Mixed bacterial liquid for improving flavor of white spirit as well as preparation method and application of mixed bacterial liquid

Abstract

The mixed bacterial liquid for improving the flavor of the white spirit comprises lactobacillus sanfrancisco, bacillus licheniformis, bacillus coagulans, Wickerhamomyces cerevisiae and absidia umbellata, and the strains are mixed according to the volume ratio of (1-2): (3-1): (2-3): (1-2): (2-1) to prepare the mixed bacterial liquid. The preparation method of the mixed bacterial liquid comprises the following steps: respectively activating the lactobacillus sanfrancisco, the bacillus licheniformis, the bacillus coagulans, the Wickerhamomyces cerevisiae and the absidia umbellata to prepare seed liquids, and carrying out mixed fermentation culture on the multi-strain seed liquids for 36-60 hours to obtain the mixed bacterial liquid. Through the synergistic effect of five microorganisms in the baijiu brewing process, the flavor quality of the baijiu is remarkably improved through the comprehensive effects of adjusting the fermentation environment, providing flavor precursor substances, directly synthesizing flavor substances, influencing metabolism of other microorganisms and the like, so that the baijiu has richer and more attractive aroma and taste characteristics, and the flavor quality of the baijiu is improved. The requirements of consumers on high-quality white spirit are met.

Description

Technical Field

[0001] The invention belongs to the technical field of liquor fermentation and brewing, and particularly relates to a mixed bacterial liquid for improving the flavor of liquor, and a preparation method and application thereof. Background Art

[0002] As a traditional drink unique to my country, baijiu is deeply loved by consumers for its unique flavor. The flavor components of baijiu are extremely complex, including esters, alcohols, aldehydes, ketones, organic acids and other compounds. These components interact with each other to form the rich and diverse aroma and taste of baijiu. Traditional baijiu brewing mainly relies on the fermentation of natural microbial communities, but due to the uncertainty of the types and numbers of microorganisms in the natural environment, it is difficult to effectively control the stability and consistency of baijiu flavor.

[0003] With the development of modern biotechnology, the use of specific microbial combinations to regulate the fermentation process of liquor and improve the flavor quality of liquor has become a hot topic in the liquor industry. The present invention aims to provide a mixed bacterial liquid composed of specific microorganisms and its production method and application, so as to overcome the shortcomings of traditional brewing technology and achieve precise regulation and improvement of liquor flavor. Summary of the invention

[0004] In order to overcome the above shortcomings, the present invention provides a mixed bacterial liquid for improving the flavor of liquor and a preparation method and application thereof. In order to achieve the above purpose, the technical solution adopted by the present invention is: A mixed bacterial liquid for improving the flavor of liquor, comprising Lactobacillus sanfranciscosi, Bacillus licheniformis, Bacillus coagulans, Wickham yeast and Absidia corymbifera, and the above strains are mixed in a volume ratio of 1-2:3-1:2-3:1-2:2-1.

[0005] Further optimization, the concentrations of Lactobacillus sanfrancisco, Bacillus licheniformis, Bacillus coagulans, Wickham yeast and Absidia corymbifera are all 10 8 -10 9 CFU / ml.

[0006] A method for preparing a mixed bacterial liquid for improving the flavor of liquor, comprising: activating Lactobacillus sanfranciscosi, Bacillus licheniformis, Bacillus coagulans, Wickham's yeast and Absidia corymbifera respectively to prepare seed liquid, and subjecting the seed liquids of the above-mentioned multiple bacterial species to mixed fermentation culture for 36-60 hours under the conditions of temperature of 28-32°C, pH of 5.5-7.0 and 130-170rpm to obtain a mixed bacterial liquid.

[0007] Further optimization, the activation of the strains is: Lactobacillus sanfrancisco, Bacillus licheniformis, Bacillus coagulans, Wickham yeast and Absidia corymbifera are inoculated into the corresponding culture medium respectively.

[0008] Further optimized, the culture medium components of Lactobacillus sanfrancisco include peptone, beef extract, yeast powder, glucose, Tween, K2HPO4·3H2O, anhydrous sodium acetate, triammonium citrate, MgSO4·7H2O, MnSO4·H2O, and each component is added with distilled water at a pH of 6.3 and mixed; The culture medium components of the Bacillus licheniformis include tryptone, yeast extract and sodium chloride, and each component is added with distilled water and mixed at a pH value of 7.0; The culture medium components of the Bacillus coagulans include peptone, beef extract and sodium chloride, and each component is added with distilled water and mixed at a pH value of 7.2±0.2; The culture medium components of the Wickham yeast include yeast extract, peptone and glucose, which are added with distilled water and mixed; The culture medium components of Absidia corymbifera include potato, glucose and agar, which are added with distilled water for mixing.

