A solid fermentation process of glutinous rice vinegar

Abstract

The application discloses a solid fermentation process of glutinous rice vinegar and relates to the technical field of vinegar brewing. The application adopts glutinous rice and sorghum as fermentation raw materials, and prepares glutinous rice vinegar with rich nutritional components, pure taste, unique flavor, short production period and high yield through alcohol fermentation and acetic acid fermentation. The total acid content (calculated by taking acetic acid as a standard) of the glutinous rice vinegar prepared by the application is greater than 6.0 g / 100mL, the non-volatile acid content (calculated by taking lactic acid as a standard) is greater than 1.5 g / 100mL, and the glutinous rice vinegar meets the requirements of GB 18187-2000 "Brewed Vinegar".

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vinegar brewing, in particular to a solid fermentation process of glutinous rice vinegar. BACKGROUND

[0002] Glutinous rice vinegar is made of glutinous rice as the main raw material through fermentation. Glutinous rice vinegar is a very good condiment, containing a small amount of acetic acid, pure aroma, and mellow sour taste, and is suitable for dipping or stir-frying. Glutinous rice vinegar contains rich alkaline amino acids, sugar substances, organic acids, vitamin B1, vitamin B2, vitamin C, inorganic salts, minerals, etc., and can also reduce fat, lower blood pressure, lower cholesterol, detoxify, relieve alcohol, digest food, lose weight, calm the nerves, prevent cardiovascular and cerebrovascular diseases.

[0003] The production of vinegar includes three processes of starch hydrolysis into sugar, sugar fermentation into alcohol, and alcohol oxidation into acetic acid. Total acid is an important quality index of vinegar. For brewing vinegar, the higher the acidity, the higher the fermentation degree, and the more concentrated the sour taste of the vinegar.

[0004] At present, vinegar is divided into solid fermentation and liquid fermentation according to the brewing process. The vinegar prepared by solid fermentation has long fermentation period, good product flavor, but relatively low yield and high production cost. The vinegar prepared by liquid fermentation has short production period, high product yield, and relatively low production cost, but the taste is not as good as that of solid fermentation. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a solid fermentation process of glutinous rice vinegar, which uses glutinous rice and sorghum as fermentation raw materials, and prepares glutinous rice vinegar with rich nutritional components, pure taste, unique flavor, short production period, and high yield.

[0006] The technical problem to be solved by the present application is solved by the following technical scheme:

[0007] A solid fermentation process of glutinous rice vinegar, comprising the following steps:

[0008] (1) Mix the sorghum and the soaked glutinous rice with water, cook, cool, then add Daqu, stir evenly, and then perform alcohol fermentation, filter, to obtain a wine mash with an alcohol content of not less than 10%vol;

[0009] (2) Add bran and chaff to the wine mash, and add immobilized acetic acid bacteria, stir evenly, and then perform acetic acid fermentation, filter, to obtain a vinegar dregs with an alcohol content of less than 0.5%vol;

[0010] (3) Add salt to the vinegar dregs, seal, mature, pour vinegar, age, filter, sterilize, and fill to obtain glutinous rice vinegar.

[0011] Further, the mass ratio of the waxy rice to the sorghum is (70-80):(20-30). The sorghum contains rich nutrients such as starch, sugar, fat, vitamins and minerals, which are helpful for the growth and reproduction of microorganisms, promote the fermentation, and improve the nutritional value of the vinegar.

[0012] Further, the adding amount of the Daqu is 1-2% of the total mass of the waxy rice and the sorghum. The microorganisms in the Daqu include molds, yeasts and lactic acid bacteria, the molds play a role in saccharification, and the yeasts play a role in decomposing the sugar into alcohol and carbon dioxide.

[0013] Further, the temperature of the alcohol fermentation is 25-30℃. The time of the alcohol fermentation is determined according to the temperature and the alcohol content, and the starch in the waxy rice and the sorghum is converted into alcohol as much as possible.

