The Australian Wine A W R I Research Institute

Technical Review

No193 August 2011

Registered by Australia Post PP 531629/00034 Table of contents

In this issue 1 AWRI notes 6

AWRI Managing Director moves on 6

Technical notes 7

‘Tropical’ thiol precursor levels in Sauvignon Blanc grapes: the effect of ripening and post-harvest transport 7

Botrytis and disease pressures from vintage 2011 11

Why should we be interested in alternative varieties? 19

Current literature 23 AWRI extension and roadshow 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.

ISSN 0816-0805

Cnr Hartley and Paratoo Rd PO Box 197 T +61 8 8313 6600 Published by The Australian Urrbrae Glen Osmond F +61 8 8313 6601 Wine Research Institute South Australia 5064 South Australia 5064 [email protected] ABN 83 007 558 296 Australia Australia www.awri.com.au In this issue

AWRI notes AWRI Managing Director moves on Dr Sakkie Pretorius, the Managing Director of The Australian Wine Research Institute, is leaving his position to take up a new appointment as Deputy Vice Chancellor and Vice President: Research and Innovation at the University of South Australia. technical notes ‘Tropical’ thiol precursor levels in Sauvignon Blanc grapes: the effect of ripening and post-harvest transport Grape ripening and post-harvest transport both influence 3-MH precursor levels and the generation of this tropical thiol during winemaking. In grape ripening, low levels of precursors were detected in berries until commercial harvest, where there was a dramatic increase in the last week or so of ripening. Once picked, the way grapes are handled before fermentation can also have a major effect on precursor levels. The length of time between harvest and pressing is an additional variable we are investigating again on a commercial- scale in this current vintage.

Botrytis and disease pressures from vintage 2011 Viticulture experiences with Botrytis cinerea this year were heightened by other fungal infections in the pre-season, coupled with a shortage of vineyard chemicals and difficulties in estimating infection levels in vineyards. Winemakers experienced problems with effective laccase detection in juice and wine and appropriate treatment options including pasteurisation. Binding of sulfur dioxide, difficulties with clarification and filtration due to Botrytis-derived glucans, and deacidification of some wines were also required this year.

Why should we be interested in alternative varieties? In recent times there has been increased interest in alternative varieties. Is this a passing fad or are there valid reasons for this interest? This article attempts to explain why this interest is quite justified. For example, alternative varieties may be better adapted to future climatic conditions than current mainstream varieties.

August 2011 Technical Review No. 193 1 CURRENT LITERATURE Oenology General (page 23) Towards better use of white wine phenolics Pinot Gris/Grigio international standard Technology traces path from vine to wine Antioxidant action of glutathione and the ascorbic acid/glutathione pair in a model white wine Juice and wine handling (page 25) Courte mise au point sur les gommes de cellulose (CMC) aprés une année d’utilisation Nouveaux outils pour lutter contre le goût de réduit The Pinot principles Le décanteur centrifuge Alfa-Laval Microbiology (page 26) Population dynamics of Saccharomyces cerevisiae during spontaneous fermentation at a British Columbia winery Influence of microbiological biodiversity and population dynamics of yeasts on wine quality – an overview Biodiversity of fungal microflora in wine-cellars Analysis and composition (page 27) Influence of yeast strain, canopy management, and site on the volatile composition and sensory attributes of Cabernet Sauvignon wines from Western Australia Stability, antioxidant activity and phenolic composition of commercial and reverse osmosis obtained dealcoholised wines Aroma changes due to second fermentation and glycosylated precursors in Chardonnay and Riesling sparkling wines Associations between the sensory attributes and volatile composition of Cabernet Sauvignon wines and the volatile composition of the grapes used for their production Identification of impact odorants contributing to fresh mushroom off-flavor in wines: incidence of their reactivity with nitrogen compounds on the decrease of the olfactory defect Influence of wine pH on changes in color and polyphenol composition induced by micro- oxygenation Authentication of Italian red wines on the basis of the polyphenols and biogenic amines Electronic nose analysis of Cabernet Sauvignon (Vitis vinifera L.) grape and wine volatile differences during cold soak and postfermentation Iron(III) tartrate as a potential precursor of light-induced oxidative degradation of white wine: studies in a model wine system Analytical and sensorial characterization of the aroma of wines produced with sour rotten grapes using GC-O and GC-MS: identification of key aroma compounds Marketing and packaging (page 32) Food and wine production practices: an analysis of consumer views The drivers of wine regionality ‘Green’ wine packaging: targeting environmental consumers How does Australia rank in the various quality segments of the world’s wine markets? Do consumers value sustainable wine claims? An international comparison Environment (page 34)

Reducing CO2, the real pollutant Review: winery wastewater quality and treatment options in Australia

2 Technical Review No. 193 August 2011 Sensory (page 35) Finding the right sweet spot U.S. drinks most wine Wine consumption habits and consumer preferences between wines aged in barrels or with chips Viticulture General (page 36) Tuning your vineyard for the next vintage Spectral discrimination of grape varieties and a search for terroir effects using remote sensing Ce qu’il faut savoir pour réussir le surgreffage Biodynamic and organic – not the only games in town Suivre la biodiversité dans le vignoble champenois Increasing vineyard profits and sustainability The potential for growth of the Tasmanian wine sector Downside of green In search of uniformity: why grape quality varies Defining sustainable viticulture from the practitioner perspective Mothball mistake? Physiology and biotechnology (page 39) Aerial root formation on winegrape cultivars after spring 2007 freeze events Influence of bunch position in the canopy on berry epicuticular wax during ripening and on weight loss during postharvest dehydration Carbohydrate reserves to help predict yields A simple microplate assay to quantify nonstructural carbohydrates of grapevine tissues Pollination dynamics in Vitis vinifera L. Influence of shriveling on berry composition and antioxidant activity of Cabernet Sauvignon grapes from Shanxi vineyards Carbohydrate metabolism in grape cultivars that differ in sucrose accumulation Climate and soils (page 42) Studying water and soil effects Vineyard management systems (page 43) Mechanized canopy management Effects of mechanical pre-bloom defoliation on cordon de Royat pruned Sangiovese (Vitis vinifera L.) vines Managing a severe frost event Integrating canopy management with mechanization Electric pruners have growers talking Grapegrower interview: Hank Ashby Pests and diseases (page 44) Association of Botryosphaeriaceae grapevine trunk disease fungi with the reproductive structures of Vitis vinifera Powdery mildew severity as a function of canopy density: associated impacts on sunlight penetration and spray coverage Crop cultural and chemical methods to control grey mould on grapes Stem injection of triazoles for the protection of Vitis vinifera L. (‘Riesling’) against powdery mildew (Uncinula necator) Resistance of rootstocks depends on the vineyard populations of root-knot nematode New fungicides fight mildew Effect of temperature on Botrytis cinerea, Colletotrichum acutatum and Greeneria uvicola mixed fungal infection of Vitis vinifera grape berries Sunlight enhances fungal disease control

August 2011 Technical Review No. 193 3 Inoculum detection to manage grape powdery mildew Irroratrici a recupero prodotto ammortamento e convenienza Le suivi biologique du mildiou Vine improvement and varieties (page 48) Barbera and Nebbiolo, selection continues Developments in Italy’s ampelographic registry Investigations on the identity of ‘Canaiolo bianco’ and other white grape varieties of central Italy Un vivaismo più integrato nella filiera Busy year ahead for Tasmanian Pinot researchers Grapevine European challenge: towards a comprehensive list Home-grown wine grape varieties go back a long way in Asia Gruner Veltliner finds a new home in the Adelaide Hills Exploration and evaluation of grapevine biodiversity using molecular markers Conservation, evaluation and revitalization of native grapevine varieties in Croatia Water and nutrition (page 51) Effects of irrigation and crop load on leaf gas exchange and fruit composition in red winegrapes grown on a loamy sand Wine and health Epidemiology (page 52) Substance use and exercise participation among young adults: parallel trajectories in a national cohort-sequential study Alcohol consumption decreases with the development of disease Commentary on Livingston (2011): alcohol outlets and domestic violence – acute effects and the social ecology of neighborhoods may both contribute to the relationship A longitudinal analysis of alcohol outlet density and domestic violence Hazardous drinking is associated with a lower risk of coronary heart disease: results from a national representative sample Adolescent computer use and alcohol use: what are the role of quantity and content of computer use? Exposure to alcohol commercials in movie theaters affects actual alcohol consumption in young adult high weekly drinkers: an experimental study Personality moderates the longitudinal relationship between psychological symptoms and alcohol use in adolescents Do the drinking motives of adolescents mediate the link between their parents’ drinking habits and their own alcohol use? Heavy episodic drinking in early adulthood and outcomes in midlife Tobacco, alcohol and illicit drug use among aboriginal youth living off-reserve: results from the youth smoking survey Risky alcohol use in adolescence: the role of genetics (DRD2, SLC6A4) and coping motives Healthy subjects with a family history of alcoholism show increased stimulative subjective effects of alcohol The influence of drinking pattern, at individual and aggregate levels, on alcohol-related negative consequences Alcohol-specific parenting and adolescents’ alcohol-related problems: the interacting role of alcohol availability at home and parental rules Characteristics of adolescent excessive drinkers compared with consumers and abstainers A meta-analysis on alcohol drinking and gastric cancer risk The ‘gray area’ of consumption between moderate and risk drinking Family relationship quality and early alcohol use: evidence for gender-specific risk processes Alcohol drinking patterns and the risk of fatty liver in Japanese men 2010 Partnership Attitude Tracking Study

4 Technical Review No. 193 August 2011 Alcohol dependence is more likely among adults with mental illness than adults without mental illness Development and pilot testing of an internet-based survey instrument to measure the alcohol brand preferences of U.S. youth Alcohol consumption and expectations of its effects in the border region of Pomerania: comparison of German and Polish adolescents Human clinical (page 56) The effects of a modest dose of alcohol on executive functioning and prospective memory Alcohol and migraine: what should we tell patients? Randomized controlled trial of a brief intervention for unhealthy alcohol use in hospitalized Taiwanese men Brain damage and alcohol dependence: how one may influence the other Phenolic compounds (page 57) Dietary supplementation of grape skin extract improves glycemia and inflammation in diet-induced obese mice fed a western high fat diet Public health policy (page 58) Influence of family factors and supervised alcohol use on adolescent alcohol use and harms: similarities between youth in different alcohol policy contexts Alcohol consumption in Southern Sweden after major decreases in Danish spirits taxes and increases in Swedish travellers’ quotas Decline in alcohol consumption in Estonia: combined effects of strengthened alcohol policy and economic downturn Should red wine be considered a functional food? Alcohol industry and non-alcohol industry sponsorship of sportspeople and drinking International use of screening tools that measure ‘standard drinks’: whose standard? Splendide mendax: false label claims about high and rising alcohol content of wine WHO global strategy to reduce the harmful use of alcohol (2010)

AWRI publications (page 60) Message in a bottle Impacts of variations in elemental nutrient concentration of Chardonnay musts on Saccharomyces cerevisiae fermentation kinetics and wine composition Comparison of methods for the analysis of smoke related phenols and their conjugates in grapes and wine The effect of winemaking techniques on the intensity of smoke taint in wine Assessing desirable levels of sensory properties in Sauvignon Blanc wines – consumer preferences and contribution of key aroma compounds The effect of bentonite fining at different stages of white winemaking on protein stability Contribution of cysteine and glutathione conjugates to the formation of the volatile thiols 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexyl acetate (3MHA) during fermentation by Saccharomyces cerevisiae Formation of damascenone under both commercial and model fermentation conditions Hpf2 glycan structure is critical for protection against protein haze formation in white wine Wine and grape tannin interactions with salivary proteins and their impact on astringency: a review of current research Response of grape and wine phenolic composition in Vitis vinifera L. cv. Merlot to variation in grapevine water status Harnessing AWRI’s yeast and bacterial research to shape ‘next-gen’ Chardonnay part 2: influence of yeast, nutritional management and malolactic fermentation Timing of malolactic fermentation inoculation in Shiraz grape must and wine: influence on chemical composition

August 2011 Technical Review No. 193 5 AWRI notes AWRI Managing Director moves on

Dr Sakkie Pretorius, the Managing Director of The Australian Wine Research Institute, is leaving his position to take up a new appointment as Deputy Vice Chancellor and Vice President: Research and Innovation at the University of South Australia.

The move was announced today by the AWRI’s Chairman, Peter Dawson. Dr Pretorius will take up his new position on 1 December.

‘The AWRI is sad to lose Dr Pretorius but we recognise the opportunity he has been offered at this stage in his career,’ said Mr Dawson. ‘The AWRI Board is grateful for Sakkie’s leadership and his passion for the Australian wine industry. Sakkie leaves the AWRI in a very strong position, where it can continue to deliver outcomes for the benefit of grape and wine producers.’

‘Dr Pretorius will continue his association with the Australian wine industry and the wider scientific community as a thought leader in the area of innovation and research.’

Dr Pretorius held senior positions in the South African higher education and wine industries prior to his appointment as Managing Director at the AWRI seven years ago.

Under his leadership, the AWRI has become recognised both nationally and internationally as a centre of excellence in the delivery of research and innovation to the Australian grape and wine sector.

‘I have thoroughly enjoyed my time at the AWRI and working together with the Australian wine industry,’ said Dr Pretorius. ‘I’m so proud of what has been achieved for the Australian grape and wine industry. I have been given the opportunity to join the University of South Australia in a position where I hope to make a significant contribution as Deputy Vice Chancellor and Vice President: Research and Innovation.’

The AWRI Board is now seeking globally for a new Managing Director, with the closing date for applications being received by the Chairman by Friday, 19 August 2011.

6 Technical Review No. 193 August 2011 Technical notes ‘Tropical’ thiol precursor levels in Sauvignon Blanc grapes: the effect of ripening and post-harvest transport

Varietal thiols are important impact odorants in wines, and are very important to the flavour of Sauvignon Blanc. The three most important varietal thiols are 4-MMP1, 3-MH2 and 3-MHA3. These compounds have some of the lowest aroma thresholds of any food odorant, in the low nanogram per litre range (Table 1). Each of these compounds can contribute to the distinctive tropical, passion-fruit flavour of many Sauvignon Blanc wines. They are important contributors to wine quality and can have a major impact on consumer preference.

In considering which of these compounds might be of greatest sensory significance, the odour activity value (OAV), which is the ratio of the concentration found in wine and the aroma threshold, provides a useful guide. Compounds with higher OAVs are likely to be of greater sensory significance. It can be seen in Table 1 that the compound 3-MH can be found well above its aroma threshold in many wines, and the OAV can thus be very high.

3-MH is found only at very low levels in grapes and musts (AWRI publication #1282). In grapes, 3-MH is bound as odourless, non-volatile conjugates which are released by the action of yeast or enzymes during fermentation. The known precursors to 3-MH are the cysteine conjugate Cys-3-MH4, and the glutathione analogue Glut-3-MH5.

Methods have been developed at the AWRI for measuring both the precursors of 3-MH (Cys and Glut-3-MH, AWRI publication #1177) and the free 3-MH concentration (AWRI publication #1282) and we have recently used these analytical methods to investigate the effect of ripening and skin contact post-harvest on levels of these compounds in Sauvignon Blanc fruit. Both studies were carried out in the 2010 vintage.

Effect of ripening Grapes from five different clones of Sauvignon Blanc vines, grown in one vineyard in the Adelaide Hills, were sampled and analysed for 3-MH precursor levels at approximately 14- day intervals during the growing season. This study was part of a collaborative trial with the Adelaide Hills Vineyard Improvement Association. The results obtained can be seen

14-mercapto-4-methylpentan-2-one 23-mercaptohexan-1-ol 33-mercaptohexyl acetate 4cysteinylhexan-1-ol 5glutathionylhexan-1-ol

August 2011 Technical Review No. 193 7 Table 1. The major varietal thiols found in wine. The odour activity value is the ratio of the concen- tration found in wine to the aroma threshold. Aroma detection Aroma Concentration found Odour activity threshold description in wine value Blackcurrant Low (up to approx. 30) 4-MMP 3 ng/L Box tree Up to 10 ng/L Passion-fruit Grapefruit 3-MH 60 ng/L High ng/L to low µg/L Up to 100 Passion-fruit Passion-fruit Up to several hundred 3-MHA 4 ng/L Box tree Up to 25 ng/L sweaty

Darriet et al. Flavour Fragr. 1995, 10, 385–392; Tominaga et al. Vitis 1996, 35, 207–210; Tominaga et al. Flavour Fragr. 1998, 13, 159–162. in Figure 1. The precursor levels were very small at veraison to mid-ripening, then slightly increased pre-harvest, and there was a large increase at the commercial harvest sampling time. The large difference between pre-harvest and commercial harvest is of great interest with an approximately 10-fold increase in the concentration of both precursors in as little as 14 days. From these results, we can see the importance of fruit ripeness for optimum flavour potential. The influence of clone type was smaller but important, and additional studies are required to assess this effect further. Nonetheless, harvest timing seems to be the crucial factor but chemical analysis of precursors is the only reliable indicator of their concentration to date.

Effect of transportation From earlier investigations we had found that berry damage influences precursor concentration, presumably due to increased formation and extraction from skins. Supporting this idea, transportation of machine harvested fruit from the vineyard to the winery has been suggested by some winemakers to result in wines with more tropical aroma than

300

250 Glut 3-MH

200 Cys 3 -MH

150

100

Concentration (µg/kg) 50

0 0 0 0 0 5 5 5 5 0 0 0 0 6 7 6 7 6 7 6 7 2 2 2 2 8 8 8 8 1 1 1 1 4 4 4 4 V V V V 7 7 7 7 3 3 3 3 V V V V V 7 V 7 V 7 V 7 9 9 9 9 5 5 5 5 5 5 5 5 F F F F F F F F Q Q Q Q H H H H

Veraison Mid Ripening Pre-harvest Harvest

Figure 1. Changes in concentration of 3-MH precursor levels across five Sauvignon Blanc clones during berry ripening. Samples were taken at approximately 14-day intervals post-veraison.

8 Technical Review No. 193 August 2011 fruit processed soon after harvest. To investigate this further, a commercial-scale study was conducted with the assistance of Casella Wines, using replicated lots of approximately 2.5 tonne grape bins, containing machine harvested fruit with different additions of sulfur dioxide and ascorbic acid added at the time of harvest. Figure 2 shows details of the treatment design. 3-MH precursor levels were analysed in samples taken from each of the grape bins at harvest and then again approximately 12 hours later, following transportation to the winery (approximately 800 km).

Antioxidants may impact on precursor concentration due to affects on glutathione or enzymatic reactions and so it was of interest to assess whether different levels of sulfur dioxide or ascorbate had an effect. As expected, the antioxidant treatments had a clear visual effect on the must, with the high SO2 treatments giving juices that were incredibly green while the samples without antioxidants were yellow-brown in colour.

The results for this experiment are shown in Figure 3. Regarding the Cys-3-MH concentration there was a very large difference due to the transport, with an approximate 10-fold increase in the concentration of the precursor in the transported fruit. The samples with the lowest precursor concentration within each set were those with the highest level of sulfur dioxide, likely due to either the SO2 preventing conjugate formation or interfering with the formation of the compound (E)-2-hexenal which is the basis for generation of the precursor. At levels likely to be used in industry, the addition of SO2 or ascorbate had minimal effect on precursor concentrations.

