Aspects on the variation of certain physical-chemical indices during must alcoholic fermentation

The paper presented data concerning the variation of physical-chemical indices during must alcoholic fermentation: DM – soluble dry matter, pH – real acidity, ITP – index of total polyphenols, χ–conductivity, TDS – total dissolved substances, Eh–redox potential, rH– index of Eh quantification. In relation to the values of these indices, we have investigated the evolution of main composition characteristics, respectively reducing sugars, alcohol, total acidity, volatile acidity and total phenolic compounds. The experiments have been conducted on two musts obtained from white varieties (Muscat Ottonel and Sauvignon) from the Vine Growing Centre of Copou-Iaşi and on marc obtained from two red varieties (Fetească neagră and Băbească neagră), from the Vine Growing Centre of Uricani, Iaşi vineyard, vintage of year 2006. White musts were obtained by grape crushing, removal of berries from cluster and by pressing the marc resulted at primary grape processing. Marc obtained from black varieties has been submitted to maceration-fermentation for 120 h, then the must-wine mixture continued its fermentation until sugar finishing. Determinations have pointed out a variation in time of the values of studied indices, according to the oenological potential of each variety and the used technology. According to these variations of the values of studied indices, one may find that after a certain period of time (72 hours), a change took place in the equilibrium condition of the compounds formed during the fermentation process, especially of those involved in the insolubilization of tartaric salts; this aspect was also supported by the evolution of the values of conductivity, of redox potential and TDS, especially in white wines

Connaissance de la Moldavie viti-vinicole

En Moldavie, la viticulture et la vinification sont pratiquées depuis des temps immémoriaux. Les amphores du modèle grec, mises à jour pendant des fouilles, confirment que le commerce du vin existait à la fin du VIIIe siècle avant notre ère, sur tout le littoral septentrionnal de la Mer Noire. Des grappes de raisin sont représentées sur certaines pièces de monnaie, des IIe et IIIe siècles avant notre ère, de la ville de Tyr (aujourd'hui Belgorod-Dniestrovski). Cela montre que la viticulture et la vinification étaient une des occupations les plus importantes des colonies helléniques

Incidence oenologique du traitement biologique de la vigne par <em>Trichoderma viride</em> a l'egard de la pourriture grise

T. viride actif contre B. cinerea et d'autres champignons parasites de la vigne (A. carneus, P. frequentans, P. roqueforti) ne modifie ni la composition du moût ni sa couleur; il ne présente aucune action inhibitrice sur S. cerevisiae, Schizosaccharomyces et L. oinos. Par son activité polysaccharidase, son développement conduit à des vins plus limpides. A la dégustation, aucune variation significative n'apparaît par rapport aux vins témoins. L'antagonisme de T. viride peut donc être utilisé sans danger pour les caractères des moûts et des vins. +++ T. viride active against B. cinerea and other parasitic fungi of the vine (A. carrneus, P. frequentans, P. roqueforti) modifies neither the must composition nor its colour : it has no inhibitory influence concerning S. cerevisiae, Schizosaccharomyces and L. oinos. By the use of its polysaccharidase activity its development gives wines with better limpidity. When tasting no significant variations appear when comparing with reference samples. So the antagonism of T. viride can be used without any danger for the must and wines characters