Proceedings Volume 2010 (format .pdf) - SimpBTH

processes that occur during the winemaking represents a characteristic of modernOenology (Blouin J., Peynaud E., 2006).For the Oltenian vineyards, one of the most important Romanian wine region(Popa. A., 2008), the biotechnological possibilities of stimulation and control ofbiochemical and biophysical phenomena represent an important opportunity toincrease the quality, expressivity and the typical of wines.MATERIALS AND METHODSThis work has been finalized based on the research made over the pastdecade at the University of Craiova, Faculty of Horticulture, Department ofOenology in the main vineyards from the hilly Oltenia, with the purpose ofimproving the white and red winemaking technologies. The targeted technologicalsequences have been mainly the based on the biophysical and biochemical complexphenomena, which occur during the transformation of must in wine – maceration,alcoholic fermentation and malolactic fermentation. From the multitude ofbiological, biochemical and technological factors involved in the control ofmentioned processes, for this work it has been retained the role of yeasts, bacteriaand enzymes as biotechnological tools of the winemaker.The research made have been done in micro-winemaking conditions in theOenology laboratory of Faculty of Horticulture or at the pilot station of CraiovaUniversity, as well as in production conditions, in famous wine cellars fromSamburesti, Dragasani, Dealurile Craiovei, Vinju Mare vineyards, with the purposeof making superior quality wines from indigenous or foreign varieties cultivated inmentioned vineyards. Therefore, this work represents a synthesis of research madeat the Oenology Department of Faculty of Horticulture, materialized in researchcontracts, doctorate thesis, university manuals and scientific works published incountry or abroad from 1997 until today.RESULTS AND DISCUSSIONSResults and discussions concerning the role of the yeastsIn wine microbiology, the yeasts are considered agents of alcoholicfermentation, being responsible for the transformation of sugar in alcohol. By theirtechnological characteristics and physiological-biochemical traits, the yeasts have asignificant influence on the main composition parameters and sensory propertiestraits of wines. In the last 2-3 decades, the use of selected yeasts in winemaking haswitnessed a great expansion due to many advantages. Despite this, it persists aseries of controversies regarding the utility of selected yeasts in relation with theindigenous yeasts. The research made in many Oltenia vineyards in the last 15years comes to a series of clarification regarding these controversies. In Table 1 ispresented a synthesis of results regarding the influence of these two types of yeastson starting and ongoing of alcoholic fermentation. The first analyzed aspect, the135