Composition, application of composition in preparation of bran vinegar and bran vinegar

Abstract

The invention relates to the field of food, in particular to a composition, application of the composition in preparation of bran vinegar and the bran vinegar. The composition provided by the invention comprises 2-4% (w / w) of wine-making yeast, 0.3-0.5% (w / w) of saccharomyces cerevisiae and 0.2-0.3% (w / w) of acetic acid bacteria. The invention provides a production process of Daqu bran vinegar and the Daqu bran vinegar. The production efficiency and the utilization rate are improved while the quality of the bran vinegar is further improved.

Description

Technical Field

[0001] The invention relates to the field of food, in particular to a composition and application thereof in preparing bran vinegar and the bran vinegar. Background Art

[0002] Sichuan bran vinegar is a traditional condiment, which is brewed by fermentation, sun-drying and other procedures of wheat bran, rice, etc., and is favored by local people because of its unique fragrance, mouthfeel and color. However, in the current bran vinegar production process, the fermentation agent used is mainly vinegar koji or directly inoculated yeast, acetic acid bacteria, etc., although this method can achieve vinegar production and corresponding yield, it may make the flavor components of vinegar in the fermentation stage more single. For this reason, a certain amount of brewing Daqu can be added in the wine stage and acetic acid fermentation stage of vinegar production, which can not only serve as an important fermentation agent in the production process, but also play the role of decomposing starch and fermenting reducing sugar. At the same time, a large amount of flavor substances and flavor-forming flora are also included in brewing Daqu, which can effectively improve the microbial community structure in the fermentation process, increase the taste, aroma and nutrients of vinegar products, and greatly improve the quality of bran vinegar.

[0003] At present, the main raw material for acetic acid fermentation in bran vinegar is wheat bran, which has a relatively low starch content. The starch content after wine mash, water, and wheat bran is about 8%. If the returned grains are used, the starch content will be even lower, which is difficult to meet the production of vinegar. The starch content in brewing Daqu is relatively high, which can reach about 57%. Appropriate addition can supplement the starch content and greatly increase the fermentation power of vinegar mash, thereby realizing the production of returned grains, ensuring that the starch content that can be used in the bran is fully used, and improving the raw material conversion rate. At the same time, the returned grains are all mature vinegar mash, which can further reduce the insulation and maturation time of vinegar mash, shorten the production cycle, and improve production efficiency. Summary of the invention

[0004] In view of this, the present invention provides a composition and its application in preparing bran vinegar and bran vinegar. The present invention provides a production process of Daqu bran vinegar and Daqu bran vinegar. The production efficiency and utilization rate are increased while further improving the quality of bran vinegar.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The invention provides a composition comprising: 2-4% (w / w) of brewing koji, 3-5‰ (w / w) of brewing yeast and 2-3‰ (w / w) of acetic acid bacteria.

[0007] In some embodiments of the present invention, the composition comprises: 3% (w / w) brewing Daqu, 4‰ (w / w) brewing yeast and 2‰ (w / w) acetic acid bacteria.

[0008] In some embodiments of the present invention, the composition comprises: 2% (w / w) brewing Daqu, 5‰ (w / w) brewing yeast and 2‰ (w / w) acetic acid bacteria.

[0009] In some embodiments of the present invention, the composition comprises: 4% (w / w) brewing Daqu, 3‰ (w / w) brewing yeast and 2‰ (w / w) acetic acid bacteria.

[0010] The invention also provides application of the composition in preparing bran vinegar.

[0011] The present invention also provides a method for preparing bran vinegar, comprising the following steps:

[0012] S1: mixing the brewing koji and brewing yeast in the above composition with cooked rice to obtain a mixed mash;

[0013] S2: subjecting the mixed mash to a first fermentation to obtain wine mash;

[0014] S3: mixing the wine mash, bran, the brewing koji in the above composition and the acetic acid bacteria, and performing a second fermentation to obtain acetic acid;

[0015] S4: performing a third fermentation on the acetic acid to obtain raw mash;

[0016] S5: post-ripening the raw mash and pouring vinegar on it to obtain raw vinegar liquid and vinegar dregs;

[0017] S6: filtering, blending, precipitating and sterilizing the original vinegar liquid to obtain the bran vinegar.