[0014] Further, the adding amount of the bran is 100-150% of the total mass of the waxy rice and the sorghum, and the adding amount of the cereal chaff is 10-50% of the total mass of the waxy rice and the sorghum. The bran and the cereal chaff can provide sufficient carbon source, nitrogen source, phosphorus source and other nutrients for the microorganisms, increase the content of sugar and amino acid in the vinegar, and play a role in loosening the vinegar, absorbing water and storing air, which is beneficial to the aerobic fermentation of the acetic acid bacteria.

[0015] Further, the preparation method of the immobilized acetic acid bacteria is as follows: the activated acetic acid bacteria and a modified polyvinyl alcohol-sodium alginate solution are mixed, the obtained suspension is dropped into a calcium chloride solution by using a sterile syringe, and distilled water is used for washing, so as to obtain the immobilized acetic acid bacteria. The immobilized acetic acid bacteria has a high acid production rate, and in the case of the same amount of acetic acid bacteria, the use of the immobilized acetic acid bacteria for acetic acid fermentation can significantly shorten the fermentation time and improve the total acid content.

[0016] Preferably, the modified polyvinyl alcohol-sodium alginate solution is obtained by mixing a modified polyvinyl alcohol solution and a sodium alginate solution, and the mass ratio of the modified polyvinyl alcohol to the sodium alginate is 3:1.

[0017] Preferably, the preparation method of the modified polyvinyl alcohol is as follows: polyvinyl alcohol is heated and dissolved in water, β-chloropropionic acid and potassium carbonate are added, the reaction is kept, the reaction is stopped after the β-chloropropionic acid is completely reacted, evaporation and concentration are performed until the water is evaporated, the concentrate is cooled and washed with cold water at 5-10℃, and drying is performed, so as to obtain the modified polyvinyl alcohol; the molar amount ratio of the polyvinyl alcohol, the β-chloropropionic acid and the potassium carbonate is 4:1:1, wherein the molar amount of the polyvinyl alcohol is calculated according to the hydroxyl content.

[0018] Further, the adding amount of the immobilized acetic acid bacteria is 5-10% of the mass of the wine mash, in terms of the acetic acid bacteria. The acetic acid bacteria plays a role in oxidizing alcohol into acetic acid in the fermentation process.

[0019] Further, the temperature of the acetic acid fermentation is 30-35℃. The time of the acetic acid fermentation is determined according to the temperature and acidity, and the taste is also considered.

[0020] Further, the added amount of the salt is 1-3% of the mass of the vinegar dregs. The addition of the salt after the acetic acid fermentation can inhibit the oxidation of the acetic acid bacteria, prevent the further decomposition of the acetic acid, and improve the taste of the glutinous rice vinegar.

[0021] The post-ripening, the vinegar pouring, the aging, the filtering and the sterilization operation in the technical solution above all adopt the common methods in the field, which can not only improve the taste and flavor of the glutinous rice vinegar, but also ensure the edible safety of the glutinous rice vinegar.

[0022] The beneficial effects of the present application are:

[0023] (1) The present application adopts glutinous rice and sorghum as the fermentation raw materials, and prepares the glutinous rice vinegar with rich nutritional components, pure taste, unique flavor, short production cycle and high yield through the alcohol fermentation and the acetic acid fermentation.

[0024] (2) The total acid content (calculated as acetic acid) of the glutinous rice vinegar prepared by the present application is greater than 6.0g / 100mL, and the non-volatile acid content (calculated as lactic acid) is greater than 1.5g / 100mL, which meets the requirements of GB 18187-2000 "Brewed Vinegar". DETAILED DESCRIPTION

[0025] In order to make the technical means, creative features, purposes and effects of the present application easy to understand, the present application is further described below in combination with specific examples.

[0026] The raw materials used in the following examples and comparative examples are described as follows:

[0027] The Daqu is from Shandong Xufang Biological Technology Co., Ltd.

[0028] The acetic acid bacteria are from Shanghai Baiyi Biological Technology Co., Ltd.

[0029] The polyvinyl alcohol is from Shanghai Aladdin Biochemical Technology Co., Ltd. 1788 type.

