Dr Rebecca Christina Deed
BSc Hons (Biological Sciences), PhD Science (Biological Sciences)
My background is in plant molecular science and wine microbiology. Previous research that I have been involved in includes the investigation of the effect of low temperature fermentation on the transcriptome of wine yeast and the production of wine aromas, as well as projects centred on unravelling the biosynthesis of volatile sulfur compounds in wine. I have also worked as a technician to develop improved commercial yeast strains for the New Zealand wine industry.
In my spare time I am a national wine judge, having judged at senior level for Liquorland, the Royal Easter Wine Awards, New World Wine Awards, and Winestate Magazine, and at associate level for the Air New Zealand Wine Awards. I hold the WSET Level 3 (Advanced) Award in Wine and Spirits and the Level 1 Award in Sake.
Research | Current
My current research areas of interest are focused on using a combination of techniques in molecular biology and analytical chemistry to understand the mechanisms behind the biological and chemical formation of aroma compounds in grape juice and wine, as well as understanding yeast metabolic pathways leading to good fermentative ability.
Topics I am working on currently include:
Elucidation of the pathway/s to volatile thiols in white wine. Current projects include the quantification of ‘pre-precursors’ glut-3SH-al and glut-3SH-SO3 in grape juice and wine, the investigation into the role of H2S-mediated thiol production requiring the presence of C6 alcohols, and potential contribution of compounds containing sulfonic adducts for thiol formation. This research is in collaboration with Dr Lisa Pilkington and A/P Bruno Fedrizzi, School of Chemical Sciences.
Pinot noir fermentation dynamics and aroma chemistry. This area of research aims to investigate the interplay between the wild microflora present over the course of Pinot noir fermentation with Pinot noir wine aroma and quality. Changes in the microbial community during fermentation will be correlated to the evolution of aroma compounds at parallel fermentation stages. Further investigation into key impact odorants, such as beta-ionone and beta-damascenone, which are linked to Pinot noir quality, will be analysed in-depth in order to identify the role of wild yeast and bacteria in their formation. This research is in collaboration with Dr Sarah Knight (School of Biological Sciences) and A/P Bruno Fedrizzi (School of Chemical Sciences), University of Auckland.
Investigation into yeast genes linked to fermentative lag phase. The primary objective of this research is to identify, from a prior list of candidates, Saccharomyces cerevisiae genes linked to the duration of the fermentation lag phase at low fermentation temperatures relevant to white winemaking. This research has the potential for use in breeding programmes to develop new wine yeast with longer or shorter fermentative lag phases, depending on industry needs.
Wine chemical features linked to positive reduction and minerality in Chardonnay wines and the potential role of yeast. This area of research aims to gain deeper insights into the role of volatile sulfur compounds (VSCs) in Chardonnay wines by identifying relationships between positive reductive characters (i.e. flintiness) identified by sensory evaluation, and match these to the aroma chemistry of the wines. This project also involves the detailed investigation of the formation pathway (biological and chemical) of benzyl mercaptan, a chemical compound associated with ‘flintiness’ in wines. The benzyl mercaptan component of this work is in collaboration with A/P Bruno Fedrizzi.
Polysulfide behaviour in wine. The main aim of this work is to understand the formation and behaviour of these chemical species in wine and how they are formed by yeast. In collaboration with A/P Bruno Fedrizzi, Dr Max Huang and Dr Katie Parish-Virtue (School of Chemical Sciences, University of Auckland).
I am also keen to discuss any research topic within the realm of wine science with interested students.
Teaching | Current
I have been involved in the University of Auckland Wine Science teaching programme since 2014, lecturing in viticulture, wine microbiology and sensory evaluation. I am the Course Coordinator of WINESCI 201 Introduction to Wine Science and I teach components of WINESCI 201, WINESCI 701, WINESCI 702, WINESCI 703, WINESCI 704 and WINESCI 707.
Daisy Zhang - Summer Scholarship, Biological Sciences - Wine chemical features linked to minerality in white wines and the contribution of yeast.
Jen Muhl - BSc (Hons) Chemistry - Contribution of glut-3SH-al and glut-3SH-SO3 for the production of impact odorant 3-sulfanylhexan-1-ol (3SH) in white wines. Co-supervised by Dr Lisa Pilkington.
