Continuous alcoholic fermentation process: model considering loss of cell viability

1999 ◽  
Vol 20 (2) ◽  
pp. 157 ◽  
Author(s):  
S. C. Oliveira ◽  
T. C. B. Paiva ◽  
A. E. S. Visconti ◽  
R. Giudici
Keyword(s):  
Cell Viability ◽  
Process Model ◽  
Fermentation Process ◽  
Alcoholic Fermentation

Achieving Procedure of a Kinetic Model to Predict the Influence of the Process Global Temperature on a Technological Alcoholic Fermentation II. An Arrhenius type Kinetic Model

2008 ◽  
Vol 59 (4) ◽  
Author(s):  
Neculai Catalin Lungu ◽  
Maria Alexandroaei
Keyword(s):  
Experimental Data ◽  
Saccharomyces Cerevisiae ◽  
Kinetic Model ◽  
Economic Efficiency ◽  
Fermentation Process ◽  
Alcoholic Fermentation ◽  
Global Temperature ◽  
Medium Temperature ◽  
Biotechnological Process

The aim of the present work is to offer a practical methodology to realise an Arrhenius type kinetic model for a biotechnological process of alcoholic fermentation based on the Saccharomyces cerevisiae yeast. Using the experimental data we can correlate the medium temperature of fermentation with the time needed for a fermentation process under imposed conditions of economic efficiency.

scholarly journals THE INFLUENCE OF YEAST RACES ON THE AROMA-FORMING SUBSTANCES OF TABLE WINES

2021 ◽  
Vol 447 (3) ◽  
pp. 13-18
Author(s):  
Z.А. Anarbekova ◽  
G.I. Baigazieva
Keyword(s):  
Direct Contact ◽  
Fermentation Process ◽  
Alcoholic Fermentation ◽  
Grape Juice ◽  
Yeast Cells ◽  
Higher Alcohols ◽  
Long Time ◽  
Speed Up ◽  
Biotechnological Processes

Wine is a product of biochemical transformations, compounds present in grape juice, by controlled alcoholic fermentation, that is, effervescence. Grape and yeast enzymes play a key role in the processing of grapes and the preparation of wine, influencing all biotechnological processes of winemaking. Adding liquid or dry active yeast to the wort allows better control of the fermentation process. Under the influence of these yeasts, sugar is converted mainly into alcohol or carbon dioxide, but the yeast itself during fermentation produces many molecules (higher alcohols, esters) that affect the aroma and taste of wine. These transformations take about two weeks and lead to a significant increase in temperature, which must be regulated, not allowing it to rise above 18-20°C: otherwise, some of the aromatic substances may evaporate and the fermentation process itself will stop. The amount of yeast that determines the correct and complete fermentation depends both on the quality of the wort itself, and on the more or less prolonged access of air, the ambient temperature. The air, or rather the oxygen of the air, has a beneficial effect on fermentation as long as there are still many nutrients (sugars) in the wort; as the latter are consumed, extremely small yeast cells are formed, which persist for a long time in the form of turbidity. The rapid course of fermentation can be greatly facilitated by the periodic stirring of yeast, which, settling to the bottom, lose direct contact with nutrients — the lower layers almost do not function. You can mix the wort mechanically or by adding healthy whole grapes to it; in this case, the wort is constantly and automatically mixed: the berries, rising up in the fermenting liquid, carry the yeast with them. In order to speed up the fermentation, the wort is sometimes ventilated, that is, air is introduced into it, by mixing. This article shows the influence of the yeast race on the fermentation dynamics of white grape must, the composition of organic acids and aroma-forming components. The races that ensure the production of highquality wine materials are identified.

scholarly journals A Knowledge-Based System as a Sustainable Software Application for the Supervision and Intelligent Control of an Alcoholic Fermentation Process

2020 ◽  
Vol 12 (23) ◽  
pp. 10205
Author(s):  
Anca Sipos
Keyword(s):  
Intelligent Control ◽  
Fermentation Process ◽  
Production Efficiency ◽  
Alcoholic Fermentation ◽  
Control Level ◽  
Exponential Growth Phase ◽  
Monitoring And Control ◽  
Software Application ◽  
Knowledge Based System ◽  
Knowledge Based