[0009] For further optimization, the culture medium of each strain was sterilized by high pressure sterilization at 121°C for 20 min after adding distilled water and mixing.

[0010] Further optimized, the method for preparing the seed solution is: the activated bacterial solution of each bacterial species is transferred to an expansion culture medium to culture to obtain the seed solution of each bacterial species.

[0011] The invention discloses an application of a mixed bacteria liquid for improving the flavor of liquor in the grain mash fermentation stage of liquor brewing.

[0012] For further optimization, the mixed bacterial liquid was added to the grain mash at 0.3-1.0% (v / w) of the grain mash mass.

[0013] The beneficial effects of the present invention are: Through the synergistic effect of the above five microorganisms in the liquor brewing process, the comprehensive effects of adjusting the fermentation environment, providing flavor precursors, directly synthesizing flavor substances and affecting the metabolism of other microorganisms can significantly improve the flavor quality of the liquor, making the liquor have richer and more attractive aroma and taste characteristics, meeting consumers' demand for high-quality liquor, and also providing an innovative and effective technical means for flavor regulation in the liquor industry. DETAILED DESCRIPTION

[0014] In order to more clearly understand the above-mentioned purposes, features and advantages of the present invention, the present invention is described in detail below in conjunction with specific embodiments. The following embodiments are implemented based on the technical solutions of the present invention, and detailed implementation methods and specific operating procedures are given. However, the present invention can also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the following embodiments.

[0015] A mixed bacterial solution for improving the flavor of liquor, the mixed bacterial solution comprising 8 -10 9 CFU / ml of Lactobacillus sanfrancisco, Bacillus licheniformis, Bacillus coagulans, Wickham yeast and Absidia corymbifera, and the above strains are mixed according to a volume ratio of 1-2:3-1:2-3:1-2:2-1.

[0016] Among them, Lactobacillus sanfrancisco produces organic acids such as lactic acid during the fermentation process. Lactic acid can adjust the pH value of the fermentation system, provide a suitable growth environment for other microorganisms, and promote the stability and coordinated fermentation of microbial communities. At the same time, lactic acid can undergo esterification reactions with alcohol substances such as ethanol to produce ester compounds such as ethyl lactate. Ethyl lactate has an elegant fruity and milky smell and is one of the important flavor esters in liquor. It can enhance the softness and complexity of the aroma of liquor and make its aroma more coordinated. In addition, the metabolic activity of Lactobacillus sanfrancisco can also affect nitrogen metabolism in the fermentation system and promote the formation of nitrogen-containing compounds such as amino acids. These nitrogen-containing compounds can participate in chemical reactions such as the Maillard reaction during subsequent fermentation and distillation to produce flavor substances such as pyrazines, adding special aromas such as baking and nutty aromas to liquor.

[0017] Bacillus licheniformis and Bacillus coagulans have strong enzyme activities, including proteases and amylases. They can decompose proteins and starches in raw materials and degrade macromolecules into small molecules such as amino acids and sugars. Amino acids are not only nutrients required for microbial growth, but also precursors of flavor substances. For example, some amino acids can generate flavor compounds such as aldehydes and ketones through reactions such as deamination and decarboxylation during the fermentation process. These compounds have unique aroma characteristics. For example, acetaldehyde has a pungent smell, but the presence of a moderate amount can increase the refreshing feeling of liquor, and some ketones have a fruity or floral smell. The generated sugar substances provide energy and carbon sources for the growth and metabolism of microorganisms on the one hand, and on the other hand, they can participate in the synthesis of alcohols and esters in the later stage of fermentation. For example, glucose can be fermented by yeast to produce ethanol, and ethanol can react with organic acids to produce esters, thereby enriching the flavor components of liquor. In addition, these two Bacillus can also produce some growth factors such as vitamins during the growth process, which promote the growth and metabolism of other microorganisms and further affect the flavor formation of liquor.

