Progress 10/01/12 to 09/30/17

Outputs
Target Audience:California wine industry. Wine Chemists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Several MS students have graduated and have now been hired in the wine industry. One postdoc has a faculty position. Two PhD students now have postdoctoral positions, and one has an industry position. A visiting student now has a faculty position. How have the results been disseminated to communities of interest?Presentation at the American Society for Enology and Viticulture, Bellevue, WA, June 27, 2017. Presentation at the American Chemical Society National Meeting, Washington D.C., August 20, 2017. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Major progress has been attained on managing microoxygenation in wine production. In addition, some new pathways of wine aging reactions were uncovered.

Publications

• Type: Journal Articles Status: Published Year Published: 2017 Citation: G Han, MR Webb, C Richter, J Parsons, AL Waterhouse. Yeast alter micro?oxygenation of wine: oxygen consumption and aldehyde production. Journal of the Science of Food and Agriculture
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Waterhouse, A.L., S. Frost, M. Ugliano, A.R. Cantu, B.L. Currie, M. Anderson, A.W. Chassy, S. Vidal, J.-B. Di�val, O. Aagaard, and H. Heymann, 2016, Sulfur Dioxide - Oxygen Consumption Ratio Reveals Differences in Bottled Wine Oxidation. American Journal of Enology and Viticulture, 67: 449-459
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Peterson, A.L., A.L. Waterhouse, 2016, 1H NMR: A Novel Approach To Determining the Thermodynamic Properties of Acetaldehyde Condensation Reactions with Glycerol,(+)-Catechin, and Glutathione in Model Wine. Journal of Agricultural and Food Chemistry, 64: 6869-6878
• Type: Journal Articles Status: Published Year Published: 2016 Citation: Nikolantonaki, M., P. Magiatis, A. L. Waterhouse. Direct analysis of free and sulfite-bound carbonyl compounds in wine by two-dimensional quantitative proton and carbon nuclear magnetic resonance spectroscopy. Analytical Chemistry, 87: 10799-10806

Progress 10/01/15 to 09/30/16

Outputs
Target Audience:Technically advanced winemakers and technical managers at large wine companies are the primary audience. Some presentations have been made for general wine industry audiences. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Ana Peterson, Graduate Student; Lingjun Ma, graduate student; Charlie Henschen, graduate student, Scott Frost, graduate student, Angela Gambuti, visiting scientist How have the results been disseminated to communities of interest?Yes. American Society for Enology and Viticulture Annual Meeting, June 2016 What do you plan to do during the next reporting period to accomplish the goals?We will work on a fast new method for the measurement of SO2 in wine.

Impacts
What was accomplished under these goals? We have helped reveal the chemical reactions of those substances initially formed in wine oxidation. It is these follow-on reactions that actually affect the stable composition of a wine and thus its flavor. We have shown how acetaldehyde, an abundant wine oxidation product, reacts with other wine components. We have also shown how the reaction ratio between the preservative SO2 and oxygen can help show how much oxidation has actually occurred to a wine.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: M Nikolantonaki, P Magiatis, AL Waterhouse. Direct analysis of free and sulfite-bound carbonyl compounds in wine by two-dimensional quantitative proton and carbon nuclear magnetic resonance spectroscopy. Analytical chemistry 87 (21), 10799-10806
• Type: Journal Articles Status: Published Year Published: 2016 Citation: AL Peterson, AL Waterhouse. 1H NMR: A Novel Approach To Determining the Thermodynamic Properties of Acetaldehyde Condensation Reactions with Glycerol,(+)-Catechin, and Glutathione in Model Wine. Journal of Agricultural and Food Chemistry 64 (36), 6869-6878

Progress 10/01/14 to 09/30/15

Outputs
Target Audience:Technically advanced winemakers and technical managers at large wine companies are the primary audience. Some presentations have been made for general industry audiences. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Ana Peterson, Graduate Student; Prokopios Magiatis, visiting scientist; Lingjun Ma, graduate student; Charlie Henschen, graduate student How have the results been disseminated to communities of interest?New Ideas for Measuring Oxidation, Wine Science Forum, Santa Rosa, May 19 Microoxygenation: Mechanisms of Oxidation Treatment, In Vino Scientia, Trento, Italy, July 15 What do you plan to do during the next reporting period to accomplish the goals?We will focus on practical measures to anticipate wine oxidation that could be used by winemakers.

Impacts
What was accomplished under these goals? We have made substantial progress towards understanding the binding of acetaldehyde to various wine compounds, sulfites, alcohols and flavonoids. These have been measured by new NMR based spectral techniques and these measurements are essential to understanding the amount of oxidation that has occurred to a wine. We have observed the behavior of microoxygenation and have developed a hypothesis that much of that treatment is controlled by microbes. Our results have elicited interest from industry.

