Background
The fermentation process of Shanxi mature vinegar includes two important links of alcohol fermentation and acetic acid fermentation, wherein different microorganisms form a multi-bacterium co-fermentation system in each link, and the multi-bacterium co-fermentation systems are mutually metabolized in a synergistic manner to generate micromolecular substances rich in esters, amino acids, organic acids, vitamins and the like. These material components also form the material basis of color, fragrance, taste and body, and the vinegar also becomes the first seasoning of five-flavor seasoning for daily diet. Although the Shanxi mature vinegar has high acid content, no irritation, soft sourness and unique flavors of acid, soft, sweet and the like, wherein the function of organic acid is very important, and the organic acid is both in acid substance and fragrance, so the composition and the content of the organic acid not only determine the unique flavor of the Shanxi mature vinegar, but also are closely related to the quality of products.
Succinic acid, which is a non-volatile acid in organic acids of vinegar, can increase the mellowness of vinegar, play a role in coordinating the flavor of vinegar and improving the taste, and can stimulate the secretion of digestive glands of a human body to stimulate the appetite.
The corynebacterium glutamicum is a facultative anaerobic microorganism, does not grow under anaerobic conditions, but can convert glucose into substances such as lactic acid, succinic acid and acetic acid, and the like, so that the acidity of the vinegar is improved. In addition, the succinic acid is produced by corynebacterium glutamicum biotransformation method, mainly by passing phosphoenolpyruvate or pyruvate obtained from glycolysis pathway (EMP) through one-step CO branch of tricarboxylic acid cycle (TCA) pathway2The succinic acid is generated by fixing and two-step reduction reaction, so that a glutamic acid bacteria preparation is added in a targeted manner in the alcohol fermentation process to promote the microbial metabolism to generate the succinic acid, and meanwhile, the industrialization and the standardization of the vinegar brewing process rich in the succinic acid are realized by utilizing fermentation equipment convenient for automatic control.
Disclosure of Invention
The invention provides a preparation method of succinic acid-rich mature vinegar and the succinic acid-rich mature vinegar, aiming at solving the problems of low succinic acid content and poor quality of vinegar in the current naturally fermented vinegar.
The invention is realized by adopting the following technical scheme: a preparation method of succinic acid-rich mature vinegar comprises the steps of taking sorghum as main grain, mixing the main grain, yeast and water according to a weight ratio of 1:0.6:3.3, dividing the mixture into 2 parts, directly carrying out alcohol fermentation and acetic acid fermentation on one part, then smoking a fermented substance, adding a corynebacterium glutamicum preparation with the weight of 4% -7% of that of fermented mash into the other part, carrying out alcohol fermentation, and then carrying out the steps of: bran: bran coat: rice hull: mixing materials according to the weight ratio of 400:120:80:80:180 of water, and performing acetic fermentation to obtain white grains; mixing the white fermented grains and the smoked fermented grains according to the weight ratio of 7:3, performing pouring on the obtained white fermented grains and the smoked fermented grains by adopting a circulating pouring method, sterilizing the obtained new vinegar, and filtering.
