Objective
The research project has an immediate multidisciplinary integrated approach: the role of sulphur dioxide during all stages of wine production will be studied in relation to the colour of red wine, the microbiological stability and sensory quality.
The interactions between malvidin-3-glucoside, the main anthocyanin in red wine made from Vitis vinifera grapes, and (+)-catechin, including the role of ferric ions and acetaldehyde was investigated in a model wine. In the presence of acetaldehyde the formation of 5 new compounds was determined by high performance liquid chromatography (HPLC); this formation was concurrent with rapid losses in the concentrations of malvidin-3-glucoside and catechin.
1 of the new compounds was a dimer consisting of malvidin 3-glucoside linked to catechin by an acetaldehyde bridge.
Concurrent with the losses in anthocyanins, qualitative and quantitative changes in visible colour were also observed, as determined by spectrophotometric measuremtns and colour changes were also monitored using the CIELAB 76 colour measurement system.
In the presence of 150 mg/kg sulphur dioxide there was an increase in extraction of colour during the first 6 days of fermentation; higher sulphur dioxide concentrations give more total phenols and total pigments in the wines. On storage all wines lost colour.
Other work achieved so far involve:
aquisition of a collection of 46 spoilage organisms;
development of a method to determine the concentration of free and total sulphur dioxide using the Tacussel sulphur dioxide analyzer, a headspace sensitive electrode (HSE);
determination of the most effective media for growth with minimal binding of sulphur dioxide;
study of the effect of different polymeric fractions from wine on the growth of yeasts and lactic acid bacteria;
testing 3 wines with differing concentrations of sulphur dioxide (0,75 and 150 ppm maximum) against wine spoilage organisms.
Points of interest to industry and consumers are:
the amount of sulphur dioxide required to make a stable wine is probably between 75 and 150 ppm;
the inhibitory moieties in wine (other than sulphur dioxide) appear to be in the fraction of lowest molecular weight, although this fraction also proved stim ulatory to some yeasts;
in model systems a dimer has been characterized as being more violet than the original wine pigments.
In the wine industry sulphur dioxide is generally used during processing and bulk storage, and a final addition is made just prior to bottling. No other single preservative fulfils the manifold properties of sulphur dioxide, since it has both antioxidant and antimicrobial activity. During bulk maturation of red wines polymers are formed some of which precipitate forming a deposit. Furthermore the colour of the wine changes to brownish red and the taste becomes softer. It is believed that the polymerized phenols may exhibit some antimicrobial action since red wine tends to become less prone to microbial spoilage as it matures.
Although there are legal guidelines regulating the maximum concentration of sulphur dioxide in bottled wine, there is little information about the optimum concentration required to prevent microbial spoilage and to ensure a stable wine colour and appearance without precipitates. More information is needed to establish the role of sulphur dioxide during the maturation of red wines with respect to the formation of stable coloured polymers and its action as an antimicrobial compound in conjunction with wine polymers. To minimize the complexity of this problem, we propose to study initially in model wines the following two aspects:
the role of sulphur dioxide in the polymerization of anthocyanins with other phenols, thereby establishing the optimum concentration of sulphur dioxide to obtain a desirable and stable wine colour and,
the sulphur dioxide tolerance of wine spoilage microorganisms and the synergistic effects between sulphur dioxide and other microbial inhibitors.
In order to validate the results obtained from work with model systems, similar studies will be done with wines. It will be necessary to establish the optimum sulphur dioxide concentrations at the various stages of wine processing that will give wine of stable coloration and microbiological characteristics. Furthermore, the effect of sulphur dioxide on the quality of the wines will be assessed by sensory analysis.
Work to be carried out:
studies using model wine systems to examine the role of sulphur dioxide in the polymerization of anthocyanins with other phenols, thereby establishing the optimum concentration of sulphur dioxide to obtain a desirable and stable wine colour;
studies on wine applying the information gained from model systems to establish the role of sulphur dioxide at various stages of processing (production, maturation and bottling), in the colour stability, microbiological stability and sensory quality of wine;
examination of the sulphur dioxide tolerance of wine spoilage organisms and the synergistic effects between sulphur dioxide and other microbial inhibitors, such as alcohol and selected wine phenolics.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
- agricultural sciences agriculture, forestry, and fisheries agriculture horticulture viticulture
- engineering and technology materials engineering colors
- natural sciences chemical sciences organic chemistry organic acids
- natural sciences chemical sciences polymer sciences
- engineering and technology industrial biotechnology bioprocessing technologies fermentation
You need to log in or register to use this function
Programme(s)
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Topic(s)
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Data not available
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Call for proposal
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Data not available
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Funding Scheme
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Coordinator
RG6 2EF Reading
United Kingdom
The total costs incurred by this organisation to participate in the project, including direct and indirect costs. This amount is a subset of the overall project budget.