[0030] The preparation method of the modified polyvinyl alcohol is as follows: the polyvinyl alcohol is heated and dissolved in water, then β-chloropropionic acid and potassium carbonate are added, and the reaction is kept warm. The reaction process is monitored by TLC. After the reaction of the β-chloropropionic acid is completed, the reaction is stopped. The concentrated solution is evaporated to dryness. The concentrated solution is cooled and washed with 5-10℃ cold water. After drying, the modified polyvinyl alcohol is obtained. The molar amount ratio of the polyvinyl alcohol, the β-chloropropionic acid and the potassium carbonate is 4:1:1, wherein the molar amount of the polyvinyl alcohol is calculated based on the hydroxyl content.

[0031] The preparation method of the immobilized acetic acid bacteria A is as follows: the activated acetic acid bacteria is mixed with the modified polyvinyl alcohol-sodium alginate solution, the obtained suspension is dropped into the 2% calcium chloride solution by using a sterile syringe, and distilled water is used for washing to obtain the immobilized acetic acid bacteria A. The modified polyvinyl alcohol-sodium alginate solution is prepared by mixing the 6% modified polyvinyl alcohol solution and the 2% sodium alginate solution according to the weight ratio of 1:1.

[0032] The preparation method of the immobilized acetic acid bacteria B is as follows: the activated acetic acid bacteria is mixed with the polyvinyl alcohol-sodium alginate solution, the obtained suspension is dropped into the 2% calcium chloride solution by using a sterile syringe, and distilled water is used for washing to obtain the immobilized acetic acid bacteria B. The polyvinyl alcohol-sodium alginate solution is prepared by mixing the 6% polyvinyl alcohol solution and the 2% sodium alginate solution according to the weight ratio of 1:1.

[0033] The preparation method of the immobilized acetic acid bacteria C is as follows: the activated acetic acid bacteria is mixed with the 8% sodium alginate solution, the obtained suspension is dropped into the 2% calcium chloride solution by using a sterile syringe, and distilled water is used for washing to obtain the immobilized acetic acid bacteria C.

[0034] The post-ripening, pickling, aging, filtering, sterilization and filling processes which are not described in detail in the following examples and comparative examples all adopt the same process conditions and parameters.

[0035] Example 1

[0036] (1) The sorghum and the glutinous rice after being soaked in water for 12 hours are mixed, the mass ratio of the glutinous rice to the sorghum is 70:30, and then the mixture is cooked and cooled, and then the Daqu is added, the addition amount of the Daqu is 2% of the total mass of the glutinous rice and the sorghum, and then the mixture is stirred uniformly, and then the alcohol fermentation is carried out, the fermentation temperature is 25-30°C, the fermentation time is 10 days, and then the filtering is carried out to obtain the wine mash with the alcohol content of not less than 10%vol.

[0037] (2) The bran and the cereal chaff are added to the wine mash, the addition amount of the bran is 120% of the total mass of the glutinous rice and the sorghum, the addition amount of the cereal chaff is 30% of the total mass of the glutinous rice and the sorghum, and then the immobilized acetic acid bacteria A is added, the addition amount of the immobilized acetic acid bacteria is 10% of the mass of the wine mash, and then the mixture is stirred uniformly, and then the acetic acid fermentation is carried out, the fermentation temperature is 30-35°C, the fermentation time is 7 days, and then the filtering is carried out to obtain the vinegar dregs with the alcohol content of less than 0.5%vol.

[0038] (3) The salt is added to the vinegar dregs, the addition amount of the salt is 2% of the mass of the vinegar dregs, the mouth is sealed, the post-ripening, pickling, aging, filtering, sterilization and filling are carried out to obtain the glutinous rice vinegar.

[0039] Example 2

[0040] (1) Mix sorghum and glutinous rice soaked in water for 12 hours, the mass ratio of glutinous rice to sorghum is 70:30, cook, cool, then add Daqu, the addition amount of Daqu is 2% of the total mass of glutinous rice and sorghum, stir uniformly, then perform alcohol fermentation, the fermentation temperature is 25-30℃, the fermentation time is 10 days, filter, and obtain wine mash with alcohol content not less than 10%vol.

