Decisions on viticulture
- As a fundamental component of the vitivinicultural "terroir", climate largely affects the vine physiology, agronomic characteristics and the final quality of its products. In order to be able to assess the scale and significance of the effect of climate change in recent decades in relation to global vitiviniculture, as well as the projections for the future, the OIV adopted a methodology so that these scientific assessments can be adapted to the vitivinicultural sector and be as accurate as possible, before proposing strategies to adapt to these present or future changes (Resolution OIV-VITI 517-2015). This methodology follows four steps: 1/ define the period of the study, 2/ define the spatial scope of the study, 3/ choose the climatic and vitivinicultural variables, and 4/ choose the climatic models and the scenarios of the study.
- Moreover, the OIV adopted recommendations for the inventory of greenhouse gas (GHG) emissions in the vine and wine sector on the subject of the GHGs as well as their global warming potential, activities and impacts to be considered (Resolution OIV-CST-503AB 2015). It also decided to provide more specific information on national and international methodologies for the valuation of GHG emissions in a separate informative report, updated on a regular basis by OIV experts. This document, based on the general principles of the OIV GHG protocol, is intended to provide specific information on the elements to be considered when calculating the GHG emissions of a company or a particular product as well as detailed information on the GHGs to be considered.
Decisions on oenological practices
Several resolutions concerning new oenological practices will be added to the International Code of Oenological Practices, in particular:
- A new oenological practice for the treatment of musts and wines using glutathione (Resolutions OIV-OENO 445-2015 and OIV-OENO 446-2015). The objective of this practice is to limit the intensity of the oxidation phenomena in musts thanks to the ability of glutathione to trap quinones and reduce their oxidasic activity, but also to protect the aromatic substances of the wine from oxidation thanks to the antioxidant properties of glutathione. For wine, it is recommended that glutathione be added during conservation and/or packaging in bottles. The dose used should not exceed 20 mg/L.
- The treatment of wines with malolactic fermentation activators was adopted. This practice is designed to promote the initiation, kinetics or completion of malolactic fermentation either by enriching the environment with nutrients and growth factors of lactic acid bacteria, or by adsorbing some bacteria inhibitors (Resolution OIV-OENO 531-2015).
Decisions on the specifications of oenological products
The following monographs have been added to the International Oenological Codex:
- a revision of the monograph on proteins of plant origin. A specification is added to the potato proteins by fixing a maximum limit for glycoalkaloids (?-solanine and ?-chaconine) smaller than 300 mg/kg of protein (Resolution OIV-OENO 557-2015);
- a revision of the monograph on tannins (Resolution OIV-OENO 554-2015). This modification concerns iron content which should be less than 50 mg/kg, with the exception of the iron content for tannins from chestnuts which was increased to 200 mg/kg;
- a revision of the monograph on casein (Resolution OIV-OENO 555-2015). This revision concerns the modification of the level of potassium carbonate and/or potassium hydrogen carbonate in the mixture of soluble caseins and the level of ashes, which should be less than 3% for acid casein and less than 23% for the acid casein and potassium carbonate, or potassium hydrogen carbonate, mixture.
Decisions on Methods of Analysis
During this same session, new methods of analysis were adopted and will be added to the analytical corpus of the OIV. These include, in particular:
- Specific methods for the analysis of grape sugars (rectified concentrated grape musts). These methods involve, in particular, the determination of meso-inositol, scyllo-inositol and sucrose through gas chromatography following silanisation (Resolution OIV-OENO 419C-2015) and the introduction of the Folin-Ciocalteu Index. Phenolic compounds of MCR are oxidised by the Folin-Ciocalteu reagent and the blue colour produced is measured using spectrophotometry at 750 nm (Resolution OIV-OENO 419D-2015).
- Two methods were slightly modified. These were the section addressing the preparation of the sample for the method to determine the volatile acidity in wines (Resolution OIV-OENO 549-2015) and for the method to determine the total acidity in wine (Resolution OIV-OENO 551-2015).
- A method relating to the determination of the distribution of deuterium in acetic acid extracted from wine vinegar using nuclear magnetic resonance (NMR) (Resolution OIV-OENO 527-2015). This method makes it possible to analyse of isotopic ratio of hydrogen (D/H)CH3 of the methyl group of acetic acid extracted from wine vinegar. This method is based on the principle that the deuterium content in the sugar and water of the grape must is divided following fermentation into molecules of wine ethanol, and following acetic fermentation into molecules of acetic acid. This method also facilitates the determination of the origin of the alcohol in wine vinegars
Decisions on safety and health
In accordance with the Agreement establishing the Organisation, the OIV adopted two resolutions on research policy regarding the consumption of wine products and the effects on health.
- These involve guidelines for future research on the effects of the consumption of grapes or grape juice on health (Resolution OIV-SECSAN 429-2015). CONSIDERING that the consumption of fresh grapes and grape juice is a source of phenolic compounds, the OIV recommended that research include: 1/ the conducting of in vitro and in vivo studies on the effects of the consumption of grapes or grape juice on human health, such as the biochemical and physiological activities associated with chronic degenerative diseases; 2/ the development of human intervention studies to evaluate the impact of grape juice consumption on health; 3/ an assessment of whether the polyphenols, flavonoids and other grape-derived compounds act in synergistic effects on health; 4/ an evaluation of the antibacterial activity of grape polyphenols for pathogenic strains.
- Other guidelines for future research on the effects of wine consumption (Resolution OIV-SECSAN 463-2015) were also adopted. These include recommending the development of research: 1/ on the possible relationship between moderate wine consumption with meals and the decrease of the oxidative effects of ethanol; 2/ on carefully controlled and randomised studies in appropriate populations; 3/ to clarify the conditions under which light to moderate wine consumption may reduce the risk of death and certain diseases; 4/ to determine whether alcohol, phenolic compounds and other components of wine provide different protective effects in the body's cells, organs and tissues; and 5/ in relation to the diversity of consumer motivation.
The full texts of the resolutions adopted by the 13th OIV General Assembly will shortly be available on the OIV website, www.oiv.int