Mathilde Saint-Picq - Intern - Release of grape-derived precursors by wild microflora.
Ciel Li - MSc Wine Science - Identification of Saccharomyces cerevisiae genes linked to lag phase during fermentation.
Yifeng Qiao - MSc Wine Science - Understanding the microbial contribution to beta-damascenone and beta-ionone formation in Pinot noir. Co-supervised by Dr Sarah Knight.
Ziqi Chen - MSc Food Science - Development of novel Goji berry wines. Co-supervised by A/P Siew-Young Quek.
Rorric Hou - PhD Chemistry (co-supervisor) - Exploiting New Zealand fungal communities to enhance tropical aroma in wine. Main supervisor - A/P Bruno Fedrizzi.
Areas of expertise
Wine Advisory Board member.
FoS Equity Committee member.
Selected publications and creative works (Research Outputs)
- Deed, R. C., Pilkington, L. I., Herbst-Johnstone, M., Miskelly, G. M., Barker, D., & Fedrizzi, B. (2019). A new analytical method to measure S-methyl-l-methionine in grape juice reveals the influence of yeast on dimethyl sulfide production during fermentation. Journal of the science of food and agriculture, 99 (15), 6944-6953. 10.1002/jsfa.9983
Other University of Auckland co-authors: Lisa Pilkington, Gordon Miskelly, David Barker, Bruno Fedrizzi
- Pilkington, L., Deed, R., Parish-Virtue, K., Huang, C., Walker, M., Jiranek, V., ... Fedrizzi, B. (2019). Iterative synthetic strategies and gene deletant experiments enable the first identification of polysulfides in Saccharomyces cerevisiae. Chemical Communications, online first10.1039/C9CC03020D
Other University of Auckland co-authors: Lisa Pilkington, David Barker, Bruno Fedrizzi
- Deed, R. C., Hou, R., Kinzurik, M. I., Gardner, R. C., & Fedrizzi, B. (2018). The role of yeast ARO8, ARO9 and ARO10 genes in the biosynthesis of 3-(methylthio)-1-propanol from L-methionine during fermentation in synthetic grape medium. FEMS Yeast Research10.1093/femsyr/foy109
Other University of Auckland co-authors: Rorric Hou, Bruno Fedrizzi
- Clark, A. C., & Deed, R. C. (2018). The Chemical Reaction of Glutathione and trans-2-Hexenal in Grape Juice Media To Form Wine Aroma Precursors: The Impact of pH, Temperature, and Sulfur Dioxide. Journal of agricultural and food chemistry, 66 (5), 1214-1221. 10.1021/acs.jafc.7b04991
- Rozali, S. N. M., Milani, E. A., Deed, R. C., & Silva, F. V. M. (2017). Bacteria, mould and yeast spore inactivation studies by scanning electron microscope observations. International Journal of Food Microbiology, 263, 17-25. 10.1016/j.ijfoodmicro.2017.10.008
Other University of Auckland co-authors: Filipa Silva
- Deed, R. C., Fedrizzi, B., & Gardner, R. C. (2017). Influence of Fermentation Temperature, Yeast Strain, and Grape Juice on the Aroma Chemistry and Sensory Profile of Sauvignon Blanc Wines. Journal of agricultural and food chemistry, 65 (40), 8902-8912. 10.1021/acs.jafc.7b03229
Other University of Auckland co-authors: Bruno Fedrizzi
- Deed, R. C., Fedrizzi, B., & Gardner, R. C. (2017). Saccharomyces cerevisiae FLO1 gene demonstrates genetic linkage to increased fermentation rate at low temperatures. G3: Genes, Genomes, Genetics, 7 (3), 1039-1048. 10.1534/g3.116.037630
Other University of Auckland co-authors: Bruno Fedrizzi
- Deed, R. C., Deed, N. K., & Gardner, R. C. (2015). Transcriptional response of Saccharomyces cerevisiae to low temperature during wine fermentation. Antonie Van Leeuwenhoek, 107 (4), 1029-1048. 10.1007/s10482-015-0395-5