Preparation method of blueberry and mulberry vinegar

Abstract

The invention discloses a making method of blueberry and mulberry vinegar, and belongs to the technical field of food processing. According to the method, the raw material ratio (45-55% of blueberry juice, 20-35% of mulberry juice and 8-12% of lily juice) is optimized, segmented temperature control fermentation (temperature is optimized by stages in alcoholic fermentation and acetic fermentation) is introduced, the utilization rate of the raw materials is increased through secondary alcoholic fermentation, and a non-thermal sterilization process (ultrasonic and ultraviolet) is adopted, so that the fermentation period is remarkably shortened, and meanwhile, active ingredients such as anthocyanin are reserved. The product disclosed by the invention has high antioxidant activity, soft sourness and stability, and is suitable for the development of functional beverages and seasonings.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a method for preparing blueberry mulberry vinegar. Background Art

[0002] In the traditional fruit vinegar production process, high-temperature sterilization and single-strain fermentation mode easily lead to thermal degradation and oxidative loss of active ingredients (such as anthocyanins, vitamins, etc.), while long-term fermentation significantly increases energy consumption and production costs. In addition, the diaphragm design in the existing technology is not adaptable enough to the volume change of the electrode. The mechanical stress generated by the expansion and contraction of the porous electrode during the charging and discharging process can easily cause material pulverization and structural fatigue damage, thereby reducing the battery cycle life. For example, traditional polyolefin diaphragms have poor thermal stability and a single pore size, making it difficult to balance ion migration efficiency and mechanical buffering requirements, resulting in reduced battery safety. Although studies have attempted to optimize diaphragm performance through multi-layer microporous structures or composite coatings, there are still problems such as insufficient pore gradient design and a single interface regulation mechanism, which cannot take into account high ionic conductivity, stress dispersion and active ingredient retention. Summary of the Invention

[0003] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0004] In view of the above problems in the prior art, the inventors proposed the present invention.

[0005] Therefore, the object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing blueberry mulberry vinegar.

[0006] To solve the above technical problems, the present invention provides the following technical solution: a method for preparing blueberry mulberry vinegar, comprising the following steps:

[0007] (1) Raw material pretreatment: blueberries, mulberries, and lilies were washed and pulped to extract juice;

[0008] (2) Preparation of mixed pulp: Mix 45-55% blueberry juice, 20-35% mulberry juice, and 8-12% lily juice according to weight percentage;

[0009] (3) Pre-cooking to inactivate enzymes: cook the mixed slurry at 100°C for 45-55 minutes;

[0010] (4) Adjusting the sugar content: adding sugar to 13°Bx; the sugar is one or more of white sugar, glucose, and fructose syrup, preferably white sugar; Bx is the Brix unit, which represents the mass percentage concentration of soluble solids in the solution (based on sucrose);

[0011] (5) Alcohol fermentation: add 0.10-0.15% active dry yeast, ferment in two stages at 25-30°C (primary fermentation for 5-8 days + secondary fermentation of residue for 3-5 days);

[0012] (6) Acetic acid fermentation: inoculate acetic acid bacteria and ferment at controlled temperature in stages (first stage at 30°C / 20-30 days, second stage at 25°C / 40-50 days);

[0013] (7) Preparation: Add 3-8% honey, 6-9% maltose, and 0.05-0.1% trehalose;

[0014] (8) Sterilization and filling: ultrasonic sterilization (800-1000W, 15-30 minutes) combined with ultraviolet radiation (200-300J / m2).

[0015] As a preferred solution of the method for preparing blueberry mulberry vinegar of the present invention, the raw material ratio is: 50% blueberry juice, 30% mulberry juice, 10% lily juice, 5% honey, and 5% maltose.

[0016] As a preferred embodiment of the method for producing blueberry mulberry vinegar of the present invention, 25°Bx sugar water is added to the residue during the secondary fermentation stage of the alcohol fermentation, and the amount of sugar water added is 50% of the weight of the residue.

[0017] As a preferred embodiment of the method for producing blueberry mulberry vinegar of the present invention, the acetic acid bacteria is the Shanghai Niang 1.01 strain, and the inoculation amount is 8-10% of the volume of the fermentation liquid.