The Glut-3-MH behaved similarly to the Cys-3-MH, with a large increase observed after transportation, but this time with an approximate doubling of the precursor. More details regarding this study can be found in AWRI publication #1281. Treatment 1 Treatment 2 Treatment 3 Treatment 4 Treatment 5 Treatment 6 500mg 50mg 50mg 500mg No SO No SO SO SO 2 2 SO SO 2 2 100mg No Asc 2 2 500mg 100mg No Asc No Asc Asc Asc Asc

Figure 2. Experimental design of the different treatments monitored before and after transportation. Each grape bin was approximately 2.5 tonnes and treatments were conducted in triplicate. Asc: ascorbate

August 2011 Technical Review No. 193 9 600

Cys -3-MH 500 Glut-3-MH

) 400 L / g µ (

n o i

t 300 a r t n e c n o

C 200

100

0 c c c c c c c c c c c c c c s s s s s s s s s s s s s s a a a a a a a a a a a a a a 0 0 0 o 0 0 o 0 0 0 o o o o 0 0 0 n 0 0 n 0 0 0 n n n n ______5 5 1 5 1 5 1 1 _ _ _ 2 _ _ 2 _ _ _ 2 2 2 2 2 2 2 2 2 2 2 2 o o o o o o s s s s s s o o o o o o o o l l l l s s s s s s s s o o l l l l l l g g g g o o n n g g g g g g m m m m n n m m 0 m m 0 m m 0 0 0 0 0 0 0 0 0 0 5 5 0 0 5 5 5 5 5 5 5 5

Prior to Transportation After Transportation

Figure 3. Concentration in (µg/L) obtained for the Sauvignon Blanc fruit including the different treatments prior and after transportation.

Conclusion There are two factors that can have a very large influence on 3-MH precursor levels and presumably on the generation of this tropical thiol during winemaking. During grape ripening, low levels of precursors were detected in berries until commercial harvest, where there was a dramatic increase in the last week or so of ripening. This may have significant implications for producers in being able to pick fruit at different times to greatly enhance or reduce the tropical aromas in the subsequent wine. In addition, once the fruit is picked at a desirable ripeness, the way in which it is handled before fermentation can also have a major effect on precursor levels. Berry rupture and length of time through transport of machine harvested fruit gives rise to large increases in thiol precursor levels. The length of time between harvest and pressing is an additional variable we are investigating again on a commercial- scale in this current vintage. Together, these results have important practical implications for producers, as they highlight the fact that there is an opportunity to manipulate tropical thiol precursor concentrations in must, allowing added product value.

Dimitra Capone, Senior Scientist [email protected]

References AWRI publication #1177 Capone, D.L., Sefton, M.A., Hayasaka, Y., Jeffery, D.W. (2010) Analysis of precursors to wine odorant 3-mercaptohexan-1-ol using HPLC–MS/MS: resolution and quantitation of diastereomers of 3-S-cysteinylhexan-1-ol and 3-S-glutathionylhexan-1-ol. J. Agric. Food Chem. 58: 1390–1395. AWRI publication #1281 Capone, D.L. and Jeffery, D.W. (2011) Effects of transporting and processing Sauvignon Blanc grapes on 3-mercaptohexan-1-ol precursor concentrations. J. Agric. Food Chem. 59: 4659–4667. AWRI publication #1282 Capone, D.L., Sefton, M.A. and Jeffery, D.W. (2011) Application of a modified method for 3-mercaptohexan-1-ol determination to investigate the relationship between free thiol and related conjugates in grape juice and wine. J. Agric. Food Chem. 59: 4649–4658.

10 Technical Review No. 193 August 2011 Botrytis and disease pressures from vintage 2011

In what turned out to be the wettest season on record for many grapegrowers, it was little wonder that the most challenging fungal disease that attacks Vitis vinifera – Botrytis cinerea – was a factor to contend with at the end of the season. Botrytis thrives in wet conditions, producing a huge spore load that infects susceptible and decaying tissue. Berries are not immune and relatively clean fruit can quickly be colonised by the disease in warm and moist conditions.

In addition to unfavourable weather, disease control was made even more difficult by the: • widespread shortage of chemical options; • pathway to infection paved by other fungal diseases that occurred earlier in the season; and • large canopies and yields that made spraying the target effectively harder than usual.

The AWRI’s Industry Development and Support team exists to provide technical advice and assistance and each year fields hundreds of queries from grapegrowers and winemakers. This year was exceptional in that a high proportion of the calls were related to fungal diseases which were not only causing difficulty in the vineyard, but also flowed onto significant challenges for winemakers in the winery at all stages during production.

Early in the season, the AWRI pursued off-label permits with Australia’s agrochemical regulatory body, the APVMA. This resulted in growers being able to benefit from access to products that are not normally registered for viticulture. More than half of the viticulture- related queries received were about fungal issues. We promoted actively the advice about cultural practices that can restrict the development and progression of disease. The GWRDC Innovators Network resources were utilised and presentations were held in NSW, Victoria and ACT to spread important messages. Advice for winemaking technical assistance continued as vintage progressed, but unfortunately so did the rain, and almost one in every five requests for assistance taken by the AWRI’s Winemaking and Extension Services team was related in some way to the presence of botrytis and laccase. Technical requests ranged from estimating botrytis-infected fruit in the vineyard, processing botrytis-infected fruit from in the cellar, basic winemaking strategies to reduce and eliminate laccase activity from botrytis, laccase testing, interpreting laccase testing results on both wine and juice and pasteurisation of infected juice and wine.

Problems with detecting laccase Wines made from grapes affected by Botrytis cinerea may contain laccase, a polyphenol

August 2011 Technical Review No. 193 11 oxidase enzyme which, due to its relative stability in wine, is capable of causing serious oxidative damage. Where fruit has been harvested and rot is present (even at low levels), winemakers should be prudent regarding residual laccase activity both before and after primary fermentation. Laccase can continue to be active post-fermentation, causing browning and premature ageing. Under these conditions, the use of sulfur dioxide even at elevated levels, or intervention by normally accepted winemaking techniques, will prove ineffective. Oxidation of wine due to laccase activity will only occur in the presence of oxygen, therefore maintaining anaerobic conditions at all times during the winemaking process is of paramount importance.

Qualitative test for laccase testing in wine A simple bench test can be used to obtain a qualitative result. Sulfur dioxide is added to the sample in question to give a total SO2 concentration of about 60 mg/L. The sample is then poured into two wine glasses (approximately 50 mL of sample in each glass) and each glass is covered with a watch glass or petri dish lid. One sample is placed in a refrigerator, whilst the other sample is left ‘on the bench’. The samples are examined after 24 hours and compared for any change in colour or quality. If there is laccase activity, the sample left on the bench should be more brown than the sample left in the fridge and there may be an oily film on the surface of the wine.

Quantitative test for laccase activity The measurement of laccase activity is traditionally conducted by determining the rate at which the laccase enzyme oxidises the phenolic substrate syringaldazine to a purple-coloured oxidation product. The colour change is measured using a spectrophotometer set at 530nm wavelength with the activity expressed as Units of laccase activity per mL (U/mL) (Grassin and Dubourdieu 1989). Grassin and Dubourdieu (1989) report that visually low levels of botrytis (<10% infection) result in <4 U/mL laccase activity with visually high levels of botrytis reporting levels from 4–30 U/mL.

Quantitative determination of laccase activity can be achieved using a number of test kits available commercially based on the Grassin and Dubourdieu method above. Instead of using a spectrophotometer to quantify units of activity however, the activity is determined by comparing the colour change to an incremental colour scale provided in the kits indicative of increasing oxidative risk. Generally speaking, the lowest levels on the several scales we have observed are indicative of positive botrytis infection.

It is important to note that the kits available commercially have different incremental colour scales which cannot be interchanged for laccase activity interpretation. Some kits report

12 Technical Review No. 193 August 2011 laccase activity in Units of activity per mL (U/mL) as per Grassin and Dubourdieu (1989), which allows comparison with the results obtained by these authors, whilst other kits report laccase activity as simply ‘units of laccase’.

Interpretation of laccase activity in some red juice and wines has proved difficult this year. In the case of juice samples, in particular red juice, there have been observations that laccase test kits may underestimate potential laccase activity in wine. Reasons for this could be that laccase is extracted further from skins in red ferments, and/or there might be compounds present which might protect the laccase enzyme from destruction. Additionally, lightly pressed red juice samples may not provide the most adequate representation of laccase extraction in a red wine ferment. Therefore, it is essential that laccase tests are repeated when botrytis-affected fruit is fermented into wine, especially if a negative, or a low positive, result is obtained at the juice stage. Interestingly, a high number of calls received by our team were requests for assistance in interpreting laccase test results, in particular the results from the ‘Dolmar’ test kit which had a reporting scale from 0.2 to 1.5 laccase ‘units’. Previous advice provided to winemakers on laccase test results have been limited to results obtained using the Botrytis Test Kit marketed by Novo, now marketed through Laffort, which reports laccase levels from 0 to 20 laccase units/mL, as discussed above.

Interpretation of laccase activity in deeply coloured Shiraz has also provided winemakers with challenges this year, as the method relies on the ability to detect a purple colour change. If red juice or wine samples are ineffectively decolourised, the samples used in the test can already begin with a slight ‘purple’ tinge that could be misread as a ‘positive’ laccase result. Different kits provide different means to decolourise samples, generally through a mixture of PVPP and carbon. Samples should ideally be colourless before performing the test to aid with interpretation.

Anthocyanins are also able to bind to the active sites of laccase, inhibiting the enzyme, thus showing further the need to remove these phenolic compounds before laccase testing. It has also been reported that the laccase enzyme can use anthocyanins and some procyanidins as substrates and therefore its activity can also continue in the wine after fermentation.

Pfanz and Oppmann (1991) indicated that bisulfite and sulfite, the anions of sulfur dioxide

(SO2), are strong inhibitors of the dehydration of syringaldazine, which occurs during its laccase-mediated oxidation. Consequently, kits based on the syringaldazine method described by Grassin and Dubourdieu (1989) will usually require that juice and wines containing free

SO2 be treated with hydrogen peroxide (H2O2) to remove the free SO2 just before the analysis. However, given that Edens et al. (1999) indicated that laccase was reversibly inhibited by

August 2011 Technical Review No. 193 13 H2O2, it might be prudent to treat a wine containing free SO2 with H2O2 before commencing analysis, and allow time for all of the H2O2 to be consumed. Alternatively, it might be better to add a slight stoichiometric excess of acetaldehyde, which binds free SO2, rather than H2O2.

Of the 101 samples tested by the AWRI Commercial Services team so far this year, mostly Shiraz fruit was submitted for laccase testing due to its varietal ripening period and the timing of rain events during the growing season.

Filtration/Polysaccharides/Glucans When grapes are infected by botrytis, glucans are secreted by the mould between the pulp and the skin of the berry, and can be subsequently released into juice and the resultant wine. The amount released into the juice is related to grape handling and treatment conditions. Any rough handling of grapes and juice will diffuse more glucan into the juice and make it more difficult to clarify.

Botrytis specifically produces a beta glucan. Glucans are polysaccharides and are large molecules that are not adsorbed by the common fining agents. Glucans are often only first observed when the wine is subjected to finer levels of filtration. You can test for glucans using the polysaccharides test described below (Villettaz et al. 1984). Glucanase enzymes (available commercially) break down these glucans which then allow the wine to be filtered. A list of enzymes available for winemaking can be found in Technical Review issue 182 (October 2010).

Alcohol precipitation test for polysaccharides To a test tube containing 10 mL of wine, add 5 mL of 96% v/v ethanol and mix thoroughly. The formation of white filaments is indicative of the presence of polysaccharides. If filaments do not form, but a haze develops upon mixing, the following more sensitive test may be performed. After mixing the 10 mL of wine with 10 mL of 96% v/v ethanol, allow the mixture to stand for 30 minutes and then centrifuge, decant and discard the supernatant. Redissolve the deposit in 2 mL of water and add 1 mL of 96% v/v ethanol. The formation of filaments is indicative of polysaccharides.

Pasteurisation

Unrealistically high levels of SO2 are required, particularly in red wines, in order to significantly inhibit the destructive activity of the polyphenol oxidase enzyme laccase

(Boulton et al. 1996, Somers 1983). Consequently, an alternative approach to SO2 additions must be used if oxidative spoilage of wine is to be avoided.

The best option for inactivating the laccase enzyme is the application of heat treatment

14 Technical Review No. 193 August 2011 (pasteurisation) following fermentation (Leske 1993, Somers 1983). With red wines, it may be necessary to inoculate with malolactic bacteria in order to conduct the malolactic fermentation (MLF), as indigenous bacteria will most likely be destroyed during heating. Some winemakers might prefer to wait until after MLF before pasteurising. If so, the risk of the steady deterioration of a wine that might occur whilst waiting for the MLF to finish, and the risk of oxidation that might occur during any clarification, must be considered (Godden 2000).

What temperature and for how long? Ribéreau-Gayon et al. (1976) indicated that holding wine at a temperature of 40°C for 20 minutes or 45°C for 5 minutes decreased the activity of laccase by 95%. Leske (1993) indicated anecdotal evidence suggested 1–2 minutes at 60°C was sufficient to deactivate laccase, whilst Somers (1983) found that treatment for 20–30 seconds at 70°C rendered wine stable to subsequent oxidative exposure. The AWRI is aware of at least one winery that has inactivated laccase successfully in a number of 2011 red wines by heating to 70°C for 40 seconds, with laccase inactivity confirmed by both qualitative and quantitative analysis following treatment.

The AWRI is currently working with Memstar Pty Ltd in order to find the optimum time and temperature for laccase inactivation in wine. Results so far suggest that a minimum of 65°C for 20 seconds is required to inactivate laccase in wine using heat treatment1. It should be noted that laccase activity actually increases with increasing temperature up to the destruction temperature, so the temperature increase during heat treatment of wine should be rapid in order to minimise oxidation (Leonowicz and Grzywnowicz 1981, Ribéreau-Gayon et al. 2000). Subsequent cooling after heat treatment should also be rapid, in order to minimise any negative effects of the treatment.

Sensory effects of heat treatment Somers (1983) indicated that there should be no adverse effects from heat treatment when appropriate heat exchange equipment is used and provided wines are filtered beforehand (there is a risk of off-flavour production if suspended solids are present during heating). Godden (2000) indicated that the sensory properties of a heat-treated wine can be good initially, but it can be difficult to predict how the wine will develop. One winemaker, who heat treated a wine in 1999, indicated that the wine possibly developed sooner than might have been expected. Another winemaker, who is currently heat treating 2011 laccase-affected

1Whilst we have not conducted trials on juice, it is suggested that the lack of alcohol (which denatures protein – laccase is a protein) in juice and the presence of possible ‘laccase protection factors’ (i.e. compounds which might protect the enzyme from destruction), the recommendation for treating juice is 65°C for 40 seconds.

August 2011 Technical Review No. 193 15 wines, has indicated that ‘the sensory effect of pasteurisation on red wines, not surprisingly, is best described as cooked’. However, many current vintage wines requiring heat treatment due to the presence of laccase might be affected by mouldy characters associated with botrytis and other fungal diseases, and might also be affected by other off-characters due to higher- than-usual microbial loads. Regardless of the possible negative effects of heat treatment, it should be remembered that the potential for negative effects from laccase if the heat treatment is not performed is probably much greater.

Deacidification One of the decisions a winemaker must make when botrytis is spreading throughout the vineyard, is whether to pick early and risk low flavour and high acidity, or to wait and risk not having any clean fruit to harvest at all. With imminent rain and persistent poor weather predictions during the 2011 vintage in certain regions, a number of winemakers chose to harvest early, even though optimal maturity or ripeness had not been achieved. One of the consequences of picking early is the higher than desirable acidity levels in the juice, which can leave the resultant wine unbalanced and affecting the mouth-feel of the wine.

One of the options available to winemakers in situations like this is deacidification, which is defined as simply the reduction or adjustment of acidity (titratable acidity or TA) of a juice or wine to achieve a better acid balance. The options available for deacidification include chemical deacidification, via the addition of agents such as such as calcium carbonate, potassium carbonate, potassium bicarbonate, and Acidex (double salt of calcium carbonate), and microbial deacidification such as malolactic fermentation (MLF). The degree to which the acidity of a juice or a wine should be reduced, should be determined first via a laboratory bench trial where the different rates of your chosen agent are added and the resulting wines tasted to determine the appropriate level of acidity reduction. At this point, you should also measure the pH and TA of the wines and compare these values to your chosen rate, as ultimately the chosen rate is based on taste, and not just specific pH and TA values.

The best options for deacidification are probably treating the wine with either calcium carbonate or potassium bicarbonate, with the latter being favoured by winemakers, as it is less likely to cause subsequent calcium instability problems and is a less ‘vigorous’ process

(less foaming from CO2 evolution). If treating juice, the deacidification should be carried out on clarified (i.e. carefully racked) juice, that should have been stored at or near 0°C for some time to remove as much acid as possible through natural precipitation. It is recommended that after deacidification, the heat and cold stability of the wine be re-checked.

16 Technical Review No. 193 August 2011 Table 1 provides an example of two deacidification trials conducted on red wines from different regions, showing the effect on pH and TA at differing rates of potassium bicarbonate.

Binding of SO2 Winemakers should be aware that diseased grapes can sometimes lead to high levels of bound SO2 in the finished wine due to the presence of higher than usual levels of pyruvic and α-ketoglutaric acids, as well as oxidised sugars. Elevated levels of pyruvic acid and α-ketoglutaric acid are mainly caused by nutritional deficiencies, especially vitamins due to mould infection of grapes (Boulton et al. 1996). Additionally, the presence of large quantities of oxidised sugars is typically associated with wines made from grapes affected by Botrytis cinerea and various forms of rot (Ribéreau-Gayon et al. 2000).

If fruit that is heavily diseased is to be processed, it can be beneficial to add 0.5 mg/L of thiamine to juice which has been clarified and which has previously had SO2 added. Addition of thiamine in such cases has been shown to diminish the concentration of pyruvic and a-ketoglutaric acids and consequently the concentration of bound SO2 in the finished wine (Ribéreau-Gayon et al. 2000).

Do you need help? The AWRI’s Industry Development and Support team are here to help grape and wine producers. Should you require assistance, please contact us on 08 8313 6600 or by email: [email protected] or [email protected]

Table 1. Data from two deacidification trials on red wines from McLaren Vale and the Hunter Valley Rate of addition Titratable acidity pH of KHCO3 (g/L) (g/L) McLaren Vale Shiraz 0 2.94 10.2

1 3.15 9.4

2 3.29 8.3

3 3.50 7.0

4 3.76 5.7

5 4.00 4.9

Hunter Valley Merlot 0 3.36 7.5

0.2 3.42 7.4

0.4 3.48 7.6

0.6 3.54 7.4

0.8 3.57 7.2

1.0 3.61 6.8

August 2011 Technical Review No. 193 17 References Boulton, R.B., Singleton, V.L., Bisson, L.F., Kunkee, R.E. (1996) Principles and practices of winemaking. New York: Chapman & Hall: 459–161. Edens, W.A., Goins, T.Q., Dooley, D., Henson, J.M. (1999) Purification and characterization of a secreted laccase of Gaeumannomyces graminis var. tritici. Appl. Environ. Microbiol. 65: 3071–3074. Godden, P. (2000) Bunch rots – understanding the winemaker’s dilemma. Davies, C. (eds). Managing bunch rots: proceedings of a seminar; 28 July 2000, Mildura Arts Centre, Mildura, Victoria. Aust. Soc. Vitic. Oenol.: Adelaide, S.A.: 52–54. Grassin, C., Dubourdieu, D. (1989) Quantitative determination of botrytis laccase in musts and wines by the syringaldazine method. J. Sci. Food Agric. 48: 369–376. Leonowicz, A., Grzywnowicz, K. (1981) Quantitative estimation of laccase forms in some white-rot fungi using syringaldazine as a substrate. Enzyme Microb. Technol. 3(1): 55–58. Leske, P. (1993). Laccase – A threat in 1993. Aust. N.Z. Wine Ind. J. 8(2): 122–124. Pfanz, H., Oppmann, B. (1991) Inhibition of lignifying processes by sulfur dioxide. 96:1; Conference: Annual meeting of the American Society of Plant Physiology, Albuquerque, NM (United States), 28 Jul – 1 Aug 1991. Ribéreau-Gayon, J., Peynaud, E., Ribéreau-Gayon, P., Sudraud, P. (1976) Sciences et techniques du vin. Tome 3. Vinifications, Transformations du vin. Paris: Dunod. Ribéreau-Gayon, P., Glories, Y., Maujean, A., Dubourdieu, D. (2000) Handbook of Eenology volume 1: The chemistry of wine stabilisation and treatments. Chichester: John Wiley & Sons Ltd; 186–189, 348. Somers, T.C. (1984) Botrytis cinerea – consequences for red wines. Aust. Grapegrower Winemaker 244: 80, 83, 85. Villettaz, J.C., Steiner, D., Trogus, H. (1984) The use of a beta glucanase as an enzyme in wine clarification and filtration. Am. J. Enol. Vitic. 35(4): 253–256.

