Talking about the role of lactic acid bacteria in the production of yellow wine

Talking about the role of lactic acid bacteria in the production of yellow wine

Lactic acid bacteria promote the fermentation of winemaking, maintain and maintain the micro-ecological environment of winemaking; the metabolites of lactic acid bacteria have diversity, and the main metabolites of lactic acid and other organic acids have the pH value of fermentation, inhibit the production of bacteria, maintain normal fermentation, and improve The role of the rate of alcohol. At the same time, lactic acid bacteria are important basic substances for the formation of ethyl lactate and other aroma components, which have the effects of correcting aroma and taste, increasing the sense of thickness, stabilizing the aroma, softening the body and improving the quality of the rice wine.

Lactic acid bacteria are named after metabolites. They are a general term for a group of bacteria that are fermented into lactic acid by using carbohydrates (mainly glucose). There are mainly fungi (Rhizobium, Mucor, and Mycorrhizal), yeasts, and bacteria (cocci). With bacillus). Among them, bacteria are more common. At present, there are 50 kinds of lactic acid bacteria found.

Lactic acid bacteria fermentation is divided into two categories: one type is homo-type fermentation, and only lactic acid is produced during fermentation, and the same type of lactic acid fermentation is carried out by streptococci, streptococcus, bacteria, bacillus, lactobacillus, etc.; The heterogeneous lactic acid fermented microorganisms include Enterobacteriaceae, Lactobacillus brevis, Lactobacillus plantarum, Lactobacillus lactis, Rhizopus and Mucor in fungi, and the lactic acid bacteria produce lactic acid in addition to fermentation. It can also produce trace amounts of organic acids such as acetic acid, succinic acid, fumaric acid, and pyruvic acid, as well as ethanol and carbon dioxide.

1 relationship between lactic acid bacteria and rice wine brewing

The brewing of yellow wine is inseparable from the biochemical reaction of lactic acid bacteria. To some extent, the lactic acid produced by the metabolism of lactic acid bacteria reacts with the alcohol produced by yeast fermentation to form the content of ethyl lactate, which determines the flavor of yellow wine. Therefore, in order to brew famous rice wine, it is necessary to understand the lactic acid bacteria system in rice pulp water and fermentation. Mastering the system and function of lactic acid bacteria can help control the process conditions, promote the growth of beneficial bacteria and improve the quality of yellow wine products.

1.1 Breeding and research of lactic acid bacteria isolated from rice wine rice water.

The rice immersed in the rice wine process is not only convenient for cooking, but also the lactic acid produced in the rice immersion process exists in the rice pulp water, and has a practical effect on the yellow wine brewing. Due to the long time of the traditional rice immersion process, the starch loss of rice is much. Through anaerobic culture, the lactic acid bacteria isolated from the rice pulp water will be immersed in the lactic acid bacteria in the immersed rice at 2% - 3%, and the immersion rice time is 9 days, so that the lactic acid bacteria volume is increased to 1 More than 100 million / l, the acidity is 13.8g / l, basically meet the requirements.

According to the results of the production test, it meets the Shaoxing rice wine standard and the flavor is slightly higher than the traditional original rice wine.

1.2 The role of lactic acid bacteria in the fermentation process of rice wine.

Traditional high-concentration liquid French yellow wine is open and semi-open and restrained. It enters the wine cellar through pulp water, koji, rice wine, and brewing water. Due to the differences in microbial communities in wheat koji, syrup, rice wine, brewing water and fermentation vessels, the differences in material metabolism and energy metabolism lead to differences in the characteristic flavor of rice wine. Lactic acid bacteria are not only the main microorganisms in the production of yellow wine, but also important functional bacteria in the pulp water.

1.2.1 Lactic acid bacteria can adjust the pH value of wine cellar, inhibit the growth and reproduction of bacteria, and play the role of acid acid.

