Vintage Effect on the Strain Dependent Dynamics of Ethanol Production in Vineries of Tokaj (original) (raw)
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Global Journal of Science Frontier Research D: Agriculture & Veterinary, 2020
The dynamics of ethanol production of wine yeasts were examined in model experiments as well as in the winery. The ethanol concentration in young wines fermented by local strains of Saccharomyces cerevisiae, S. uvarum or Starmerella bacillaris (21, 2 and 2, respectively) did not vary considerably (c.v. 1.9 %). All of them produced significantly higher amounts of ethanol than the type strain [ATCC 26108] of S. cerevisiae. However, their performance during the fermentation process diverged significantly. Thus the lag phase varied between 33 and 123 hours, while the time requested to produce half of the final ethanol concentration varied between 67 and 294 hours. The dynamics of ethanol production differed at high degree between S. cerevisiae strains isolated of several vintages of local wines (c.v. 25 %), where the intensity of specific ethanol production (ISEP) varied between 0.81-4.56 % ethanol per day. Reverse relationship was revealed between the Lag phase and the ISEP (r2 =0.858, p>0.01), and the circumstances of fermentation did affect this trend. Based on their properties, S. uvarum and St. bacillaris strains applied nowadays in wine making have been positioned in the ranges of S. cerevisiae strains. Baule-Mitherlich, Gompertz, hyperbolic, logistic, logarithmic, polynomial, and probit functions were applied to analyze the dynamics of fermentation. All functions fitted well to experimentally measured values at the range of 2 to 9 % of ethanol, that means, the half time could be approached by any of them at p<0.05. However, the predictive power of these functions differed significantly; both Lag phase and End point of fermentation could be calculated with requested precision (p<0.001) only with a polynomial function. The constant and secondary coefficients of this function counteracted to the primary one strictly in strain dependent manner, and the role of these three factors groups also varied in strain-dependent manners during the vinification process. Cite as: Kállai Z., Antunovics Z., Oros G. (2020): Comparative Evaluation of the Dynamics of Alcohol Production of Wine Yeast Strains Isolated in Tokaj Region. Global Journal of Science Frontier Research D: Agriculture & Veterinary, 20(6):1-22. https://doi.org/10.34257/GJSFRDVOL20IS6PG1
Global Journal of Science Frontier Research, 2020
The dynamics of ethanol production of wine yeasts were examined in model experiments as well as in the winery. The ethanol concentration in young wines fermented by local strains of Saccharomyces cerevisiae, S. uvarumor Starmerella bacillaris (21, 2 and 2, respectively) did not vary considerably (c.v. 1.9 %). All of them produced significantly higher amount of ethanol than the type strain [ATCC 26108] of S. cerevisiae. However, their performance during the fermentation process diverged significantly. Thus the lag phase varied between 33 and 123 hours, while the time requested to produce half of the final ethanol concentration varied between 67 and 294 hours.
The aptitude of commercial yeast strains for lowering the ethanol content of wine
Food Science & Nutrition, 2020
The high alcohol content in wine usually has a negative impact on its sensory properties, but can also affect the general health of the consumers. The possibility to reduce ethanol production in wines during fermentation involves the use of different yeast strains characterized by the increased production of fermentation by‐products (glycerol, 2,3‐butanediol, etc.) from the available sugar. The activity of these strains should not impair the sensory properties of the wine. In general, the use of genetically and evolutionarily (non‐GM) engineered Saccharomyces cerevisiae strains is still not close enough to commercial application, and therefore, it is unavailable for wine producers. Thus, the aim of this study was to examine the possibility of reducing the production of ethanol in wines using different selected yeast strains (S. cerevisiae, Saccharomyces bayanus, Torulaspora delbrueckii, and Metschnikowia pulcherrima) available at the market. The application of individual yeast and s...
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South African Journal for Enology and Viticulture
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