Przeglądaj wg Autor "Stalev, Bojan"

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  • Miniatura
    PozycjaOpen Access
    Comparison of Processing Fruit Quality of Several Grape Varieties Cultivated in Climatic Conditions of Poland and Bulgaria
    (Wydawnictwo Uczelniane Zachodniopomorskiego Uniwersytetu Technologicznego w Szczecinie, 2015) Angelov, Ludmil; Stalev, Bojan; Ochmian, Ireneusz; Mijowska, Kamila; Chełpiński, Piotr; Faculty of Viticulture and Horticulture, Agricultural University in Plovdiv, Mendeleev 12, 4000 Plovdiv, Bulgaria; Faculty of Viticulture and Horticulture, Agricultural University in Plovdiv, Mendeleev 12, 4000 Plovdiv, Bulgaria; Department of Horticulture, West Pomeranian University of Technology, Szczecin, Juliusza Słowackiego 17, 71-434 Szczecin, Poland; Department of Horticulture, West Pomeranian University of Technology, Szczecin, Juliusza Słowackiego 17, 71-434 Szczecin, Poland; Department of Horticulture, West Pomeranian University of Technology, Szczecin, Juliusza Słowackiego 17, 71-434 Szczecin, Poland
    Wine producers have been working on selecting the most suitable grape variety for specific regions and therefore improving wine production technology for numerous years. Climate changes lead to change in grape quality; in the future these changes will have to be considered by the vineyard owners as they will affect cultivation methods, harvest dates and vinification process. The aim of this paper is to compare the quality of several grape varieties cultivated in different climatic conditions. Research material was collected from vineyards situated in the Szczecin Lowlands (Poland) and Plovdiv (Bulgaria). The study focused on three grape varieties: Cabernet Sauvignon, Cabernet Franc and Pinot Noir. Measured characteristics included contained physical parameters: ruit weight, bunch weight and length and firmness as well as chemical composition: soluble solids, acidity, pH, ascorbic acid and nitrates levels, anthocyanin index. Analysed fruit was also examined in terms of colouration and must colour changes during maceration. Climatic conditions of the crop location had significant influence on the chemical composition of fruits, for example Bulgarian fruit featured higher levels of extract and pH combined with lower acidity. The Cabernet Sauvignon variety, regardless of crop location, had the highest levels of extract and organic acids. The juice obtained from Bulgarian grapes was darker (L*) than the juice from the fruit harvested in Poland. On the other hand, the juice of Polish fruit had more blue pigment (b*). It was also found that a* and b* fruit colour parameters are highly correlated with the anthocyanin index.
  • Miniatura
    PozycjaOpen Access
    Jakość owoców dwóch odmian winorośli oraz wpływ sposobu ich maceracji na barwę moszczu
    (Wydawnictwo Uczelniane Zachodniopomorskiego Uniwersytetu Technologicznego w Szczecinie, 2012) Ochmian, Ireneusz; Chełpiński, Piotr; Rozwarski, Rafał; Strzelecki, Roman; Pantecki, Paweł; Angelov, Ludmil; Stalev, Bojan; Pracownia Sadownictwa, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Pracownia Sadownictwa, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Pracownia Sadownictwa, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Pracownia Sadownictwa, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Pracownia Sadownictwa, Zachodniopomorski Uniwersytet Technologiczny w Szczecinie; Katedra Winiarstwa, Uniwersytet Rolniczy w Plovdiv, Bułgaria; Katedra Winiarstwa, Uniwersytet Rolniczy w Plovdiv, Bułgaria
    The research was conducted in the years 2010–2011 at the Fruit Farming Laboratory of the West Pomeranian University of Technology in Szczecin. Two cultivars of grapevine were examined, Regent and Cabernet Sauvignon. The size of clusters and fruits, the content of extract and organic acid and juice yield of the grape must obtained were examined. The changes of grape must colour in the process of warm (20–22oC) and cold (7–10oC) maceration were evaluated. It was shown that the Regent cultivar was characterized by larger fruits. Grapes from this cultivar also had a higher content of organic acids, vitamin C and yielded more juice, compared to Cabernet Sauvignon fruits. However, a lower extract content was found in Regent cultivar fruits. It was also found that the temperature of grape must maceration affects its colour. The release of dark dye from grape skins occurred more rapidly during warm maceration. More substances which give wine its red colour were found in the grape must prepared from Cabernet Sauvignon fruits. The measurement performed on the last day of maceration of both cultivars under analysis, regardless of the temperature at which this process was conducted, revealed the highest value of the b* parameter which defines the blue colour.