Перегляд за Автор "S. Kovalchuk, T. Mudrak"

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  • Документ
    A RESOURCE-SAVING AND ENERGY-EFFICIENT TECHNOLOGY OF FERMENTATION OF WORT FROM STARCH-CONTAINING RAW MATERIALS FOR BIOTHETANOL PRODUCTION
    (2022) S. Kovalchuk, T. Mudrak
    In the context of market economy, an urgent task of the alcohol industry is reducing the cost of commercial products by creating and introducing innovative energy-efficient and resource-saving technologies. In this aspect, a task of current importance is developing a technology that involves using new high-yielding races of distiller’s yeast to ferment highly concentrated wort obtained from grain raw materials. The wort used for fermentation was from different types of grain raw materials: maize, rye, wheat. The studies have shown that an increase in the concentration of dry matter of maize wort (up to 30%) makes it possible to obtain wash with the alcohol concentration 15.65% vol., an increase in the dry mater concentration of wheat wort (up to 27%) – 14.10% vol., in that of rye wort (up to 24%) – 13.00% vol. ethanol. With the standard yield of alcohol from 1 tonne of standard starch, the maximum alcohol content in the maize wash was 14.91% vol., while in the wheat wash, it was 14.1% vol., and in the rye wash, 13.0% vol. It has been studied how the temperature of fermentation of high-concentration wort affects the chemical and technological parameters of fermented maize wash. It has been established that the stage-by-stage fermentation of maize grain wort (at 35 and 30°С) creates conditions for additional saccharification of dextrins in the wort and for its effective end-fermentation. Therefore, this technique is especially effective in the fermentation of high-concentration wort. The introduction of the technology developed will allow efficiently processing agricultural raw materials into alcohol and reducing production waste (post-alcohol stillage). To validate the results of the theoretical and laboratory studies, the technology of highly concentrated alcohol wash from grain raw materials has been tested in the conditions of alcohol production at the company TOV FAZOR in Kozhanka, Fastiv District, Kyiv Region (capacity 6000 dal of alcohol-containing liquids a day). For the manufacturing tests, technological guidelines were developed and approved according to the due procedure.
  • Документ
    INFLUENCE OF DRY CONCENTRATION OF DRY SUBSTANCES ON FEATURES OF OSMOPHILIC ALCOHOLIC RACES OF YEAST
    (2021) S. Kovalchuk, T. Mudrak
    The main factors influencing the cultivation environment on the growth and development of different races of alcoholic yeast have been studied. The following races were selected for studies of the influence of wort dry matter concentration on morpho-physiological features of alcoholic yeast yeast cells: S. cerevisiae ДО–16, ДО–11, K-81, XII. The novelty of the work lies in the study of the influence of the concentration of dry matter of the wort on the morpho-physiological features of alcoholic yeast, screening of alcoholic races for fermentation of highly concentrated wort. The morphology of cells of alcoholic races of the yeast S. cerevisiae, which are cultured on starch-containing medium, has been insufficiently studied. It was found that the cells of the alcoholic yeast race S. cerevisiaeДО-16 and ДО-11 had smaller cell sizes in comparison with the thermotolerant and mesophilic races S. cerevisiae K-81 and XII at a concentration of DM wort of 28%. However, the number of yeast cells in S. cerevisiae ДО-16 and ДО-11 races is higher. During the fermentation of highly concentrated wort, these indicators characterize the increase in the working surface of the yeast in the fermented medium, which allows to intensify the fermentation process. Studies have been conducted on the effect of dry matter concentration on the size and shape of giant colonies of alcoholic races of yeast. Culture samples were taken in the stationary phase of growth. Studies of giant colonies of alcoholic breeds of yeast cultured on wort at a concentration of 28% DM indicate that the race of S. cerevisiae ДО-16, in comparison with other races, is able to withstand high concentrations of wort. After all, the size and shape of the giant colonies of this race indicate that the yeast cells were in a satisfactory physiological condition. According to morpho-physiological characteristics, alcoholic yeast of race S. cerevisiae ДО–16, ДО–11, K–81, XII with thermotolerant and osmophilic properties for fermentation of highly concentrated wort was screened Based on theoretical and experimental studies, it was found that the selected race of yeast S. cerevisiae ДО-16 on morpho-physiological characteristics has advantages over races ДО-11, K-81, XII for fermentation of high concentrations of wort. Thus, for fermentation of highly concentrated wort from grain raw materials, a highly productive race of alcoholic yeast with increased osmophilicity - S. cerevisiae ДО –16 was selected.
  • Документ
    SELECTION OF THE TECHNOLOGICAL PARAMETERS OF FERMENTATION OF HIGH-CONCENTRATION WORT WITH OSMOPHILIC YEAST RACES FOR OBTAINING BIOETHANOL
    (2021) S. Kovalchuk, T. Mudrak
    Bioethanol production is a key issue that helps meet the growing demand for energy resources and ensure a sustainable economy. A promising direction is producing bioethanol by using the technology of fermentation of high-concentration wort obtained from the dry matter of grain raw materials. The purpose of this work is researching osmophilic races of distiller’s yeast under the conditions of fermentation of high-concentration wort at increased acidity. Selective breeding of a new strain of the yeast Saccharomyces cerevisiae DO-16 has allowed obtaining ethanol producers able to ferment grain wort with the dry matter concentration 24–34% at pH 6.0–3.0, with alcohol accumulation in the fermented wash up to 17% vol.  It has been studied how the pH of wort affects the dynamics of yeast cell synthesis by the distiller’s yeast races Saccharomyces cerevisiae DO-11 and Saccharomyces cerevisiae DO-16. It has been established that at the pH values 2.5, 3.0, 3.5, and 4.0, the concentration of yeast cells in the race Saccharomyces cerevisiae DO-16 was higher by 2.6, 1.7, 1.5, and 1.4 times respectively, as compared with Saccharomyces cerevisiae DO-11. It has been found that culturing industrial yeast of these races at low pH values ​​will provide not only the required sterility of the substrate, but also a high content of yeast cells, which is 250–320 million/cm³. The chemical and technological parameters of the fermented wash obtained by using the yeast races Saccharomyces cerevisiae DO-11 and DO-16 at the wort concentration 20–34% DM have been studied. It has been found that under all research conditions, the yeast of the race Saccharomyces cerevisiae DO-16 synthesised more ethanol than the strain Saccharomyces cerevisiae DO-11 did. The use of a new high-productive strain of Saccharomyces cerevisiae DO-16 will allow fermenting wort with a high ethanol concentration in the wash. It will also reduce the consumption of heat expended on isolating alcohol from the wash and of water expended on cooling, and lessen the amount of post-alcohol stillage.