[0041] (2) Add bran and chaff to the wine mash, the addition amount of bran is 120% of the total mass of glutinous rice and sorghum, the addition amount of chaff is 30% of the total mass of glutinous rice and sorghum, and add immobilized acetic acid bacteria A, the addition amount of immobilized acetic acid bacteria is 8% of the mass of wine mash, stir uniformly, then perform acetic acid fermentation, the fermentation temperature is 30-35℃, the fermentation time is 7 days, filter, and obtain vinegar dregs with alcohol content less than 0.5%vol.

[0042] (3) Add salt to the vinegar dregs, the addition amount of salt is 3% of the mass of vinegar dregs, seal, post-ripen, pour vinegar, age, filter, sterilize, and fill to obtain glutinous rice vinegar.

[0043] Example 3

[0044] (1) Mix sorghum and glutinous rice soaked in water for 12 hours, the mass ratio of glutinous rice to sorghum is 75:25, cook, cool, then add Daqu, the addition amount of Daqu is 2% of the total mass of glutinous rice and sorghum, stir uniformly, then perform alcohol fermentation, the fermentation temperature is 25-30℃, the fermentation time is 10 days, filter, and obtain wine mash with alcohol content not less than 10%vol.

[0045] (2) Add bran and chaff to the wine mash, the addition amount of bran is 100% of the total mass of glutinous rice and sorghum, the addition amount of chaff is 50% of the total mass of glutinous rice and sorghum, and add immobilized acetic acid bacteria A, the addition amount of immobilized acetic acid bacteria is 5% of the mass of wine mash, stir uniformly, then perform acetic acid fermentation, the fermentation temperature is 30-35℃, the fermentation time is 7 days, filter, and obtain vinegar dregs with alcohol content less than 0.5%vol.

[0046] (3) Add salt to the vinegar dregs, the addition amount of salt is 2% of the mass of vinegar dregs, seal, post-ripen, pour vinegar, age, filter, sterilize, and fill to obtain glutinous rice vinegar.

[0047] Example 4

[0048] (1) Mix sorghum and glutinous rice soaked in water for 12 hours, the mass ratio of glutinous rice to sorghum is 80:20, cook, cool, then add Daqu, the addition amount of Daqu is 1% of the total mass of glutinous rice and sorghum, stir uniformly, then perform alcohol fermentation, the fermentation temperature is 25-30℃, the fermentation time is 10 days, filter, and obtain wine mash with alcohol content not less than 10%vol.

[0049] (2) Adding bran and rice chaff to the wine mash, the bran being added in an amount of 100% of the total mass of the waxy rice and the sorghum, the rice chaff being added in an amount of 25% of the total mass of the waxy rice and the sorghum, and adding immobilized acetic acid bacteria A, the immobilized acetic acid bacteria being added in an amount of 5% of the mass of the wine mash, stirring uniformly, and then performing acetic acid fermentation, the fermentation temperature being 30-35°C, the fermentation time being 7 days, filtering, and obtaining vinegar dregs with an alcohol content of less than 0.5% vol.

[0050] (3) Adding salt to the vinegar dregs, the salt being added in an amount of 2% of the mass of the vinegar dregs, sealing, post-ripening, pouring vinegar, aging, filtering, sterilizing, filling, and obtaining waxy rice vinegar.

[0051] Example 5

[0052] (1) Mixing the sorghum and the waxy rice soaked in water for 12 h, the mass ratio of the waxy rice to the sorghum being 70:30, cooking, cooling, then adding Daqu, the Daqu being added in an amount of 1% of the total mass of the waxy rice and the sorghum, stirring uniformly, and then performing alcoholic fermentation, the fermentation temperature being 25-30°C, the fermentation time being 10 days, filtering, and obtaining wine mash with an alcohol content of no less than 10% vol.

[0053] (2) Adding bran and rice chaff to the wine mash, the bran being added in an amount of 110% of the total mass of the waxy rice and the sorghum, the rice chaff being added in an amount of 20% of the total mass of the waxy rice and the sorghum, and adding immobilized acetic acid bacteria A, the immobilized acetic acid bacteria being added in an amount of 10% of the mass of the wine mash, stirring uniformly, and then performing acetic acid fermentation, the fermentation temperature being 30-35°C, the fermentation time being 7 days, filtering, and obtaining vinegar dregs with an alcohol content of less than 0.5% vol.