[0018] As a preferred embodiment of the method for preparing blueberry mulberry vinegar of the present invention, the method further comprises adding 0.1% pectinase after pre-cooking in step (3) and performing enzymolysis at 45° C. for 1 hour.

[0019] As a preferred solution of the method for preparing blueberry mulberry vinegar of the present invention, 3-5% wolfberry juice is added in the preparation stage and mixed with the blueberry juice simultaneously.

[0020] As a preferred embodiment of the method for preparing blueberry mulberry vinegar of the present invention, the ultrasonic sterilization parameters are 900W, 20 minutes, and the ultraviolet dose is 250J / m 2 .

[0021] As a preferred embodiment of the method for producing blueberry mulberry vinegar of the present invention, the temperature is dynamically adjusted by online pH monitoring during the acetic acid fermentation stage, and the low-temperature fermentation is switched to 25°C when the pH is ≤3.5.

[0022] As a preferred embodiment of the method for producing blueberry mulberry vinegar of the present invention, the honey is acacia honey, and the maltose is maltooligosaccharide (DE value 10-15).

[0023] As a preferred embodiment of the method for producing blueberry mulberry vinegar of the present invention, the anthocyanin content of the final product is ≥120 mg / 100 mL, and the pH value is 3.2-3.5.

[0024] Beneficial effects of the present invention: The present invention systematically solves the problems of active ingredient loss, long cycle, high energy consumption, etc. in traditional fruit vinegar processes through segmented temperature-controlled fermentation, non-thermal sterilization technology and functional ingredient enhancement. The anthocyanin retention rate is improved, the fermentation cycle energy consumption is shortened, the shelf life is extended, and the microbial safety meets national standards. This technology not only has significant scientific innovation, but also shows broad market prospects in the field of functional foods, providing a reliable technical path for the upgrading of the fruit vinegar industry. In the future, the competitiveness of products can be continuously improved by further optimizing the selection of strains (such as acid-resistant acetic acid bacteria) and process parameters (such as ultrasonic frequency gradient design). DETAILED DESCRIPTION

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0026] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0027] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it constitute a separate or selective embodiment that is mutually exclusive with other embodiments.

[0028] Example 1

[0029] This embodiment provides a method for making blueberry mulberry vinegar, specifically, a basic formula and segmented temperature control.

[0030] Ingredients: 50kg blueberry juice, 30kg mulberry juice, 10kg lily juice, 5kg honey, 5kg maltose.

[0031] step:

[0032] After beating the raw materials, the enzyme was pre-cooked (100°C, 50 minutes) and 0.1% pectinase was added (45°C, 1 hour);

[0033] Alcoholic fermentation: add 0.12% Angel DV10 yeast, ferment at 28℃ for 7 days, and add 25°Bx sugar water to the residue for secondary fermentation for 4 days;

[0034] Acetic acid fermentation: inoculate Shanghai Brewing 1.01 acetic acid bacteria (10% inoculation amount), ferment at 30℃ for 30 days, then at 25℃ for 40 days;

[0035] After preparation, ultrasonic sterilization (900W, 20 minutes) + ultraviolet (250J / m 2 ).

[0036] Principle analysis:

[0037] Segmented temperature-controlled fermentation significantly improves fermentation efficiency by optimizing the microbial metabolic environment.

[0038] Alcohol fermentation: The primary fermentation stage (28°C) promotes rapid yeast proliferation and converts sugar into ethanol. The secondary fermentation stage (residue + 25°Bx sugar water) utilizes the residual sugar and cellulose in the residue, increasing the ethanol yield from 78% to 92%, reducing raw material waste.

[0039] Acetic acid fermentation: The first stage (30°C) accelerated the growth of acetic acid bacteria (Shanghai Brewing 1.01), increasing biomass by 40%. The second stage (25°C) slowed down the metabolic rate, stabilized acid production, and reduced acetic acid volatilization, with the final concentration reaching 5.8g / 100mL.

[0040] Sterilization process: Ultrasonic wave (900W) destroys the cell wall of microorganisms through cavitation effect, ultraviolet light (250J / m 2 ) induced DNA breakage, synergistically reduced the loss of heat-sensitive components, and the anthocyanin retention rate was 85%.

[0041] Example 2

[0042] This embodiment provides a method for preparing blueberry mulberry vinegar, the difference being that wolfberry juice is added and the temperature is dynamically controlled.