[0018] In some embodiments of the present invention, the preparation method S3 further includes a step of returning the slag before the second fermentation; the returning the slag is a step of adding vinegar slag; the vinegar slag is obtained in step S5.

[0019] In some embodiments of the present invention, the mass ratio of the wine mash, the bran, the vinegar lees and the brewing Daqu in the above preparation method is: 40:20:30:5.

[0020] In some embodiments of the present invention, the time of the first fermentation in the above-mentioned preparation method S2 is 36 to 40 hours.

[0021] In some embodiments of the present invention, the time of the first fermentation in the above preparation method S2 is 36 h, 38 h or 40 h.

[0022] In some embodiments of the present invention, the sign indicating the end of the first fermentation in the above preparation method S2 is that the alcohol content reaches 8°.

[0023] In some embodiments of the present invention, the temperature of the second fermentation in the above preparation method S3 is 37-39°C.

[0024] In some embodiments of the present invention, the time of the third fermentation in the above preparation method S4 is 13 to 15 days.

[0025] In some embodiments of the present invention, the time of the third fermentation in the above preparation method S4 is 13d, 14d or 15d.

[0026] In some embodiments of the present invention, the post-ripening temperature in the above preparation method S5 is 55-65° C. and the time is 35-50 days.

[0027] In some embodiments of the present invention, the post-ripening temperature in the above preparation method S5 is 55°C, 60°C or 65°C.

[0028] In some embodiments of the present invention, the ripening time in the above preparation method S5 is 35 to 50 days.

[0029] In some embodiments of the present invention, the ripening time in the above preparation method S5 is 35 days, 45 days or 50 days.

[0030] In some embodiments of the present invention, the method for preparing the cooked rice in the above preparation method comprises the following steps: mixing rice with water and steaming to obtain the cooked rice.

[0031] In some embodiments of the present invention, the volume ratio of the rice to the water in the above preparation method is: 1:1.1.

[0032] In some embodiments of the present invention, the cooking temperature in the above preparation method is 90-95° C. and the cooking time is 30-40 min.

[0033] In some embodiments of the present invention, the temperature of the cooked rice during mixing in the above preparation method is 36-38°C.

[0034] In some embodiments of the present invention, the post-ripening of the raw mash in the above-mentioned preparation method S5 also includes a step of sealing with 5‰ salt.

[0035] The invention also provides bran vinegar obtained by the preparation method.

[0036] The beneficial effects of the present invention include:

[0037] The beneficial effects of the present invention are as follows:

[0038] (1) The brewing koji addition process adopted in the present invention can significantly improve the flavor substances and microbial brewing flora in the vinegar brewing process, so that the content of aroma substances, flavor substances and nutrients formed in the fermentation process is greatly increased, and the product quality of bran vinegar is significantly improved.

[0039] (2) The addition of brewing koji combined with the lees return process adopted in the present invention can greatly improve the starch utilization rate in the process of brewing bran vinegar, significantly improve the raw material and vinegar conversion rate, and also further shorten the bran vinegar production cycle, which has positive significance for saving raw materials, improving product quality, and increasing production rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0041] Figure 1 The figure shows the appearance comparison of vinegar produced by different processes; wherein: the left one is the embodiment and comparative example 1, and the right one is comparative examples 2 and 3. DETAILED DESCRIPTION

[0042] The invention discloses a composition, application of the composition in preparing bran vinegar and the bran vinegar.

[0043] It should be understood that the expression "one or more of..." includes each of the items recited after the expression individually and in various different combinations of two or more of the recited items, unless otherwise understood from the context and usage. The expression "and / or" in combination with three or more recited items should be understood to have the same meaning, unless otherwise understood from the context.

[0044] The use of the terms "comprising", "having" or "containing", including their grammatical synonyms, should generally be understood as open and non-restrictive, for example not excluding other unrecited elements or steps, unless otherwise specifically stated or otherwise understood from the context.

[0045] It should be understood that the order of steps or the order in which certain actions are performed is not important as long as the present invention remains operable. In addition, two or more steps or actions may be performed simultaneously.

