CN103793543A - Rice wine fermentation dynamical model - Google Patents

Abstract

The invention relates to a rice wine fermentation dynamical model. According to the method, the relations between rules of state variables, such as bacterium concentration, substrate concentration and product concentration, changing with time, and control variables (temperature, pH and dissolved oxygen) of the state variables, during the rice wine fermentation process, are pinpointed by data fitting; a rice wine fermentation process bacterium growth dynamical model, a substrate consumption dynamical model, and a product (alcohol) generation dynamical model are established by means of Matlab with csape, fnder, ppval and nlinfit. The rice wine fermentation dynamical model is of important significance and practical value to actively controlling rice wine fermentation process conditions and guaranteeing product stability; meanwhile, the rice wine fermentation dynamical model also provides theoretical basis for the amplification of the fermentation process and the transition from batch fermentation to fed-batch fermentation and continuous fermentation.

Description

A kind of kinetic model of yellow wine fermentation

Technical field

The invention belongs to the dynamic (dynamical) model of a kind of yellow wine fermentation, what relate generally to is a kind of yellow wine fermentation kinetic model.

Background technology

Yellow rice wine is one of the world's three great Gu wine, comes from China, and only state-owned it.The yellow rice wine place of production is wider, and kind is a lot.Yellow rice wine is rich in the compositions such as carbohydrate, amino acid, vitamin, protein, enzyme, trace element, ester class, and easily digested, so be described as " liquid cake ".

Over the past thousands of years, yellow rice wine hover all the time using pithos, Tao Tan in the handicraft workshop formula mode of production of round.But along with the raising of people's material life, in drinks market, no longer pursue strong white wine, and progressively to the development of low-alcoholicity nutrient type yellow rice wine, quality and the demand of market to yellow rice wine is increasing.But be subject to traditional handicraft to affect yellow rice wine increase of production speed slow, yellow rice wine quality discrepancy is larger.And people still control yellow wine fermentation process by natural climate condition in traditional yellow rice wine production technology, people are also difficult to sweat to control.This causes between every batch of yellow rice wine quality to have a long way to go even with also not identical between batch wine.This makes the large tank of mechanization produce the inexorable trend that becomes yellow wine production technology innovation.

And up till now, the mode of production of yellow rice wine is still brewageed as main take manual, and brewages as orthodox school depending on manual, and the shared proportion of mechanization yellow rice wine is less than 1/3rd of total production, manufacturing enterprise also can produce traditional yellow rice wine with oneself and take pride in, and even brags about the product " altar altar is manual " of oneself.If a kind of product is take handicraft as characteristic, determine its value with creator's skill height, calligraphy and drawing sculpture, traditional dress and Chinese lute manufacture etc. so, the height of manual skill can determine the quality of product really.But have while contacting closely when a kind of product has been formed as the large production of socialization and its essence and scientific and technological content, so manual can only be the yoke that hinders yield-power development, and the production of yellow rice wine just belongs to the latter.Proposing this viewpoint is not the traditional-handwork technique that will totally repudiate rice wine production, but will make full use of the reasonable intension of yellow rice wine traditional handicraft, in conjunction with the state-of-the-art technology of modern science and technology, the production technology of yellow rice wine is reached a new high.

Beer, automatic and mechanical degree vinous are more and more higher, and technology is more and more advanced, and production efficiency improves constantly.And hinder the main cause that mechanization large jar yellow wine develops, except small enterprise's fund and technical strength deficiency and idea problem, main cause is still produced gordian technique in yellow rice wine process to large tank and could not enough be broken through.Before shao-hsing rice wine, ferment tank maximum volume is 60m at present ³, and beer fermentation tank volume reaches 100m ³-600m ³.After beer fermentation container maximizes, due to fermentation substrate and yeast convection current acquisition strengthening, accelerate fermentation, shortened fermentation period, significantly reduced tank number, reduced investment outlay.

Biochemical Engineering had once produced very large impact about amplification work to the development of fermentation industry, due to various amplification method developments, the knowledge of microorganism and fermentation aspect is in continuous accumulation, and Biochemical Engineering teacher are devoted to amplification work and have gradually become more accurately with more effective.But yellow rice wine is high thick mash fermentation, fermentation substrate and fermentation character are all larger with beer difference, people's Changing Pattern such as temperature, pH in large jar yellow wine sweat is not also grasped completely, bulk fermentation technique carries out initiatively opening rake by filtrated air in addition, automatically seethe with guiding karusen, discharge carbon dioxide, carry out aerobic metabolism to reach yeast, but when ventilate, on thalli growth, metabolism has or not in the problems such as impact and can not solve throughput size.Cause yellow rice wine bulk fermentation process mathematical model to be set up based on these factors and be difficult to, thereby round maximization also still there are many technical barriers to need to solve.