[0043] Ingredients: 55kg blueberry juice, 25kg mulberry juice, 8kg lily juice, 3kg wolfberry juice, 8kg honey, 4kg maltose.

[0044] The difference is that 8kg of honey, 4kg of maltose, and 3kg of wolfberry juice are added to the filtered fermentation liquid and stirred to mix evenly. (Polyphenol content increases by 15%). Acetic acid fermentation uses dynamic temperature control: when pH ≤ 3.5, it automatically switches to 25°C.

[0045] Sterilization process: pasteurization (75℃, 15 minutes) combined with ultraviolet (300J / m 2 ).

[0046] From the data:

[0047] Total polyphenol content: Example 2 is 135 mg / 100 mL, Example 1 is 115 mg / 100 mL;

[0048] Fermentation period: 65 days (70 days in Comparative Example 1).

[0049] Further, from the principle analysis:

[0050] Adding wolfberry juice: The polyphenols in wolfberry and blueberry anthocyanins synergistically enhance antioxidant activity, increasing the total polyphenol content by 15% (135 mg / 100 mL) and the free radical scavenging rate by 20%.

[0051] Dynamic temperature control: Online pH monitoring (switch to 25°C when pH ≤ 3.5) prevents excessive acid from inhibiting the activity of acetic acid bacteria, increasing the survival rate to 90% and shortening the fermentation cycle to 65 days.

[0052] Sterilization optimization: Pasteurization (75°C) combined with ultraviolet light balances sterilization effect and protection of heat-sensitive ingredients, extending the shelf life to 16 months.

[0053] Example 3

[0054] This embodiment provides a method for preparing blueberry mulberry vinegar.

[0055] Raw materials: 45kg blueberry juice, 35kg mulberry juice, 12kg lily juice, 3kg honey, 9kg maltose, 0.1% trehalose.

[0056] The difference is: after pre-cooking, 0.2% complex enzyme (pectinase + cellulase 1:1) was added and enzymatic hydrolysis was carried out at 50℃ for 2 hours;

[0057] Alcohol fermentation is divided into three stages (25°C × 3 days → 30°C × 4 days → 28°C × 3 days);

[0058] Sterilization is done by 1000W ultrasonic wave for 30 minutes + ultraviolet light 200J / m 2 .

[0059] In terms of effect:

[0060] 1. Anthocyanin retention rate is 91%, vitamin C retention rate is 89%;

[0061] 2. The shelf life is extended to 18 months (12 months with traditional technology).

[0062] Further, from the principle analysis:

[0063] Composite enzymatic hydrolysis: Pectinase and cellulase (1:1) work synergistically to destroy pectin and cell wall structure, increasing juice yield by 12% and anthocyanin retention rate to 91%.

[0064] Three-stage alcohol fermentation: Gradient temperature increase (25℃→30℃→28℃) ​​adapts to the different growth stages of yeast, and the ethanol conversion rate is increased by 10%.

[0065] Sterilization parameter optimization: high-intensity ultrasound (1000W) with extended action time (30 minutes) completely inactivates heat-resistant spores, with a shelf life of 18 months.

[0066] Comparative Example 1 (traditional long-cycle fermentation)

[0067] Process: Acetic acid fermentation for 85 days, boiling water sterilization for 30 minutes19.

[0068] From the test data:

[0069] 1. Anthocyanin loss rate of 42%, large pH fluctuation (3.0-3.8);

[0070] 2. The fermentation cycle is long and energy consumption increases by 35%.

[0071] Comparative Example 2 (single sterilization process)

[0072] Process: Only ultrasonic sterilization (900W, 20 minutes) was used, omitting the UV step.

[0073] From the test data:

[0074] 1. The residual microorganisms exceed the standard (total colony count> 100 CFU / mL);

[0075] 2. The shelf life is shortened to 10 months.

[0076] Comparative Example 3 (no segmented temperature control)

[0077] Process: Acetic acid fermentation is carried out at 30℃ throughout the whole process.

[0078] From the test data:

[0079] 1. The acetic acid concentration is only 4.2 g / 100 mL (5.8 g / 100 mL in Example 1);

[0080] 2. The survival rate of acetic acid bacteria was reduced to 60% (85% in Example 1).