Publications

• Type: Journal Articles Status: Published Year Published: 2015 Citation: A.L. Waterhouse and M. Nikolantonaki, Quinone Reactions in Wine Oxidation, in Advances in Wine Research, eds S.E. Ebeler, P. Winterhalter, S. Vidal, G. Sacks. ACS Symposium Series 1203: 303-324.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: Gambuti, A., G. Han, A.L. Peterson, A.L. Waterhouse, Effect of sulfur dioxide and glutathione on wine composition during micro -oxygenation of red wine. AJEV, posted online

Progress 10/01/13 to 09/30/14

Outputs
Target Audience: Technically advanced winemakers and technical managers at large wine companies are the primary audience. Some presentations have been made for general industry audiences. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Ana Peterson, Graduate Student; Prokopios Magiatis, visiting scientist; Guomin Han, visiting student; Lingjun Ma, graduate student. How have the results been disseminated to communities of interest? Measuring and Managing Oxidation and Sulfur Dioxide, CWWGR Conference, Davis, Feb 12 Will Uncorking Become a Lost Custom, Webinar, SCI and Wiley, Feb 25 Closure Consistency, VEN Program at Napa Valley Vintners Association, CIA, St. Helena, Feb 27 RAVE, The Latest on Wine Oxidation, Davis, Mar 12 New Tools for Managing Wine Oxidation, Davis, May 30 New Insights into Managing Microoxygenation, ASEV Annual Meeting, Austin, TX, June 24 Wine Closure Performance, Gallo-Suntory Visit, Davis, July 10 What do you plan to do during the next reporting period to accomplish the goals? We will focus on practical measures to anticipate wine oxidation that could be used by winemakers.

Impacts
What was accomplished under these goals? We have made substantial progress towards understanding the binding of SO2 to the carbonyl compounds, the aldehydes and ketones, as well as understanding the other reactions of the carbonyl compounds. We have developed specific analytical methods to quantify the free and SO2-bound aldehydes, as well as a method to quantify the amount of the acetals derived from acetaldehyde. Both of these measurements are essential to understanding the amount of oxidation that has occurred to a wine. These methods have already been applied on two current studies of wine oxidation, furthering our understanding of the oxidation process.

Publications

• Type: Journal Articles Status: Published Year Published: 2012 Citation: Nikolantonaki M., and A. L. Waterhouse, A method to quantify quinone reaction rates with wine relevant nucleophiles: a key to understanding oxidative loss of varietal thiols, Journal of Agricultural and Food Chemistry, 60:8484-8491
• Type: Journal Articles Status: Published Year Published: 2014 Citation: Nikolantonaki, M., P. Magiatis, A. L. Waterhouse, Measuring protection of aromatic wine thiols from oxidation by competitive reactions vs wine preservatives with ortho-quinones, Food Chemistry, 163: 61-67.
• Type: Journal Articles Status: Published Year Published: 2015 Citation: G. Han, H. Wang, M.R. Webb, A. L. Waterhouse. A rapid, one step preparation for measuring selected free plus SO2-bound wine carbonyls by HPLC-DAD/MS. Talanta, 134: 596-602.
• Type: Journal Articles Status: Accepted Year Published: 2015 Citation: Peterson A. L, A. Gambuti, A. L. Waterhouse, Rapid Analysis of Heterocyclic Acetals in Wine by Stable Isotope Dilution Gas Chromatography-Mass Spectrometry, Tetrahedron, in press. Revisions submitted 12/29.

Progress 01/01/13 to 09/30/13

Outputs
Target Audience: Technically advanced winemakers and technical managers at large wine companies are the primary audience. Some presentations have been made to general industry audiences. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Maria Nikolantonaki, Postdoctoral Associate; Michael Webb, Postodoctoral Associate; Ana Peterson, Graduate Student; Prokopis Magiatis (visiting scientist); Jillian Guernsey, undergraduate research student; Guomin Han, visiting student; Mara Couch, undergraduate student. How have the results been disseminated to communities of interest? Control of Wine Oxidation, Grape and Wine Research Conference, Davis, Feb 21 MicroOxygentaion Project Update, Modesto, Feb 22 Oxygen Cascade in Wine. Oxygen and Wine Quality Wine Science Forum, Napa, Mar 11 Wine Oxidation Chemistry, VEN Outreach Program, Lodi, April 9 Innovations in Wine Chemistry, Pride Mountain Wine, Napa, April 12 Wine Flavor 101: Wine Oxidation, April 18 Innovations in Wine Closures, Acampo, June 19 Sulfur Dioxide-Oxygen Consumption Ratio Reveals Differences in Post-Bottling Oxygen Development in Chardonnay Wines, American Society for Enology and Viticulture, Annual Meeting, Monterey, June 26 Managing Oxidation of Wine Tannins, ASEV Tannin Symposium, Monterey, June 28 Quinone Reaction Kinetics and Oxidation Mechanisms, Wine Oxidation Workshop, Nelson, New Zealand, July 25 New Developments in Wine Closures, Jackson Family Wines Visit, UC Davis, August 6 Understanding Wine Oxidation, Grape Day, UCCE Kearney Agricultural Center, August 13 What do you plan to do during the next reporting period to accomplish the goals? During this period we plan to study methods to better measure sulfur dioxide as well as follow up on other observations.