Adrian Coulter, Senior Oenologist Geoff Cowey, Senior Oenologist Marcel Essling, Viticulturist Matt Holdstock, Senior Oenologist Creina Stockley, Health and Regulatory Information Manager [email protected]

18 Technical Review No. 193 August 2011 Why should we be interested in alternative varieties?

At the present time, there is much interest in alternative winegrape varieties in Australia. However, there are skeptics, self-termed ‘varietal elitists’, who believe that there are the ‘great varieties’—and then there are ‘the rest’. While they concede that ‘the rest’ may be good enough when grown in a few key locations, it is safer to focus on the few ‘great varieties’. In contrast, the ‘varietal multiculturalists’ among us agree with Andrew Jefford who wrote the following in the May 2011 issue of Decanter: “My joy in wine is predicated on its complex multiplicity. Origin, vintage and variety are the chief sources of that. I’m reluctant to abandon the third. Indeed, encouraging greater varietal diversity in non-European vineyards seems to me to be an evolutionary imperative just now. I don’t believe that the world’s greatest winegrowing locations will reveal all their splendours via a mere half-dozen varieties”.

The varietal elitists also conveniently overlook that, just a few decades ago, Chardonnay, Merlot, Pinot Noir, Pinot Gris/Grigio and Sauvignon Blanc would have been considered to be ‘alternative varieties’ by today’s definition—they are now among the top 10 varieties in Australia and collectively make up almost 40% of the national tonnage. Therefore, today’s alternative variety may be tomorrow’s most important variety—as is now the case for Chardonnay.

Why should we be interested in alternative varieties?

The threat of climate change to the quality of mainstream winegrape production could be alleviated by adaptation measures and scientists are investigating opportunities in this area. An alternative to implementing what are possibly complicated and unsustainable management practices in an attempt to maintain the status quo is to switch to a suite of varieties that are more appropriate for the conditions. Growing fruit that is better suited to the conditions will require less interference and management input. Many of the alternative varieties may be more appropriate for climatic conditions of the future than our current mainstream varieties, particularly in terms of heat and drought tolerance. The Mediterranean area is a logical place to source varieties that have such desirable characteristics. This region has a genetic resource that is largely unexploited elsewhere. There are unique varieties, i.e. not grown elsewhere in many countries: for example, at least 25 in Morocco, more than 40 in the Balearic Islands of Spain, more than 80 in Mediterranean Italy and more than 30 in Greece. Why has there been little interest in such varieties until recently? In general, they have not been used for the well-known appellations of Europe, with the exception of Grenache and Mourvedre. Their wines were rarely consumed outside of their region of origin. Often, their potential was been ‘hidden’ by poor or inappropriate handling and winemaking—for example, Verdejo from

August 2011 Technical Review No. 193 19 Spain was traditionally used for a sherry-style wine because it is prone to oxidation. Today it is used for a fresh table wine because its fruit is processed with non-oxidative handling.

There are many benefits to be gained by growing alternative varieties in greater quantities in various locations. The ‘new’ fruit will provide winemakers and consumers with a greater range of flavours to work with and enjoy. This will also provide new opportunities in terms of potential wine styles. In the last few years a changing economic environment has seen export demand swing away from the traditional European/North American market towards the Asian economies. A re-evaluation of wine styles and products is required for this market, with its distinctly different consumer preferences. Varieties such as Fiano, Verdejo, Petit Manseng, Montepulciano, Lagrein, Tannat and Saperavi have potential to produce wines that are well-matched to Asian food according to CSIRO research (P. Clingeleffer, pers. comm).

Alternative varieties represent an opportunity to add incremental sales growth for the future, whether viewed from the perspective of an individual producer, a specific brand or the wine industry as a whole. They also represent a point of interest for a producer, region or a country and can represent a unique selling point. Because of the interest in new and unique wines produced from alternative varieties, their introduction represents a publicity opportunity for a producer; and an opportunity to position the producer as innovative and dynamic, e.g. as in the case with the alternative varieties championed by Brown Brothers and Yalumba. At the regional level, the producers within the Granite Belt (Qld) have used their Strange Bird wine trail to introduce consumers to alternative varieties and to attract more consumers to their cellar doors to try the wines of their mainstream varieties.

There has been a recent trend towards lower alcohol wines. These require adequate flavours at lower sugar levels, or varieties that lend themselves to the appropriate winemaking techniques to achieve this style. There may be a niche for alternative varieties that are better suited than existing varieties for the production of low alcohol wine: Corvina, Dolcetto, Frappato, Ribolla Gialla, Schiava and Vermentino appear to have this ability. Also, some of the new varieties can offer white wines with more texture, savouriness and minerality than our existing varieties: examples include Fiano, Greco and Gruener Veltliner.

The Australian Wine Research Institute (AWRI) has developed recently a new Research to Practice (RTP) program, ‘Alternative varieties: emerging options for a changing environment’. Market research indicated that there is much interest currently in alternative varieties and an urgent need for more information, particularly in a consolidated and readily-accessible format. Thus far, this RTP program has been presented in Riverina, Adelaide Hills, Langhorne Creek and McLaren Vale regions and to Treasury Wine Estates.

20 Technical Review No. 193 August 2011 The one-day seminar is available to regional groups, wine companies or other organisations by negotiation. For example, growers should contact their regional organisation and request that it contacts The Australian Wine Research Institute to arrange presentation in their region. At each seminar, the focus varieties are chosen, in consultation with the regional organisation, on the basis of their suitability for that particular region. The seminar includes a tasting of wines from at least 12 focus varieties. Local wines are chosen, when possible, because they generally indicate best the potential of the variety under Australian conditions, and Australian viticultural and winemaking practices. For those varieties that are not grown currently in Australia, the best examples of overseas wines are sourced for the tasting.

Registrants of the program are provided with a 142-page manual—this is the most up-to- date and comprehensive compilation of information on alternative varieties in the English language on the international scene. Both the seminar and the manual include the following topics: the direct and indirect effects of climate change on viticulture and winemaking and the options for adaptation; how varieties differ in heat and drought tolerance; sources of information on alternative varieties—monographs, journals and electronic sources from many countries; grapevine import requirements, the quarantine process and multiplication for source block establishment and information on AQIS approved post-entry quarantine facilities, approved sources of germplasm for importation; ensuring that the planting material is true to type by ampelography and DNA technology; and the introduction of a new variety into the market place.

The manual contains the profiles of 40 winegrape varieties that are considered to have potential under Australian conditions. At least 30 are already known to be in Australia. There are 20 white wine and 20 red wine varieties in the list: 19 from Italy; five each from France and central/eastern Europe; four each from Portugal and Spain; and three from Greece. Although the list contains varieties suitable for the whole range of climatic regions in Australia, there is a strong emphasis on varieties that are potentially heat and drought tolerant, most of which originate from the Mediterranean area. The varieties were chosen as a result of our research and in consultation with industry representatives who have extensive experience with alternative varieties.

The new Alternative Varieties RTP is a unique and exciting package that has been created to meet industry demand. For more information, the contact person at the AWRI is Marcel Essling ([email protected]; tel. 08 8313 6600).

August 2011 Technical Review No. 193 21 Further reading Dry, P.R., Tassie, L. and Essling, M. (2011) Launch of the Alternative Varieties ‘Research to Practice’. Proceedings of the ASVO Symposium ‘Think Global: Plant Local’, Mildura, November 2010; Australian Society of Viticulture and Oenology: 1-3.

Peter Dry, Viticulture Consultant, [email protected]

22 Technical Review No. 193 August 2011 Highlights this issue

AWRI Managing Director moves on ...... 6

‘Tropical’ thiol precursor levels in Sauvignon Blanc grapes: the effect of ripening and post-harvest transport ...... 7

Botrytis and disease pressures from vintage 2011 ...... 11

Why should we be interested in alternative varieties? ...... 19

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1294 [0.50] 1292 [1.20] 1296 [0.60] 1297 [0.80] 1298 [1.70]

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4 Technical Review No. 193 August 2011 Current literature

Copies of all articles listed in this section are available for private study on

request from the AWRI. Please use the request form provided in the centre pages of this issue. Currently a service charge of A$7.00 per request is applicable, plus a supply charge of 10¢ per page, plus postage will apply (inclusive of GST).

In compliance with copyright legislation, abstracts are reproduced here exactly as originally printed.

Oenology

General

193.01 Anon. Towards better use of white wine phenolics. Aust. N.Z. Grapegrower Winemaker 567, p.3; 2011.

A greater understanding of white wine phenolics is being sought through research by The Australian Wine Research Institute (AWRI). This will enhance the capacity of winemakers to manage the final style of their white wines.

© Reprinted with permission from Anon. Towards better use of white wine phenolics. Aust. N.Z. Grapegrower Winemaker 567, p.3; 2011. Copyright 2011 Winetitles Pty Ltd.

193.02 Simon, J. Pinot Gris/Grigio international standard. World Fine Wine 31, 162–169; 2011.

Abstract not available for reproduction

193.03 Barwick, J. Technology traces path from vine to wine. Aust. N.Z. Grapegrower Winemaker 566, 47–50; 2011.

The ability to track and trace the grape from the field to the winery has significant implications for the grape and wine industry.

© Reprinted with permission from Barwick, J. Technology traces path from vine to wine. Aust. N.Z. Grapegrower Winemaker 566, 47–50; 2011. Copyright 2011 Winetitles Pty Ltd. C

August 2011 Technical Review No. 193 23 L 193.04 Sonni, F., Clark, A.C., Prenzler, P.D., Riponi, C., Scollary, G.R. Antioxidant action of glutathione and the ascorbic acid/glutathione pair in a model white wine. J. Agric. Food Chem. 59(8), 3940–3949; 2011.

Glutathione was assessed individually, and in combination with ascorbic acid, for its ability to act as an antioxidant with respect to color development in an oxidizing model white wine system. Glutathione was utilized at concentrations normally found in wine (30 mg/L), as well as at concentrations 20-fold higher (860 mg/L), the latter to afford ascorbic acid (500 mg/L) to glutathione ratios of 1:1. The model wine systems were stored at 45°C without sulfur dioxide and at saturated oxygen levels, thereby in conditions highly conducive to oxidation. Under these conditions the results demonstrated the higher concentration of glutathione could initially provide protection against oxidative coloration, but eventually induced color formation. In the period during which glutathione offered a protective effect, the production of xanthylium cation pigment precursors and o-quinone-derived phenolic compounds was limited. When glutathione induced coloration, polymeric pigments were formed, but these were different from those found in model wine solutions without glutathione. In the presence of ascorbic acid, high concentrations of glutathione were able to delay the decay in ascorbic acid and inhibit the reaction of ascorbic acid degradation products with the wine flavanol compound (+)-catechin. However, on depletion, the glutathione again induced the production of a range of different polymeric pigments. These results highlight new mechanisms through which glutathione can offer both protection and spoilage during the oxidative coloration of a model wine.

© Reprinted with permission from Sonni, F., Clark, A.C., Prenzler, P.D., Riponi, C., Scollary, G.R. Antioxidant action of glutathione and the ascorbic acid/glutathione pair in a model white wine. J. Agric. Food Chem. 59(8), 3940–3949; 2011. Copyright 2011 American Chemical Society.

24 Technical Review No. 193 August 2011 Juice and wine handling

193.05 Bliard, C., Marchal, R., Robillard, B. Courte mise au point sur les gommes de cellulose (CMC) aprés une année d’utilisation. Rev. Oenol. 139, 49–51; 2011.

[French] Abstract not available for reproduction

193.06 Roger, B., Barbier, J.-E., Robillard, B., Vasserot, Y. Nouveaux outils pour lutter contre le goût de réduit. Rev. Oenol. 138, 27–29; 2011.

[French] Abstract not available for reproduction

193.07 Byrne, M. The Pinot principles. Wine Viti. J. 26(2), 32–37; 2011.

During the Mornington Peninsula International Pinot Noir Celebration held in late January, WVJ journalist Matt Byrne was in attendance to hear winemakers express many views on the best way to make a great Pinot, and reported that there was lively debate particularly in regard to vine density, whole bunch fermentation, filtration, fining, time in oak, and bottle age. Immediately following the event, the Journal invited some of the winemakers present at the Pinot Celebration to share their current practices in relation to these areas, their reasons for doing them and whether or not they have changed in recent years. Tasmanian-based contract winemaker Julian Alcorso joins Mornington vignerons Lindsay McCall, Nat White, David Lloyd, Sandro Mosele and George Mihaly in disclosing their experiences.

© Reprinted with permission from Byrne, M. The Pinot principles. Wine Viti. J. 26(2), 32–37; 2011. Copyright 2011 Winetitles Pty Ltd.

193.08 Eudier, L., Samson, A., Caille, S., Aguera, E., Bes, M., Dangleville, G., De Vlieger, L., Salmon, J.-M. Le décanteur centrifuge Alfa-Laval. Rev. Oenol. 138, 18–20; 2011.

[French] Abstract not available for reproduction

C

August 2011 Technical Review No. 193 25 L Microbiology

193.09 Hall, B., Durall, D.M., Stanley, G. Population dynamics of Saccharomyces cerevisiae during spontaneous fermentation at a British Columbia winery. Am. J. Enol. Vitic. 62(1), 66–72; 2011.

Spontaneous fermentation is thought to provide conditions where diversity of indigenous Saccharomyces cerevisiae strains can flourish. A broad diversity of strains may provide unique characteristics to a wine and enhance its sensorial attributes. Population dynamics of S. cerevisiae strains were followed during a spontaneous fermentation of Vitis vinifera L. var. Pinot Noir grapes at a winery in Kelowna, British Columbia, Canada, to determine the relative contribution of commercial active dry yeast (ADY) and indigenous strains during fermentation. Grapes were harvested, processed, and fermented separately. Yeasts from grapes were isolated and plated onto culture media. Fermentation tanks were sampled at early, mid, and late stages of fermentation. Yeast strains were isolated onto culture media at each stage. DNA was extracted from yeast cultures and amplified using primers defining six different microsatellite loci. Results were compared with a database comprising DNA fingerprints from commercially produced ADY strains used previously by the winery. Strains isolated from fermentation tanks were all ADY strains closely related or identical to those in the winery database. Strain richness tended to be greater in the mid and final stages than in the early stage. Lalvin ICV D254/Fermol Premier Cru and Red Star Premier Cuvée were the dominant yeasts during the mid and final stages. The former was the only strain found in all tanks in the mid and final stages. An ADY strain, Fermol Arome-Plus, was isolated from both grapes and spontaneous fermentation. This strain could represent a resident strain, where it persists year after year and cycles annually between the winery and vineyard.

© Reprinted with permission from Hall, B., Durall, D.M., Stanley, G. Population dynamics of Saccharomyces cerevisiae during spontaneous fermentation at a British Columbia winery. Am. J. Enol. Vitic. 62(1), 66–72; 2011. Copyright 2011 American Society for Enology and Viticulture.

193.10 Gafner, J. Influence of microbiological biodiversity and population dynamics of yeasts on wine quality – an overview. Mitt. Klosterneuburg Rebe Wein 60(3), 338–344; 2010.

[German] Abstract not available for reproduction

193.11 Mandl, K., Schattauer, D., Geyrhofer, A., Weingartmann, H. Biodiversity of fungal microflora in wine-cellars. Mitt. Klosterneuburg Rebe Wein 60(3), 350–354; 2010.

[German] Abstract not available for reproduction

26 Technical Review No. 193 August 2011 Analysis and composition

193.12 Robinson, A.L., Boss, P.K., Heymann, H., Solomon, P.S., Trengove, R.D. Influence of yeast strain, canopy management, and site on the volatile composition and sensory attributes of Cabernet Sauvignon wines from Western Australia. J. Agric. Food Chem. 59(7), 3273–3284; 2011.

Understanding what factors are the major influences on wine composition will assist in the successful management of grape composition in the vineyard and/or variables in the winery to produce wines with specific sensory attributes. A recently developed analytical method [headspace solid-phase microextraction comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry] was employed to analyze over 350 volatile compounds in research scale wines and was combined with descriptive sensory analysis. Both compositional and sensory results showed significant differences among the wines, and in many cases, multiple factors influenced the abundance of wine volatile compounds. Site had the most significant influence on sensory scores and wine composition, followed by canopy management. Unexpectedly, yeast strain had no significant sensory effect despite the fact that a number of volatile compounds were significantly different in the wines made from different strains. PLS analysis, combining the sensory and chemical analyses, also supports the concept of volatile compound interactions contributing to the aroma characteristics of Cabernet Sauvignon wine.

© Reprinted with permission from Robinson, A.L., Boss, P.K., Heymann, H., Solomon, P.S., Trengove, R.D. Influence of yeast strain, canopy management, and site on the volatile composition and sensory attributes of Cabernet Sauvignon wines from Western Australia. J. Agric. Food Chem. 59(7), 3273–3284; 2011. Copyright 2011 American Chemical Society.

193.13 Bogianchini, M., Cerezo, A.B., Gomis, A., López, F., García-Parrilla, M.C. Stability, antioxidant activity and phenolic composition of commercial and reverse osmosis obtained dealcoholised wines. LWT 44(6), 1369–1375; 2011.

Abstract available online at http://www.sciencedirect.com/science/article/pii/S0023643811000570

193.14 Ganss, S., Kirsch, F., Winterhalter, P., Fischer, U., Schmarr, H.-G. Aroma changes due to second fermentation and glycosylated precursors in Chardonnay and Riesling sparkling wines. J. Agric. Food Chem. 59(6), 2524–2533; 2011.

Aroma changes in Chardonnay and Riesling base wines caused by the second fermentation were investigated by a targeted component analysis: A stable isotope dilution approach using headspace solid phase microextraction coupled online to gas chromatography mass spectrometry (HS- SPME-GC-MS) was applied to quantify 37 compounds relevant for sparkling wine aroma. In an enrichment experiment, glycosylated precursors isolated from one Chardonnay and one Riesling base wine were used to double the original amount in these base wines. Along with increased concentrations of precursor-derived volatiles after the second fermentation, descriptive sensory C

August 2011 Technical Review No. 193 27 L evaluation revealed an enhancement of fruity aroma impressions reminiscent of, for example, peach or cantaloupe. Except for benzyl alcohol, linalool, and 3-methylpentanol, no quantitative 2-fold increase of volatiles was found with a 2-fold increase in precursor concentration, as other metabolic pathways seem to interfere with aroma formation from glycosides.

© Reprinted with permission from Ganss, S., Kirsch, F., Winterhalter, P., Fischer, U., Schmarr, H.-G. Aroma changes due to second fermentation and glycosylated precursors in Chardonnay and Riesling sparkling wines. J. Agric. Food Chem. 59(6), 2524–2533; 2011. Copyright 2011 American Chemical Society.

193.15 Forde, C.G., Cox, A., Williams, E.R., Boss, P.K. Associations between the sensory attributes and volatile composition of Cabernet Sauvignon wines and the volatile composition of the grapes used for their production. J. Agric. Food Chem. 59(6), 2573–2583; 2011.