[0018] In addition to producing ethanol, Wickham yeast can also synthesize a variety of higher alcohols, such as isopentanol and n-propanol, during the fermentation process. A proper amount of higher alcohols can give the liquor a full taste, but an excessive amount will cause the liquor to have a pungent smell and a bad taste. Wickham yeast can convert precursors such as amino acids into higher alcohols, and by adjusting its own metabolic pathways, it controls the production of higher alcohols within a suitable range. At the same time, Wickham yeast can also synthesize esters, such as ethyl acetate. Ethyl acetate is one of the main aroma components of liquor, with a fruity and fragrant smell. Its content and proportion have a decisive influence on the aroma style of liquor. Under the optimal fermentation conditions, the ethyl acetate production of this strain reached 16.92g / L. There is a complex interaction between Wickham yeast and other microorganisms. It can utilize the metabolites produced by other microorganisms, and its own metabolites can also be utilized or converted by other microorganisms. This synergistic fermentation promotes the diversified generation of flavor substances. For example, some organic acids produced by Wickham yeast can be used by lactic acid bacteria to synthesize esters, while certain vitamins and other substances produced by lactic acid bacteria can promote the growth and metabolism of Wickham yeast.

[0019] Absidia corymbosa can secrete a variety of enzymes, such as cellulase and pectinase. These enzymes can decompose cellulose, pectin and other substances in the raw materials and convert them into sugars and other substances that can be used by other microorganisms, increasing the utilization rate of fermentation raw materials. At the same time, Absidia corymbosa can synthesize some special flavor compounds, such as certain ketones, during the metabolism process. These ketone compounds have unique aroma characteristics and can add a fresh and elegant flavor to liquor. In addition, Absidia corymbosa can also interact with other microorganisms in the fermentation system to regulate the fermentation microecological environment. It can change the physical and chemical parameters such as oxygen content and pH value in the fermentation system, affect the growth and metabolic pathways of other microorganisms, and indirectly promote the synthesis and balance of more flavor substances. For example, Absidia corymbosa consumes oxygen during its growth, creating a relatively anaerobic environment, which is conducive to the growth and metabolism of anaerobic microorganisms such as lactic acid bacteria, promotes the production of organic acids such as lactic acid, and then affects the synthesis of ester substances.

[0020] A method for preparing a mixed bacterial liquid for improving the flavor of liquor comprises bacterial strain activation, seed liquid preparation and mixed culture.

[0021] Bacteria activation Lactobacillus sanfrancisco: The freeze-dried bacteria were inoculated into a 500 mL Erlenmeyer flask containing 100 mL of LMRS liquid culture medium and cultured in a constant temperature shaking incubator at 37°C and 150 rpm for 24 h.

[0022] Bacillus licheniformis: inoculate the freeze-dried bacteria into 100 mL of LB liquid culture medium and culture at 35°C and 180 rpm for 20 h.

[0023] Bacillus coagulans: inoculate into 100 mL of nutrient broth liquid culture medium and culture at 37°C and 150 rpm for 24 h.

[0024] Wickham yeast: cultured in 100 mL YPD liquid medium at 28°C and 200 rpm for 36 h.

[0025] Absidia corymbifera: inoculate into 100 mL of potato glucose liquid medium and culture at 26°C and 120 rpm for 48 h.

[0026] Seed solution preparation Lactobacillus sanfrancisco: Transfer the activated bacterial solution at 5% (v / v) into a 1000-mL Erlenmeyer flask containing 200 mL of fresh MRS medium and culture at 37°C and 170 rpm for 13 h.

[0027] Bacillus licheniformis: Transfer to 200 mL LB medium at 4% (v / v) and culture at 35°C and 190 rpm for 11 h.

[0028] Bacillus coagulans: Transfer to 200 mL nutrient broth at 5% (v / v) and culture at 38°C and 160 rpm for 15 h.

[0029] Wickham yeast: transfer to 200 mL YPD medium at 6% (v / v) and culture at 28°C and 220 rpm for 25 h.

[0030] Absidia corymbifera: Transfer to 200 mL of potato dextrose liquid medium at 5% (v / v) and culture at 26°C and 140 rpm for 35 h.

[0031] Mixed culture The seed liquids of Lactobacillus sanfranciscosi, Bacillus licheniformis, Bacillus coagulans, Wickham's yeast, and Absidia corymbifera were mixed in a 5 L fermentation tank according to a volume ratio of 1-2:3-1:2-3:1-2:2-1.

[0032] The fermentation tank parameters were set to a temperature of 30°C, a pH of 6.0, and a stirring speed of 150 rpm, and mixed fermentation culture was carried out for 48 hours to obtain a mixed bacterial solution.