Impacts
What was accomplished under these goals? The understanding of wine oxidation chemistry and what reactions are critical to its progress and control are becoming clearer. We now have a ranking of how fast specific wine components react under particular oxidation steps and that will allow us to predict how much preservatives are needed to prevent oxidation from occurring.

Publications

• Type: Journal Articles Status: Published Year Published: 2012 Citation: Nikolantonaki, M. Waterhouse, A.L. (2012) Quinone reaction kinetics suggest oxidation management strategies. American Journal of Enology and Viticulture 63: 442a-442a.
• Type: Journal Articles Status: Published Year Published: 2013 Citation: Kreitman, G.Y.; Cantu, A.; Waterhouse, A.L. Elias, R.J. (2013) Effect of metal chelators on the oxidative stability of model wine. Journal of Agricultural and Food Chemistry 61: 9480-9487.

Progress 01/01/12 to 12/31/12

Outputs
OUTPUTS: During this period we studied the comparative reaction rate of various substances with quinones in order to model the first phase of wine oxidation. The relative rates were those predicted by the individual reactions, so no particular synergy or suppression was detected. The specific chemical products of the oxidation process were characterized by high resolution MS. We have also been collecting data from an experiment treating wines with oxygen, as well as a closure trial with different wine bottle closures, observing the transmission of oxygen into bottles. PARTICIPANTS: Individuals: Maria Nikolantonaki (current postdoc), Jillian Guernsey (undergraduate research student), Guomin Han (visiting student), Ana Peterson (graduate student), Mauri Anderson (staff researcher), Michael Webb (current postdoc), Prokopis Magiatis (visiting scientist), Mara Couch (undergraduate student). Partner Organizations: E&J Gallo wine company, University of Athens, Northewest A&F University, Yangling, Plumpjack Wines. TARGET AUDIENCES: Technically advanced winemakers and technical managers at large wine companies. Some presentations have been made to general industry audiences. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The new data suggests that the standard tests for sulfur dioxide levels used for winemaking are not providing useful information, as the model data shows that sulfur dioxide reacts much more quickly with quinones than the aromatic thiols. If that were the case, very little sulfur dioxide would be needed to protect wine, but in fact winemakers find they need a large amount to have a useful protective effect. Thus our next phase of study will be to better understand how or why the standard tests are not predictive.

Publications

• Waterhouse, A. L., 2011. Wine Oxidation: Recent Revelations, Observations and Predictions, in Flavor Chemistry of Wine and Other Alcoholic Beverages, M. Qian (Ed.) ACS Symposium Series, 1104. American Chemical Society, Washington D.C., pp 159-166.
• Nikolantonaki, M., and A. L. Waterhouse. 2012. A method to quantify quinone reaction rates with wine relevant nucleophiles: a key to understanding oxidative loss of varietal thiols, Journal of Agricultural and Food Chemistry, 60:8484-8491.