The method specifically comprises the following steps:
(1) raw material treatment: removing impurities from sorghum, pulverizing to 10-20 mesh, puffing under steam pressure of 0.3MPa to obtain staple food grain, and pulverizing Daqu to curved surface fineness of 10-20 mesh;
(2) mixing materials: mixing the puffed staple food, the yeast and water according to the weight ratio of 1:0.6:3.3, then averagely dividing the mixture into 2 parts, carrying out white fermented grain fermentation on 1 part, and carrying out fumigation fermented grain fermentation on 1 part;
(3) fermenting the white fermented grains: A. alcohol fermentation: adding a corynebacterium glutamicum preparation into the mixed materials in proportion for alcoholic fermentation, controlling the fermentation temperature to be 28-30 ℃, finishing the main fermentation after 48-72h, then sending into a mash tank for anaerobic after-ripening, controlling the temperature to be 15-20 ℃, and finishing the alcoholic fermentation for 15 d; B. acetic acid fermentation: uniformly stirring bran, rice hulls and bran coat, steaming for 15 min, cooling to 25-30 ℃, adding fermented grains, sending into an intelligent continuous drum type solid state fermentation device for acetic acid fermentation, inoculating fermented grains with water content of 63 +/-1% and alcoholic strength of 5.5%, wherein the fermented grains are 10% -15% of the weight of materials in the fermentation device, and fermenting for 9-10d to obtain vinegar fermented grains; compacting mature vinegar grains, sealing, storing for 7 days under anaerobic condition, controlling the temperature at 15-24 deg.C, and then feeding into a white leaching tank;
(4) smoking and fermenting: feeding the mixture for fumigating fermentation into an intelligent continuous rotary drum type solid state fermentation device for alcohol fermentation and acetic acid fermentation, wherein the fermentation conditions are the same as the fermentation conditions of white fermentation, feeding the fermented mature vinegar into a fumigating fermentation unit, fumigating for 5 days, feeding into a fumigating and showering pool, controlling the temperature of the fermented grains to be 85 +/-5 ℃, stirring once every day, and stirring for 10min in a forward rotation mode and 10min in a reverse rotation mode under the stirring conditions;
(5) pouring vinegar: and (3) pouring the obtained white and smoked fermented grains by adopting a circulating pouring method, and sterilizing and filtering the obtained new vinegar.
The ageing time of the Daqu is more than 6 months, and the saccharifying power is 800 enzyme activities.
The corynebacterium glutamicum preparation is corynebacterium glutamicum (C.) (Corynebacterium glutamicum) The preparation method of the fermentation liquor and the corynebacterium glutamicum preparation comprises the following steps: (1) activating strains: glutamic acid stick for preserving refrigeratorInoculating bacillus on a slant activation culture medium in a streaking manner, and activating for 24 hours at the temperature of 28-30 ℃, wherein the activation culture medium comprises the following components in percentage by weight: 1.0L of beef extract, 10.0g of peptone, 5.0g of NaCl and 20.0-25.0 g of agar, and adding water to a constant volume of 1L and a pH value of 7.2-7.4; the preparation method of the beef extract comprises the following steps: cleaning lean beef, chopping, soaking 550 g chopped lean beef in 1375ml water overnight, filtering, and packaging the filtrate to obtain 0.6kg/cm2Sterilizing for 40 min; (2) transferring strains: inoculating the activated strain into BM liquid culture medium, and shake culturing at 30-32 deg.C for 24 hr at 100 r/min; (3) fermentation of a Corynebacterium glutamicum preparation: transferring the transferred strain into a sterilized fermentation tank filled with a fermentation culture medium according to the inoculum concentration of 10-15%, and fermenting for 24-36 hours at 30-32 ℃ by a shaking table at 200r/min, wherein the mixture ratio of the fermentation culture medium is as follows: KH (Perkin Elmer)2PO4 0.5g,K2HPO4 0.5g,MgSO4·7H2O 0.5g,FeSO4·7H2O 0.0006g,MnSO4·H20.0042g of O, 0.0002g of biotin and 0.0002g of thiamine, and water is added to the mixture until the volume is 1L and the pH value is 7.0-7.2. When the corynebacterium glutamicum grows to the logarithmic phase, the logarithmic phase reaches 108-109Can be used at a dose of one ml.
Corynebacterium glutamicum (C) used in the present inventionCorynebacterium glutamicum) Purchased from China center for preservation and management of industrial microbial strains, and numbered as follows: CICC 10186.
The invention has the beneficial effects that: on the basis of the traditional vinegar alcohol fermentation process, the corynebacterium glutamicum preparation is added, the targeted control of metabolism to generate succinic acid improves the succinic acid content and acidity in vinegar, enhances the delicate flavor of vinegar, and has softer and lingering taste. The fermented white grains are fermented by anaerobic post-ripening alcohol after aerobic fermentation, and the industrial and standardized production of vinegar fermentation is realized by adjusting the temperature, the dissolved oxygen and the like. The rotary drum type solid state fermentation equipment which is developed by oneself is adopted in the process of smoking the unstrained spirits, and the simultaneous implementation of alcoholic fermentation and acetic fermentation is realized.