[0046] The use of any and all examples or exemplary language, such as "for example" or "including", herein is intended only to better illustrate the invention and does not limit the scope of the invention unless otherwise claimed. No language in this specification should be construed as indicating that any non-claimed element is essential to the practice of the invention.

[0047] In addition, the numerical ranges and parameters used to define the present invention are approximate values, and the relevant values ​​in the specific embodiments have been presented as accurately as possible. However, any numerical value inherently inevitably contains standard deviations due to individual test methods. Therefore, unless otherwise expressly stated, it should be understood that all ranges, quantities, values ​​and percentages used in this disclosure are modified by "about". Here, "about" generally means that the actual value is within plus or minus 10%, 5%, 1% or 0.5% of a specific value or range.

[0048] One aspect of the present invention provides a production process of Daqu bran vinegar, comprising the following steps:

[0049] S1. Mix the rice with 1.1 times the volume of water, steam and cook for 30-40 min at a temperature of 90-95°C to obtain a cooked material, while killing the bacteria in the raw material to prevent the bacteria from becoming the dominant strain during the wine fermentation and acetic acid fermentation process;

[0050] S2. After the cooked rice is cooled to 35-38°C, it is mixed with water in a ratio of 1:1, and brewing koji and yeast are added;

[0051] S3, maintaining the temperature of the mixed mash at 28°C, and fermenting at a constant temperature to produce alcohol to obtain wine mash;

[0052] S4, mixing the wine mash with vinegar lees, bran and brewing koji, inoculating acetic acid bacteria at the same time, and fermenting to produce acetic acid at a temperature of 37-39°C in the early stage. After 3 days of acetic acid fermentation, the mash is broken and turned over, and then turned over every other day to ensure that the acetic acid fermentation temperature is around 36°C;

[0053] S5. After 13-15 days of acetic acid fermentation, the fermentation is completed and the vinegar is put into a vinegar jar. The mouth of the jar is sealed with 5‰ salt to prevent contamination by miscellaneous bacteria;

[0054] S6, transferring the vinegar jar filled with the vinegar mash to a mature mash room, keeping the aged mash warm and maturing it to obtain mature vinegar mash;

[0055] S7, pouring vinegar on the cooked mash to obtain raw vinegar liquid and vinegar lees, a part of which is used as livestock feed, and the rest is used for returning the lees, which is mixed with water, wine mash liquid and bran in the next batch of production and continued to be used in production;

[0056] S8. Filter, blend, precipitate and sterilize the original vinegar solution to obtain finished vinegar.

[0057] In one embodiment, in step S2, the amount of Daqu used is 2% to 5% of the mass of rice, and the amount of yeast used is 3‰ to 5‰ of the mass of rice.

[0058] In one embodiment, in step S3, the alcohol fermentation time is 36 to 40 hours, and the fermentation end mark is that the alcohol content of the mash is ≥8°.

[0059] In one embodiment, in step S4, the ratio of wine mash: bran: returned lees: brewing koji is 40:20:30:5.

[0060] In one embodiment, in step S4, the inoculation amount of acetic acid bacteria is 2‰ of the total material.

[0061] In one embodiment, in step S5, the end of acetic acid fermentation is marked as the end of fermentation after acetic acid stops increasing.

[0062] In one embodiment, in step S6, the temperature of the vinegar mash is kept at 55-65° C., and the keeping time is 35-50 days.

[0063] Another aspect of the present invention provides a Daqu gluten vinegar, which is prepared by using the above-mentioned production process of Daqu gluten vinegar.

[0064] The brewing yeast involved in the present invention was purchased from Angel Yeast Co., Ltd.; the brewing Daqu was purchased from Luzhou Laojiao Co., Ltd.; and the acetic acid bacteria was purchased from Shanghai Difa Brewing Biological Products Co., Ltd.

[0065] Regarding Daqu bran vinegar, currently Daqu vinegar is mainly Shanxi aged vinegar. The starchy raw material of Daqu bran vinegar is mainly bran, while that of Shanxi aged vinegar is mainly sorghum. The starch content of the two raw materials differs by 3 times. Therefore, the production processes, raw materials, taste, production cycles, etc. of the two vinegars are very different, making them difficult to simply copy and use. Using Daqu to brew bran vinegar requires certain technical innovations.

