| Department of Viticulture and Oenology (DVO) & Institute for Wine Biotechnology (IWBT)
The DVO and IWBT at this University are the only in the country to offer opportunities for undergraduate and postgraduate study in Viticulture and Oenology.
Department of Viticulture and Oenology
Viticulture. The generation of new, innovative and applicable knowledge on the grapevine and its cultivation is the focus of the viticultural research undertaken by the DVO. The focus of the research and experimentation in the field of vine sciences (wine and table grape) is on the effect of abiotic factors (light, temperature, wind and water) on the ecophysiology of vine functioning, berry growth and composition. Vineyard locations and cultivars are chosen according to scientific and practical questions that need to be addressed. Studies focus on the plant, organ and cell levels, so greenhouse and in vitro culture facilities have also been implemented. Remote sensing and the development of new technologies (decision-making tools) are also used intensively in research and experimentation in viticulture. Most of the studies are done in conjunction with oenology to better understand the effect of the abiotic factors and of cultural practices, including canopy manipulation (training system) and irrigation, on the composition and style of wine.
Oenology. The oenological research focuses on the influence of the vinification process (such as oxygen additions), microorganisms (yeasts and bacteria), additives (such as enzymes and CMC) and maturation on wine composition, style and quality, as well as the effects of various factors on wine ageing. Researchers work closely with industry partners and help to resolve issues facing winemakers at both a fundamental and a practical level.
Antonio Ferreira’s research focuses on the flavour chemistry of alcoholic beverages, and in particular the correlation of sensory and chemical data in the perception of quality. Most of his works have been in collaboration with Portuguese wine/beer companies or other research groups in Europe. His research projects have resulted in the development of new methodologies allowing quantification of flavour relevant substances in wines, perceived as off-flavours or in-flavours. The application of hybrid techniques and a holistic approach are used with sensory quality questions concerning aroma, mouthfeel sensations, etc. The research workflow includes integrating the most advance chemical/sensory techniques and then using the set of information to design a prediction model. This vision is achieved with a multidisciplinary research group.
Alain Deloire’s research and experimentation focuses on the ecophysiology of berry growth and composition in relationship to wine composition and style. The research projects try to understand the effect of abiotic factors (light, temperature, wind and water) on berry growth and composition. In an appropriate vineyard, the experiments are designed to create extreme conditions at the microclimatic level (bunch and canopy) to study the limit of vine functioning, berry growth and ripening. New decision-making tools to predict the harvest date of red and white cultivars have been calibrated for South Africa. The practical targets of these studies are related to water management, to site x cultivar adaptation and to the matching of ripening and wine style.
Albert Strever’s research focuses on understanding grapevine variability through non-destructive techniques, including field spectroscopy, thermal imaging and multispectral remote sensing. His PhD study also incorporated growth modelling and leaf age determination techniques within a study in which the interaction of plant water status and canopy manipulation was investigated. Other projects include studying grapevine yield component and growth balance (Anneli Bosman), and using remote sensing in climate studies (also incorporating thermal satellite imagery) (Tara Mehmel).
Anneli Bosman specialises in grapevine architecture and alternative trellis systems. Her research is focused on the use of alternative trellis systems in order to optimise productivity in vineyards whilst preserving or improving grape quality, relative to a specific production goal and price point. This involves observing the vine’s compensation mechanism in reaction to the modification of its balances. Sustainable practices include the alteration of grapevine architecture, amongst others to be more environmentally friendly and cost effective, whilst ways to improve product marketability are also investigated.
Erna Blancquaert’s research addresses the environmental factors that have a significant impact on wine grape composition and wine quality and style. Research is currently being conducted on the influence of abiotic factors (light, temperature) on tannin and phenolic development in the berry and the mouthfeel characteristics of the wines.
Marianne McKay is involved in ongoing research on the so-called ‘burnt rubber (BR)’ taint. Members of the BR team have conducted many tastings and have isolated some of the factors that may contribute to this off-flavour. Various analytical methods help identify the compounds that could be responsible, and students, including Valeria Panzeri and Annette van Zyl, have investigated factors in the vineyard which may enhance the aroma. Marianne is also involved in research on teaching and training in the wine industry, with a focus on looking at methods that enhance professionalism and graduate attributes.
Wessel du Toit’s research team (in collaboration with Auckland University in New Zealand) was involved in investigating the effect of different oxygen additions on the chemistry and sensorial quality of Sauvignon blanc wine. Part of this study entails characterising South African Sauvignon blanc wines in terms of their chemical and sensory composition. The effect of different winemaking practices on glutathione in wine was also investigated. Other research projects investigated the tannin and anthocyanin concentrations in red grapes and how these are reflected in the corresponding wines. Advanced analytical techniques, such as GCMS, HPLC and infrared spectroscopy, have been developed and are being used in these studies.
Institute for Wine Biotechnology
The Grapevine Molecular and Biotechnology Programme.
Prof Melané Vivier, Dr Philip Young, Dr John Moore and Dan Jacobson are involved in fundamental and applied studies of grapevine in interaction with pathogens and the environment, supported by a grapevine transformation and regeneration platform. The ability to genetically transform grapevine enables in-depth studies of grapevine through overexpression and silencing approaches, as well as a range of other tissue culture applications. The research is progressively being integrated into viticultural field studies to “profile” grapevines growing under different conditions so that the plant’s response to these factors can be understood on a plant biological level. Transcriptomic, proteomic, metabolite as well as hormone profiling are used to provide layers of data that are then overlaid with viticultural and oenological data to obtain a holistic view of the grape-growing process and its impact on the vine as a system.
The Microbiology Programme.
