The Australian Wine Research Institute

A rewarding year of activity from the AWRI for grape and wine producers

The AWRI’s annual report to Australian grapegrowers, winemakers and other stakeholders has been produced and was distributed at the end of November. An electronic copy of the report is available from our website. The AWRI’s Managing Director will also present our annual report to the various state-based wine industry associations over the next few months. We also publish a review of our activities in the November issue of the Australian and New Zealand Grapegrower and Winemaker.

We are pleased to publish the highlights from our very rewarding year of activity below. Please contact us should you require further information on any aspect of our research, development, extension or commercialisation activities.

1. The AWRI and two partners developed and prepared for commercialisation an instrument for rapid non-destructive, in-bottle measurement of wine compositional variables.
2. Crystal structure for a grape thaumatin-like protein solved. This detailed information at the molecular level of wine protein structure will help us to better identify and target proteases and to identify those parts of the protein likely to interact with other wine components, such as phenolic compounds. Ultimately, this knowledge might lead to new technologies to control haze formation in white wine.
3. State-of-the-art gene chip technology and genome sequencing has been used to determine genetic differences across ten strains of the MLF bacterium Oenococcus oeni. This work has revealed that there is a very high level of genetic variation between strains, and novel genes have been identified that encode putative glycosyl hydrolases (enzymes that can shape the flavour of wine be releasing flavour compounds from inactive precursors). This work paves the way for the development of new, more robust strains that will enhance the sensory attributes of wine.
4. Identification of the glutathione conjugate of 4-mercapto-4-methylpentan-2-one (glut-4-MMP) in Sauvignon Blanc juice using HPLC-MS/MS and by comparison of data with a synthetic reference sample. This showed for the first time that there is a glutathione precursor to 4-MMP, which in all likelihood could also act as a precursor to the volatile 4-MMP found in wine. This finding will assist future studies aimed at identifying the role of glutathione precursors from grapes and determine the importance of them for thiol release into wine, especially in varieties that are low in cysteine precursors.
5. Synthesis of glutathione precursors to the varietal thiol 3-mercaptohexan1-ol, along with their deuterated analogues, was completed. Ultimately, the successful synthesis of glutathione conjugates has allowed us to assign precursor stereochemistry, better understand their formation, and develop analytical methods for their quantitation in juice and wine.
6. Two approaches have been developed to assess smoke taint in grapes and wines. The first approach measures smoke intensity in a vineyard during a bushfire event and uses the smoke intensity data to assess the extent to which smoke has impacted on grape quality. The second approach identifies guaiacol precursors in grapes using stable isotope techniques; as precursors are good candidates for markers to assess the degree of smoke-affect. It is hoped that a combination of the two new approaches, along with traditional approaches, will allow winemakers to better understand the likelihood of smoke taint in wine.
7. Calibration models were developed using a portable Bruker ATR-mid-infrared spectrophotometer, for ammonia, yeast assimilable nitrogen (YAN), total soluble solids and pH in juice and fermentation samples, the method requiring little sample preparation.
8. Recent experimental data show that highest residual H₂S in finished wine is associated with late onset of H2S production. Conversely early onset and cessation of sulfide production led to little or no residual H₂S in wine.
9. New, so-called, ‘omics technologies coupled with high powered computing and mathematical modeling take us into the arena of systems biology, which is poised to revolutionise wine research. The AWRI is fortunate to both house the South Australian node of Metabolomics Australia (formally launched this year) and have had a model wine yeast adopted by the Government-funded Bioplatforms Australia as a demonstration project to show how systems biology can be undertaken in Australia. This project will open up many opportunities for the development of greatly improved wine yeast strains.
10. A closure trial study showed clearly that the presence of even low level oxidation, TCA or reductive flavour can strongly influence consumers.
11. From a study of different varieties and vintages from various regions the vast majority (62%) of the wines that contained rotundone, were Shiraz. Perhaps not surprisingly, above-threshold levels of rotundone (>16 ng/L) were often encountered in wine originating from cool climate regions.
12. Non destructive spectral scanning of bottles further validated as useful tool. We used the Sauvignon Blanc bottling trial to demonstrate that it was indeed possible to collect bottle scans throughout the year-long trial period and then determine the free and total SO₂ levels of individual bottles retrospectively. This had not been previously demonstrated and was an extension and validation of the concepts we had described previously.