[0066] Daqu bran vinegar combined with the process of returning the lees and aging the mash has produced unexpected results. Since bran vinegar uses wheat bran as the main starch raw material, and in recent years, due to the progress of wheat separation technology, the starch content in wheat bran has been further reduced, currently only between 20-25%. The lower starch content also reduces the starch content in the mash. If returning the lees is used, starch raw materials must be supplemented or the acidity in the mash must be reduced. Daqu (Luzhou-flavor Daqu) has a higher starch content. Adding it to the mash not only improves the aroma and increases the fermentation rate, but also supplements the starch raw materials, ensuring the acidity in the mash. In addition, the addition of Daqu in combination with the aging process not only accelerates the maturation of the vinegar mash by utilizing the Maillard reaction, but also the higher amount of Daqu added ensures the rate of microbial reaction during the aging process. Therefore, the addition of Daqu and the aging process in combination with the return process (the vinegar mash at the end of fermentation contains a certain amount of mature vinegar mash) further reduces the aging time and ensures the aging effect, which to a certain extent solves the problems of long production cycle and low efficiency of bran vinegar.

[0067] In Examples 1 to 3, Comparative Examples 1 to 3 and Effect Examples of the present invention, all the raw materials and reagents used can be purchased from the market.

[0068] The present invention will be further described below in conjunction with embodiments:

[0069] Example 1

[0070] The present embodiment provides a production process of Daqu bran vinegar, comprising the following steps:

[0071] S1. Rice steaming: 1 part of rice is mixed with 1.1 parts of water and steamed at high temperature at 93° C. for 35 min to obtain cooked rice.

[0072] S2. Cooling and inoculation: After the cooking is completed, wait for the raw materials to cool to 38°C and mix them with an equal mass of water, and inoculate them with 3% brewing Daqu and 4‰ brewing yeast.

[0073] S3. Wine mash: Maintain the temperature of the mixed mash at 28°C and ferment it at a constant temperature to produce alcohol to obtain wine mash. After 38 hours of fermentation, the alcohol content reaches 8°.

[0074] S4. Acetic acid fermentation: Mix the wine mash: bran: returned lees: brewing koji in a ratio of 40:20:30:5, inoculate 2‰ acetic acid bacteria at the same time, and ferment to produce acetic acid under heat preservation. Start breaking the lees and turning the mash 3 days after the acetic acid fermentation, and then turn it every other day.

[0075] S5. Put the raw mash into the jar: After 13 days of acetic acid fermentation, the acidity of the mash is stable, and the raw mash is obtained and put into the vinegar jar. The mouth of the jar is sealed with 5‰ salt to prevent contamination by miscellaneous bacteria.

[0076] S6. Keeping the aged mash warm: Transfer the vinegar jar filled with the vinegar mash to the mature mash room, keep the aged mash at 55°C for 50 days, and obtain mature vinegar mash.

[0077] S7. Pour vinegar on the mature mash: Pour vinegar on the mature mash to obtain original vinegar liquid and vinegar dregs. The vinegar dregs are used as returned dregs according to the mixing ratio, and are mixed with water, mash liquid and bran in the next batch of production and continue to be used in production.

[0078] S8. Sterilization and refining: Filter, blend, precipitate and sterilize the original vinegar liquid to obtain the finished vinegar.

[0079] Example 2

[0080] The present embodiment provides a production process of Daqu bran vinegar, comprising the following steps:

[0081] S1. Rice steaming: 1 part of rice is mixed with 1.1 parts of water and steamed at high temperature at 95° C. for 30 min to obtain cooked rice.

[0082] S2. Cooling and inoculation: After the cooking is completed, wait for the raw materials to cool to 36°C and mix them with an equal mass of water, and inoculate them with 2% brewing Daqu and 5‰ brewing yeast.

[0083] S3. Wine mash: Maintain the temperature of the mixed mash at 28°C and ferment it at a constant temperature to produce alcohol to obtain wine mash. After 36 hours of fermentation, the alcohol content reaches 8°.

[0084] S4. Acetic acid fermentation: Mix the wine mash: bran: returned lees: brewing koji in a ratio of 40:20:30:5, inoculate 2‰ acetic acid bacteria at the same time, and ferment to produce acetic acid under heat preservation. Start breaking the lees and turning the mash 3 days after the acetic acid fermentation, and then turn it every other day.