The sensory properties of wine are influenced by the chemical composition of the grapes used to produce them. Identification of grape and wine chemical markers associated with the attributes perceived by the consumer of the wine will enable better prediction of the potential of a parcel of grapes to produce wine of a certain flavor. This study explores the relationships between Cabernet Sauvignon grape volatile composition and wine volatile profiles with the sensory properties of wines. Twenty grape samples were obtained from nine vineyard sites across three vintages and wines vinified from these parcels using controlled winemaking methods. The volatile composition of the grapes were analyzed by SBSE-GCMS, the wines were analyzed by SPME-GCMS, and these data sets were compared to that obtained from the sensory analysis of the wines. Statistical treatment of the data to account for vintage and region effects allowed underlying relationships to be seen between wine sensory attributes and wine or grape volatile components. The observed associations between grape or wine volatile compounds and wine sensory attributes has revealed target compounds and pathways whose levels may reflect the biochemical effects on grape composition by differing growth conditions during berry development and ripening. The compounds identified in this study may be useful grape or wine markers for potential wine sensory characteristics.

© Reprinted with permission from Forde, C.G., Cox, A., Williams, E.R., Boss, P.K. Associations between the sensory attributes and volatile composition of Cabernet Sauvignon wines and the volatile composition of the grapes used for their production. J. Agric. Food Chem. 59(6), 2573–2583; 2011. Copyright 2011 American Chemical Society.

193.16 Pons, M., Dauphin, B., La Guerche, S., Pons, A., Lavigne-Cruege, V., Shinkaruk, S., Bunner, D., Richard, T., Monti, J.-P., Darriet, P. Identification of impact odorants contributing to fresh mushroom off-flavor in wines: incidence of their reactivity with nitrogen compounds on the decrease of the olfactory defect. J. Agric. Food Chem. 59(7), 3264–3272; 2011.

Analysis of wines from different grape varieties marked by sometimes intense aromatic nuances of fresh mushroom was performed by gas chromatography coupled with olfactometry. This analysis has led to the identification of several odoriferous zones, which were recalling a fresh mushroom odor. Two trace compounds responsible for these odoriferous zones, 1-nonen-3-one and 1-octen-3-one, have been identified and their content has been determined by using either a

28 Technical Review No. 193 August 2011 multidimensional gas chromatography technique coupled to olfactometry and mass spectrometry detection (in the case of 1-nonen-3-one) or the preparation of the derivative with O-2,3,4,5,6- pentafluorobenzylhydroxylamine hydrochloride in the presence of the deuterated form, as the internal standard (in the case of 1-octen-3-one), then gas chromatography coupled to mass spectrometry detection. The assays allowed the quantification of these compounds at concentration levels sometimes well above their detection and recognition olfactory threshold. We show that adding nitrogen compounds to the altered wines, such as an amino acid (glycine) or a tripeptide (glutathione), led to lower concentrations of 1-octen-3-one in wines and diminished smell of fresh mushrooms. The study of the reaction in a model medium, whose composition is close to wine, by liquid chromatography coupled to mass spectrometry demonstrated the formation of adducts between 1-octen-3-one and glycine, and 1-octen-3-one and glutathione characterized by NMR.

© Reprinted with permission from Pons, M., Dauphin, B., La Guerche, S., Pons, A., Lavigne-Cruege, V., Shinkaruk, S., Bunner, D., Richard, T., Monti, J.-P., Darriet, P. Identification of impact odorants contributing to fresh mushroom off-flavor in wines: incidence of their reactivity with nitrogen compounds on the decrease of the olfactory defect. J. Agric. Food Chem. 59(7), 3264–3272; 2011. Copyright 2011 American Chemical Society.

193.17 Kontoudakis, N., Gonzlez, E., Gil, M., Esteruelas, M., Fort, F., Canals, J.M., Zamora, F. Influence of wine pH on changes in color and polyphenol composition induced by micro- oxygenation. J. Agric. Food Chem. 59(5), 1974–1984; 2011.

The presence of oxygen in red wine leads to the transformation of ethanol into ethanal, which after capturing a proton will react with flavanols to start the process of forming ethyl bridges between flavanols and between flavanols and anthocyanins. Wine pH also conditions the equilibrium between the different anthocyanin structures and may thus affect anthocyanin reactivity. Consequently, the aim of this paper was to study how the pH can affect the changes induced by micro-oxygenation in two wines with different phenolic composition. The differences between micro-oxygenated wines and their controls were, in general, greater when the pH was more acidic. Specifically, the differences between micro-oxygenated wines and their corresponding controls in terms of color intensity, anthocyanin concentration, PVPP index, ethyl-linked pigments, B-type vitisins, polymeric pigments, and ethylidene-bridged flavanols were greater at lower pH. In contrast, the effects of micro-oxygenation when the pH was less acidic were much less evident and sometimes practically nonexistent. These results demonstrate for the first time that the pH of the wine has a great influence on oxygen-induced changes of color and phenolic compounds.

© Reprinted with permission from Kontoudakis, N., Gonzlez, E., Gil, M., Esteruelas, M., Fort, F., Canals, J.M., Zamora, F. Influence of wine pH on changes in color and polyphenol composition induced by micro- oxygenation. J. Agric. Food Chem. 59(5), 1974–1984; 2011. Copyright 2011 American Chemical Society.

193.18 Galgano, F., Caruso, M., Perretti, G., Favati, F. Authentication of Italian red wines on the basis of the polyphenols and biogenic amines. Eur. Food Res. Technol. 232(5), 889–897; 2011. Abstract available online at http://www.springerlink.com/content/42466q648k488878/ C

August 2011 Technical Review No. 193 29 L 193.19 Gardner, D.M., Zoecklein, B.W., Mallikarjunan, K. Electronic nose analysis of Cabernet Sauvignon (Vitis vinifera L.) grape and wine volatile differences during cold soak and postfermentation. Am. J. Enol. Vitic. 62(1), 81–90; 2011.

Cold soak is a prefermentation maceration process at cold temperatures, traditionally used to enhance red wine color. This study monitored changes in Vitis vinifera L. cv. Cabernet Sauvignon volatiles using a commercial conducting polymer electronic nose (ENose) during a five-day cold soak and postfermentation. Principal component analysis (PCA) of juice volatiles detected by the ENose during cold soak showed PC1 accounted for 95.7% of the variation. Various volatile associations were made with specific ENose sensors. In comparison, PCA of must chemistries had 52.4% of the variation accounted for by PC1. The PCA of wine volatiles detected by GC-MS showed PC1 accounted for 97.1% of the variation between control and cold soak treatment, where control wine volatiles were associated with several ethyl esters, while cold soak wine volatiles were associated with diethyl succinate, isovaleric acid, benzyl alcohol, 3-methyl butanol, cis-3-hexenol, γ-nonalactone, benzaldehyde, 2-methyl propanol, phenethyl acetate, 1-octanol, β-damascenone, terpinene-4-ol, γ-butyrolactone, ethyl acetate, hexanoic acid, citronellol, phenethyl alcohol, and n-butanol. Comparatively, PC1 accounted for 100% of the total variance when using the ENose to measure volatile composition. Sensory evaluation did not demonstrate significant differences in aroma between control and cold soak wines. This study demonstrates differences in volatile chemistry between control and cold soak wines, as well as the ability to use a conducting polymer ENose as a simple tool for analysis of volatiles.

© Reprinted with permission from Gardner, D.M., Zoecklein, B.W., Mallikarjunan, K. Electronic nose analysis of Cabernet Sauvignon (Vitis vinifera L.) grape and wine volatile differences during cold soak and postfermentation. Am. J. Enol. Vitic. 62(1), 81–90; 2011. Copyright 2011 American Society for Enology and Viticulture.

193.20 Clark, A.C., Dias, D.A., Smith, T.A., Ghiggino, K.P., Scollary, G.R. Iron(III) tartrate as a potential precursor of light-induced oxidative degradation of white wine: studies in a model wine system. J. Agric. Food Chem. 59(8), 3575–3581; 2011.

The potential for iron(III) tartrate to act as a photoactivator in light-induced oxidative degradation of white wine is described. Using a tartaric-acid-based model wine system containing 5 mg/L iron, exposure to light from a xenon arc lamp led to the oxidative degradation of tartaric acid and the production of glyoxylic acid. The critical wavelength of light for the degradation process was found to be below 520 nm. No glyoxylic acid was formed in the absence of iron and/or light. Flint glass offered little protection from the light-induced photodegradation of tartaric acid. Antique Green glass offered more protection but did not stop the photodegradation process.

© Reprinted with permission from Clark, A.C., Dias, D.A., Smith, T.A., Ghiggino, K.P., Scollary, G.R. Iron(III) tartrate as a potential precursor of light-induced oxidative degradation of white wine: studies in a model wine system. J. Agric. Food Chem. 59(8), 3575–3581; 2011. Copyright 2011 American Chemical Society.

30 Technical Review No. 193 August 2011 193.21 Barata, A., Campo, E., Malfeito-Ferreira, M., Loureiro, V., Cacho, J., Ferreira, V. Analytical and sensorial characterization of the aroma of wines produced with sour rotten grapes using GC-O and GC-MS: identification of key aroma compounds. J. Agric. Food Chem. 59(6), 2543–2553; 2011.

In the present work, the aroma profiles of wines elaborated from sound and sour rot-infected grapes as raw material have been studied by sensory analysis, gas chromatography−olfactometry (GC-O), and gas chromatography−mass spectrometry (GC-MS), with the aim of determining the odor volatiles most likely associated with this disease. The effect of sour rot was tested in monovarietal wines produced with the Portuguese red grape variety Trincadeira and in blends of Cabernet Sauvignon and sour rotten Trincadeira grapes. Wines produced from damaged berries exhibited clear honey-like notes not evoked by healthy samples. Ethyl phenylacetate (EPhA) and phenylacetic acid (PAA), both exhibiting sweet honey-like aromas, emerged as key aroma compounds of sour rotten wines. Their levels were 1 order of magnitude above those found in controls and reached 304 and 1668 μg L−1 of EPhA and PAA, respectively, well above the corresponding odor thresholds. Levels of γ-nonalactone also increased by a factor 3 in sour rot samples. Results also suggest that sour rot exerts a great effect on the secondary metabolism of yeast, decreasing the levels of volatiles related to fatty acids and amino acid synthesis. The highest levels of γ-decalactone of up to 405 μg L−1 were also found in all of the samples, suggesting that this could be a relevant aroma compound in Trincadeira wine aroma.

© Reprinted with permission from Barata, A., Campo, E., Malfeito-Ferreira, M., Loureiro, V., Cacho, J., Ferreira, V. Analytical and sensorial characterization of the aroma of wines produced with sour rotten grapes using GC-O and GC-MS: identification of key aroma compounds. J. Agric. Food Chem. 59(6), 2543–2553; 2011. Copyright 2011 American Chemical Society.

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August 2011 Technical Review No. 193 31 L Marketing and packaging

193.22 Forbes, S.L., Cullen, R., Cohen, D.A., Wratten, S.D., Fountain, J. Food and wine production practices: an analysis of consumer views. J. Wine Res. 22(1), 79–86; 2011.

This study was designed to ascertain the degree to which consumers are concerned about human health and environmental issues arising from both food and wine production. In particular, this study sought, for the first time, to compare consumer perceptions regarding food production practices and wine production practices. Interviewer-administered questionnaires were completed with 109 consumers inside supermarkets, general liquor stores and specialty wine stores in the city of Christchurch, New Zealand. In general, consumers expressed a high level of concern regarding the effects of agricultural (food) production practices on both their own health and on the health of the environment. Consumers were found to be less concerned about the effects of wine production practices on their health and the environment, but a large segment reported that they did not know how wine was produced and thus had not, as yet, formed either positive or negative views about the effects of wine production practices. At a practical level, this paper suggests that wine marketers have a window of opportunity in which to positively influence the large number of consumers who currently do not hold any views regarding the effects of wine production on their health or the environment. This paper is of significant value because it provides a unique comparison of consumer views regarding food production and wine production and it has added to our knowledge of the ‘green’ consumer.

© Reprinted with permission from Forbes, S.L., Cullen, R., Cohen, D.A., Wratten, S.D., Fountain, J. Food and wine production practices: an analysis of consumer views. J. Wine Res. 22(1), 79–86; 2011. Copyright 2011 Routledge.

193.23 Easingwood, C., Lockshin, L., Spawton, A. The drivers of wine regionality. J. Wine Res. 22(1), 19–33; 2011.

Regionality is the reputation a wine region has for producing wines with a particular style. In a world of over supply, its importance is recognised, but the causes or drivers of regionality have not been researched. This research explored the bases of regionality, first of all in discussions with 20 specialists in Australia, followed then by a survey of 89 wine professionals on the possible drivers of regionality in leading wine regions in Australia. This identified 14 potential drivers of regionality and a discriminant analysis showed the three key drivers to be: specialisation, much discussed by opinion formers, and a well-defined wine style.

© Reprinted with permission from Easingwood, C., Lockshin, L., Spawton, A. The drivers of wine regionality. J. Wine Res. 22(1), 19–33; 2011. Copyright 2011 Routledge.

32 Technical Review No. 193 August 2011 193.24 Barber, N. ‘Green’ wine packaging: targeting environmental consumers. Int. J. Wine Bus. Res. 22(4), 423–444; 2010.

Abstract available online at http://www.emeraldinsight.com/journals.htm?articleid=1895916& show=abstract

193.25 Anderson, K., Nelgen, S. How does Australia rank in the various quality segments of the world’s wine markets? Wine Viti. J. 26(2), 64–65; 2011.

This article is based on a section in the global Wine Statistical Compendium, compiled and published by the University of Adelaide, which for the first time attempts to summarise global shares of value categories. Among the findings is that New Zealand is ahead of Australia in the share of the world’s super-premium still wine exports.

© Reprinted with permission from Anderson, K., Nelgen, S. How does Australia rank in the various quality segments of the world’s wine markets? Wine Viti. J. 26(2), 64–65; 2011. Copyright 2011 Winetitles Pty Ltd.

193.26 Remaud, H., Chabin, Y., Mueller, S. Do consumers value sustainable wine claims? An international comparison. Bull. OIV 956-958, 523–533; 2011.

In the last few months, there hasn’t been a single week without an article appearing in one of the various wine magazines and wine news telling the story of a winery or a wine region being engaged in a sustainable programme. At the same time, very little is known about consumers’ preferences and acceptance of such claims. We aim to fill this gap by presenting preliminary findings of a cross- cultural research project conducted for the French wine association IGP Pays d’Oc. A quantitative survey was conducted in five countries (France, UK, Germany, Canada, US) in December 2009 with a total of 11,312 regular wine consumers. Using a discrete choice experiment with visual shelf simulations, we substantiate the relative importance and monetary value of various sustainable wine claims for all consumers on the different markets. Such an approach provides the opportunity to estimate utilities and willingness to pay for each attribute tested and for each market segment. Preliminary findings at the aggregated level indicate that for two countries sustainable claims are valued as highly as French regions of origin and for one country their importance was even higher. Our findings provide wine producers, marketers and policy makers with valuable insights and present the capabilities of a sophisticated and highly valid research method.

© Reprinted with permission from Remaud, H., Chabin, Y., Mueller, S. Do consumers value sustainable wine claims? An international comparison. Bull. OIV 956-958, 523–533; 2011. Copyright 2011 Organisation International de la Vigne et du Vin.

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August 2011 Technical Review No. 193 33 L Environment

193.27

Smart, R. Reducing CO2, the real pollutant. Pract. Winery Vineyard 32(2), 46–48; 2011.

In this article, the author examines the impact of CO2 emissions on vineyards.

© Reproduced with permission from Smart, R. Reducing CO2, the real pollutant. Pract. Winery Vineyard 32(2), 46–48; 2011. Copyright 2011 Practical Winery and Vineyard Incorporated.

193.28 Mosse, K.P.M., Patti, A.F., Christen, E.W., Cavagnaro, T.R. Review: winery wastewater quality and treatment options in Australia. Aust. J. Grape Wine Res. 17(2), 111–122; 2011.

Commercial production of wine results in the generation of large volumes of wastewater, which typically contains large amounts of organic material and salts as a result of product loss and cleaning processes. The treatment and management of this waste stream is of significant concern, especially considering increasing environmental restrictions. There are numerous treatment options available for the management of wastewaters, which vary with respect to efficacy, cost and reliability. This review presents a summary of these treatment options, and describes the mechanism of each process, as well as the advantages and disadvantages of their use within the wine industry. The current knowledge of winery wastewater (WWW) composition and current and emerging management and/or treatment options are described, within an Australian context. Firstly WWW composition is discussed, and then both established and emerging physicochemical and biological treatment options reviewed, and options for disposal/re-entry to the environment considered. Knowledge gaps and a way forward are presented in conclusion, and focus primarily on research in areas relating to WWW composition, and effects of WWW application on soil and plant health.

© Reprinted with permission from Mosse, K.P.M., Patti, A.F., Christen, E.W., Cavagnaro, T.R. Review: winery wastewater quality and treatment options in Australia. Aust. J. Grape Wine Res. 17(2), 111–122; 2011. Copyright 2011 Australian Society of Viticulture and Oenology.

34 Technical Review No. 193 August 2011 Sensory

193.29 Caporn, S. Finding the right sweet spot. Aust. N.Z. Grapegrower Winemaker 568, 45–48; 2011.

The best-selling branded red wines in the UK and US are often heavily sweetened. Sam Caporn, writer for Meiningers Wine Business International, has conducted research into the reactions of consumers with varying wine knowledge to differing levels of residual sugar.

© Reprinted with permission from Caporn, S. Finding the right sweet spot. Aust. N.Z. Grapegrower Winemaker 568, 45–48; 2011. Copyright 2011 Winetitles Pty Ltd.

193.30 Lavin, K. U.S. drinks most wine. Wines Vines 92(5), p.20; 2011.

The U.S. surpassed France as the No. 1 wine-consuming country in 2010, a new report states.

© Reprinted with permission from Lavin, K. U.S. drinks most wine. Wines Vines 92(5), p.20; 2011. Copyright 2011 The Hiaring Company.

193.31 Pérez-Magariño, S., Ortega-Heras, M., González-Sanjosé, M.L. Wine consumption habits and consumer preferences between wines aged in barrels or with chips. J. Wine Res. 91(5), 943–949; 2011.

Background: The use of oak wood pieces in winemaking is increasing, but the acceptance of this technique by consumers is unknown. For that reason, the main aim of this study was to measure consumers’ opinion of red wines made with this new technique, their acceptance of them and their intention to purchase these wines. A preference ranking test was also carried out. Results: A specific questionnaire was drawn up for this study and 65 frequent red wine consumers tasted four wines, two aged traditionally in barrels and two macerated with chips, and a forced choice preference test was carried out. Fifty-five per cent of respondents said that they would not buy wines made using oak chips, although most respondents would buy these wines if, after tasting them, they were as pleasant and had the same quality as the wines aged traditionally in barrels. Conclusion: Wines obtained with oak wood fragments were not significantly rejected either by consumers who answered the questionnaire or by consumer tasters, which could be due to the large disparity of preferences found among tasters. The results clearly indicate that producers should develop each wine taking into account the specific preferences of each consumer group.

© Reprinted with permission from Pérez-Magariño, S., Ortega-Heras, M., González-Sanjosé, M.L. Wine consumption habits and consumer preferences between wines aged in barrels or with chips. J. Wine Res. 91(5), 943–949; 2011. Copyright 2011 Routledge.

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August 2011 Technical Review No. 193 35 L Viticulture General

193.32 McGourty, G. Tuning your vineyard for the next vintage. Wines Vines 92(4), 60–63; 2011.

Good winegrowing is as much about timing as knowing precisely what to do. The author lists priorities for spring vineyard tasks to set vines up for a healthy year. Disease control, cover crops and canopy management need attention during the first 80 to 90 days of growth.