One goal of specialists in food processing is to increase production efficiency in accordance with sustainability by optimising the consumption of raw food materials, water, and energy. One way to achieve this purpose is to develop new methods for process monitoring and control. In the winemaking industry, there is a lack of procedures regarding the common work based on knowledge acquisition and intelligent control. In the present article, we developed and tested a knowledge-based system for the alcoholic fermentation process of white winemaking while considering the main phases: the latent phase, exponential growth phase, and decay phase. The automatic control of the white wine’s alcoholic fermentation process was designed as a system on three levels. Level zero represents the measurement and adjustment loops of the bioreactor. At the first level of control, the three phases of the process are detected functions of the characteristics of the fermentation medium (the initial substrate concentration, the nitrogen assimilable content, and the initial concentration of biomass) and, thus, functions on the phase’s duration. The second level achieves the sequence supervision of the process (the operation sequence of a fermentation batch) and transforms the process into a continuous one. This control level ensures the quality of the process as well as its diagnosis. This software application can be extended to the industrial scale and can be improved by using further artificial intelligence techniques.

Influence of various yeast strains and selected starchy raw materials on production of higher alcohols during the alcoholic fermentation process

2014 ◽  
Vol 240 (1) ◽  
pp. 233-242 ◽  
Author(s):  
Grzegorz Kłosowski ◽  
Dawid Mikulski ◽  
Dorota Macko ◽  
Beata Miklaszewska ◽  
Katarzyna Kotarska ◽  
...  
Keyword(s):  
Fermentation Process ◽  
Alcoholic Fermentation ◽  
Raw Materials ◽  
Higher Alcohols ◽  
Yeast Strains

Gas chromatographic quantitative analysis of the gaseous emissions and carbon balance in the alcoholic fermentation

OENO One ◽  
1997 ◽  
Vol 31 (2) ◽  
pp. 85
Author(s):  
C. Chon ◽  
Alain Poulard ◽  
Claude Rabiller
Keyword(s):  
Nmr Spectroscopy ◽  
Liquid Phase ◽  
Fermentation Process ◽  
Alcoholic Fermentation ◽  
Balance Sheet ◽  
Volatile Components ◽  
Dynamic Mode ◽  
Gaseous Emissions ◽  
Head Space ◽  
C Nmr

<p style="text-align: justify;">The balance of the carbon transfers occuring during the fermentation of sugar is still poorly defined. To our knowledge, no description exists which accounts at each moment of the process for the components in the liquid phase and the evolution of the gaseous carbon components. However, this question is of prime importance for the vinification process. The gap between the concentration of fermentable sugars in a must and the theoritical potential alcoholic degree is always significant. The same is true for chaptalisation, in which vinters generally use more sugar than needed to obtain a given alcoholic degree. In both cases, the question is : what happens to the carbon matter lost? Is it transformed into liquid and/or gaseous metabolites or simply evaporated as ethanol or as other volatile components?</p><p style="text-align: justify;">ln order to try to answer to this question, methods able to analyse simultaneously and quantitatively the liquid phase, the gaseous emissions and the biomass are needed. Recently, we have shown that under suitable defined conditions <sup>13</sup>C NMR spectroscopy allows the quantitative measurement of at least eight components present at a concentration up to 5 x 10<sup>-3</sup>M (glycerol, glucose, butandiols, tartric, malic, lactic, citric and succinic acids) in a short time (one hour) with a precision of about 3 p. cent. The measurements of the ethanol concentrations and of the amount of carbon transferred in the biomass are easily achieved using respectively ebullioscopic and standard combustion techniques. We are now able to extend these results and to show that, by using gas chromatography in a continuous dynamic mode and under a sweep of air at the head space of the fermentor, it is possible to measure quantitatively the mixture of volatile substances (composed mainly of air, carbon dioxide, ethanol and water) emanating from an alcoholic fermentation. The results obtained, when correlated with quantitative <sup>13</sup>C NMR spectroscopy on the medium components permits the total balance sheet of the carbon transfers occuring during the fermentation process betwcen the liquid and the gaseous phases to be established. Our results indicate that the losses of ethanol during the fermentation process conducted under an air flow at the head space of the fermentor, may reach about 10 p. cent of the theoretical maximal amount of ethanol produced. The experiments presented here could explain the ethanol losses observed during some vinification processes conducted in open tanks.</p>

Kinetic Study of the Alcoholic Fermentation Process, in the Presence of Free and Immobilized Saccharomyces Cerevisiae Cells, at Different Initial Glucose Concentrations by Reversed Flow GC

2010 ◽  
Vol 72 (11-12) ◽  
pp. 1149-1156 ◽  
Author(s):  
Georgia Ch. Lainioti ◽  
John Kapolos ◽  
Lambros Farmakis ◽  
Athanasia Koliadima ◽  
George Karaiskakis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Kinetic Study ◽  
Fermentation Process ◽  
Alcoholic Fermentation ◽  
Reversed Flow
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