[0085] S5. Put the raw mash into the jar: After 14 days of acetic acid fermentation, the acidity of the mash is stable, and the raw mash is obtained and put into the vinegar jar. The mouth of the jar is sealed with 5‰ salt to prevent contamination by miscellaneous bacteria.

[0086] S6. Keeping the aged mash warm: Transfer the vinegar jar filled with the vinegar mash to the mature mash room, keep the aged mash at 60°C for 45 days, and obtain mature vinegar mash.

[0087] S7. Pour vinegar on the mature mash: Pour vinegar on the mature mash to obtain original vinegar liquid and vinegar dregs. The vinegar dregs are used as returned dregs according to the mixing ratio, and are mixed with water, mash liquid and bran in the next batch of production and continue to be used in production.

[0088] S8. Sterilization and refining: Filter, blend, precipitate and sterilize the original vinegar liquid to obtain the finished vinegar.

[0089] Example 3

[0090] The present embodiment provides a production process of Daqu bran vinegar, comprising the following steps:

[0091] S1. Rice steaming: 1 part of rice is mixed with 1.1 parts of water and steamed at high temperature at 90° C. for 40 min to obtain cooked rice.

[0092] S2. Cooling and inoculation: After the cooking is completed, wait for the raw materials to cool to 37°C and mix them with an equal mass of water, and inoculate them with 4% brewing Daqu and 3‰ brewing yeast.

[0093] S3. Wine mash: Maintain the temperature of the mixed mash at 28°C and ferment it at a constant temperature to produce alcohol to obtain wine mash. After 40 hours of fermentation, the alcohol content reaches 8°.

[0094] S4. Acetic acid fermentation: Mix the wine mash: bran: returned lees: brewing koji in a ratio of 40:20:30:5, inoculate 2‰ acetic acid bacteria at the same time, and ferment to produce acetic acid under heat preservation. Start breaking the lees and turning the mash 3 days after the acetic acid fermentation, and then turn it every other day.

[0095] S5. Put the raw mash into the jar: After 15 days of acetic acid fermentation, the acidity of the mash is stable, and the raw mash is obtained and put into the vinegar jar. The mouth of the jar is sealed with 5‰ salt to prevent contamination by miscellaneous bacteria.

[0096] S6. Keeping the aged mash warm: Transfer the vinegar jar filled with the vinegar mash to the mature mash room, keep the aged mash at 65°C for 35 days to obtain mature vinegar mash.

[0097] S7. Pour vinegar on the mature mash: Pour vinegar on the mature mash to obtain original vinegar liquid and vinegar dregs. The vinegar dregs are used as returned dregs according to the mixing ratio, and are mixed with water, mash liquid and bran in the next batch of production and continue to be used in production.

[0098] S8. Sterilization and refining: Filter, blend, precipitate and sterilize the original vinegar liquid to obtain the finished vinegar.

[0099] Comparative Example 1

[0100] The existing sun-dried vinegar brewing process of bran vinegar is to use wheat bran and rice as the main raw materials for wine fermentation and then acetic acid fermentation, and then naturally sun-dried the fermented grains, which includes the following steps:

[0101] S1: Rice steaming: Mix 1 part of rice with 5 parts of water, stir to make them completely mixed, and steam and cook for 30 minutes at a steaming temperature of 95°C to obtain cooked grain.

[0102] S2: Saccharification and decomposition: After the cooking is completed, wait for the raw materials to cool naturally to 50°C, add 3‰ of saccharifying enzyme and 1.5‰ of amylase for rice, stir and mix thoroughly, keep warm and let stand for 11 hours to decompose the starch in the rice into reducing sugar.

[0103] S3: Alcohol fermentation: The decomposed mug is naturally cooled to 28°C, and activated yeast with a rice dosage of 1‰ is added. The sample is fermented at a constant temperature to produce alcohol. The sample is fermented for 72 hours, and samples are taken every 12 hours to measure the alcohol content and starch. After the sample has been fermented for 3 days and the alcohol content reaches 5.5°, the fermentation is terminated to obtain the mug.

