Projects / Programmes
The use of oxygen in the new vinification technologies of the white and red
| Code |
Science |
Field |
Subfield |
| 4.03.00 |
Biotechnical sciences |
Plant production |
|
| Code |
Science |
Field |
| T430 |
Technological sciences |
Food and drink technology |
oxygen, wine, grapes, microoxygenation, hiperreduction, aromatic compounds, glutathione, hydroxycinnamic acids, fermentation, yeasts
Researchers (8)
Organisations (1)
Abstract
Oxygen plays a very important role in the vinification of wines. It is already known that exposure of must or wine to air is in most cases detrimental to its quality (oxidation, loss of fruitiness, caramelization,…). ‘Hyperreduction’ – a technology in which the whole vinification chain ‘from berry to bottle’ is led without oxygen - appears as a competitive advantage in the vinification and quality improvement of varietal white wines.
This technology offers extensive advantages; the absence of oxygen prevents enzymatic and non-enzymatic oxidation which leads to a more expressed varietal aroma.
On the other hand, micro-oxygenation – addition of micro quantities of oxygen to red wines is used to optimise and accelerate the aging of red wines. It is also often used in the fermentation of white and red wine; therefore, its use seems multidisciplinary and very important for the improvement of Slovenian wines.
Both technologies require the use of special equipment, which is hardly accessible to Slovenian winemakers at the moment. Therefore, the first phase of the project will be focused on the development of appropriate equipment for reasonable price. To implement this goal, cooperation with Faculty of Engineering Construction of the Ljubljana University and the metallurgic company Škrlj d.o.o. is planned to develop equipment for hyperreduction and microoxigenation.
In the second phase of the project the use of this equipment and technologies will be verified on different Slovenian grape varieties which are important for the Slovenian viticulture. In order to verify these new technologies, new analytical methods will be set up at Agricultural Institute of Slovenia. They will include determination of both non-volatile and volatile (aromatic) compounds of must and grapes.
The research will reveal the following knowledge on technologies which have been gaining on importance in the world:
- a hyperreductive press, which ensures a complete absence of oxygen and, consequently, the oxidation of must, would be introduced in Slovenia for the first time,
- the first Slovenian micro-oxygenator, a device used for dosage of micro quantities of oxygen in wine,
- both technologies would be checked on Slovenian autochthonous varieties in different Slovenian wine cellars situated in various vine growing regions,
- new methods for the monitoring of new technologies, i.e. analyses of hydroxycinnamic acids, glutathione, average degree of polymerisation of tannins, esters, higher alcohols, terpenes, methoxypyraziones and volatile sulphur thiols.
The knowledge obtained will have a strategic meaning for the Slovenian wine making since it will enable the processing of grapes using the state-of-the-art technologies, optimise the aging of white and red wines and, for the first time, produce spectre of polyphenolic, aromatic components and glutathione in autochthonous and other varieties on the territory of Slovenia.
In order to make the results available to a wider a population of winemakers the former will be presented as workshops in each vine growing region. We also plan to publish articles in relevant publications and professional magazines.
Significance for science
The research intensified the knowledge on the influence of oxygen during the vinification of white and red wines and its direct influence on the wine components responsible for its quality. As ecpected hyperreductive technology showed higher concentration of hidroxycinnamic acids, glutathione and lower concentration of sulphur dioxide, three very important factors from the aspect of dietetics and impact of wine on human health.
Beside this, for the first time in Slovenia, we showed above average concentration of hydroxycinnamic acids in local vatriety cv. Zelen and present our result at international conference in France. Oxygen research also led us to acquire new knowledge about influence of oxygen and sulphur dioxide on glutathione, volatile thiols and methoxypyrazines. In order to analyze glutathione on HPLC - FD, we set up and validated new method, which will be published in scientific article. For the first time we analyzed the content of terpenes and their contribution on sensory of Zelen wines.
Significance for the country
For the first time in Slovenia, a hyperreductive technology was introduced in which the whole chain of white wine vinification 'from berry to bottle’ takes place in the complete absence of oxygen.
By the use of hyperreduction, Slovenian white wines may be able to improve substantially their varietal character and their typical characteristics and distinctiveness in given environment. With the transfer of new technology into practice and its establishment in Slovenia the improvement of quality of autochthonous Slovenian varieties such as Zelen and Pinela is expected. The results were shown at different symposia, congresses and in scientific articles.
The spectre of different wine components may serve to a better knowledge of the treated varieties and thus better deciding on their further technology.
Students working on their diploma and masters degree were also included in the project and used the acquired data and research.
With the applicative project the users obtained a technical and 'know-how' support in setting up and introduction of new technology. Mutual work had strengthened and linked together the cooperation between industry and research institution both in the project mentioned and in any further project. A series of performed trials and analysed components will serve for the optimisation of the equipment and technology. The company Škrlj d.o.o. will be able to increase its production with the new product and raise the level of offer at the national and international market.
New analytical methods (analyses of terpenes, esters, glutathione, methoxypyrazines...) have opened a new chapter in the vinification analyses. The work on autochthonous wine varieties has raised the level of knowledge on these varieties and the improvement of their quality will indirectly influence their better selling and establishment on the national and international market.
Most important scientific results
Annual report
2008,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2008,
final report,
complete report on dLib.si