© Reprinted with permission from McGourty, G. Tuning your vineyard for the next vintage. Wines Vines 92(4), 60–63; 2011. Copyright 2011 The Hiaring Company.

193.33 Cemin, G., Ducati, J.R. Spectral discrimination of grape varieties and a search for terroir effects using remote sensing. J. Wine Res. 22(1), 57–78; 2011.

Satellite images are used to determine the reflectance dependency on wavelength in different grape varieties (Cabernet Sauvignon, Merlot, Pinot Noir, and Chardonnay). The terroir influence is investigated through a study of vineyards in France, Brazil and Chile. Statistical techniques (ANOVA, cluster and discriminant analysis) are applied. Results indicate that there are consistent spectral features, mainly in the near infrared, which can lead to variety identification. Discriminant functions were derived; these separate grape varieties for the regions studied. Spectral features are affected by terroir effects, since the reflectance spectra showed similarities between regions, specially for Cabernet Sauvignon; phenological factors, expressed by the NDVI, further contribute to variety differentiation. It is concluded that remote sensing data are effective for terroir and grape variety studies.

© Reprinted with permission from Cemin, G., Ducati, J.R. Spectral discrimination of grape varieties and a search for terroir effects using remote sensing. J. Wine Res. 22(1), 57–78; 2011. Copyright 2011 Routledge.

193.34 Stef, C. Ce qu’il faut savoir pour réussir le surgreffage. La Vigne 230, 38–39; 2011.

[French] Abstract not available for reproduction

193.35 Karlholm, U. Biodynamic and organic – not the only games in town. Wine Technol. NZ 9(1), 12–13; 2011.

It is easy to get the impression that, apart from conventional practices, there are only two options available in viticulture: organic and biodynamic. However, there are other methods being developed, writes Ulf Karlholm.

36 Technical Review No. 193 August 2011 193.36 Bonomelli, A., Descôtes, A., Moncomble, D., Preud-Homme, R.-L. Suivre la biodiversité dans le vignoble champenois. Le Vigneron Champenois 132(2), 58–69; 2011.

[French] Abstract not available for reproduction

193.37 Atkinson, J. Terroir and the Côte de Nuits. J. Wine Res. 22(1), 35–41; 2011.

Within Burgundy, qualitative differences between wines are ascribed to terroir, even though the relationships between the variables that constitute terroir are rarely articulated. The production of red Burgundy has been, and continues to be, deeply personalised, and terroir boundaries have relied upon human judgements of value and taste for their establishment; borrowing from Goethe, their existence is testament to the operation of a ‘tender empiricism’ across the centuries, rather than the pursuit of antecedently agreed criteria. Recent studies in viticulture have established how berry composition and morphology are influenced by a range of environmental factors, physical, chemical and biological and an understanding of these interactions further supports the attribution of terroir to the Grands Crus vineyards of the Côte de Nuits.

© Reprinted with permission from Atkinson, J. Terroir and the Côte de Nuits. J. Wine Res. 22(1), 35–41; 2011. Copyright 2011 Routledge.

193.38 Mulville, K. Increasing vineyard profits and sustainability. Aust. N.Z. Grapegrower Winemaker 568, 22–26; 2011.

In an era of declining resources, US-based vineyard consultant Kelly Mulville writes of his experience to develop viticulture methods that eliminate the need for mechanical or hand cultivation, mowing, tillage and suckering while simultaneously improving soil health (sequestering carbon), increasing biodiversity and reducing irrigation needs.

© Reprinted with permission from Mulville, K. Increasing vineyard profits and sustainability. Aust. N.Z. Grapegrower Winemaker 568, 22–26; 2011. Copyright 2011 Winetitles Pty Ltd.

193.39 Smart, R. The potential for growth of the Tasmanian wine sector. Wine Viti. J. 26(2), 50–54; 2011.

This article highlights some aspects of the potential for growth of the Tasmanian wine sector in the short to medium term and is based on an analysis of Tasmania’s resources.

© Reprinted with permission from Smart, R. The potential for growth of the Tasmanian wine sector. Wine Viti. J. 26(2), 50–54; 2011. Copyright 2011 Winetitles Pty Ltd.

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August 2011 Technical Review No. 193 37 L 193.40 Prather, J. Downside of green. Pract. Winery Vineyard 32(2), 71–73, 88–89; 2011.

The 2010 harvest in the United States proved challenging for growers seeking organic certification as many of the products certified couldn’t manage disease issues caused by the unusual cold and rain. The author shares the experiences of several organic growers in this article.

© Reproduced with permission from Prather, J. Downside of green. Pract. Winery Vineyard 32(2), 71–73, 88–89; 2011. Copyright 2011 Practical Winery and Vineyard Incorporated.

193.41 Keller, M. In search of uniformity: why grape quality varies. Pract. Winery Vineyard 32(2), 62–66; 2011.

TheScience of Grapevines is a new 400-page book that comprehensively explores the physiology of the grapevine as it occurs around the world. It focuses on the whole plant rather than at the cellular and organ levels, providing an understanding of whole-plant function. Comprehensive coverage of the role of water relations and temperature prepares the reader for changing climate impacts. Worldwide information on grapes and grape-related industries provides important insights into implications of differences – and similarities. The truly unique approach of this book is the scientifically-grounded exploration, often applying discoveries in other plant species, of the main physiological processes underlying grapevine form and function, their interactions, developmental and environmental control, and their implications for practical vineyard management. The article is an excerpt from Chapter 6, Developmental Physiology.

© Reprinted with permission from Keller, M. In search of uniformity: why grape quality varies. Pract. Winery Vineyard 32(2), 62–66; 2011. Copyright 2011 Practical Winery and Vineyard Incorporated.

193.42 Hoffman, M., Lubell, M., Hillis, V. Defining sustainable viticulture from the practitioner perspective. Pract. Winery Vineyard 32(2), 74–89; 2011.

The findings presented in this paper come from a series of studies that analyzed definitions of sustainable agriculture from two categories of viticulture practitioners: outreach professionals and winegrape growers. Outreach professionals provide management advice to growers and include pest control advisers, extension agents, university researchers, viticulture consultants, producer group staff, and sustainability program staff.

© Reprinted with permission from Hoffman, M., Lubell, M., Hillis, V. Defining sustainable viticulture from the practitioner perspective. Pract. Winery Vineyard 32(2), 74–89; 2011. Copyright 2011 Practical Winery and Vineyard Incorporated.

38 Technical Review No. 193 August 2011 193.42 Barwick, J. Mothball mistake? Aust. N.Z. Grapegrower Winemaker 566, 40–42; 2011.

The spread and subsequent cost of disease in vineyards has been devastating this season. As vintage arrives and harvest losses are realised many growers fear abandoned and mothballed vineyards have only added to the disease pressures. In this article, the author speaks with Riverland-based consultant Peter Magarey who says his research shows the spread of disease from abandoned vineyards is not as widespread as many growers believe.

© Reprinted with permission from Barwick, J. Mothball mistake? Aust. N.Z. Grapegrower Winemaker 566, 40–42; 2011. Copyright 2011 Winetitles Pty Ltd.

Physiology and biotechnology

193.44 Stafne, E.T., Puckette, J.A. Aerial root formation on winegrape cultivars after spring 2007 freeze events. Am. J. Enol. Vitic. 62(1), 118–121; 2011.

Post-budbreak freeze events on 7–8 Apr 2007 were followed by the development of aerial roots on winegrapes later in the spring and continuing through the summer months. Rainfall and relative humidity were much higher than average during the months of May, June, and July following the freeze events. Aerial rooting of grapes has not been previously reported in Oklahoma; therefore, quantitative counts of aerial rooting were performed to determine if there was a relationship between aerial root formation and subsequent vine productivity. Aerial root production varied by scion cultivar and the effect of rootstock was unclear. Only Petit Verdot produced significantly more roots on a rootstock than not. It appears that the formation of aerial roots on grapevines in situ is a complex interaction of freeze injury and subsequent environmental conditions to produce roots. Aerial rooting was likely a sign of injury, but the number of aerial roots produced did not necessarily represent the degree of injury. Few or no roots may be produced when injury or damage is slight, more with moderate injury or damage, and few again when significant injury or damage is sustained.

© Reprinted with permission from Stafne, E.T., Puckette, J.A. Aerial root formation on winegrape cultivars after spring 2007 freeze events. Am. J. Enol. Vitic. 62(1), 118–121; 2011. Copyright 2011 American Society for Enology and Viticulture.

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August 2011 Technical Review No. 193 39 L 193.45 Muganu, M., Bellincontro, A., Barnaba, F.E., Paolocci, M., Bignami, C., Gambellini, G., Mencarelli, F. Influence of bunch position in the canopy on berry epicuticular wax during ripening and on weight loss during postharvest dehydration. Am. J. Enol. Vitic. 62(1), 91–98; 2011.

Passito wine, made with dehydrated grapes, is widespread in Italy. The quality of the grapes to be withered is strongly influenced by qualitative factors and the anatomy and morphology of the berry, which in turn, are affected by vineyard management and microclimate. In Trebbiano Toscano and Rossetto vines grown in the Latium region, the epicuticular wax of berries from bunches developed in intracanopy and extracanopy positions was analyzed from preveraison to preharvest during the 2007 and 2008 growing seasons. At harvest, the characteristics of cuticle and epidermis of each sample were examined using light and electron microscopy. The berries were then dehydrated at 20°C to 45% moisture to evaluate differences in water loss rate and the mechanical characteristics of the skin. The amount of epicuticular wax decreased during berry development. SEM observations of the berry skin at harvest showed differences in the structure of the epicuticular wax layers, with a wider berry surface covered with plate-like wax in extracanopy berries. The number of cell layers and the thickness of the berry skin were significantly different between cultivars and canopy positions, but these factors did not affect cuticle thickness. Shaded berries of both varieties dehydrated more slowly, particularly in vigorous Trebbiano toscano vines, in which intracanopy berries reached 40% weight loss later than the extracanopy berries. During dehydration, the berry skin color (hue angle) decreased and berries of both varieties increased skin resistance to puncturing; this was not affected by the position of the berry in the canopy.

© Reprinted with permission from Muganu, M., Bellincontro, A., Barnaba, F.E., Paolocci, M., Bignami, C., Gambellini, G., Mencarelli, F. Influence of bunch position in the canopy on berry epicuticular wax during ripening and on weight loss during postharvest dehydration. Am. J. Enol. Vitic. 62(1), 91–98; 2011. Copyright 2011 American Society for Enology and Viticulture.

193.46 Barwick, J. Carbohydrate reserves to help predict yields. Aust. N.Z. Grapegrower Winemaker 566, 28–29; 2011.

Research at the National Wine and Grape Industry Centre into the carbohydrate storing capacity of grapevines could offer a ‘crystal ball’ for growers eager to predict crop yields and quality.

© Reprinted with permission from Barwick, J. Carbohydrate reserves to help predict yields. Aust. N.Z. Grapegrower Winemaker 566, 28–29; 2011. Copyright 2011 Winetitles Pty Ltd.

40 Technical Review No. 193 August 2011 193.47 Edwards, E.J., Downie, A.F., Clingeleffer, P.R. A simple microplate assay to quantify nonstructural carbohydrates of grapevine tissues. Am. J. Enol. Vitic. 62(1), 133–137; 2011.

Knowledge of total nonstructural carbohydrates in plant material is useful for understanding the effects of environmental conditions and vineyard management decisions on grapevine physiology. While many techniques are described in the literature, varying in degree of sophistication, few have been validated in grapevines. We describe the miniaturization of a simple extraction method and microplate based colorimetric assay for the measurement of nonstructural carbohydrates in a range of grapevine tissues. The method provides quantitative results for soluble carbohydrates and starch in samples containing as low as 20 μg carbohydrate.

© Reprinted with permission from Edwards, E.J., Downie, A.F., Clingeleffer, P.R. A simple microplate assay to quantify nonstructural carbohydrates of grapevine tissues. Am. J. Enol. Vitic. 62(1), 133–137; 2011. Copyright 2011 American Society for Enology and Viticulture.

193.48 Muñoz-Rodríguez, A.F., Tormo, R., Silva, M.I. Pollination dynamics in Vitis vinifera L. Am. J. Enol. Vitic. 62(1), 113–117; 2011.

Vitis vinifera pollen dispersal was studied using volumetric air samplers situated within a vineyard to measure airborne pollen concentration. The pollen dispersal period of Cabernet Sauvignon was seven days, reaching daily mean concentrations of about 90 grains/m3, with peak pollen dispersal near midday. Daily and hourly variations in concentration were positively correlated with temperature but negatively with relative humidity. Concentration was greatest within 1.5 m of the plants and up to 1 m aboveground, after which it diminished.

© Reprinted with permission from Muñoz-Rodríguez, A.F., Tormo, R., Silva, M.I. Pollination dynamics in Vitis vinifera L. Am. J. Enol. Vitic. 62(1), 113–117; 2011. Copyright 2011 American Society for Enology and Viticulture.

193.49 Fang, Y., Meng, J., Zhang, A., Liu, J., Xu, T., Yu, W., Chen, S., Li, H., Zhang, Z., Wang, H. Influence of shriveling on berry composition and antioxidant activity of Cabernet Sauvignon grapes from Shanxi vineyards. J. Sci. Food Agric. 91(4), 749–757; 2011.

Background: Berry shrivel (BS), a berry development disorder, appears soon after veraison. It occurs worldwide and affects the quality of grape berries and wine. However, it had not been reported in China until recently. This study aimed to investigate the changes in berry composition and antioxidant activity of Cabernet Sauvignon grapes from Xiangning Valley, Shanxi Province, China, during BS. Results: Shrinkage contributed to an increase in the concentration of basic grape ingredients such as sugar and acid. An appropriate degree of shrinkage was apparently helpful in improving the phenolic content and increasing the antioxidant activity, but the berries that continued to shrivel showed a low antioxidant activity. Further, the results indicated distinct differences between the berries harvested from the southern side of the canopy and those harvested from the northern side, presumably due to variations in sunlight exposure. Conclusion: Moderate C

August 2011 Technical Review No. 193 41 L BS was beneficial since it increased berry quality and antioxidant activity of Cabernet Sauvignon grapes from Shanxi vineyards.

© Reprinted with permission from Fang, Y., Meng, J., Zhang, A., Liu, J., Xu, T., Yu, W., Chen, S., Li, H., Zhang, Z., Wang, H. Influence of shriveling on berry composition and antioxidant activity of Cabernet Sauvignon grapes from Shanxi vineyards. J. Sci. Food Agric. 91(4), 749–757; 2011. Copyright 2011 Society of Chemical Industry.

193.50 Wu, B.-H., Liu, H.-F., Guan, L., Fan, P.-G., Li, S.-H. Carbohydrate metabolism in grape cultivars that differ in sucrose accumulation. Vitis 50(2), 51–57; 2011.

Sugar concentrations and sucrose-metabolism related enzyme activities in berries and leaves were investigated during berry development using grape cultivars with different sucrose concentrations. Sucrose concentration was significantly negatively related to acid invertase activity in berries. Acid invertase showed the lowest activities in berries of high-sucrose cultivars, ‘Honey Juice` and ‘B180’, and the highest in trace-sucrose cultivars, ‘Concord’, ‘Jingxiu’, and ‘Jingya’. Acid invertase activities in berries of low-sucrose cultivar ‘Canadice’ were between high- and trace-sucrose cultivars. There was no significant difference in glucose and fructose concentrations, the activities of neutral invertase, sucrose synthase and sucrose phosphate synthase in berries among high-, low- and trace-sucrose cultivars as acid invertase. Sugar concentrations and sucrose-metabolism related enzymes activities in leaves also did not show such difference among all cultivars. The results suggest that differences in sucrose concentration in berries among grape cultivars mainly be due to acid invertase activity. In addition, the final sucrose concentration in berries at maturity for a grape cultivar might be decided at véraison, and véraison is the key period for sucrose accumulation.

© Reprinted with permission from Wu, B.-H., Liu, H.-F., Guan, L., Fan, P.-G., Li, S.-H. Carbohydrate metabolism in grape cultivars that differ in sucrose accumulation. Vitis 50(2), 51–57; 2011. Copyright 2011 Institut für Rebenzüchtung Geilweilerhof der Bundesanstalt für Züchtungsforschung an Kulturpflanzen.

Climate and soils

193.51 Reynolds, A.G. Studying water and soil effects. Wines Vines 92(3), 46–50; 2011.

Twenty years ago winegrowing focused more on ways of manipulating grapevines, while today the emphasis is on understanding the grapevine ecosystem and the many interactions between soil, site climate, vine physiology and cultural practices. For this reason the author has chosen terroir as a theme for this column.

© Reprinted with permission from Reynolds, A.G. Studying water and soil effects. Wines Vines 92(3), 46–50; 2011. Copyright 2011 The Hiaring Company.

42 Technical Review No. 193 August 2011 Vineyard management systems

193.52 Rieger, T. Mechanized canopy management. Vineyard Winery Manage. 37(2), 38–43; 2011.

Mechanized canopy management can improve yields and grape quality in vineyards that have declined due to excess vegetative growth and inadequate canopy management. When used in combination with reduced deficit irrigation, it can improve grape quality and save water. Equipment and tools are available for mechanized pruning, shoot thinning and leaf removal in both sprawl and vertical shoot positioning (VSP) trellis systems. Mechanized pruning and canopy management can save growers significant labor costs.

© Reprinted with permission from Rieger, T. Mechanized canopy management. Vineyard Winery Manage. 37(2), 38–43; 2011. Copyright 2011 Vineyard and Winery Services, Inc.

193.53 Filippetti, I., Allegro, G., Valentini, G., Pastore, C., Poni, S., Intrieri, C. Effects of mechanical pre-bloom defoliation on cordon de Royat pruned Sangiovese (Vitis vinifera L.) vines. J. Int. Sci. Vigne Vin 45(1), 19–25; 2011.

Abstract available online at http://www.jisvv.com/sommaire_dernier_numero.php?id=446

193.54 Needs, S. Managing a severe frost event. Aust. N.Z. Grapegrower Winemaker 568, 40–42; 2011.

In October 2006, a major frost event across Victoria’s wine regions caused an estimated loss of grapes valued at $140m. It also fostered new research to look at minimising the effects of such weather events. One recent study has found the type of canopy management growers impose after a frost event can reduce its severity and effects at harvest.

© Reprinted with permission from Needs, S. Managing a severe frost event. Aust. N.Z. Grapegrower Winemaker 568, 40–42; 2011. Copyright 2011 Winetitles Pty Ltd.

193.55 Kurtural, S.K. Integrating canopy management with mechanization. Pract. Winery Vineyard 32(2), 17–25; 2011.

To help growers in the San Joaquin Valley, a four-year trial (2010 through 2013) was established to determine the effects of mechanical canopy management (dormant pruning, shoot thinning, and leaf removal) on vine production. The study will monitor canopy microclimate, cluster architecture, yield components, and ripening in Pinot Grigio and Syrah vineyards. Results from this study will expand knowledge about growing Pinot Grigio and Syrah, provide information for growers on mechanical canopy management methods, and identify any potential problems for vine health associated with the new mechanized canopy management practices.

© Reprinted with permission from Kurtural, S.K. Integrating canopy management with mechanization. Pract. C Winery Vineyard 32(2), 17–25; 2011. Copyright 2011 Practical Winery and Vineyard Incorporated.

August 2011 Technical Review No. 193 43 L 193.56 Arbuckle, K. Electric pruners have growers talking. Aust. N.Z. Grapegrower Winemaker 568, 38–39; 2011.

French power-tool company Infaco is turning heads with its innovative F3010 electric pruner and its latest development is sure to get growers talking.