[0104] S4: Mix the fermented mash: Mix the fermented mash, water and wheat bran in a ratio of 1:1.1:1.3 and stir evenly, then add 1‰ of the wheat bran into vinegar koji.

[0105] S5: Acetic acid fermentation: Place the fermented mash in a fermentation tank to keep warm and ferment to produce acetic acid. After the sample is fermented for 10 days, take samples every day to test the acidity of the fermented mash. After 16 days of fermentation, when the acidity of the fermented mash is stable, stop the acetic acid fermentation and put it into a vinegar jar, and seal the jar with 1% salt.

[0106] S6: Drying of vinegar mash: The vinegar jars filled with vinegar mash are transferred to the drying yard and exposed to the sun and dew at night. After two years of drying, the color of the vinegar mash turns black-red-brown, and the drying of the mash is finished.

[0107] S7: Refining by pouring vinegar: pour vinegar on the vinegar mash after fermentation, and use sedimentation and filtration to remove impurities, and then enter ultra-high temperature instantaneous sterilization to kill unnecessary bacteria in the vinegar to obtain the finished vinegar.

[0108] Comparative Example 2

[0109] A sun-dried vinegar brewing process of bran vinegar is to use wheat bran and rice as the main raw materials, then ferment with acetic acid, and then mature the mash, which includes the following steps:

[0110] S1. Rice steaming: 1 part of rice is mixed with 1.1 parts of water and steamed at high temperature at 93° C. for 35 min to obtain cooked rice.

[0111] S2. Cooling and inoculation: After the cooking is completed, wait for the raw materials to cool to 38°C and mix them with an equal mass of water, and inoculate them with 4‰ of brewer's yeast, 3‰ of saccharifying enzyme and liquefying enzyme.

[0112] S3. Wine mash: Maintain the temperature of the mixed mash at 28°C and ferment it at a constant temperature to produce alcohol to obtain wine mash. After 40 hours of fermentation, the alcohol content reaches 8°.

[0113] S4. Acetic acid fermentation: Mix the wine mash, bran and returned mash in a ratio of 40:20:30, and inoculate 2‰ of acetic acid bacteria and 3‰ of saccharifying enzyme and liquefying enzyme at the same time. Ferment and produce acetic acid by keeping warm. Start breaking the mash and turning it over after 3 days of acetic acid fermentation, and then turn it over every other day.

[0114] S5. Put the raw mash into the jar: After 13 days of acetic acid fermentation, the acidity of the mash is stable, and the raw mash is obtained and put into the vinegar jar. The mouth of the jar is sealed with 5‰ salt to prevent contamination by miscellaneous bacteria.

[0115] S6. Keeping the aged mash warm: Transfer the vinegar jar filled with the vinegar mash to the mature mash room, keep the aged mash at 55°C for 50 days, and obtain mature vinegar mash.

[0116] S7. Pour vinegar on the mature mash: Pour vinegar on the mature mash to obtain original vinegar liquid and vinegar dregs. The vinegar dregs are used as returned dregs according to the mixing ratio, and are mixed with water, mash liquid and bran in the next batch of production and continue to be used in production.

[0117] S8. Sterilization and refining: Filter, blend, precipitate and sterilize the original vinegar liquid to obtain the finished vinegar.

[0118] Comparative Example 3

[0119] A sun-dried vinegar brewing process of bran vinegar is to use wheat bran and rice as the main raw materials, then ferment with acetic acid, and then mature the mash, which includes the following steps:

[0120] S1. Rice steaming: 1 part of rice is mixed with 1.1 parts of water and steamed at high temperature at 93° C. for 35 min to obtain cooked rice.

[0121] S2. Cooling and inoculation: After the cooking is completed, wait for the raw materials to cool to 38°C and mix them with an equal mass of water, and inoculate them with 3% brewing Daqu and 4‰ brewing yeast.

[0122] S3. Wine mash: Maintain the temperature of the mixed mash at 28°C and ferment it at a constant temperature to produce alcohol to obtain wine mash. After 38 hours of fermentation, the alcohol content reaches 8°.