13. Sensory studies investigated such areas as: coinoculated and single strain yeast effects in white wine; the perseverance of yeast strain flavour differences over time; malolactic bacterial strain differences in red wine; the effect of closures and copper fining; the influence of nitrogen supplementation in the vineyard and in fermentation; phenolic related flavour effects on white wine; hydrogen sulfide aroma threshold in red and white wines; saltiness in red wine arising from sodium, potassium and chloride levels; and faults identified by wine show judges.
14. The AWRI technical quality panel has assessed 383 wines over the year for the incidence of off-flavours and taints, as well as technical assessment of individual wines for suspected faults.
15. Results suggest that palate viscosity in dry white wine cannot be enhanced by employing traditional winemaking approaches that elevate glycerol levels.
16. Links between composition and perceived coarseness in white wines explored. A sensory and compositional study on 24 commercial white wines showed that perceived astringency was related to the levels of residual sugar and titratable acidity as well as phenolic compounds, even in a sample set where all the wines had residual sugars less than 4 g/L. Furthermore, data from 200 consumers in Sydney indicated that a sizable proportion of consumers do not like wines with high perceived sourness and astringency, thus validating the need for research into this topic.
17. Completion of the MCP tannin assay and associated development of a database gives an overview of tannins in more than 3,000 Australian wines.
18. Bottling and storage trial completed on Sauvignon Blanc. This trial gives us additional information about the impact of closure choice on wine development and extends this to Sauvignon Blanc and the effect of copper fining.
19. An historic landmark for the AWRI has been the establishment of the first external node, based in Hobart at the Tasmanian Institute of Agricultural Research (TIAR). The primary function of this node is to collaborate with regional research programs and to foster targeted extension activities. This will form a model for possible future developments in other wine producing regions to support ‘Regional Heroes’.
20. Approval of a three year project and funding from Cancer Australia for a project entitled Resveratrol in the chemoprevention of colorectal neoplasia.
21. Research to Practice® training modules updated with grapevine nutrition, pest and disease management and winegrape quality identified as key areas of interest to grapegrowers. Two training programs ‘Managing grapevine nutrition in a changing environment’ and ‘Integrated Pest Management for changing viticultural environments’ have been developed.
22. The Advanced Wine Assessment Course was held outside of Adelaide for the first time this year (Lilydale, Vic.). An abridged version of the course was also held in Dublin and London to key trade people in these markets. The 27th full course was also held this year and over 840 wine sector professionals have now undertaken the course.
23. Support of Brand Australia through the finalisation of a partnership/joint venture agreement between the AWRI and the Institute of Masters of Wine.
24. The Industry Services team responded to more than 1,236 calls for technical advice and information, 213 wine/health, technical and regulatory requests, and 320 viticulture enquiries.
25. Twenty-one days of roadshow seminars and workshops were held in 11 Australian winemaking zones and regions.
26. 4,800 requests for information were managed by the Information Services team, a 27% increase.
27. Improved delivery of information to stakeholders achieved through upgrade of content and format of the AWRI website.
28. Nine webcasts of AWRI presentations were recorded and made available on-line via the AWRI website.
29. Eleven thousand copies of the AWRI annual publication, Agrochemicals registered for use in Australian viticulture 2008/2009 were produced and the booklet was made available from the AWRI website and distributed with the Annual Technical Issue of Australian and New Zealand Grapegrower and Winemaker. Six agrochemical updates were prepared for industry email subscribers.
30. The AWRI moved into its new home as part of the Wine Innovation Cluster, and the impact on our activities during this time was successfully managed for minimal disruption.
31. Through increased commercial activity and a greater focus on obtaining revenue from sources other than through the GWRDC, the AWRI achieved a year of record revenue. This has enabled the provision of increased resources and services to priorities of Australian grapegrowers and winemakers.
32. The Constitution of the AWRI was updated to bring it in line with modern corporate governance, and the results were communicated to key stakeholders.
33. The AWRI’s RD&E plan was amended to allow an even greater focus on issues of relevance to Australian grape and wine producers, including sustainability and regionality.
34. AWRI staff members gave 244 oral presentations, conducted 8 workshops and presented 10 posters.
35. AWRI staff members presented 36 lectures and coordinated the Grape Industry Practices, Policy and Communication six week subject to undergraduate students.
36. AWRI staff members supervised/co-supervised 17 postgraduate students.
37. AWRI staff members responded to 6,663 recorded requests for information during the 2008/2009 year, or to put the statistics into perspective, 27 people contacted the AWRI seeking information on every working day of the year (a 13% increase over last year, on top of a 14% increase over the previous year). This figure does not include the amount of problem samples investigated (1,042) or the number of Commercial Services analyses undertaken during 2008/2009.

Readers are strongly encouraged to read the 2009 Annual Report in detail rather than relying on the brief details above for information.