The invention also provides the succinic acid-rich mature vinegar produced by the preparation method of the succinic acid-rich mature vinegar, and the acidity of the succinic acid-rich mature vinegar is 5.3 degrees. Sensory evaluation tests show that: it has reddish brown color, luster, fresh fragrance, vinegar fragrance, incense, ester fragrance, sweet and sour taste, mellow taste, soft taste, lasting aftertaste, and uniform and clear body state.
The results of comparing the product of the present invention with the conventional Shanxi mature vinegar are shown in Table 1. The results show that the mature vinegar rich in succinic acid prepared by the method disclosed by the invention is higher in total ester, reducing sugar and soluble salt-free solid than the traditional Shanxi mature vinegar, and the succinic acid content is obviously higher than that of the traditional Shanxi mature vinegar.
TABLE 1 comparison of mature vinegar rich in succinic acid with conventional mature vinegar of Shanxi province
Index (I)
|
Mature vinegar rich in succinic acid
|
Traditional Shanxi mature vinegar
|
Total acid (g/100 mL)
|
5.32
|
5.28
|
Non-volatile acid (g/100 mL)
|
1.43
|
1.03
|
Total esters (g/100 mL)
|
2.92
|
2.45
|
Reducing sugar (g/100 mL)
|
1.48
|
1.28
|
Amino acid nitrogen (g/100 mL)
|
0.18
|
0.16
|
Soluble salt-free solid (g/100 mL)
|
11.60
|
10.39
|
Succinic acid (mg/L)
|
1418
|
892 |
Detailed Description
The present invention is further illustrated by the following examples, which are not intended to limit the scope of the invention.
Example 1: a preparation method of succinic acid-rich mature vinegar comprises the steps of taking sorghum as main grain, mixing the main grain, yeast and water according to a weight ratio of 1:0.6:3.3, dividing the mixture into 2 parts, directly carrying out alcohol fermentation and acetic acid fermentation on one part, then smoking the other part, adding a corynebacterium glutamicum preparation with the weight being 6% of that of fermented mash into the other part, carrying out alcohol fermentation, and then carrying out the following steps: bran: bran coat: rice hull: mixing materials according to the weight ratio of 400:120:80:80:180 of water, and performing acetic fermentation to obtain white grains; mixing the white fermented grains and the smoked fermented grains according to the weight ratio of 7:3, performing pouring on the obtained white fermented grains and the smoked fermented grains by adopting a circulating pouring method, sterilizing the obtained new vinegar, and filtering.
The method specifically comprises the following steps:
(1) raw material treatment: accurately weighing 70kg of sorghum, removing impurities, crushing to 10 meshes, performing puffing treatment under the steam pressure of 0.3MPa to obtain staple food, inspecting and qualifying the yeast with the saccharifying power of 800 enzyme activity, crushing to the curved surface fineness of 12 meshes, and putting into a temporary storage bin for later use;
(2) mixing materials: mixing the puffed staple food, the yeast and water according to the weight ratio of 1:0.6:3.3, then averagely dividing the mixture into 2 parts, carrying out white fermented grain fermentation on 1 part, and carrying out fumigation fermented grain fermentation on 1 part;
(3) fermenting the white fermented grains: A. alcohol fermentation: adding a corynebacterium glutamicum preparation into the mixed materials in proportion for alcoholic fermentation, controlling the fermentation temperature to be 30 ℃, finishing the main fermentation after 48 hours, sending into a mash tank for anaerobic after-ripening, controlling the temperature to be 20 ℃, and finishing the alcoholic fermentation for 15 days; B. acetic acid fermentation: uniformly stirring bran, rice hulls and bran coat, steaming for 15 min, cooling to 30 ℃, adding wine mash, sending into intelligent continuous drum type solid state fermentation equipment for acetic acid fermentation, stirring with unstrained spirits with the water content of 63% and the alcoholic strength of 5.5%, inoculating unstrained spirits with the weight of 10% in the fermentation equipment, and fermenting for 9d to obtain vinegar unstrained spirits; compacting mature vinegar grains, sealing, storing for 7 days under anaerobic condition, controlling the temperature at 20 ℃, and then putting into a white leaching tank;
(4) smoking and fermenting: feeding the mixture for fumigating fermentation into an intelligent continuous rotary drum type solid state fermentation device for alcohol fermentation and acetic acid fermentation, wherein the fermentation conditions are the same as the fermentation conditions of white fermentation, feeding the fermented mature vinegar into a fumigating fermentation unit, fumigating for 5 days, feeding into a fumigating and showering pool, controlling the temperature of the fermented grains to be 85 ℃, stirring once every day, and stirring for 10min in a forward rotation manner and 10min in a reverse rotation manner under the stirring conditions;
(5) pouring vinegar: and (3) performing pouring on the obtained white and smoked fermented grains by adopting a circulating pouring method, and sterilizing, filtering, performing low-temperature vacuum concentration, blending flavor, performing fine filtration, and performing hot filling on the obtained new vinegar to obtain a finished product.
