Of course it is more completely the sameMoreover the market opens to public authoritiesDesigned by Thierry de Baschmakoff designerIn September 2007 he announced a grand debate on this topic see belowThe Indiana pensioners are not responsible for the bankruptcy of Chrysler68 of the French say have a poor opinion of the professiontemporary decree for a period of five yearsThe French shareholders speak with one voiceThere are also mud flats herbariums etcThe final balance sheet reports of two deadTo reduce the level of alcohol in wine without removing the aromas. It is the objective of the technical component of the project of "quality with reduced alcohol wine" (VDQA), led by the national Institute of agronomic research (Inra) and its partners. One of the laboratories of the Inra, based at Grignon, Yvelines, seeks precisely to assess one of the approaches rarely used so far: the membrane technique. The tests are performed with a device, Liquicel, provided by the American company Celgard.
The principle is to circulate two fluids, and other membrane and in direction opposite: the wine on the one hand, the water on the other. Because of the difference in concentration and the principle of osmotic distillation, alcohol of wine is attracted by water. Passing in the pores of the membrane, alcohol, very volatile, passes to the gaseous state, and then becomes soluble in contact with water. The problem is that alcohol and the aromas of wine are small molecules of equivalent size. Hence the difficulty of moving the first without leaving to escape the seconds.
The objective of the tests conducted in the laboratories of the Inra is to precisely quantify the phenomenon. To do this, the experiment is carried out with a "model" wine of 13.6 degrees. It is a transparent as water laboratory solution easier to scan through the absence of color pigments and which has only 15 aroma molecules, while a wine has a hundred.
Moderate cost
"The interest is to remove the"variability"found one wine to the other." "This allows to compare treatments," says Isabelle Souchon, research fellow at the laboratory of engineering and microbiology of food processes for Inra.
After treatment, different solutions are analysed precisely through gas chromatography apparatus. It must quantify the presence of the remaining flavours in partially dry wine, but also in water some flavourings being passed through the membrane at the same time as the alcohol. "To find the best solution, we play on the flow of water and wine", says Violaine Athès, lecturer at the Inra. The laboratory may also test other types of membrane.
The interest of the membrane technique is its low cost, its footprint reduces and the fact that it can be used at room temperature. "This small device of 20 cm has a surface of membrane of 1.4 per square metre." "This provides a performance/footprint report five hundred times better than a conventional rig", insists Isabelle Souchon.
Large scale
Two other methods are tested, including reverse osmosis and distillation under vacuum, in other laboratories of the Inra. The most well known technique today, osmosis reverse, requires a further distillation to recover water which is a party with alcohol. This year, the project partners will choose one that will be the most effective and implement larger scale at the Inra experimental unit, installed on the field of Pech-red, in the Aude.
The samples will be then produced in large quantities to be subjected to tastings and very extensive sensory analyses, especially with the Pernod Ricard research centre. "We expect an aromatic loss." What you want to know exactly, it is what loss of alcohol. Is this from 1 degree, 2 of 5 ", wondered what Nathalie Jacquet, responsible for the project in Pernod Ricard.