[0123] S4. Acetic acid fermentation: Mix the wine mash, bran and Daqu in a ratio of 40:20:5, inoculate 2‰ of acetic acid bacteria at the same time, and ferment to produce acetic acid. Start breaking the dregs and turning the mash 3 days after the acetic acid fermentation, and then turn it every other day.

[0124] S5. Put the raw mash into the jar: After 13 days of acetic acid fermentation, the acidity of the mash is stable, and the raw mash is obtained and put into the vinegar jar. The mouth of the jar is sealed with 5‰ salt to prevent contamination by miscellaneous bacteria.

[0125] S6. Keeping the aged mash warm: Transfer the vinegar jar filled with the vinegar mash to the mature mash room, keep the aged mash at 55°C for 50 days, and obtain mature vinegar mash.

[0126] S7. Vinegar pouring on mature mash: Vinegar pouring on mature mash can obtain original vinegar liquid and vinegar dregs, which can be sold and used as feed.

[0127] S8. Sterilization and refining: Filter, blend, precipitate and sterilize the original vinegar liquid to obtain the finished vinegar.

[0128] Effect example

[0129] The soluble solids, total acid and non-volatile acid contents of the vinegar produced in the embodiment and the comparative example were detected, and the sensory indexes were compared.

[0130] Table 1 Comparison of bran vinegar brewed by different processes

[0131]

[0132] Compared with the comparative example, the bran vinegar brewed in the embodiment has a brown-red color without precipitation, and is close to the traditional sun-made bran vinegar in flavor, but the ester fragrance is more intense, which greatly improves the quality of vinegar. The traditional bran vinegar produced in comparative example 1 has good quality, but the starch conversion rate is low, and the production cycle is long. In comparative example 2, Luzhou-flavor Daqu is not added, resulting in a low acidity, poor color, and weak sour fragrance of the vinegar. In comparative example 3, the return dregs process is not adopted, resulting in a relatively weak color of the vinegar, and the acid content is low, so the sour fragrance is not soft. In summary, Daqu addition, return dregs process, etc. greatly improve the starch utilization rate in the raw materials, improve the output rate of the product and simplify the production process, greatly reduce the production cycle of the product, and also have significant advantages in saving raw material costs and improving equipment utilization. It is of positive significance to improve the quality of brewing bran vinegar.

[0133] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. Composition, It is characterized in that include: 2~4% (w / w) brewing Daqu, 3~5‰ (w / w) brewing yeast and 2~3‰ (w / w) acetic acid bacteria.

2. Use of the composition as claimed in claim 1 in preparing bran vinegar.

3. The preparation method of bran vinegar, It is characterized in that The steps include: S1: mixing the brewing koji and the brewing yeast in the composition according to claim 1 with cooked rice to obtain a mixed mash; S2: subjecting the mixed mash to a first fermentation to obtain wine mash; S3: mixing the wine mash, bran, the brewing koji in the composition according to claim 1, and the acetic acid bacteria, and performing a second fermentation to obtain acetic acid; S4: performing a third fermentation on the acetic acid to obtain raw mash; S5: post-ripening the raw mash and pouring vinegar on it to obtain raw vinegar liquid and vinegar dregs; S6: filtering, blending, precipitating and sterilizing the original vinegar liquid to obtain the bran vinegar.

4. The preparation method according to claim 3, It is characterized in that In S3, before the second fermentation, the step of returning the slag is also included; the step of returning the slag is the step of adding vinegar slag; the vinegar slag is obtained in step S5.

5. The preparation method according to claim 4, It is characterized in that The mass ratio of the wine mash, the bran, the vinegar lees and the wine-making koji is 40:20:30:

5.

6. The preparation method according to any one of claims 3 to 5, It is characterized in that The time of the first fermentation in S2 is 36 to 40 hours.

7. The preparation method according to any one of claims 3 to 6, It is characterized in that The temperature of the second fermentation in S3 is 37-39°C.

8. The preparation method according to any one of claims 3 to 7, It is characterized in that The time of the third fermentation in S4 is 13 to 15 days.

9. The preparation method according to any one of claims 3 to 8, It is characterized in that The post-ripening temperature is 55-65°C and the time is 35-50 days.

10. The bran vinegar obtained by the preparation method according to any one of claims 3 to 9.

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