[0054] (3) Adding salt to the vinegar dregs, the salt being added in an amount of 1.5% of the mass of the vinegar dregs, sealing, post-ripening, pouring vinegar, aging, filtering, sterilizing, filling, and obtaining waxy rice vinegar.

[0055] Comparative Example 1

[0056] (1) Mixing the sorghum and the waxy rice soaked in water for 12 h, the mass ratio of the waxy rice to the sorghum being 70:30, cooking, cooling, then adding Daqu, the Daqu being added in an amount of 2% of the total mass of the waxy rice and the sorghum, stirring uniformly, and then performing alcoholic fermentation, the fermentation temperature being 25-30°C, the fermentation time being 10 days, filtering, and obtaining wine mash with an alcohol content of no less than 10% vol.

[0057] (2) Adding bran and rice chaff to the wine mash, the bran being added in an amount of 120% of the total mass of the waxy rice and the sorghum, the rice chaff being added in an amount of 30% of the total mass of the waxy rice and the sorghum, and adding immobilized acetic acid bacteria B, the immobilized acetic acid bacteria being added in an amount of 10% of the mass of the wine mash, stirring uniformly, and then performing acetic acid fermentation, the fermentation temperature being 30-35°C, the fermentation time being 7 days, filtering, and obtaining vinegar dregs with an alcohol content of less than 0.5% vol.

[0058] (3) adding salt into the vinegar dregs, the adding amount of the salt is 2% of the mass of the vinegar dregs, sealing, post-ripening, vinegar pouring, aging, filtering, sterilizing, filling, and obtaining the glutinous rice vinegar.

[0059] Comparative Example 2

[0060] (1) mixing the sorghum and the glutinous rice after soaking in water for 12 hours, the mass ratio of the glutinous rice to the sorghum being 70:30, steaming and cooling, then adding Daqu, the adding amount of the Daqu being 2% of the total mass of the glutinous rice and the sorghum, stirring uniformly, and then performing alcohol fermentation, the fermentation temperature being 25-30℃, and the fermentation time being 10 days, and then filtering to obtain the wine mash with the alcohol content not less than 10%vol.

[0061] (2) adding bran and cereal chaff into the wine mash, the adding amount of the bran being 120% of the total mass of the glutinous rice and the sorghum, the adding amount of the cereal chaff being 30% of the total mass of the glutinous rice and the sorghum, and adding immobilized acetic acid bacteria C, the adding amount of the immobilized acetic acid bacteria being 10% of the mass of the wine mash, stirring uniformly, and then performing acetic acid fermentation, the fermentation temperature being 30-35℃, and the fermentation time being 7 days, and then filtering to obtain the vinegar dregs with the alcohol content being less than 0.5%vol.

[0062] (3) adding salt into the vinegar dregs, the adding amount of the salt being 2% of the mass of the vinegar dregs, sealing, post-ripening, vinegar pouring, aging, filtering, sterilizing, filling, and obtaining the glutinous rice vinegar.

[0063] The above Comparative Example 1 is that the immobilized acetic acid bacteria A in Example 1 is replaced by immobilized acetic acid bacteria B, that is, polyvinyl alcohol-sodium alginate is used as the embedding agent in the preparation of the immobilized acetic acid bacteria; and the above Comparative Example 2 is that the immobilized acetic acid bacteria A in Example 2 is replaced by immobilized acetic acid bacteria C, that is, sodium alginate is used as the embedding agent in the preparation of the immobilized acetic acid bacteria.

[0064] The total acid content and the non-volatile acid content in the glutinous rice vinegar prepared in the above examples and comparative examples are respectively determined, the total acid content is determined according to the standard GB / T 5009.41-2003, and the non-volatile acid content is determined according to the standard GB / T 18187-2000, and the determination results are shown in Table 1.