[0081] The summary and data comparison are shown in the table below:

[0082]

[0083]

[0084] Analysis and comparison of the three comparative examples revealed that in Comparative Example 1, 85 days of single-temperature fermentation resulted in an oxidative loss of 42% of anthocyanins (high temperature accelerated enzymatic browning); pH fluctuations (3.0-3.8) reduced product stability; energy consumption increased by 35%, and the acetic acid concentration was only 4.9 g / 100 mL.

[0085] In Comparative Example 2, due to the lack of ultraviolet ray synergy, sterilization was not thorough and the shelf life was shortened to 10 months. This was because ultrasound had limited inactivation effect on radioresistant bacteria and needed to be supplemented by ultraviolet rays.

[0086] In Comparative Example 3, the entire temperature of 30°C caused the acetic acid bacteria to die prematurely, and the acetic acid concentration was only 4.2 g / 100 mL; this was because high temperature accelerated bacterial metabolism, but long-term high temperature caused metabolic product inhibition.

[0087] From the above analysis, we can see that traditional fruit vinegar fermentation often uses a single temperature control, resulting in a mismatch between microbial metabolic rate and product accumulation. The segmented temperature-controlled fermentation of the present invention significantly optimizes the growth environment of yeast and acetic acid bacteria by dynamically adjusting the temperature:

[0088] Alcohol fermentation stage (25-30℃, divided into two stages):

[0089] Main fermentation stage (5-8 days, 28-30°C): Higher temperature accelerates yeast proliferation, shortens the lag phase, and quickly converts sugars into ethanol, with an ethanol yield of up to 92% (compared to 78% in a single fermentation).

[0090] Secondary fermentation stage of residue (3-5 days, 25°C): The metabolic rate of yeast decreases at low temperatures, but the unused cellulose and pectin in the residue release residual sugars after enzymatic hydrolysis, further improving the ethanol conversion rate and reducing raw material waste.

[0091] Acetic acid fermentation stage (30℃→25℃ divided into two stages):

[0092] The first stage is high temperature (30°C, 20-30 days): Acetobacterium (Shanghai Brewing 1.01) rapidly proliferates at a suitable temperature, and the biomass increases by 40%, laying the foundation for subsequent acid production.

[0093] The second stage is low temperature (25°C, 40-50 days): lowering the temperature slows down the metabolic rate of acetic acid bacteria, avoiding excessive volatilization of acetic acid (the loss in traditional processes can reach 15%), while stabilizing the pH value (3.2-3.5), and the final acetic acid concentration reaches 5.8g / 100mL (compared to 4.2g / 100mL in Comparative Example 3).

[0094] The microbial growth curve is divided into lag phase, log phase, stationary phase, and decay phase. Segmented temperature control adapts the temperature to the needs of different phases, such as high temperature accelerating growth in the log phase and low temperature extending acid production in the stationary phase, thereby improving overall fermentation efficiency.

[0095] Furthermore, traditional high-temperature sterilization (such as boiling water sterilization) can easily lead to the degradation of heat-sensitive components (such as anthocyanins and vitamin C). The present invention uses ultrasound combined with ultraviolet sterilization to inactivate microorganisms through physical action and reduce chemical or thermal damage:

[0096] Ultrasonic sterilization (800-1000W, 15-30 minutes): The local high-pressure shock wave generated by the cavitation effect destroys the cell walls of microorganisms, and the inactivation rate of heat-resistant spores can reach 99.9%.

[0097] Ultraviolet radiation (200-300J / m 2 ): Ultraviolet rays induce microbial DNA to form pyrimidine dimers, blocking the replication process, and have a targeted inactivation effect on ultrasound-resistant bacteria (such as mold spores).

[0098] The two technologies complement each other: ultrasound removes large impurities and disperses bacterial colonies, while ultraviolet light penetrates deep into the liquid to inactivate residual microorganisms. In Example 3, the anthocyanin retention rate reached 91%, demonstrating the significant advantage of non-thermal sterilization.

[0099] Furthermore, pectinase and cellulase act synergistically: adding 0.1% pectinase (Example 1) or a combined enzyme (Example 3) after pre-cooking hydrolyzes pectin and cellulose, releasing more fermentable sugars and encapsulated active substances. In Example 3, combined enzymatic hydrolysis increased juice yield by 12% and anthocyanin retention to 91%.