Progress 01/01/11 to 12/31/11

Outputs
OUTPUTS: Outputs include the rate by which hydroxycinnamates react with ethanol free radicals, and the reduction in the formation of the oxidation product acetaldehyde in model wines. The second output is the measurement of the rate by which thiols, amino acids, phloroglucinol, sulfur dioxide and other nucleophiles react with a quinone, specifically the quinone of 4-methylcatechol. Another output was the chemical change in wine stored under different closures that exposed the bottled wines to different levels of oxygen during storage. PARTICIPANTS: Individuals: Ryan Elias (assistant professor, Penn State University), Bruce Currie (retired), Annegret Cantu (Research Manager), Nick Gislason (winemaker), Maria Nikolantonaki (current postdoc), Michael Webb (current postdoc), Guomin Han (visiting student), Ana Peterson (graduate student), Mauri Anderson (staff researcher), Sisse Jongberg (visiting student), Jillian Guernsey (undergraduate student) Partner Organizations: E&J Gallo, Plumpjack Wines, University of Copenhagen, Northwest A & F University, Yangling. The partnership with Univ Copenhagen was an extension of collaboration from the past. Collaborators: L. Skibsted and others at Univ Copenhagen. Professional Development: All individual participating in the oxidation projects are encouraged to present their results at professional meetings, as well as prepare their results for publication. In addition participants assist in grant proposal preparation. All these activities develop important skills in critical thinking and expression. Students are also introduced to potential employers by working on the projects as well as by attending meetings. Guernsey is current discussing part time employment with one partner company. All past students and postdocs who worked on wine oxidation are currently employed to the level they desire, generally within the wine industry or academia. TARGET AUDIENCES: Target Audience: Technically advanced winemakers and technical support staff in such companies. In the future, as more applied work is carried out, our results will be of direct interest to winemakers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
During this period there were three important outcomes. The first was the discovery of a novel antioxidant process, previously not observed in food, whereby the cinnamates found in wine trap free radicals caused by oxidation, slowing the oxidation process. The second is that we have measured the specific rates by which the quinones created by oxidation in wine react with the various nucleophiles available. This second outcome will directly lead to tests in wine of this reaction that will help provide specific recommendations to winemakers regarding how to manage wine oxidation. The third important outcome was that lees storage of wine prior to bottling appears to protect the wine from oxidative change during bottle storage.

Publications

• Elias, R.J. and A.L. Waterhouse. 2010. Controlling the Fenton reaction in wine. Journal of Agricultural and Food Chemistry 58: 1699-1707.
• Gislason, N. and A.L. Waterhouse. 2010. Hydroxycinnamate alpha,beta-unsaturated sidechain moieties are potent antioxidants. American Journal of Enology and Viticulture 61: 428a-428a.
• Gislason, N.E., B.L. Currie and A.L. Waterhouse. 2011. Novel antioxidant reactions of cinnamates in wine. Journal of Agricultural and Food Chemistry 59: 6221-6226.
• Jongberg, S., N.E. Gislason, M.N. Lund, L.H. Skibsted and A.L. Waterhouse. 2011 Thiol-quinone adduct formation in myofibrillar proteins detected by LC-MS. Journal of Agricultural and Food Chemistry 59: 6900-6905.
• Jongberg, S., N.E. Gislason, M.N. Lund, L.H. Skibsted and A.L. Waterhouse. 2011 Thiol-quinone adduct formation in myofibrillar proteins detected by lc-ms. Journal of Agricultural and Food Chemistry 59: 6900-6905.

Progress 01/01/10 to 12/31/10

Outputs
OUTPUTS: One approach to studying oxidation is to trap the free radical intermediates. Attempts to undertake this work at UC Davis with my students using borrowed time on EPR instruments were not fruitful, so I arranged a collaboration with an EPR expert in Denmark and sent my postdoc to work there for a few months. Ryan Elias came back with excellent data showing that the most important wine radical was the ethoxyl radical, the oxidation intermediate of ethanol (Elias, 2009). Another benefit was that both I and Elias independently have ongoing collaborations with the Skibsted lab, certainly the most important food chemistry lab in Denmark. Elias completed his studies at Davis documenting the characteristics of the Fenton reaction under wine conditions, and various means to affect its outcome (Elias 2009b). PARTICIPANTS: Individuals: Ryan J. Elias (currently Assistant Professor at Penn State) Bruce Currie Annegret Rust (winemaker) Adrianna Gozza (winemaker) Nick Gislason (winemaker) TARGET AUDIENCES: Technically advanced winemakers and technical support staff in such companies. In the future, as more applied work is carried out, our results will be of direct interest to winemakers. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The data collected above has suggested some specific additional experiments that are directly related to controlling wine oxidation in the course of production. We are looking at the effect of different oxygen transmission rates in bottle wines. The data from these investigations is now being analyzed. These data are leading us to specific tests of wine oxidation.

Publications

• Elias, R. J., M. L. Andersen, L. H. Skibsted, and A. L. Waterhouse. 2009. Identification of free radical intermediates in oxidized wine using electron paramagnetic resonance spin trapping. Journal of Agricultural and Food Chemistry 57:4359-4365.
• Elias, R. J., M. L. Andersen, L. H. Skibsted, and A. L. Waterhouse. 2009b Key factors affecting radical formation in wine studied by spin trapping and EPR spectroscopy. American Journal of Enology and Viticulture 60:471-476. Additional manuscripts have been submitted for publication.