[0065] Table 1 Total acid content and non-volatile acid content of glutinous rice vinegar

[0066]

[0067] It can be seen from the data in Table 1 that the total acid content and the non-volatile acid content in the glutinous rice vinegar prepared by the present application all meet the requirements of GB 18187-2000 “Brewed Vinegar”, and the immobilized acetic acid bacteria prepared by the present application is helpful to improve the total acid content and the non-volatile acid content in the prepared glutinous rice vinegar.

[0068] The foregoing is considered as illustrative only of the principles of the application and the forms thereof shown and described by way of example. Further, those skilled in the art will realize that the mechanism of the present application is capable of other modes of practice and still be within the spirit and scope of the application. For example, the application can be used in other types of systems and / or methods. The disclosure should be understood, therefore, as not being so limited, but rather directed primarily to the principal of the application and the major features thereof. Further, changes and modifications can be obvious to those skilled in the art, and are intended to be included within the spirit and scope of the application as defined by the following claims.

Claims

1. A solid state fermentation process for glutinous rice vinegar, characterized by, The method comprises the following steps: (1) mixing sorghum and soaked glutinous rice with water, cooking, cooling, then adding Daqu, stirring uniformly, then performing alcohol fermentation, filtering, obtaining wine mash with alcohol content not less than 10%vol; (2) adding bran and cereal chaff to the wine mash, adding immobilized acetic acid bacteria, stirring uniformly, then performing acetic acid fermentation, filtering, obtaining vinegar dregs with alcohol content less than 0.5%vol; (3) adding salt to the vinegar dregs, sealing, post-ripening, pouring vinegar, aging, filtering, sterilizing, filling, obtaining glutinous rice vinegar; The preparation method of the immobilized acetic acid bacteria is as follows: mixing activated acetic acid bacteria with modified polyvinyl alcohol-sodium alginate solution, then dropping the obtained suspension into calcium chloride solution by using a sterile syringe, washing with distilled water, obtaining immobilized acetic acid bacteria; The modified polyvinyl alcohol-sodium alginate solution is obtained by mixing modified polyvinyl alcohol solution and sodium alginate solution, and the mass ratio of modified polyvinyl alcohol to sodium alginate is 3:

1. The preparation method of the modified polyvinyl alcohol is as follows: heating and dissolving polyvinyl alcohol in water, then adding β-chloropropionic acid and potassium carbonate, keeping warm, stopping the reaction after the reaction of β-chloropropionic acid is completed, evaporating and concentrating to dryness, washing the concentrate with cold water at 5-10 ℃ after cooling, drying, obtaining modified polyvinyl alcohol; the molar amount ratio of polyvinyl alcohol, β-chloropropionic acid and potassium carbonate is 4:1:1, wherein the molar amount of polyvinyl alcohol is calculated based on the hydroxyl content.

2. The solid state fermentation process for glutinous rice vinegar as claimed in claim 1, characterized by: The mass ratio of the glutinous rice to the sorghum is (70-80):(20-30).

3. The solid state fermentation process for glutinous rice vinegar as claimed in claim 1, characterized by: The addition amount of the Daqu is 1-2% of the total mass of the glutinous rice and the sorghum.

4. The solid state fermentation process for glutinous rice vinegar as claimed in claim 1, characterized by: The temperature of the alcohol fermentation is 25-30 ℃.

5. The solid state fermentation process for glutinous rice vinegar as claimed in claim 1, wherein: The addition amount of the bran is 100-150% of the total mass of the glutinous rice and the sorghum, and the addition amount of the cereal chaff is 10-50% of the mass of the glutinous rice.

6. The solid state fermentation process for glutinous rice vinegar as claimed in claim 1, characterized by: The addition amount of the immobilized acetic acid bacteria is 5-10% of the mass of the wine mash, calculated based on the acetic acid bacteria.

7. The solid state fermentation process for glutinous rice vinegar as claimed in claim 1, characterized by: The temperature of the acetic acid fermentation is 30-35 ℃.

8. The solid state fermentation process for glutinous rice vinegar as claimed in claim 1, wherein: The addition amount of the salt is 1-3% of the mass of the vinegar dregs.

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