Wherein: the corynebacterium glutamicum preparation is corynebacterium glutamicum (C.) (Corynebacterium glutamicum) The preparation method of the fermentation liquor and the corynebacterium glutamicum preparation comprises the following steps: (1) activating strains: the corynebacterium glutamicum strain preserved in a refrigerator is streaked and inoculated on a slant activation culture medium, and is activated for 24 hours at the temperature of 28-30 ℃, wherein the proportion of the activation culture medium is as follows: 1.0L of beef extract, 10.0g of peptone, 5.0g of NaCl and 20.0-25.0 g of agar, and adding water to a constant volume of 1L and a pH value of 7.2-7.4; the preparation method of the beef extract comprises the following steps: cleaning lean beef, chopping, weighing 550 g chopped lean beefSoaking in 1375ml water overnight, filtering, and packaging the filtrate to 0.6kg/cm2Sterilizing for 40 min; (2) transferring strains: inoculating the activated strain into BM liquid culture medium, and shake culturing at 30-32 deg.C for 24 hr at 100 r/min; (3) fermentation of a Corynebacterium glutamicum preparation: transferring the transferred strain into a sterilized fermentation tank filled with a fermentation culture medium according to the inoculum concentration of 10-15%, and fermenting for 24-36 hours at 30-32 ℃ by a shaking table at 200r/min, wherein the mixture ratio of the fermentation culture medium is as follows: KH (Perkin Elmer)2PO4 0.5g,K2HPO4 0.5g,MgSO4·7H2O 0.5g,FeSO4·7H2O 0.0006g,MnSO4·H20.0042g of O, 0.0002g of biotin and 0.0002g of thiamine, and water is added to the mixture until the volume is 1L and the pH value is 7.0-7.2. The viable count of Corynebacterium glutamicum in Corynebacterium glutamicum preparation is 108-109Can be used at a dose of one ml.
Example 2: a preparation method of mature vinegar rich in succinic acid comprises the following specific steps: the sorghum is crushed to 15 meshes, the Daqu is crushed to the curved surface fineness of 10 meshes, and during fermentation of white grains: controlling the fermentation temperature of the alcoholic fermentation to be 29 ℃, finishing the main fermentation after 62 hours, controlling the anaerobic after-ripening temperature to be 18 ℃ and the time to be 15 d; in the acetic acid fermentation: steaming bran, rice hulls and bran coat, cooling to 27 ℃, mixing fermented grains with the water content of 64%, inoculating fermented grains with the weight of 13% in fermentation equipment, fermenting for 10 days, and performing anaerobic storage at the controlled temperature of 15 ℃; in the process of smoking and fermenting: the temperature of the fermented grains is controlled to be 90 ℃, and other preparation methods are the same as the method described in the example 1.
Example 3: a preparation method of mature vinegar rich in succinic acid comprises the following specific steps: the sorghum is crushed to 20 meshes, the Daqu is crushed to the curved surface fineness of 20 meshes, and during fermentation of white grains: controlling the fermentation temperature of the alcoholic fermentation to be 28 ℃, finishing the main fermentation after 72 hours, controlling the anaerobic after-ripening temperature to be 15 ℃, and controlling the time to be 15 d; in the acetic acid fermentation: steaming bran, rice hulls and bran coat, cooling to 25 ℃, mixing fermented grains with the water content of 62%, inoculating fermented grains with the weight of 15% in fermentation equipment, fermenting for 9.5 days, and performing anaerobic storage at the controlled temperature of 24 ℃; in the process of smoking and fermenting: the temperature of the fermented grains is controlled to be 80 ℃, and other preparation methods are the same as the method described in the example 1.