Fermentation dynamics is to realize the precondition of sweat optimum control, is also to study sweat amplification and be transitioned into stream from batch fermentation to add fermentation, the theoretical foundation of continuously fermenting.The present invention is based on biology, chemistry, physics, the prerequisite of the development of the science such as computing machine, and people are in yellow wine fermentation process, complicated chemical reaction, accurate and quantitative understanding and the description of the metabolic mechanism of thalline etc., set up one and comprised numerous empirical factors (pH value, initial substrate concentration, the type of substrate sugar, temperature, dissolved oxygen DO etc.) at interior kinetics equation and correlation model, this will be conducive to grasp more accurately, understand each important parameter of yellow wine fermentation process, realize yellow wine fermentation robotization, the important prerequisite of yellow wine fermentation equation and research direction after being.

Therefore, the present invention to wine fermentation process condition, guarantee the significant and practical value of product stability, this is also that sweat amplifies and is transitioned into stream from batch fermentation and adds fermentation, the theoretical foundation of continuously fermenting simultaneously.

Summary of the invention

The invention provides a kind of kinetic model of yellow wine fermentation, feature of the present invention is: by data fitting being found accurately to the state variables such as cell concentration, concentration of substrate, production concentration in the yellow wine fermentation process relation between rule and control variable (temperature, pH value and dissolved oxygen DO) thereof over time, set up the kinetic model that kinetic model, nutrient uptake kinetics model, the product (alcohol) of thalli growth in yellow wine fermentation process generate.Described model can be estimated the state such as cell concentration, concentration of substrate, production concentration in yellow wine fermentation process.

(1) foundation of kinetics equation

Set up the kinetic model that the kinetic model, nutrient uptake kinetics model, product (alcohol) of thalli growth in yellow wine fermentation process generate, the data that must obtain experiment are carried out matching and are obtained cell concentration, concentration of substrate, production concentration kinetics equation.

The data that first the present invention obtains experiment are carried out matching, adopt Logistic equation form, obtain the logarithmic relationship model of yeast cells quality and time.Because the rice wine production cycle is long, the growth of yeast cells can obviously be divided into early stage (growth period and stationary phase) and two stages of later stage (decline phase), therefore adopts piecewise function to be described the upgrowth situation of yeast:

A) earlier fermentation:

c _X(t)＝0.004lnt+0.012，R ²＝0.9663

Wherein: c _xfor thalline mass concentration; T is fermentation time.

B) in the fermentation later stage, yeast cells enters decline phase, and in the ecological deterioration of decline phase Growth of Cells, living cells rate of death increases, and cell concentration reduces rapidly.The rate of death of cell is also followed one-level reflection kinetics relation, the yeast cells quality of matching decline phase and the numerical relationship model of time:

c _X(t)＝0.033e ^-0.11t(t＞8d)，R ²＝0.975

Wherein: c _xfor thalline mass concentration; T is fermentation time.

Then, data are carried out to matching, obtain the logarithmic relationship model of alcohol quality concentration and time:

c _P(t)＝2.706ln?t+6.653，R ²＝0.960

Wherein: c _pfor alcohol quality concentration; T is fermentation time.

Again, data are carried out to matching, obtain the logarithmic relationship model of remaining total sugar concentration and time:

c _S(t)＝-27.2ln?t+78.36，R ²＝0.966

Wherein: c _sfor residual sugar mass concentration; T is fermentation time.

(2) yeast growth model

Describe the yeast cells growing state in early stage according to Logistic equation, have:

$V_x=\frac{\mathrm{dX}}{\mathrm{dt}}={\mathrm{\μ}}_{\max }(1-\frac{c_x}{c_{x\_\max }})c_x$

That is:

$\mathrm{\μ}={\mathrm{\μ}}_{\max }(1-\frac{c_x}{c_{x\_\max }})c_x$

Wherein: c _xfor barm cell concentration; μ _maxand c _x-maxfor undetermined coefficient.

According to experimental data, yeast growth kinetics equation is carried out to nonlinear regression and fitting, solving model parameter:

μ＝0.1864(1-0.204c _x)，R ²＝0.966

Wherein: μ is thalline specific growth rate, c _xfor barm cell concentration.

The mass mortality of subordinate phase yeast cells, cell concentration reduces rapidly, does not do to consider at this.