The lactic acid bacteria group participates in the fermentation of rice wine together with yeast and Aspergillus, commonly known as "trilateral fermentation". Mao Qingzhong believes that Lactobacillus can withstand low pH (pH 3.3-3.5) in the article "The work of Lactobacillus in the fermentation process of yellow wine", and fermented sugar produces a large amount of lactic acid. During the fermentation of rice wine, the low pH value is lowered and maintained to form the active ingredient lactic acid in rice wine. Yellow wine is an open fermentation, and the large growth of Lactobacillus can produce and accumulate Lactobacillus and maintain a low pH value, inhibit the growth and reproduction of other bacteria, and have no inhibitory effect on yeast.

In order to adapt to the environment of the fermentation sputum, the yeast itself performs a specific rearrangement of the specific chromosome, and the yeast species itself can adapt to the environment of low-pH or yellow wine fermentation sputum such as lactobacilli.

1.2.2 Provide nutrients for the yellow wine fermenting microorganisms to promote the growth and reproduction of the brewing microorganisms.

The lactic acid bacteria group normally exerts metabolic activity in the production process of rice wine, and can directly provide other microorganisms with essential amino acids (such as lysine, methionine, etc.) and various vitamins which can be used for growth and reproduction, and can also improve the biological activity of mineral elements.

1.2.3 Promote the saccharification and fermentation of enzymes in rice wine brewing. Some lactic acid bacteria can self-dissolve to produce active ingredients.

The acidic metabolites produced by the lactic acid bacteria themselves maintain and ensure the slightly acidic environment of the wine fermentation, which is conducive to the smooth progress of the saccharification and fermentation of the rice wine brewing enzyme and improve the utilization rate of raw materials.

1.2.4 is conducive to maintaining and improving the micro-ecological environment in the production of yellow wine.

During the pre-fermentation and main fermentation of rice wine, it is mainly the growth, reproduction and fermentation of high-temperature lactic acid bacteria. In the later stage of wine fermentation, it is mainly the growth, reproduction and fermentation of low-temperature lactic acid bacteria. Due to the reproduction of anaerobic lactic acid bacteria, more lactic acid is produced by metabolism, which increases the acidity of the wine cellar and effectively inhibits the metabolic activities of other bacteria. At the same time, in the process of lactic acid bacteria growth and metabolism, some substances with antimicrobial activity, such as organic acids, hydrogen peroxide, carbon dioxide, etc., are produced. These substances all exhibit antibacterial activity in vitro, and many lactic acid bacteria can produce bacteriocins, such as nisin, phage, lactobacillus, etc., which maintain and improve the stability of the micro-ecological environment of rice wine brewing. Coordination plays an important regulatory role. Moreover, in the post-fermentation, due to the decrease of the temperature, the formation of part of the high-temperature lactic acid bacteria is dead and autolyzed, and provides abundant nutrients for the fermentation of yeast and low-temperature lactic acid bacteria. Synergistic action of lactic acid bacteria group with yeast and Aspergillus.

1.2.5 The formation of precursor substances that promote the aroma of the wine and the aroma.

Lactic acid bacteria mainly produce lactic acid in the fermentation of rice wine, and also produce a small amount of acetic acid, succinic acid, fumaric acid, formic acid, propionic acid, carbon dioxide and other trace alcohols, aldehydes, acids and the like. Lactic acid is esterified to form ethyl lactate or the like.

Under different conditions, different lactic acid bacteria produce different ratios of lactic acid and other organic acids, and also produce different amounts of D-lactic acid, L-lactic acid and DL-lactic acid. Therefore, the use of lactic acid as a precursor material can produce a variety of flavors of yellow wine, which improves the complexity and perfection of the flavor of yellow wine.

1.2.6 Mixed growth and reproduction of various lactic acid bacteria is beneficial to improve the biological activity of microorganisms in yellow wine brewing.