© Reprinted with permission from Arbuckle, K. Electric pruners have growers talking. Aust. N.Z. Grapegrower Winemaker 568, 38–39; 2011. Copyright 2011 Winetitles Pty Ltd.

193.57 Daniel, L. Grapegrower interview: Hank Ashby. Wines Vines 92(3), 24–29; 2011.

In this article, Paso Robles grapegrower, Hank Ashby, shares his experience with vineyard mechanisation including his thoughts on the Morris-Oldridge system of mechanising vineyard production.

© Reproduced with permission from Daniel, L. Grapegrower interview: Hank Ashby. Wines Vines 92(3), 24–29; 2011. Copyright 2011 The Hiaring Company.

Pests and diseases

193.58 Wunderlich, N., Ash, G.J., Steel, C.C., Raman, H., Savocchia, S. Association of Botryosphaeriaceae grapevine trunk disease fungi with the reproductive structures of Vitis vinifera. Vitis 50(2), 89–96; 2011.

Several species belonging to the Botryosphaeriaceae were isolated from grapevine (Vitis vinifera) tissue other than wood during a survey of two vineyards planted to cultivars ‘Chardonnay’ and ‘Shiraz’ in the Hunter Valley, New South Wales, Australia over the 2007/08 and 2008/09 growing seasons. A total of 188 isolates corresponding to nine different species Diplodia, Dothiorella and Neofusicoccum anamorphs were isolated from dormant buds, flowers, pea-sized berries and mature berries prior to harvest in addition to 142 isolates from the trunks of the same vines. Furthermore, the occurrence of Dothiorella viticola, Diplodia mutila and Neofusicoccum australe is reported here for the first time from grapevines in the Hunter Valley. These findings may provide important information for the management and spread of Botryosphaeriaceae in vineyards where they are considered serious wood-invading pathogens. Botryosphaeriaceae are occasionally found on bunches, however, until now they have not directly been related to bunch rots. Control strategies for trunk diseases caused by Botryosphaeriaceae are currently limited to remedial surgery and wound protection. These strategies do not consider other grapevine tissue as potential inoculum sources for infection of Botryosphaeriaceae in the vineyard.

© Reprinted with permission from Wunderlich, N., Ash, G.J., Steel, C.C., Raman, H., Savocchia, S. Association of Botryosphaeriaceae grapevine trunk disease fungi with the reproductive structures of Vitis vinifera. Vitis 50(2), 89–96; 2011. Copyright 2011 Institut für Rebenzüchtung Geilweilerhof der Bundesanstalt für Züchtungsforschung an Kulturpflanzen.

44 Technical Review No. 193 August 2011 193.59 Austin, C.N., Grove, G.G., Meyers, J.M., Wilcox, W.F. Powdery mildew severity as a function of canopy density: associated impacts on sunlight penetration and spray coverage. Am. J. Enol. Vitic. 62(1), 23–31; 2011.

Variable canopy densities and associated differences in sunlight distribution within the fruit zones on clusters were quantified and correlated with variable severities of powdery mildew within vineyards in the states of New York, Washington, and South Australia. Canopy density was measured with enhanced point quadrat analysis (EPQA), and the number of shading layers and the photon flux within the fruit zone of individual vines indicated that less disease developed on clusters with more exposure to sunlight. When clusters were categorized as heavily shaded (≤10% photosynthetic photon flux), moderately exposed, or well exposed (≥51% photosynthetic photon flux), vines with the least disease were also shown to have a significantly greater proportion of clusters in the well-exposed category relative to vines with the highest powdery mildew ratings. Consequently, these latter vines had significantly more heavily shaded clusters. The correlation remained strong and the relationship linear even with biweekly applications of either 2 kg/ha or 9 kg/ha of wettable sulfur during the growing season. Additionally, through the use of a fluorescent tracer and EPQA assessments, the deposit of spray materials on clusters was shown to be linearly related to their degree of exposure. Thus, canopy management practices designed to optimize sunlight exposure of grape clusters for fruit quality purposes should also significantly assist in the management of powdery mildew.

© Reprinted with permission from Austin, C.N., Grove, G.G., Meyers, J.M., Wilcox, W.F. Powdery mildew severity as a function of canopy density: associated impacts on sunlight penetration and spray coverage. Am. J. Enol. Vitic. 62(1), 23–31; 2011. Copyright 2011 American Society for Enology and Viticulture.

193.60 Molitor, D., Rothmeier, M., Behr, M., Fischer, S., Hoffmann, L., Evers, D. Crop cultural and chemical methods to control grey mould on grapes. Vitis 50(2), 81–87; 2011.

The efficiency of crop cultural (leaf removal) as well as of chemical methods (plant growth regulator, botryticide) to control grey mould caused by Botrytis cinerea was investigated in two seasons (2008 and 2009) on the varieties ‘Pinot blanc’ and ‘Pinot Gris’ in the Moselle valley (Luxembourg). The application of the plant growth regulator Regalis® (a.i. prohexadione-Ca) led to a considerably more flexible cluster structure and a slight decrease of grey mould disease severity. The reduction of bunch rot infestation was of the same level than obtained by a single application of a botryticide (a.i. fenhexamid) before berries touching. Leaf removal reduced the cluster density slightly and proved to be more efficient againstB. cinerea than the chemical treatments (reduction of grey mould disease severity of 57% on average). Thus, leaf removal in the cluster-zone shortly after bloom can be recommended as an important tool in integrated as well as in organic bunch rot protection strategies. The best loosening effect on the cluster structure as well as the best B. cinerea reduction efficiency (75% on average) was achieved when combining leaf removal and Regalis® application. The combination of leaf removal and botryticide application showed comparable results. Simulation of the B. cinerea epidemiology demonstrated that all treatments tested might allow for a longer maturation time due to lower infestation. The longest potential harvest delay C

August 2011 Technical Review No. 193 45 L until reaching an assumed threshold of 5% disease severity was achieved by combining leaf removal and application of Regalis® or a botryticide (on average 11.6 or 9.9 days, respectively). The here presented strategies can thus be recommended to maximize wine quality in two ways – through a reduction of fungal contamination and/or an improvement of grape maturity.

© Reprinted with permission from Molitor, D., Rothmeier, M., Behr, M., Fischer, S., Hoffmann, L., Evers, D. Crop cultural and chemical methods to control grey mould on grapes. Vitis 50(2), 81–87; 2011. Copyright 2011 Institut für Rebenzüchtung Geilweilerhof der Bundesanstalt für Züchtungsforschung an Kulturpflanzen.

193.61 Düker, A., Kubiak, R. Stem injection of triazoles for the protection of Vitis vinifera L. (‘Riesling’) against powdery mildew (Uncinula necator). Vitis 50(2), 73–79; 2011.

The aim of this study was to find suitable substances to control powdery mildew by means of stem injection. The triazoles myclobutanil, penconazol and tebuconazol were used as test substances. In the first experiment, single xylem injections of these triazoles were carried out to test their effect against powdery mildew. The injections were carried out on field-grown grapevines using the ChemJet® tree injector. Applications invariably yielded efficiency factors of over 60%. A practice-oriented effect on leaves and grapes was most notably gained using tebuconazol. In the second experiment, the repeated xylem injection of myclobutanil, penconazol and tebuconazol was carried out on field-grown grapevines with a prototypal stationary injection system to evaluate the longer-term effects. Grapevines sprayed with formulated myclobutanil (Systhane 20 EW®), penconazol (Topas®) and tebuconazol (Folicur 250 EW®) enable the methods to be compared. Applications using the prototypal stationary injection system only yielded moderate efficiency factors. A practice-oriented effect was gained using the sprayed application. Future options for stem injection, such as combating wood-destroying fungi and phytoplasmosis, were discussed.

© Reprinted with permission from Düker, A., Kubiak, R. Stem injection of triazoles for the protection of Vitis vinifera L. (‘Riesling’) against powdery mildew (Uncinula necator). Vitis 50(2), 73–79; 2011. Copyright 2011 Institut für Rebenzüchtung Geilweilerhof der Bundesanstalt für Züchtungsforschung an Kulturpflanzen.

193.62 Walker, G., Cox, C. Resistance of rootstocks depends on the vineyard populations of root- knot nematode. Aust. N.Z. Grapegrower Winemaker 566, 37–39; 2011.

The resistance of seven commonly used rootstocks to root-knot nematodes in three vineyard soils varied greatly according to the population of nematode present. One soil used, from Winkie, contained an aggressive population of M. arenaria, a species particularly known for developing such populations.

© Reprinted with permission from Walker, G., Cox, C. Resistance of rootstocks depends on the vineyard populations of root-knot nematode. Aust. N.Z. Grapegrower Winemaker 566, 37–39; 2011. Copyright 2011 Winetitles Pty Ltd.

46 Technical Review No. 193 August 2011 193.63 Wilcox, W.F., Austin, C.N. New fungicides fight mildew. Wines Vines 92(4), 47–50; 2011.

Disease management in vineyards, especially in the humid and often wet climates found in the East, requires that grapegrowers integrate both chemical and non-chemical approaches. This article, part two of two for Wine East, reviews some of the new fungicides now available to help growers control both powdery and downy mildew.

© Reprinted with permission from Wilcox, W.F., Austin, C.N. New fungicides fight mildew. Wines Vines 92(4), 47–50; 2011. Copyright 2011 The Hiaring Company.

193.64 Steel, C.C., Greer, L.A., Savocchia, S., Samuelian, S.K. Effect of temperature on Botrytis cinerea, Colletotrichum acutatum and Greeneria uvicola mixed fungal infection of Vitis vinifera grape berries. Vitis 50(2), 69–71; 2011.

Detached Vitis vinifera ‘Cabernet Sauvignon’ berries (12.5°Be) were inoculated either singularly or in combination with spore suspensions of Botrytis cinerea, Colletotrichum acutatum and Greeneria uvicola and the degree of disease expression examined at either 20 or 27°C. Berries were more susceptible to B. cinerea at 20°C and to G. uvicola at 27°C but were highly susceptible to C. acutatum at either temperature. In experiments involving inoculation of berries with mixtures of fungal organisms, B. cinerea infection was diminished at 27°C by either C. acutatum or G. uvicola but only by C. acutatum at 20°C. G. uvicola infection was diminished by C. acutatum at both temperatures investigated. B. cinerea reduced the level of infection of both C. acutatum and G. uvicola at 20°C. The findings have implications for seasonal bunch rot management of grapes in relation to predicted changes in global temperature.

© Reprinted with permission from Steel, C.C., Greer, L.A., Savocchia, S., Samuelian, S.K. Effect of temperature on Botrytis cinerea, Colletotrichum acutatum and Greeneria uvicola mixed fungal infection of Vitis vinifera grape berries. Vitis 50(2), 69–71; 2011. Copyright 2011 Institut für Rebenzüchtung Geilweilerhof der Bundesanstalt für Züchtungsforschung an Kulturpflanzen.

193.65 Wilcox, W.F., Austin, C.N. Sunlight enhances fungal disease control. Wines Vines 92(3), 51–55; 2011.

Unlike the general public, grapegrowers know that disease management does not involve a choice between ‘chemical’ and ‘non-chemical’ approaches, but rather an informed integration of those components to fit each individual’s needs and philosophies. This article’s focus is the new information pertaining to a non-chemical tool for the vineyard, specifically the dramatic effect that sunlight has reducing powdery mildew development—and its implications with respect to disease management. A subsequent article will review some of the new fungicides now available to help growers control both powdery mildew and downy mildew.

© Reprinted with permission from Wilcox, W.F., Austin, C.N. Sunlight enhances fungal disease control. Wines Vines 92(3), 51–55; 2011. Copyright 2011 The Hiaring Company. C

August 2011 Technical Review No. 193 47 L 193.66 Mahaffee, W., Grove, G., Stoll, R. Inoculum detection to manage grape powdery mildew. Pract. Winery Vineyard 32(2), 26–32; 2011.

Grape powdery mildew (caused by Erysiphe necator) often develops explosively and can result in significant yield and quality losses, despite your best efforts. The threat of quality losses often leads to a low risk prophylactic regimen rather than a higher risk IPM approach. The authors have come to realize that you do not always have to spray when you think you do. E. necator inoculum was demonstrated to not always be present in a vineyard, and methods were developed to determine when it is present. These methods were then shown to be effective for initiating fungicide applications when E. necator is detected in the vineyard air. The applications resulted in 2.4 fewer fungicide applications without reducing disease control.

© Reprinted with permission from Mahaffee, W., Grove, G., Stoll, R. Inoculum detection to manage grape powdery mildew. Pract. Winery Vineyard 32(2), 26–32; 2011. Copyright 2011 Practical Winery and Vineyard Incorporated.

193.67 Corradi, C. Irroratrici a recupero prodotto ammortamento e convenienza. Vignevini 37(12), 30–35; 2010.

[Italian] Abstract not available for reproduction

© Reprinted with permission from Corradi, C. Irroratrici a recupero prodotto ammortamento e convenienza. Vignevini 37(12), 30–35; 2010. Copyright 2010 Il sole 24 ORE Edagricole Srl..

193.68 Pienne, P., Vacavant, M.-P., Panigai, L. Le suivi biologique du mildiou. Le Vigneron Champenois 123(3), 46–49; 2011.

Abstract not available for reproduction

Vine improvement and varieties

193.69 Gagliardi, A. Barbera and Nebbiolo, selection continues. Vignevini 37(12), 36–42; 2010.

[Italian] Researchers at the National Research Council’s Plant Virology Institute in Grugliasco, Turin Province, Italy continue on their work Barbera and Nebbiolo selction. This has meant upgrading tools for virus indexing of plants, including the use of bio-molecular techniques like Polymerase Chain Reaction for precision detection of a greater range of virus-causing agents. It’s vitally important that plant material destined for the market is disease-free, and tests are being run now on mother plants in vineyards. A frequent part of the selection process includes heat treatment of viruses to ensure better clone quality.

© Reproduced with permission from Gagliardi, A. Barbera and Nebbiolo, selection continues. Vignevini 37(12), 36–42; 2010. Copyright 2010 Il sole 24 ORE Edagricole Srl..

48 Technical Review No. 193 August 2011 193.70 Zavaglia, C.G., Pecile, M. Developments in Italy’s ampelographic registry. Vignevini 37(12), 28–34; 2010.

[Italian] This article provides an overview of recent revisions to Italy’s ampelographic registry.

© Reprinted with permission from Zavaglia, C.G., Pecile, M. Developments in Italy’s ampelographic registry. Vignevini 37(12), 28–34; 2010. Copyright 2010 Il sole 24 ORE Edagricole Srl..

193.71 Storchi, P., Armanni, A., Randellini, L., Giannetto, S., Meneghetti, S., Crespan, M. Investigations on the identity of ‘Canaiolo bianco’ and other white grape varieties of central Italy. Vitis 50(2), 59–64; 2011.

During research for the rescue and description of grapevine germplasm in central Italy, 28 white accessions were collected, 10 of them sharing the name ‘Canaiolo bianco’ but having different morphological and yield characteristics. ‘Canaiolo bianco’ is listed as essential in the specifications for some D.O.C.G. and D.O.C. Tuscan wines, but its correct identity is not clear. With the aim to identify and characterize our samples and to pinpoint what the true-to-type ‘Canaiolo bianco’ is, we described these accessions using a multidisciplinary approach, encompassing DNA analysis, ampelographic, phyllometric, phenological and yield descriptions. Moreover we collected as much historical information as possible about them. The 28 accessions investigated were grouped in 8 varieties with very distinct traits. The research has provided useful information for clarifying various cases of synonymy and homonymy. Moreover, we hypothesize that the true to type ‘Canaiolo bianco’ corresponds to the so called ‘Drupeggio’.

© Reprinted with permission from Storchi, P., Armanni, A., Randellini, L., Giannetto, S., Meneghetti, S., Crespan, M. Investigations on the identity of ‘Canaiolo bianco’ and other white grape varieties of central Italy. Vitis 50(2), 59–64; 2011. Copyright 2011 Institut für Rebenzüchtung Geilweilerhof der Bundesanstalt für Züchtungsforschung an Kulturpflanzen.

193.72 Montaldo, G. Un vivaismo più integrato nella filiera. Vignevini 37(12), 44–48; 2010.

[Italian] Abstract not available for reproduction

© Reprinted with permission from Montaldo, G. Un vivaismo più integrato nella filiera. Vignevini 37(12), 44–48; 2010. Copyright 2010 Il sole 24 ORE Edagricole Srl..

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August 2011 Technical Review No. 193 49 L 193.73 Smith, M. Busy year ahead for Tasmanian Pinot researchers. Wine Viti. J. 26(2), 55–57; 2011.

As part of this issue’s focus on Pinot Noir, Mark Smith provides a progress report on the work being carried by researchers in Tasmania into the variety, discovering 2011 will possibly be their busiest year yet.

© Reprinted with permission from Smith, M. Busy year ahead for Tasmanian Pinot researchers. Wine Viti. J. 26(2), 55–57; 2011. Copyright 2011 Winetitles Pty Ltd.

193.74 Lacombe, T., Audeguin, L., Boselli, M., et al. Grapevine European challenge: towards a comprehensive list. Vitis 50(2), 65–68; 2011.

Starting from the 1950s, different European countries have established official lists of grapevine varieties authorized to be cultivated. The objectives of such lists were to limit ambiguous denomination of varieties and the related trade conflicts, as well as the implementation of viticulture recovery politics through the support of certain varieties and the limitation of others. In the same direction, in 1968 the European Union (EU) decided to create a ‘common catalogue of varieties’, defined as the sum of current national catalogues (Council Directive of 9 April 1968 ‘on the marketing of material for the vegetative propagation of the vine’, 68/193/EEC, modified). These catalogues (also called ‘registers’) include all the wine varieties ‘classified’ by each Member State within the framework of the Common Organisation of the Market in wine (Council Directive No 479/2008), as well as all the non-classified varieties (table grape, rootstocks, etc.). For this work, we took the opportunity of the European research program ‘GrapeGen06’, focused on the study and the preservation of grapevine genetic resources, to contribute to the establishment and improvement of such an European catalogue. The comprehensive survey aims at two objectives: to support the implementation of European regulations on propagation of grapevine plants within the EU, and to assess priority actions, by technical and research institutes, for the conservation of grapevine genetic resources.

© Reprinted with permission from Lacombe, T., Audeguin, L., Boselli, M., et al. Grapevine European challenge: towards a comprehensive list. Vitis 50(2), 65–68; 2011. Copyright 2011 Institut für Rebenzüchtung Geilweilerhof der Bundesanstalt für Züchtungsforschung an Kulturpflanzen.

193.75 Gastin, D. Home-grown wine grape varieties go back a long way in Asia. Winestate 34(3), 40–43; 2011.

Abstract not available for reproduction

50 Technical Review No. 193 August 2011 193.76 Jacobs, L. Gruner Veltliner finds a new home in the Adelaide Hills. Wine Viti. J. 26(2), 58–60; 2011.

A clutch of local wineries growing the emerging white grape Gruner Veltliner in the Adelaide Hills have formed a collaborative project aimed at establishing the region as Australia’s pre-eminent region for the variety. The project is a joint initiative between Adelaide Hills Vine Improvement Inc. and Hahndorf Hill Winery, which produced South Australia’s first Gruner Veltliner wine in 2010.

© Reprinted with permission from Jacobs, L. Gruner Veltliner finds a new home in the Adelaide Hills. Wine Viti. J. 26(2), 58–60; 2011. Copyright 2011 Winetitles Pty Ltd.

193.77 Crespan, M. Exploration and evaluation of grapevine biodiversity using molecular markers. Mitt. Klosterneuburg Rebe Wein 60(3), 310–315; 2010.

Abstract not available for reproduction

193.78 Pejić, I., Maletić, E. Conservation, evaluation and revitalization of native grapevine varieties in Croatia. Mitt. Klosterneuburg Rebe Wein 60(3), 363–368; 2010.

