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Modern winemaking in Ukraine is being significantly transformed and is actively developing. Our state has now turned to the search for its own wines and grape varieties. For international recognition, it is important to develop your case of wines that will be able to show the diversity of wine regions from Southern Bessarabia and the Northern Black Sea Coast to Transcarpathia. There are more and more small winemakers who are experimenting with new varieties, such as Sukholimansky white, Citronny Magaracha, Zagrei, Johanniter, Zvalgate, Solaris, Aromatny, Telti Kuruk and various muscat varieties. The organoleptic profile of such wines should express the varietal characteristics of local grape varieties and the agro-climatic features of the terroir. At the same time, the modern technology of white table wines should be built on the principles of maximum preservation of varietal aroma and minimization of its oxidation during the technological process. The article reflects the results of theoretical studies of literary sources regarding the mechanisms of oxidative processes of various nature in the process of grape processing; the market of modern preparations for stabilizing wine materials is considered. According to the goal, the influence of the use of the enzyme preparation Viazim clarif one on the process of clarifying the wort was investigated. The effect of complex antioxidant pasting of wort with the stepwise application of "Tanal W4", "Polygreen" and "Granula" bentonite on aromatic compounds and the formation of the aromatic profile of the finished product was also studied. At the last stage of research, the organoleptic profile of white wine materials of the studied grape varieties was determined. It was established that the general trend of stabilization processes in modern winemaking is transferred to the wort stage. According to the results of practical tests, in the form of trial pastes of wort, it is proposed to use the enzyme preparation "Viazim clarif one" at the stage of extracting wort; the effect of complex antioxidant pasting of wort with stepwise application of "Tanal W4", "Polygreen" and "Granula" bentonite was studied. Practical recommendations have been developed for winemakers on the application of antioxidant wort pasting for domestic grape varieties Sukholimansky white and Citronny Magaracha, which are now gaining popularity in Ukraine. [ABSTRACT FROM AUTHOR]

For wine quality management, nitrogen metabolism should be considered as a key process in the system "grape-wine". Nitrogen is one of the dominant elements a grapevine receives from the soil. It is important in many biological processes of the plant itself and of the microorganisms involved in fermentation. Nitrogen-containing compounds are nutrients necessary for yeast growth, in particular, for stable fermentation. This group of compounds directly and indirectly affects the aromatic and taste qualities of wine during its maturation and largely determines its stability. Nitrogen compounds are transferred to wine directly from grapes and yeast during fermentation. Since their role in the formation and maturation of wine is significant, it is highly important to regulate their metabolism in the fermenting must. On analysing literature references and summarising the information on the metabolism of nitric substances, a scheme has been developed reflecting how these substances influence the formation of the quality characteristics of grape wines. The paper presents the results of studying the metabolism of total nitrogen and amino nitrogen in grape must during its fermentation. The grape variety considered in the research was Sukholimansky White bred by the National Science Centre "Tairov Institute of Viticulture and Winemaking" and harvested in 2015–2017. It has been established that nitrogen metabolism during fermentation does not depend on the feedings added. However, the yeast race affects the physicochemical parameters, namely the content of volatile acids. It has been observed that during fermentation, the amine nitrogen concentration decreases by 90% and the total nitrogen concentration by 40–50%. Regarding the factors that effect on the quality characteristics of wines produced in the South of Ukraine, the physicochemical parameters of wine materials can be improved by using the active dry yeast Vitilevure Quartz and the nutritional supplements Actiferm 1 and Actiferm 2, in combination with aeration. This allows revealing fruity aromas, and achieving the right acidity and harmony of taste due to the presence of the descriptors (butter, apple, peach, apricot, and geranium) characteristic of the grape variety Sukholimansky White. [ABSTRACT FROM AUTHOR]

One of the most important problems of the modern wine technology is the production of high quality and competitive products. It is commonly known that the quality of a wine largely depends on the yeast race. The main requirement for yeast is completeness of fermentation, which depends on the amount of yeast involved, aeration, initial content of various substances in the must, temperature, pH of the environment. Using imported materials in the specific conditions of national winemaking requires laboratory and industrial research to rationalize the use of local and foreign pure yeast cultures and to accelerate the process of grape must fermentation. So, this study considers how the yeast origin and additional nutrition effect on grape must fermentation and influence the physicochemical and organoleptic characteristics of wine materials obtained from the white grape varieties Aromatny and Zagrei of the generative breeding by the National Scientific Centre Tairov Viticulture and Winemaking Institute. Besides, it has been concluded whether using additional nutrition is practical. It has been established that the fermentation process was complete in both the control and the experimental samples. There were no facts of underfermentation. When supplementary nitrogenous nutrition was used, the fermentation activity of yeast increased and the fermentation process ended faster. The dynamics of the total number of cells of the Aromatic and Zagrei varieties was the same during the years 2015-2017 and did not depend on the fermentation scheme. It has been found that the fermentation process does not depend on supplementary nutrition, but the yeast race effects on the physicochemical parameters, namely on the volatile acids content. The results obtained have shown the effect of a yeast race and supplementary nutrition on the organoleptic characteristics of these varieties. In Southern Ukraine, to control the quality characteristics of wine materials, using active dry yeast Saccharomyces cerevisiae with a two-stage nutrition complex has a positive effect on the physicochemical parameters of the corresponding grape variety and allows revealing its varietal characteristics. [ABSTRACT FROM AUTHOR]