In the traditional yellow wine brewing process, a variety of microorganisms coexist, various brewing microorganisms are closely related, a variety of lactic acid bacteria mixed growth and reproduction, anaerobic strains and non-strict anaerobic strains co-cultivate, can improve the yellow wine during the whole fermentation period It is the quantity and survival rate of anaerobic bacteria in the later stage, which can prolong the survival time of microorganisms in the fermentation process of rice wine and increase the activity of fermentation microorganisms. Among them, lactic acid and succinic acid have the same effect of promoting the growth of acetic acid bacteria.

2, lactic acid bacteria metabolites in the wine in the Chinese wine newspaper: postal code 23-189 local post office can subscribe to the content and role

2.1 The status and production pathway of lactic acid in organic acids.

In addition to producing lactic acid, lactic acid bacteria can produce a variety of trace organic acids in the fermentation of rice wine. Using lactic acid as a substrate, it can also produce other organic acids such as propionic acid and butyric acid. The above organic acids (including lactic acid) are esterified to form the corresponding ethyl ester, which is an important source of flavor for rice wine. The organic acid in rice wine is mainly lactic acid. The highest lactic acid content in Shaoxing rice wine is 4642.8mg/l, the lowest is 2952.4mg/l, and the organic acid content of Shaoxing rice wine is 40%-60%. The content of citric acid in the previous literature is generally not high, but in the new study, the content is 1306.3mg / l - 3709.9mg / l, accounting for 20.14% - 46.96% of the total acid in the wine sample.

Lactic acid is mainly produced in rice wine. When rice is cultivated in a rice wine, the medicinal liquor and mucor are mainly used to produce lactic acid and other succinic acid and fumaric acid. The rest are in the clear water and the yellow wine cellar. The action of Lactobacillus and Streptococcus produces an organic acid such as lactic acid.

2.2 Lactic acid is an organic acid that represents the characteristics of various types of yellow wine.

The main acid in each type of rice wine is lactic acid, followed by phosphoric acid, succinic acid, malic acid, citric acid, tartaric acid and the like. Among the four major acids (lactic acid, phosphoric acid, succinic acid, citric acid), the highest content of lactic acid.

In dry type Shanghai Jiahuang wine, lactic acid accounted for 83.52%-70.71% of total acid, semi-dry type lactic acid content accounted for 76.55% of total acid in Huadiao wine, and lactic acid content of sweet-type sealed cylinder wine accounted for 73.47% of total acid, Jiangsu The lactic acid content of the old wine accounted for 71.95% of the total acid, and the lactic acid content of the Changchun corn wine accounted for 67.97% of the total acid.

2.3 The content and status of ethyl lactate in the aromatic ester of rice wine.

A part of ethyl lactate in rice wine is formed by the esterification of lactic acid to produce ethyl lactate: CH3CHOHCOOH + C2H5OH - C2H4OHCOOC2H5 + H2O, that is, 76.18 mg of lactic acid per 100 mg of ethyl lactate. The content of ethyl lactate in rice wine is 341.29mg/l-917.50mg/l, and the lactic acid is 260mg/l-698.9mg/l. Therefore, a certain amount of lactic acid forms ethyl lactate under yeast lipidation; and the content of lactic acid and ethyl lactate increases after aging of yellow wine.

The content of ethyl lactate has an important position in the alcoholic esters, which accounts for 83.18%-70.73% of the total esters. It is precisely because of the different proportions of the content of aroma components in the characteristics of yellow wine. The rich aroma of the type of yellow wine.

3. Function and role of lactic acid bacteria metabolites in the flavor of yellow wine

3.1 The role and status of lactic acid in the flavor of yellow wine.

3.1.1 Performance and characteristics of lactic acid.

The main metabolite of lactic acid bacteria is lactic acid, and α-hydroxypropionic acid, which contains a hydroxyl group and a carboxyl group. The fermented lactic acid is mostly L-type, with a melting point of 16.8 ° C, a boiling point of up to 122 ° C, and a relative density of 1.249. When the lactic acid reaches a high concentration, the ester is condensed to form an equilibrium state. An ester obtained by condensing two molecules of lactic acid is called lactyl lactic acid, and then dehydrated to form lactide.