Abstract not available for reproduction

Water and nutrition

193.79 Bowen, P., Bogdanoff, C., Usher, K., Estergaard, B., Watson, M. Effects of irrigation and crop load on leaf gas exchange and fruit composition in red winegrapes grown on a loamy sand. Am. J. Enol. Vitic. 62(1), 9–22; 2011.

Effects of reducing irrigation from fruit set to veraison or harvest combined with crop-load adjustment by cluster or shoot thinning were determined for Merlot and Cabernet Sauvignon grapevines cultured on a coarse loamy sand. Geographic information system tools were used to develop maps of moisture distribution in the soil profile, which revealed reductions in total moisture levels and increased spatial variation in response to reduced emitter density. Stomatal conductance and leaf gas exchange decreased in response to reduced irrigation but also declined across all treatments during the lag phase of berry development and then increased postveraison. Pruning mass was affected little by treatments in Merlot but was reduced by either shoot or cluster thinning in Cabernet Sauvignon. Berry mass and anthocyanin and tannin contents were affected little and inconsistently by irrigation and crop-load adjustment and varied mostly among years, indicating a dominant influence of seasonal climate on berry development and composition.

© Reprinted with permission from Bowen, P., Bogdanoff, C., Usher, K., Estergaard, B., Watson, M. Effects of irrigation and crop load on leaf gas exchange and fruit composition in red winegrapes grown on a loamy sand. Am. J. Enol. Vitic. 62(1), 9–22; 2011. Copyright 2011 American Society for Enology and Viticulture.

August 2011 Technical Review No. 193 51 Wine and health Epidemiology

193.80 Terry-McElrath, Y.M., O’Malley, P.M. Substance use and exercise participation among young adults: parallel trajectories in a national cohort-sequential study. Addiction doi: 10.1111/j.1360‐0443.2011.03489.x, 1–36; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1360-0443.2011.03489.x/ abstract

193.81 Shaper, A.G. Alcohol consumption decreases with the development of disease. Addiction 106(5), 1023–1025; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1360-0443.2011.03372.x/ abstract

193.82 Leonard, K.E. Commentary on Livingston (2011): alcohol outlets and domestic violence – acute effects and the social ecology of neighborhoods may both contribute to the relationship. Addiction 106(5), 926–927; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1360-0443.2011.03396.x/ abstract

193.83 Livingston, M. A longitudinal analysis of alcohol outlet density and domestic violence. Addiction 106(5), 919–925; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1360-0443.2010.03333.x/ abstract

193.84 Le Strat, Y., Gorwood, P. Hazardous drinking is associated with a lower risk of coronary heart disease: results from a national representative sample. Am. J. Addict 20(3), 257–263; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1521-0391.2011.00125.x/ abstract

193.85 Epstein, J.A. Adolescent computer use and alcohol use: what are the role of quantity and content of computer use? Addictive Behaviours 36(5), 520–522; 2011.

Abstract available online at http://www.sciencedirect.com/science/article/pii/S0306460311000025

52 Technical Review No. 193 August 2011 193.86 Koordeman, R., Anschutz, D.J., Engels, R.C.M.E. Exposure to alcohol commercials in movie theaters affects actual alcohol consumption in young adult high weekly drinkers: an experimental study. Am. J. Addict 20(3), 283–291; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1521-0391.2011.00134.x/ abstract

193.87 Mackie, C.J., Castellanos-Ryan, N., Conrod, P.J. Personality moderates the longitudinal relationship between psychological symptoms and alcohol use in adolescents. Alcohol. Clin. Exp. Res. 35(4), 703–716; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1530-0277.2010.01388.x/ abstract

193.88 Müller, S., Kuntsche, E. Do the drinking motives of adolescents mediate the link between their parents’ drinking habits and their own alcohol use? J. Stud. Alcohol Drugs 72(3), 429–437; 2011.

Abstract available online at http://www.jsad.com/jsad/article/Do_the_Drinking_Motives_of_ Adolescents_Mediate_the_Link_Between_Their_Paren/4574.html

193.89 Sloan, F., Grossman, D., Platt, A. Heavy episodic drinking in early adulthood and outcomes in midlife. J. Stud. Alcohol Drugs 72(3), 459–470; 2011.

Abstract available online at http://www.jsad.com/jsad/article/Heavy_Episodic_Drinking_in_ Early_Adulthood_and_Outcomes_in_Midlife/4578.html

193.90 Elton-Marshall, T., Leatherdale, S.T., Burkhalter, R. Tobacco, alcohol and illicit drug use among aboriginal youth living off-reserve: results from the youth smoking survey. CMAJ 183(8), 480–486; 2011.

Background: Despite the high prevalence of smoking among Aboriginal youth, there is a paucity of research related to tobacco use and other risk behaviours among Aboriginal youth living off-reserve in Canada. We used data from the national Youth Smoking Survey to characterize non-traditional tobacco use, exposure to second-hand smoke, and alcohol and drug use among Aboriginal youth living off-reserve. We examined whether these youth were at increased health risk compared with non-Aboriginal youth. Methods: We examined cigarette smoking behaviour, use of other tobacco products, use of alcohol and other drugs, and exposure to second-hand smoke among 2620 Aboriginal youth living off-reserve and 26 223 non-Aboriginal youth in grades 9 to 12 who participated in the 2008/09 Youth Smoking Survey. Results: The prevalence of current smoking among the Aboriginal youth was more than double that among non-Aboriginal youth (24.9% v. C

August 2011 Technical Review No. 193 53 L 10.4%). Aboriginal youth also had a higher prevalence of regular exposure to second-hand smoke at home (37.3% v. 19.7%) and in cars (51.0% v. 30.3%). Aboriginal youth were more likely than non-Aboriginal youth to be current smokers, to be regularly exposed to second-hand smoke, to have tried marijuana and other illicit drugs, and to engage in binge drinking. They were less likely than non-Aboriginal youth to have tried to quit smoking. Interpretation: Current national estimates of smoking, and alcohol and illicit drug use among youth underestimate the prevalence of these behaviours among Aboriginal youth living off-reserve. Our findings highlight the need for culturally appropriate prevention and cessation policies and programs for this at-risk population.

193.91 Van der Zwaluw, C.S., Kuntsche, E., Engels, R.C.M.E. Risky alcohol use in adolescence: the role of genetics (DRD2, SLC6A4) and coping motives. Alcohol. Clin. Exp. Res. 35(4), 756–764; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1530-0277.2010.01393.x/ abstract

193.92 Söderpalm Gordh, A.H.V., Söderpalm, B. Healthy subjects with a family history of alcoholism show increased stimulative subjective effects of alcohol. Alcohol. Clin. Exp. Res. 35(8), 1–9; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1530-0277.2011.01478.x/ abstract

193.93 Astudillo, M., Kuntsche, S., Graham, K., Gmel, G. The influence of drinking pattern, at individual and aggregate levels, on alcohol-related negative consequences. Eur. Addict. Res. 16(3), 115–123; 2010.

Abstract available online from http://www.karger.com/ear

193.94 Van den Eijnden, R., Mheen, D.V.D., Vet, R., Vermulst, A. Alcohol-specific parenting and adolescents’ alcohol-related problems: the interacting role of alcohol availability at home and parental rules. J. Stud. Alcohol Drugs 72(3), 408–417; 2011.

Abstract available online at http://www.jsad.com/jsad/article/AlcoholSpecific_Parenting_and_ Adolescents_AlcoholRelated_Problems_The_I/4572.html

54 Technical Review No. 193 August 2011 193.95 Tomcikova, Z., Geckova, A.M., Dijk, J.P.V., Reijneveld, S.A. Characteristics of adolescent excessive drinkers compared with consumers and abstainers. Drug Alcohol Rev. 30(2), 157–165; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1465-3362.2010.00209.x/ abstract

193.96 Tramacere, I., Negri, E., Pelucchi, C., Bagnardi, V., Rota, M., Scotti, L., Islami, F., Corrao, G., Vecchia, C.L., Boffetta, P. A meta-analysis on alcohol drinking and gastric cancer risk. Ann. Oncol. doi:10.1093/annonc/mdr135, 1–9; 2011.

Abstract available online at http://annonc.oxfordjournals.org/content/early/2011/05/02/annonc. mdr135.abstract

193.97 Dawson, D.A., Grant, B.F. The ‘gray area’ of consumption between moderate and risk drinking. J. Stud. Alcohol Drugs 72(3), 453–458; 2011.

Abstract available online at http://www.jsad.com/jsad/article/The_Gray_Area_of_Consumption_ Between_Moderate_and_Risk_Drinking/4577.html

193.98 Kelly, A.B., Toumbourou, J.W., O’Flaherty, M., Patton, G.C., Homel, R., Connor, J.P., Williams, J. Family relationship quality and early alcohol use: evidence for gender-specific risk processes. J. Stud. Alcohol Drugs 72(3), 399–407; 2011.

Abstract available online at http://www.jsad.com/jsad/article/Family_Relationship_Quality_and_ Early_Alcohol_Use_Evidence_for_GenderSpec/4571.html

193.99 Hiramine, Y., Imamura, Y., Uto, H., Koriyama, C., Horiuchi, M., et al. Alcohol drinking patterns and the risk of fatty liver in Japanese men. J. Gastroenterol. 46(4), 519–528; 2011.

Abstract available online at http://www.springerlink.com/content/0944-1174/46/4/

193.100 Anon. 2010 Partnership Attitude Tracking Study 6 April 2011, 1–21; 2011.

Full paper available for download from http://www.drugfree.org/wp-content/uploads/2011/04/ FULL-REPORT-FINAL-PATS-Teens-and-Parent-April-6-2011-1.pdf

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August 2011 Technical Review No. 193 55 L 193.101 Substance Abuse and Mental Health Services Administration Alcohol dependence is more likely among adults with mental illness than adults without mental illness. NSDUH Report 31 May 2011, 1–1; 2011.

Alcohol dependence is 4 times as likely to occur among adults with mental illness than adults with no mental illness (9.6 percent vs. 2.2 percent). Furthermore, the rate of alcohol dependence increases as the severity of mental illness increases. Providers working with individuals with either a substance use or a mental health problem may want to consider screening for a co-occurring disorder and providing an integrated treatment program.

© Reprinted with permission from Substance Abuse and Mental Health Services Administration Alcohol dependence is more likely among adults with mental illness than adults without mental illness. NSDUH Report 31 May 2011, 1–1; 2011. Copyright 2011 Substance Abuse and Mental Health Services Administration.

193.102 Siegel, M., Diloreto, J., Johnson, A., Fortunato, E.K., Dejong, W. Development and pilot testing of an internet-based survey instrument to measure the alcohol brand preferences of U.S. youth. Alcohol. Clin. Exp. Res. 35(4), 765–772; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1530-0277.2010.01394.x/ abstract

193.103 Zimmermann, J., Junge, C., Niemann, J., Wong, J.W.M., Preuss, U.W. Alcohol consumption and expectations of its effects in the border region of Pomerania: comparison of German and Polish adolescents. Eur. Addict. Res. 16(3), 170–178; 2010.

Abstract available online from http://www.karger.com/ear

Human clinical

193.104 Montgomery, C., Ashmore, K.V., Jansari, A. The effects of a modest dose of alcohol on executive functioning and prospective memory. Hum. Psychopharmacol. Clin. Exp. 26(3), 208–215; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1002/hup.1194/abstract

193.105 Panconesi, A., Bartolozzi, M.L., Guidi, L. Alcohol and migraine: what should we tell patients? Curr. Pain Headache Rep. 15(3), 177–184; 2011.

Abstract available online at http://www.springerlink.com/content/9054p62370873n85/

56 Technical Review No. 193 August 2011 193.106 Liu, S.-I., Wu, S.-I, Chen, S.-C., Huang, H.-C., Sun, F.-J., Fang, C.-K., Hsu, C.-C., Huang, C.-R., Yeh, H.-M., Shih, S.-C. Randomized controlled trial of a brief intervention for unhealthy alcohol use in hospitalized Taiwanese men. Addiction 106(5), 928–940; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1360-0443.2010.03330.x/ abstract

193.107 Syapin, P.J. Brain damage and alcohol dependence: how one may influence the other. Alcohol. Treatment Quarterly 29(2), 132–145; 2011.

Abstract available online at http://www.tandfonline.com/doi/abs/10.1080/07347324.2011.557985

Phenolic compounds

193.108 Hogan, S., Canning, C., Sun, S., Sun, X., Kadouh, H., Zhou, K. Dietary supplementation of grape skin extract improves glycemia and inflammation in diet-induced obese mice fed a western high fat diet. J. Agric. Food Chem. 59(7), 3035–3041; 2011.

Dietary antioxidants may provide a cost-effective strategy to promote health in obesity by targeting oxidative stress and inflammation. We recently found that the antioxidant-rich grape skin extract (GSE) also exerts a novel anti-hyperglycemic activity. This study investigated whether 3-month GSE supplementation can improve oxidative stress, inflammation, and hyperglycemia associated with a Western diet-induced obesity. Young diet-induced obese (DIO) mice were randomly divided to three treatment groups (n = 12): a standard diet (S group), a Western high fat diet (W group), and the Western diet plus GSE (2.4 g GSE/kg diet, WGSE group). By week 12, DIO mice in the WGSE group gained significantly more weight (24.6 g) than the W (20.2 g) and S groups (11.2 g); the high fat diet groups gained 80% more weight than the standard diet group. Eight of 12 mice in the W group, compared to only 1 of 12 mice in the WGSE group, had fasting blood glucose levels above 140 mg/dL. Mice in the WGSE group also had 21% lower fasting blood glucose and 17.1% lower C-reactive protein levels than mice in the W group (P < 0.05). However, the GSE supplementation did not affect oxidative stress in diet-induced obesity as determined by plasma oxygen radical absorbance capacity, glutathione peroxidase, and liver lipid peroxidation. Collectively, the results indicated a beneficial role of GSE supplementation for improving glycemic control and inflammation in diet-induced obesity.

© Reprinted with permission from Hogan, S., Canning, C., Sun, S., Sun, X., Kadouh, H., Zhou, K. Dietary supplementation of grape skin extract improves glycemia and inflammation in diet-induced obese mice fed a western high fat diet. J. Agric. Food Chem. 59(7), 3035–3041; 2011. Copyright 2011 American Chemical Society.

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August 2011 Technical Review No. 193 57 L Public health policy

193.109 McMorris, B.J., Catalano, R.F., Kim, M.J., Toumbourou, J.W., Hemphill, S.A. Influence of family factors and supervised alcohol use on adolescent alcohol use and harms: similarities between youth in different alcohol policy contexts. J. Stud. Alcohol Drugs 72(3), 418–428; 2011.

Abstract available online at http://www.jsad.com/jsad/article/Influence_of_Family_Factors_and_ Supervised_Alcohol_Use_on_Adolescent_Alcoho/4573.html

193.110 Gustafsson, N.-K.J. Alcohol consumption in Southern Sweden after major decreases in Danish spirits taxes and increases in Swedish travellers’ quotas. Eur. Addict. Res. 16(3), 152–161; 2010.

Abstract available online from http://www.karger.com/ear

193.111 Lai, T., Habicht, J. Decline in alcohol consumption in Estonia: combined effects of strengthened alcohol policy and economic downturn. Alcohol Alcohol. 46(2), 200–203; 2011.

Abstract available online at http://alcalc.oxfordjournals.org/content/46/2/200.abstract

193.112 Yoo, Y.J., Saliba, A.J., Prenzler, P.D. Should red wine be considered a functional food? Comp. Rev. Food Sci. Food Safety 9(5), 530–551; 2010.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1541-4337.2010.00125.x/ abstract

193.113 O’Brien, K.S., Miller, P.G., Kolt, G.S., Martens, M.P., Webber, A. Alcohol industry and non-alcohol industry sponsorship of sportspeople and drinking. Alcohol Alcohol. 46(2), 210–213; 2011.

Abstract available online at http://alcalc.oxfordjournals.org/content/46/2/210.abstract

58 Technical Review No. 193 August 2011 193.114 Bright, S., Singh, D., Fink, A. International use of screening tools that measure ‘standard drinks’: whose standard? Addiction 106(5), 1022–1023; 2011.

Abstract available online at http://onlinelibrary.wiley.com/doi/10.1111/j.1360-0443.2011.03366.x/ abstract

193.115 Alston, J.M., Fuller, K.B., Lapsley, J.T., Soleas, G., Tumber, K.P. Splendide mendax: false label claims about high and rising alcohol content of wine. AAWE 82, 1–37; 2011.

Article available online at http://www.wine-economics.org/workingpapers/AAWE_WP82.pdf

193.116 McGovern, T.F., Manning, S., McMahon, T. WHO global strategy to reduce the harmful use of alcohol (2010). Alcohol. Treatment Quarterly 29(2), 170–175; 2011.

Excerpt available online at http://www.tandfonline.com/doi/abs/10.1080/07347324.2011.562795

August 2011 Technical Review No. 193 59 AWRI publications

1289 Pretorius, S. Message in a bottle. Adelaide Review 377; 2011.

Article available online at http://www.adelaidereview.com.au/article/926

1290 Schmidt, S.A., Dillon, S., Kolouchova, R., Henschke, P.A., Chambers, P.J. Impacts of variations in elemental nutrient concentration of Chardonnay musts on Saccharomyces cerevisiae fermentation kinetics and wine composition. Appl. Microbiol. Biotechnol. 91(2), 365–375; 2011.

Abstract available online at http://www.springerlink.com/content/88x732451t6h3515/

1291 Wilkinson, K.L., Ristic, R., Pinchbeck, K.A., Fudge, A.L., Singh, D.P., Pitt, K.M., Downey, M.O., Baldock, G.A., Hayasaka, Y., Parker, M., Herderich, M.J. Comparison of methods for the analysis of smoke related phenols and their conjugates in grapes and wine. Aust. J. Grape Wine Res. 17(2), 22–28; 2011.

Background and Aims: Australian grape growers and winemakers have typically relied on guaiacol and 4-methylguaiacol measurements to determine smoke exposure of grapes following bushfires or prescribed burns. However, the guaiacol and 4-methylguaiacol content of grapes does not always correlate with the extent of taint in resultant wines. This study compared several methods for the analysis of smoke related phenols and their conjugates in grapes and wine, to determine their capacity as diagnostic assays for smoke exposure. Methods and Results: Smoke-affected grapes were sourced from commercial vineyards exposed to bushfire smoke and from experimental field trials involving the application of smoke to grapevines, and small-scale wines were made from a number of these samples. Several analytical methods were applied to grapes and wine to determine the concentration of smoke related phenols and their conjugates. Strong correlations were observed between the glycoconjugate content of smoke-affected grapes and the concentration of guaiacol and 4-methylguaiacol released following acid hydrolysis of juice. Conclusions: Where smoke- affected grapes contain low or non-detectable levels of guaiacol and 4-methylguaiacol, analytical methods that quantify their glycoconjugate forms (either directly or indirectly) provide a better indication of the extent of smoke exposure. Significance of the Study: This is the first study to compare different methods for assessing smoke exposure in grapes and wine, through analysis of free and bound guaiacol and 4-methylguaiacol. These methods will allow grape growers and winemakers to more reliably assess smoke exposure of grapes, enabling better informed decisions to be made with regards to harvesting and processing smoke-affected grapes.

© Reprinted with permission from Wilkinson, K.L., Ristic, R., Pinchbeck, K.A., Fudge, A.L., Singh, D.P., Pitt, K.M., Downey, M.O., Baldock, G.A., Hayasaka, Y., Parker, M., Herderich, M.J. Comparison of methods for the analysis of smoke related phenols and their conjugates in grapes and wine. Aust. J. Grape Wine Res. 17(2), 22–28; 2011. Copyright 2011 Australian Society of Viticulture and Oenology.

