Journal paper #41069

Summary translation

Proposed by FOULON-SOPAGLY society and INRA, a six years applied research program wasdeveloped in France to enable creation of create specific lines to elaborate high quality juice with new adaptedgrapevine varieties and specialized vineyards, with adapted technology. 448 vine varieties from INRA Vassalfirst international collection of grapevine species were evaluated to finally select 14: 2 V. vinifera, 9 hybrids,and 3 from INRA creation (ref A. Bouquet) by hybridization. These last references, obtained from 4 or 5 backcrossing between Muscadinia. rotondifolia.X. V.vinifera, have in particular a high level of resistance againstmildew and oidium.These varieties have RUN 1 and RPV1. resistance genes, with several other secondarygenes on one chromosome locus. This makes access to organic market easier. Agronomic criteria are studiedfor this selection. Among the 14 selected grapevine species, some have high level of polyphenols (6 times morethan alicante). Others (white and red) have a high aromatic potential. Others have a low sugar content 135 g/lto 150 g/l) and adapted sugar/ acidity ratio. -In the cellar: The absence of fermentation and alcohol requiresoptimization of the process for juice making. For example by increasing polyphenols extraction and colourstability by using thermo-treatment. Flash release process coupled with enzymatic soaking on grapes at 45◦Cfor example, increases 2 or 3 fold polysaccharide juice content, and increases anthocyanins extraction andhence colour intensity. With this process the draining of grape marc and juice production increase. Pressuretechnology by on line horizontal decanter is possible. -In juice storehouse. Electro membrane process,(oenodia membrane process) with specific membranes gives possibilities to achieve two objectives on juice:- Decrease pH and increase acidity of juice and colour stabilization, without any additive.