[0033] Application of mixed bacterial liquid in liquor brewing At the early stage of fermentation of grain mash in liquor brewing, 500 g of grain mash was taken, and mixed bacterial liquid was added according to 0.5% (v / w) of the mass of grain mash. After stirring evenly, fermentation was carried out according to the traditional solid-state fermentation liquor brewing process. The fermentation cycle was 30 days, and then distillation operation was carried out to obtain liquor.

[0034] The flavor substances in the liquor were analyzed and sensory evaluated by using the mixed bacterial liquid of the present invention and the liquor brewed by the traditional process. Subsequently, the flavor substances in the liquor were quantitatively analyzed by using a gas chromatography-mass spectrometer (GC-MS).

[0035] Table 1 Changes in the content of flavor substances before and after liquor fortification The mixed bacterial liquid regulates the fermentation environment, provides flavor precursors, and synthesizes a variety of flavor substances through the synergistic effect of various strains, significantly improving the flavor quality of liquor. The increase in the total amount of ester substances, the optimization of the content of higher alcohols, and the appropriate increase in organic acids make the aroma of liquor richer and the taste softer, which has important application value and broad market prospects.

[0036] The above shows and describes the main features, methods of use, basic principles and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements according to actual conditions, and these changes and improvements fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A mixed bacterial liquid for improving the flavor of liquor, characterized in that: The mixed bacterial liquid includes Lactobacillus sanfrancisco, Bacillus licheniformis, Bacillus coagulans, Wickham yeast and Absidia corymbifera, and the above strains are mixed according to the volume ratio of 1-2:3-1:2-3:1-2:2-1.

2. The mixed bacterial liquid for improving the flavor of liquor according to claim 1, characterized in that: The concentrations of Lactobacillus sanfrancisco, Bacillus licheniformis, Bacillus coagulans, Wickham yeast and Absidia corymbifera were all 10 8 -10 9 CFU / ml.

3. A method for preparing a mixed bacterial liquid for improving the flavor of liquor, characterized in that: The Lactobacillus sanfranciscosi, Bacillus licheniformis, Bacillus coagulans, Wickham's yeast and Absidia corymbifera are activated respectively to prepare seed liquid, and the seed liquids of the above multiple strains are mixed and fermented for 36-60 hours under the conditions of temperature of 28-32°C, pH of 5.5-7.0, and 130-170rpm to obtain a mixed bacterial liquid.

4. The method for preparing a mixed bacterial liquid for improving the flavor of liquor according to claim 3, characterized in that: The activation of the strains is as follows: Lactobacillus sanfrancisco, Bacillus licheniformis, Bacillus coagulans, Wickham yeast and Absidia corymbifera are inoculated into corresponding culture media respectively.

5. The method for preparing a mixed bacterial liquid for improving the flavor of liquor according to claim 4, characterized in that: The culture medium components of the Lactobacillus sanfrancisco include peptone, beef extract, yeast powder, glucose, Tween, K2HPO4·3H2O, anhydrous sodium acetate, triammonium citrate, MgSO4·7H2O, and MnSO4·H2O, and each component is added with distilled water at a pH of 6.3 and mixed; The culture medium components of the Bacillus licheniformis include tryptone, yeast extract and sodium chloride, and each component is added with distilled water and mixed at a pH value of 7.0; The culture medium components of the Bacillus coagulans include peptone, beef extract and sodium chloride, and each component is added with distilled water and mixed at a pH value of 7.2±0.2; The culture medium components of the Wickham yeast include yeast extract, peptone and glucose, which are added with distilled water and mixed; The culture medium components of Absidia corymbifera include potato, glucose and agar, which are added with distilled water for mixing.

6. The method for preparing a mixed bacterial liquid for improving the flavor of liquor according to claim 5, characterized in that: The culture medium of each strain was sterilized by high pressure sterilization at 121°C for 20 min after adding distilled water and mixing.

7. The method for preparing a mixed bacterial liquid for improving the flavor of liquor according to claim 3, characterized in that: The method for preparing the seed solution is as follows: the activated bacterial solutions of the various bacterial species are transferred to expansion culture media to culture the seed solutions of the various bacterial species.

8. The use of the mixed bacterial liquid as claimed in claim 1, characterized in that: The mixed bacterial liquid is used in the grain mash fermentation stage of liquor brewing.

9. The use of the mixed bacterial liquid as claimed in claim 8, characterized in that: Add the mixed bacterial liquid to the mash at 0.3-1.0% (v / w) of the mass of the mash.

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