME ______________________________________________________ COMPANY ______________________________________________________ ADDRESS ______________________________________________________ ______________________________________________________ POSTCODE ______________________________________________________ PLEASE RETURN to: AWRI Library The Australian Wine Research Institute PO Box 197, Glen Osmond, SA 5064 T: (08) 8303 6626 F: (08) 8303 6628 E: [email protected] 4 Technical Review No. 186 June 2010 In this issue AWRI NOTES 14th Australian Wine Industry Technical Conference – starts next month Everything is pointing to another successful and exciting AWITC to be held on 3–8 July 2010 in Adelaide. TECHNICAL NOTES Aroma detection threshold study of methanethiol in white and red wine The presence of methanethiol (MeSH) in wine has been reported to cause off-aromas at low concentrations. However, no aroma detection threshold for MeSH in wine has been reported in the literature. This led to the determination of the aroma detection threshold in red and white wine by an in-house panel of judges. Reducing alcohol levels in wine High alcohol levels in wine can negatively affect flavour, attract high taxes in some export markets, and, in the context of public health, is of growing concern. This article provides practical information on a range of approaches that may be adopted by grapegrowers and winemakers to adjust alcohol concentration. Studies involving precursors to the tropical wine odorant 3-mercaptohexan-1-ol 3-Mercaptohexan-1-ol (3-MH), a significant varietal aroma compound, is among a group of thiols that impart pleasant aromas to wine. Precursors to 3-MH are conjugates involving the amino acid cysteine and the tripeptide glutathione, with the free thiol being released during fermentation. We have undertaken synthetic and analytical studies to examine aspects relating to precursor structure and abundance in juices and wines and have presented a summary of our findings. CURRENT LITERATURE Oenology General (page 20) Tempranillo varietal report Grace under pressure: Graciano offers quality in warm and dry conditions Gewürztraminer varietal report Perfect storm revisited: predicting future trends and opportunities June 2010 Technical Review No. 186 1 Juice and wine handling (page 22) A brief look at exogenous enzyme function in winemaking Bottling preparation — getting it right on a small scale Removal of ochratoxin A from contaminated red wines by repassage over grape pomaces Fermenting red must in oak barrels Maturation of rosé wines ‘sur lies’ Investigating Syrah and Viognier co-fermentation Seed removal remains challenging Creating conditions for graceful aging With fermenters, does size matter? How and why to do barrel trials Mouth-feel of different white wine treatments Analysis and composition (page 26) 4-Ethylphenol and 4-ethylguaiacol contents in bottled wines from the German ‘Württemberg’ region Quantitation of the homocysteine content in wine Aroma active compounds during the drying of grapes cv. Pedro Ximenez destined to the production of sweet sherry wine Anthocyanins, flavonols and hydroxycinnamates: an attempt to use them to discriminateVitis vinifera L. cv. ‘Barbera’ clones Use of ATR-FTIR microspectroscopy to monitor autolysis of Saccharomyces cerevisiae cells in a base wine Changes in the volatile compound production of fermentations made from musts with increasing grape content The influence of stereochemistry of antioxidants and flavanols on oxidation processes in a model wine system: ascorbic