Progress 01/01/09 to 12/31/09

Outputs
OUTPUTS: During this year our experiments have tested the effect of chelating agents on the oxidation of wine. Due to the key role of metals, chelating agents could dramatically affect the process. Testing was carried out on both model solutions and wine. In addition, the effect of phenolics on the Fenton was tested. These appear to have little effect. Papers have been published on the EPR data on wine oxidation. Presentations were made at the American Society for Enology and Viticulture, as well as at the research meeting presented by the Viticulture Consortium West. PARTICIPANTS: Individuals: Annegret Cantu, Adrianna Gozza, Bruce Currie, Nick Gislason Training: Cantu, Gozza and Gislason earned their M.S. degrees in Viticulture and Enology while working on the study of wine oxidation. TARGET AUDIENCES: Technically advanced winemakers and technical support staff in such companies. In the future, as more applied work is carried out, our results will be of direct interest to winemakers. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The chelation studies showed that this approach to slowing wine oxidation is statistically significant, but the effect is small and so the importance to wine production is highly questionable. The impact of the phenolic compounds on wine oxidation showed marginal effect. A surprising result with hydroxycinnamates is being studied.

Publications

• Waterhouse, A.L., 2008. A Wine Oxidation Mechanism: The Seminal Study of Wildenradt and Singleton, Proceedings of Phenolics Substances in Grapes and Wines: A Symposium Honoring Dr. Vernon L. Singleton, CD publication, asev.or.
• Elias, R.J., M.L. Andersen, L. H. Skibsted, and A.L. Waterhouse, 2009. Identification of Free Radical Intermediates in Oxidized Wine Using Electron Paramagnetic Resonance Spin Trapping, Journal of Agricultural and Food Chemistry, 57: 4359-4365.
• Elias, R.J., M.L. Andersen, L.H. Skibsted, and A.L. Waterhouse, 2009. Key Factors Affecting Radical Formation in Wine Studied by Spin Trapping and EPR Spectroscopy, American Journal of Enology and Viticulture, 60: 471-476.
• Elias, R.J. and A. L. Waterhouse, Controlling the Fenton Reaction in Wine. Journal of Agricultural and Food Chemistry, online January 4, 2010, DOI: 10.1021/jf903127r.

Progress 01/01/08 to 12/31/08

Outputs
OUTPUTS: This research project has made progress in testing the oxidation pathway proposed earlier. Much data was collected by electron paramagnetic resonance by a collaboration in Denmark with a well known food oxidation laboratory run by Professor Skibsted. This has established which free radicals exist in oxidized wine. The study also looked at the effect of metals, and those increased the formation of free radicals; increased sulfites decreased free radical levels. In addition, our studies of the Fenton reaction have been largely completed and the data show the kinetics of the various oxidation reactions tested, as well as reactions between oxidants and sulfur dioxide. A number of presentations have been made, including at the national American Society for Enology and Viticulture annual meeting, as well as at my Department's annual industry symposium, Recent Advances in Viticulture and Enology, and at the technical meetings of large companies, when invited. PARTICIPANTS: Individuals: V. Felipe Laurie Ryan J. Elias Bruce Currie Annegret Rust Adrianna Gozza TARGET AUDIENCES: Technically advanced winemakers and technical support staff in such companies. In the future, as more applied work is carried out, our results will be of direct interest to winemakers. PROJECT MODIFICATIONS: Not relevant to this project.

Impacts
The data collected above has suggested some specific additional experiments that are directly related to controlling wine oxidation in the course of production. Since metal is so important, one current experiment involves looking at metal complexing agents. We are also looking at the effect of different oxygen transmission rates in bottle wines. The data from both of these investigations is now being collected.

Publications

• Waterhouse, A.L., V.F. Laurie, 2006. Oxidation of Wine Phenolics: a Critical Evaluation and Hypothesis. American Journal of Enology and Viticulture, 57: 306-313.
• Laurie, V.F., A.L. Waterhouse, 2006. Glyceraldehyde Bridging between Flavanols and Malvidin-3-glucoside in Model Solutions, Journal of Agricultural and Food Chemistry, 54: 9105-9111.
• Laurie, V.F., R. Law, W.J. Joslin, and A.L. Waterhouse, 2008. In-situ Measurements of Dissolved Oxygen during Low-level Oxygenation in Red Wines, American Journal of Enology and Viticulture, 59: 215-219.
• Elias, R.J., V.F. Laurie, S.E Ebeler, J. W. Wong, and; A. L. Waterhouse, 2008. Analysis of Selected Carbonyl Oxidation Products in Wine by Liquid Chromatography with Diode Array Detection, Analytica Chimica Acta, 626: 104-110.