60 Technical Review No. 193 August 2011 1292 Ristic, R., Osidacz, P., Pinchbeck, K.A., Hayasaka, Y., Fudge, A.L., Wilkinson, K.L. The effect of winemaking techniques on the intensity of smoke taint in wine. Aust. J. Grape Wine Res. 17(2), 29–40; 2011.

Background and Aims: The chemical composition and sensory properties of smoke-affected grapes and wine has been the subject of several recent studies. However, while this research has addressed early knowledge gaps surrounding the effect of smoke on grapes and wine, to date, no practical solutions that mitigate the incidence or severity of smoke taint have been reported. The current project therefore aimed to identify winery processing methods that minimise the sensory impact of smoke taint in wine. Methods and Results: Different winemaking techniques were used to process smoke-affected grapes, i.e. cold maceration, the use of different yeast strains for primary fermentation and the use of oak and tannin additives. The extent of smoke taint in the resulting wines was determined by quantification of volatile phenols using GC-MS, followed by descriptive sensory analysis. Conclusions: Applied winemaking practices showed significant impacts on reducing the negative implications of smoke exposure on the chemical composition and sensory properties of wines. Winery processing methods that reduced skin contact time enhanced fruit character, produced wines with reduced ‘smoke’ aromas and flavours and less apparent taint. Selected yeast strains can be used as a tool for altering smoke-related aromas, flavours, colour and chemical composition of wines. The addition of oak chips and tannin enhanced the complexity of wines thereby reducing the perception of smoke-related attributes. Significance of the Study: These findings will enable winemakers to make more informed decisions when processing smoke- affected grapes, in order to minimise the severity of smoke taint perception in resulting wine.

© Reprinted with permission from Ristic, R., Osidacz, P., Pinchbeck, K.A., Hayasaka, Y., Fudge, A.L., Wilkinson, K.L. The effect of winemaking techniques on the intensity of smoke taint in wine. Aust. J. Grape Wine Res. 17(2), 29–40; 2011. Copyright 2011 Australian Society of Viticulture and Oenology.

1293 King, E.S., Osidacz, P., Curtin, C., Bastian, S.E.P., Francis, I.L. Assessing desirable levels of sensory properties in Sauvignon Blanc wines – consumer preferences and contribution of key aroma compounds. Aust. J. Grape Wine Res. 17(2), 169–180; 2011.

Background and Aims: This study aimed to investigate the sensory properties and aroma compounds responsible for driving consumer preference of Sauvignon Blanc wines. Methods and Results: Three thiols, including their respective enantiomers, a methoxypyrazine and a combination of esters were added singly and in combinations to a neutral white wine at realistic concentrations to mimic Sauvignon Blanc wines. A sensory descriptive analysis of 21 samples was conducted. While each thiol contributed to tropical and cat urine/sweaty attributes, 3-mercaptohexyl acetate (3MHA) was of particular importance. The ‘green’ characteristics were primarily related to methoxypyrazine, but thiols were also found to contribute to a cooked green vegetal attribute. The aroma and flavour of the methoxypyrazine dominated the sensory properties of other components. The thiol S-enantiomers gave higher cooked green vegetal or cat urine/ sweaty than their R-counterparts. Six combinations and the base wine were evaluated for liking by 150 consumers. One cluster of consumers (31%) preferred wines with higher tropical and

August 2011 Technical Review No. 193 61 confectionary aroma; a second cluster (43%) preferred wines with ‘green’ attributes; and the final cluster’s liking was positively related to solvent and ‘green’ attributes, and negatively to tropical and cat urine/sweaty. Conclusions: There were strong and varied interactive effects among the compounds studied. A sizeable proportion of consumers tested preferred the samples with ‘green’ attributes, with a minority preferring the ‘fruit’ aromas. Significance of the Study: This study has shown clear definition of sensory attributes resulting from aroma compounds important to Sauvignon Blanc wines, their interactions and their effects on consumer preference.

© Reprinted with permission from King, E.S., Osidacz, P., Curtin, C., Bastian, S.E.P., Francis, I.L. Assessing desirable levels of sensory properties in Sauvignon Blanc wines – consumer preferences and contribution of key aroma compounds. Aust. J. Grape Wine Res. 17(2), 169–180; 2011. Copyright 2011 Australian Society of Viticulture and Oenology.

1294 Pocock, K.F., Salazar, F.N., Waters, E.J. The effect of bentonite fining at different stages of white winemaking on protein stability. Aust. J. Grape Wine Res. 17(2), 280–284; 2011.

Background and Aims: Bentonite fining to remove protein is the most widely used treatment to prevent protein haze in white wines. Bentonite can be added at different stages during winemaking. This study aimed to determine the best time to add bentonite. Methods and Results: Unstable juices were vinified after bentonite fining of juice, or with bentonite added either early or late in fermentation. Different addition rates of bentonite were used and bentonite was either added in one or two additions. Fermentation rates were observed and protein stability and bentonite fining rates of the resultant wines were determined. Conclusions: Adding bentonite during fermentation or fining finished wines was the most efficient option in terms of amounts of bentonite required. Fermenting with bentonite present also may increase fermentation rates. Significance of the Study: Using the least bentonite necessary for heat stability is important for winemakers for quality, cost and environmental reasons. This study describes ways in which bentonite addition rates can be minimised.

© Reprinted with permission from Pocock, K.F., Salazar, F.N., Waters, E.J. The effect of bentonite fining at different stages of white winemaking on protein stability. Aust. J. Grape Wine Res. 17(2), 280–284; 2011. Copyright 2011 Australian Society of Viticulture and Oenology.

1295 Winter, G., Van der Westhuizen, T., Higgins, V.J., Curtin, C., Ugliano, M. Contribution of cysteine and glutathione conjugates to the formation of the volatile thiols 3-mercaptohexan- 1-ol (3MH) and 3-mercaptohexyl acetate (3MHA) during fermentation by Saccharomyces cerevisiae. Aust. J. Grape Wine Res. 17(2), 285–290; 2011.

Background and Aims: 3-Mercaptohexan-1-ol (3MH) and its ester 3-mercaptohexyl acetate (3MHA) are potent aromatic thiols that substantially contribute to varietal wine aroma. During fermentation, non-volatile 3MH conjugates are converted by yeast to volatile 3MH and 3MHA. Two types of 3MH conjugates have been identified, S-3-(hexan-1-ol)-L-cysteine (Cys-3MH) and S-3-(hexan-1-ol)-glutathione (GSH-3MH). Yeast-driven formation of 3MH from these precursors has been previously demonstrated, while the relationship between 3MHA and GSH-3MH remains to be established. This paper aims to investigate yeast conversion of GSH-3MH to 3MH and

62 Technical Review No. 193 August 2011 3MHA, and to assess the relative contribution of each individual conjugate to the 3MH/3MHA pool of finished wines. Methods and Results: Fermentation experiments were carried out in model grape juice containing Cys-3MH and GSH-3MH. We found 3MH formation from GSH-3MH to be significantly less efficient than that of Cys-3MH. Conversely, esterification of 3MH to 3MHA was higher when 3MH was formed from GSH-3MH. Additional in vitro assays for measuring enzyme cleavage activity suggest the involvement of a different mechanism in 3MH conversion for the two precursors. Conclusions: These results indicate that although both 3MH conjugates can be converted by yeast, the type of precursor affects the rate of formation of 3MH and 3MHA during fermentation. Significance of the Study: Management of the pool of aromatic thiols during fermentation can depend on relative proportions of different 3MH conjugates.

© Reprinted with permission from Winter, G., Van der Westhuizen, T., Higgins, V.J., Curtin, C., Ugliano, M. Contribution of cysteine and glutathione conjugates to the formation of the volatile thiols 3-mercaptohexan- 1-ol (3MH) and 3-mercaptohexyl acetate (3MHA) during fermentation by Saccharomyces cerevisiae. Aust. J. Grape Wine Res. 17(2), 285–290; 2011. Copyright 2011 Australian Society of Viticulture and Oenology.

1296 Lloyd, N.D.R., Capone, D.L., Ugliano, M., Taylor, D.K., Skouroumounis, G.K., Sefton, M.A., Elsey, G.M. Formation of damascenone under both commercial and model fermentation conditions. J. Agric. Food Chem. 59(4), 1338–1343; 2011.

The fermentations, at a commercial winery, of six different grape musts encompassing the varieties Riesling, Chardonnay, Sauvignon Blanc, Shiraz, Grenache, and Pinot Noir were monitored for damascenone concentration. In every case, the concentration of damascenone increased during fermentation from low or undetectable levels to concentrations of several parts per billion. Further increases in damascenone concentration were observed during barrel aging of three of these wines. Two ketones, megastigma-4,6,7-triene-3,9-dione (4) and 3-hydroxymegastigma-4,6,7-trien-9-one (5), were synthesized and subjected to fermentation conditions using two yeasts, AWRI 796, and AWRI 1537. In the case of the former compound, 4, synthesis confirmed the original, tentative assignment of the structure and confirmed 4 as a natural product, isolated from honey. Both compounds, under the action of both yeasts, produced appreciable amounts of damascenone (1), with ketone 5 and AWRI 796 yeast yielding the highest concentration of 1.

© Reprinted with permission from Lloyd, N.D.R., Capone, D.L., Ugliano, M., Taylor, D.K., Skouroumounis, G.K., Sefton, M.A., Elsey, G.M. Formation of damascenone under both commercial and model fermentation conditions. J. Agric. Food Chem. 59(4), 1338–1343; 2011. Copyright 2011 American Chemical Society.

August 2011 Technical Review No. 193 63 1297 Schmidt, S.A., Tan, E.L., Brown, S., Nasution, U.J., Pettolino, F., Macintyre, O.J., Lopes, M.D.B., Waters, E.J., Anderson, P.A. Hpf2 glycan structure is critical for protection against protein haze formation in white wine. J. Agric. Food Chem. 57(8), 3308–3315; 2009.

Grape-derived proteins can form haze in wine. Some cell-wall glycoproteins of Saccharomyces cerevisiae are capable of reducing protein haze formation. The basis of their haze protective activity is not yet understood. One of the S. cerevisiae cell-wall proteins, Hpf2, was produced in Pichia pastoris. An altered glycan structure in the P. pastoris-produced protein was associated with decreased solubility in water and reduced capacity to mitigate haze formation compared to native Hpf2 protein from S. cerevisiae. α-1,2-Linked mannose in the glycan chain was shown to be required for haze protective activity using a series of S. cerevisiae deletion mutants (mnn1-Δ, mnn2-Δ, mnn4-Δ, and mnn5-Δ), defective in different aspects of glycan processing. The effect of media additives phthalate, casamino acids, and yeast nitrogen base on Hpf2 production in P. pastoris were also evaluated. Casamino acids were shown to suppress Hpf2 production in P. pastoris.

© Reprinted with permission from Schmidt, S.A., Tan, E.L., Brown, S., Nasution, U.J., Pettolino, F., Macintyre, O.J., Lopes, M.D.B., Waters, E.J., Anderson, P.A. Hpf2 glycan structure is critical for protection against protein haze formation in white wine. J. Agric. Food Chem. 57(8), 3308–3315; 2009. Copyright 2009 American Chemical Society.

1298 McRae, J.M., Kennedy, J.A. Wine and grape tannin interactions with salivary proteins and their impact on astringency: a review of current research. Molecules 16(3), 2348–2364; 2011.

Astringency is an important characteristic of red wine quality. The sensation is generally thought to be produced by the interaction of wine tannins with salivary proteins and the subsequent aggregation and precipitation of protein-tannin complexes. The importance of wine astringency for marketability has led to a wealth of research on the causes of astringency and how tannins impact the quality of the sensation, particularly with respect to tannin structure. Ultimately, the understanding of how tannin structure impacts astringency will allow the controlled manipulation of tannins via such methods as micro-oxygenation or fining to improve the quality of wines.

© Reprinted with permission from McRae, J.M., Kennedy, J.A. Wine and grape tannin interactions with salivary proteins and their impact on astringency: a review of current research. Molecules 16(3), 2348–2364; 2011. Copyright 2011 MDPI Publishing.

1299 Bindon, K., Myburgh, P., Oberholster, A., Roux, K., Du Toit, C. Response of grape and wine phenolic composition in Vitis vinifera L. cv. Merlot to variation in grapevine water status. S. Afr. J. Enol. Vitic. 32(1), 71–88; 2011.

Grape and wine phenolic composition was monitored over two consecutive seasons in Vitis vinifera cv. Merlot following application of irrigation treatments that produced seasonal average stem water potentials ranging between -0.7 MPa and -1.4 MPa. Fresh weight of berries was significantly reduced in response to water deficit, primarily due to decreases in pericarp weight. Increases in

64 Technical Review No. 193 August 2011 the concentration of grape anthocyanins and flavonols in response to water deficit were found when expressed per unit grape berry fresh weight. Skin-derived tannin concentration in grape berries was not affected by the irrigation treatments. The concentration of grape-derived phenolics was monitored during five days of fermentation in a small-lot winemaking experiment. During fermentation, the concentration of anthocyanins and flavonols in wine were highest in the non- irrigated and low-frequency-irrigated treatments, which was reflected in changes in the wine colour of ferments. Finished wines from non-irrigated and low-frequency-irrigated grapevines showed increases in bisulphite-resistant pigments when compared with those irrigated at a high frequency, but differences in phenolic composition were minor. Increases in bisulphite-resistant pigments were associated with increases in vitisin A and polymeric pigment in the first and second seasons of the study respectively. Ageing of wines for an 18-month period increased bisulphite-resistant pigments, and treatment differences in wine colour density were enhanced, such that increases in both parameters were associated with the non-irrigated and low-frequency-irrigated treatments.

© Reprinted with permission from Bindon, K., Myburgh, P., Oberholster, A., Roux, K., Du Toit, C. Response of grape and wine phenolic composition in Vitis vinifera L. cv. Merlot to variation in grapevine water status. S. Afr. J. Enol. Vitic. 32(1), 71–88; 2011. Copyright 2011 South African Society for Enology and Viticulture.

1300 Curtin, C.D., Bellon, J.R., Bartowsky, E.J., Henschke, P.A., Chambers, P.J., Herderich, M.J., Pretorius, I.S. Harnessing AWRI’s yeast and bacterial research to shape ‘next- gen’ Chardonnay part 2: influence of yeast, nutritional management and malolactic fermentation. Wine Viti. J. 26(2), 15–24; 2011.

In Part 1 of this article the impact of ‘wild’ and non-conventional yeast on Chardonnay style was demonstrated. ‘Wild’ ferments were a hot topic at the ‘Next-gen Chardonnay’ workshop (14th AWITC, July 2010) – adventurous winemakers finding their additional complexity consistent with stylistic goals in the development of ‘Next-gen’ Chardonnay wines. In Part 2, the authors explore conventional options available to winemakers for modulation of Chardonnay aroma. Can commercially available yeast, with appropriate nutritional management, be harnessed to generate aromas and flavours consistent with ‘Next-gen’ Chardonnay styles? The authors also revisit malolactic fermentation (MLF). While associated strongly with classical styles of Chardonnay, MLF can be used to enhance complexity without imparting ‘buttery’ characters through careful application of appropriate bacterial strains.

© Reprinted with permission from Curtin, C.D., Bellon, J.R., Bartowsky, E.J., Henschke, P.A., Chambers, P.J., Herderich, M.J., Pretorius, I.S. Harnessing AWRI’s yeast and bacterial research to shape ‘next-gen’ Chardonnay part 2: influence of yeast, nutritional management and malolactic fermentation. Wine Viti. J. 26(2), 15–24; 2011. Copyright 2011 Winetitles Pty Ltd.

August 2011 Technical Review No. 193 65 1301 Abrahamse, C.E., Bartowsky, E.J. Timing of malolactic fermentation inoculation in Shiraz grape must and wine: influence on chemical composition. World J. Microbiol. Biotechnol. DOI 10.1007/s11274-011-0814-3, 1–11; 2011.

Malolactic fermentation (MLF) is an integral step in red winemaking, which in addition to deacidifying wine can also influence the composition of volatile fermentation-derived compounds with concomitant affects on wine sensory properties. Long-established winemaking protocols for MLF induction generally involve inoculation of bacteria starter cultures post alcoholic fermentation, however, more recently there has been a trend to introduce bacteria earlier in the fermentation process. For the first time, this study shows the impact of bacterial inoculation on wine quality parameters that define red wine, including wine colour and phenolics, and volatile fermentation-derived compounds. This study investigates the effects of inoculating Shiraz grape must with malolactic bacteria at various stages of alcoholic fermentation [beginning of alcoholic fermentation (co-inoculation, with yeast), mid-alcoholic fermentation, at pressing and post alcoholic fermentation] on the kinetics of MLF and wine chemical composition. Co-inoculation greatly reduced the overall fermentation time by up to 6 weeks, the rate of alcoholic fermentation was not affected by the presence of bacteria and the fermentation-derived wine volatiles profile was distinct from wines produced where bacteria were inoculated late or post alcoholic fermentation. An overall slight decrease in wine colour density observed following MLF was not influenced by the MLF inoculation regime. However, there were differences in anthocyanin and pigmented polymer composition, with co-inoculation exhibiting the most distinct profile. Differences in yeast and bacteria metabolism at various stages in fermentation are proposed as the drivers for differences in volatile chemical composition. This study demonstrates, with an in-depth analysis, that co-inoculation of yeast and bacteria in wine fermentation results in shorter total vinification time and produces sound wines, thus providing the opportunity to stabilise wines more rapidly than traditional inoculation regimes permit and thereby reducing potential for microbial spoilage.

© Reprinted with permission from Abrahamse, C.E., Bartowsky, E.J. Timing of malolactic fermentation inoculation in Shiraz grape must and wine: influence on chemical composition. World J. Microbiol. Biotechnol. DOI 10.1007/s11274-011-0814-3, 1–11; 2011. Copyright 2011 Springer Science + Business Media.

66 Technical Review No. 193 August 2011 AWRI extension and roadshow calendar

August 2011 Technical Review 193 August 2011 AWRI Seminars: North East Victoria Zone - Victoria. Location: Rutherglen. Date: 23August. Central Victoria Zone - Victoria. Location: Bendigo. Date: 24 August. Fleurieu Zone - South Australia. Location: McLaren Vale. Date: 31 August. AWRI Workshop Gippsland Zone - Victoria. Location: Gippsland. Date: 17 August. North East Victoria Zone - Victoria. Locations Rutherglen. Date: 19 August. North East Victoria Zone - Victoria. Location: Bendigo. Date: 24 August. Queensland. Location: Stanthorpe. Date: 30 August. Wine Assessment Hunter Valley Zone - New South Wales. Location: Hunter Valley. Date: 11 August. September 2011 AWRI Seminar: Lower Murray Zone - South Australia. Locations: Renmark & Mildura. Date: TBA AWRI Workshop Lower Murray Zone - South Australia. Locations: Renmark & Mildura. Date: TBA October 2011 Technical Review 194 October 2011 AWRI Workshops Central Victoria Zone – Bendigo, VIC Port Phillip Zone – Geelong, VIC Western Victoria Zone – Avoca/Pyrenees, VIC AWRI Seminar: Limestone Coast Zone – Coonawarra, SA Mount Lofty Ranges Zone – Clare, SA

For further information, please contact Virgina Phillips on (08) 8313 6687 or [email protected].

* Details subject to change without notice. Please visit the AWRI website to view the most up to date copy of this calendar at www.awri.com.au/events/calendar/. All information was accurate at time of compilation.

August 2011 Technical Review No. 193 67 The Technical Review is published bimonthly by The Australian Wine Research Institute. It is available free of charge to Australian grape and wine sector members paying a levy under the Wine Grapes Levy Act, however, other interested organisations and individuals may subscribe to Technical Review.

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68 Technical Review No. 193 August 2011