(3) alcohol generation model

The formation of alcohol is that based on this theory, the formation model of alcohol should be relevant to the mass concentration of thalline because of the metabolic result of yeast cells.Adopt the comparatively general mathematical model being proposed in nineteen fifty-nine by LuedekingR and PiretEL:

$\frac{{\mathrm{dc}}_p}{\mathrm{dt}}=\mathrm{\α}\frac{{\mathrm{dc}}_x}{\mathrm{dt}}-{\mathrm{\βc}}_x$

Wherein: α, β are respectively the kinetic constant relevant with cell enlargement speed and cell concentration.

That is:

q _p＝αμ+β

Utilize q _swith the correlativity of μ, utilize graphing method to solve α and β.Solve α=-661.0; β=19.30.Alcohol generation kinetic model is during the fermentation: q _p=-661.0 μ+19.3, R ²=0.958.

(4) substrate sugar consumption model

Base consumption model is mainly divided into base consumption three parts and considers: form product, supply with thalli growth, maintain cellular respiration metabolism, based on this principle, the model form of foundation is:

$\frac{{\mathrm{dc}}_s}{\mathrm{dt}}=-\frac{1}{Y_{X/S}}\frac{{\mathrm{dc}}_X}{\mathrm{dt}}-{\mathrm{mc}}_X-\frac{1}{Y_{P/S}}\frac{{\mathrm{dc}}_P}{\mathrm{dt}}$

Wherein: Y _x/sthe yield coefficients of thalline to substrate, dimensionless; Y _p/sthe yield coefficients of alcohol to substrate, dimensionless; M is for maintaining coefficient, h ^-1.

Produce this physiology course of alcohol for culture propagation, produce the substrate that consumes of alcohol come from Growth of Cells maintain can substrate, the now generation of product is directly associated with the production of energy, and therefore the wear rate equation of substrate does not comprise independent product generating item, can formerly by equation abbreviation be:

$\frac{{\mathrm{dc}}_s}{\mathrm{dt}}=-\frac{1}{Y_{X/S}}\frac{{\mathrm{dc}}_X}{\mathrm{dt}}-{\mathrm{mc}}_X$

That is:

$q_a=-\frac{\mathrm{\μ}}{Y_{X/S}}-m$

Utilize q _swith the correlativity of μ, utilize graphing method to solve Y _x/Sand m.

Solve Y _x/S=6.69 × 10 ^-9gg ^-1; M=192.5gh ^-1g ^-1, nutrient uptake kinetics model is during the fermentation: q _s=11447 μ+192.5, R ²=0.956.

Accompanying drawing explanation

Fig. 1 is q _swith the correlationship figure of μ, utilize graphing method to solve the auxiliary view of α and β.

Fig. 2 is q _swith the correlationship figure of μ, utilize graphing method to solve Y _x/Sauxiliary view with m.

Claims (4)

1. a kinetic model for yellow wine fermentation, described model can be estimated the state such as cell concentration, concentration of substrate, production concentration in yellow wine fermentation process, it is characterized in that comprising the steps:

A) according to normal yellow rice wine method for making, different pH values are set and ferment, adopt respectively direct titrimetric method, use determination of distillation method, cell dry mass weight method to measure alcohol quality, cell dry mass in soluble sugar, karusen.Obtain the relation between pH value and growth kinetics of cells parameter.

B) according to normal yellow rice wine method for making, different fermentations temperature is set and ferments, adopt (1) described identical method to obtain yellow wine fermentation procedure parameter under different temperatures.

C) according to normal yellow rice wine method for making, different dissolved oxygen is set and ferments, adopt (1) described method to obtain yellow wine fermentation procedure parameter under different dissolved oxygen.

D) find the state variables such as cell concentration in sweat, concentration of substrate, the production concentration relation between rule and control variable (temperature, pH value and dissolved oxygen DO) thereof over time accurately by data fitting, use Matlab, in conjunction with csape, fnder, ppval, nlinfit, set up the kinetic model that the kinetic model, nutrient uptake kinetics model, product (alcohol) of thalli growth in yellow wine fermentation process generate.

2. according to the method described in claims 1, apply Logistic equation, set up the kinetic model of thalli growth in yellow wine fermentation process, its model is as follows:

μ＝0.1864(1-0.204c _x)，R ²＝0.966

Wherein: μ is thalline specific growth rate, c _xfor barm cell concentration.

3. according to the method described in claims 1, set up the kinetic model that product in yellow wine fermentation process (alcohol) generates, its model is as follows:

q _S＝11447μ+192.5，R ²＝0.958

Wherein, q _sfor product (alcohol) is than productive rate, μ is specific growth rate.

4. set up nutrient uptake kinetics model in yellow wine fermentation process according to the method described in claims 1, its model is as follows:

q _p＝-661.0μ+19.3，R ²＝0.956

Wherein, q _pfor than base consumption speed, μ is specific growth rate.

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