This programme is driven by Prof Florian Bauer, Prof Maret du Toit, Dr Evodia Setati, Dr Benoit Divol and Ms Anita Smit and involves fundamental and applied studies of all wine microorganisms, with a specific emphasis on those responsible for alcoholic and malolactic fermentations. Within this extensive research programme, specific attention is given to aspects ranging from the microbial ecology of grape berries and grape juice, to survival strategies of spoilage microorganisms and the impact of non-Saccharomyces yeasts on wine composition. The different research projects make use of all standard microbiological and molecular biology techniques, as well as genomics-, metagenomics-, transcriptomics-, proteomics- and metabolomics-based approaches. The outcomes of these studies are also used to isolate, select and/or generate yeast and bacteria with enhanced oenological properties.
The Computational Biology Programme.
This programme is driven by Dan Jacobson and involves the development/application of mathematical, statistical and computational methods to biological data sets in order to yield new insights and thus transform data into knowledge. Areas of mathematics of interest in this programme include the use of Graph Theory and Markov Clustering, Wavelet Theory, and Machine Learning. Areas of Statistics of particular interest to this programme are the use of both frequentist (parametric and non-parametric) and Bayesian methods,as well as the development of new methods in Multivariate Statistics (Chemometrics). These methods are applied to various data sets to better understand the transcriptional, translational and chemical (kinetic) regulatory networks in the organisms and chemical systems involved in wine. This programme is actively involved with undergraduate and postgraduate students from the Biomathematics programme in the Department of Applied Mathematics, the African institute for Mathematical Sciences (AIMS) and, together with colleagues in Engineering and Information Technology, oversees the High Performance Computing (HPC) facility on campus.
The Chemistry and Sensory Programme.
Dr Andreas Tredoux is involved in the development of novel chromatographic methods for the analysis of targeted and untargeted compounds in wine, grapes and grapevine, including the analysis of 57 important volatiles in wine. Solid phase micro-extraction (SPME) with gas chromatography-mass spectrometry (GC-MS) is used for the analysis of odour-active carbonyl compounds and volatile phenols in wine. Ultraperformance liquid chromatography (UPLC) methods for analysis of non-volatile wine compounds and 2D-GC-MS (GCxGC-MS) methods have been developed in collaboration with Dr André de Villiers (Department of Chemistry). SPME and liquid-liquid extraction (LLE) are used in combination with GC-MS in untargeted analysis, in collaboration with Prof AC Silva Ferreira (Department of Viticulture and Oenology). Another focus is bioprocess monitoring of wine fermentations and the combination of sensory studies with chemistry in collaboration with Dr Hélène Nieuwoudt.
Dr Hélène Nieuwoudt is involved in the development of rapid analytical techniques based on near- and mid-infrared spectroscopy and chemometrics data analysis tools for qualitative and quantitative applications in wine biotechnology. Together with colleagues in Food Science, chemical and sensory profiling of South African Chenin blanc wines was undertaken. This project was initiated in 2010 and is part of an international research collaboration, ConsumerCheck, with Prof Tormod Naes (Technical University of Norway) as programme leader. Achievements include chemical and sensory profiling of Chenin blanc and noble late harvest wines. A flavour wheel was developed for noble late harvest wines.
DVO-IWBT: Towards an integrated approach
The NRF-funded Wine Science Research Niche Area Programme (RNA). The Wine Science RNA embodies a drive for excellence in grapevine and wine research. The programme provides a specific focus on training and research and has contributed significantly to strengthening the postgraduate programmes and outputs of the DVO and IWBT. It provides opportunities to collaborate and integrate knowledge from a range of fields and to develop critically scarce skills. The key partners in this RNA are the Institute for Wine Biotechnology (IWBT), the Department of Viticulture and Oenology (DVO), the Department of Chemistry and Polymer Science and the Department of Food Science (Sensory)
Prof FF Bauer (Yeast Molecular and Cellular Biology)
EH Blanquaert (Viticulture)
A Bosman* (Viticulture)
Prof AC Da Silva Ferreira (Flavour Chemistry)
Prof AJ Deloire (Chairperson, Grapevine Physiology and Berry Ripening)
Dr BT Divol (Wine Biotechnology)
Prof M du Toit (Wine Microbiology and Biopreservation)
Dr WJ du Toit (Wine Chemistry)
D Jacobson* (Computational Biology)
Dr E Kraeva* (Grapevine Histology and Biochemistry)
MA McKay (Wine Chemistry, Wine Aroma, Sensory Evaluation)
Dr JP Moore (Grapevine Biochemistry, Metabolomics)
Dr HH Nieuwoudt* (Spectroscopy)
Prof BA Prior (Microbiology)
AY Smit* (Yeast Biotechnology)
C Stander* (Grapevine Biotechnology)
Dr AE Strever (Grapevine Cultivation and Remote Sensing)
Dr AJG Tredoux (Analytical Wine Chemistry)
Prof MA Vivier (Grapevine Molecular and Cellular Biology)
Prof MB von Wechmar* (Microbe Biodiversity)
Dr PR Young* (Grapevine Molecular Physiology, Biotechnology)
Prof JJ Hunter* (Viticulture)
Prof MG Lambrechts* (Oenology, Wine Biotechnology)
Prof P van Rensburg* (Wine Fermentation and Processing)
Dr H Schoeman*
Cellar and vineyard assistantsw
A van Wyk
J van der Merwe*
+ Resigned/work contract expired
Department of Viticulture and Oenology and IWBT
Ms S Baard
T: 021 808 3797/4545 • firstname.lastname@example.org • www.sun.ac.za/agric/viti_oenol