When the lactic acid flavor characteristic is from 0.007g/100ml to 0.016g/100ml, it is soft and thick, and excessively hairy.

3.1.2 Lactic acid can reduce the activity of rice wine and increase the alcohol and degree of the wine.

Although lactic acid has a small molecular weight and contains a hydroxyl group and a carboxyl group, it easily forms hydrogen bonds with water molecules and ethanol molecules. It is because lactic acid has strong adhesion in wine, which means that it takes a long time to interact with the taste organs of the mouth. At the same time, lactic acid can bind to the volatile small molecules in the wine through hydrogen bonds, and acts as a bridge and bond between the small molecules and the macromolecules, so that the macromolecules, small molecules and trace elements in the wine body are more likely to form colloids. The lactic acid itself has the characteristics of slightly acidic, slightly sinuous, soft, and thick.

3.1.3 Lactic acid can reconcile the taste, soften the body and stabilize the aroma.

Because of the high content of lactic acid in rice wine, the wine is soft and rich, which brings good flavor to rice wine. At the same time, it is blended with other organic acids and the content is softer and smoother. It balances the taste of the wine, makes the wine blend and reduces the spicy taste. Moreover, lactic acid has the characteristics of large viscosity, high boiling point and easy solidification, so it can change the volatilization speed of odor molecules in the wine, and play the role of reconciling the taste of the system and stabilizing the aroma of the wine.

3.1.4 Lactic acid is an effective catalyst and stabilizer for the old wine of old wine.

For a long time, for the problem of the new yellow wine aging Chen, the rice wine industry has used a variety of methods, but the effect is not obvious.

In fact, the organic acid in rice wine is a good old-fashioned catalyst, and lactic acid is more special. From the molecular structure of lactic acid, it is water-soluble, alcohol-soluble, and ester-soluble, and it is in the wine and in the wine. The scent of the flavor component and the connecting agent form a colloid, which can effectively alleviate the hydrolysis of the ester in the wine, promote the stability of the wine, and is also beneficial to the ripening of the new wine, improve the degree of fusion of various flavor substances in the wine, and increase the body of the wine. The complexity of the aroma shows the effect of the stable old aging agent of lactic acid.

3.2 The role and status of ethyl lactate in the flavor of yellow wine.

3.2.1 Characteristics and characteristics of ethyl lactate.

Ethyl lactate is a colorless, volatile liquid with a special rum, fruit and creamy aroma. The boiling point of 154 ° C, a flash point of 46 ° C. Miscible in water, alcohols, ketones, ethers and greases.

3.2.2 Increase the sweetness of rice wine.

The flavor characteristic of ethyl lactate is that the flavor is weak and the taste is slightly sweet, and an appropriate amount of ethyl lactate has a rich feeling.

Yellow rice wine contains high ethyl lactate, which can increase the coordination and sweetness of the wine. At the same time, it can also increase the alcohol and degree of the wine.

3.2.3 Extend the aftertaste of yellow wine and enrich the taste.

Ethyl lactate has good miscibility with ethanol, esters and water due to its molecular composition. This trait determines that it is a non-volatile ester, and its total ester regularity is ethyl lactate>acetic acid B. Ester > Diethyl succinate > Ethyl formate.

It is because of the high content and proper content and proportion that it can prolong the rich taste of the wine and coordinate the aroma. The source of the article is to increase the aftertaste.

3.2.4 Increase the aroma and softness of the rice wine.

Ethyl lactate forms a colloidal solution in the body with the molecules of each component, which has a softer taste. It is present in the wine in an appropriate proportion and content, which can alleviate the irritating feeling of the wine and is better. It reflects the softness and warmness of the yellow wine and the aroma of the aroma.