[0100] Dynamic pH monitoring (Example 2): An online pH sensor monitors the acidity of the fermentation broth in real time. When the pH is ≤3.5, the fermentation is automatically switched to low-temperature fermentation (25°C) to avoid the inhibition of acetic acid bacteria activity by an overly acidic environment (survival rate 90% vs. 60% in Comparative Example 3) while stabilizing the acetic acid concentration.

[0101] A comprehensive comparison of the examples and comparative examples shows that Example 2 shortens the total cycle to 65 days through dynamic temperature control, which is 23.5% less than Comparative Example 1. Reduced energy consumption: Segmented temperature control reduces the proportion of high-temperature stages, and Example 1 reduces energy consumption by 34% compared to the traditional process.

[0102] Addition of wolfberry juice (Example 2): The polyphenols in wolfberry and blueberry anthocyanins synergistically act as antioxidants, increasing the total polyphenol content by 15% and the DPPH free radical scavenging rate by 20%.

[0103] Composite enzymatic hydrolysis (Example 3): destroys the cell wall structure, releases more polyphenols, and increases the vitamin C retention rate to 89%.

[0104] Ultrasound combined with ultraviolet light reduces the residual microorganisms to less than 10 CFU / mL (national standard ≤ 100 CFU / mL), and the shelf life is extended to 18 months.

[0105] pH control: Dynamic monitoring avoids acetic acid bacteria inhibition caused by excessive acidity. The product stability is significantly better than that of Comparative Example 1 (pH fluctuation range 3.0-3.8).

[0106] In summary, the present invention adapts to the growth and metabolic needs of microorganisms by dividing the temperature stages of alcohol and acetic acid fermentation, improves ethanol and acetic acid yields, and shortens the total cycle by more than 20%. Dynamic pH control (Example 2) further optimizes the fermentation environment and avoids metabolite inhibition. Ultrasound and ultraviolet light work synergistically, with an inactivation rate of >99.99% and anthocyanin retention rate of ≥85%, breaking through the technical bottleneck of traditional high-temperature sterilization.

[0107] Optimally, the addition of goji berry juice and complex enzymatic hydrolysis enhances polyphenol and antioxidant activity, meeting market demand for functional foods. Secondary alcoholic fermentation utilizes residual sugars, increasing ethanol yield to 92% and reducing raw material costs by 15%. Its high anthocyanin content (≥120mg / 100mL) and antioxidant activity allow it to be positioned as a high-end health drink, satisfying consumer demand for natural health products.

[0108] Preferably, the sour taste is mild (pH 3.2-3.5) and rich in active ingredients, suitable for healthy seasoning scenarios such as salad vinegar and dipping sauces.

[0109] From the perspective of commercial production feasibility: the process cycle is shortened to 65-70 days, and production capacity is increased by 30%; non-thermal sterilization technology reduces energy consumption and the cost per ton is reduced by 12%.

[0110] Environmental and social benefits: Reduces raw material waste and energy consumption, in line with the trend of green manufacturing; high value-added products contribute to rural revitalization (driven by the economy of raw material production areas such as blueberries and mulberries).

[0111] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing blueberry mulberry vinegar, characterized in that: The production method comprises the following steps: Using blueberries, mulberries and lilies as raw materials, a mixed pulp is prepared, wherein the mixed pulp comprises: blueberry juice, mulberry juice and lily juice, and the weight percentage of the mixed pulp is 45-55% of blueberry juice, 20-35% of mulberry juice, and 8-12% of lily juice; The mixed slurry is pre-boiled and sterilized by boiling at 100° C. for 45-55 minutes, and then sugar is added to adjust the sugar content to 13° Bx to obtain a mixed slurry with adjusted sugar content; Adding 0.10-0.15% active dry yeast to the mixed slurry with adjusted sugar content, and performing alcohol fermentation in two stages at 25-30° C. to obtain an alcohol fermentation product, wherein the alcohol fermentation includes a primary fermentation for 5-8 days and a secondary fermentation of the residue for 3-5 days; Inoculating acetic acid bacteria into the alcohol fermentation product, performing two-stage temperature-controlled acetic acid fermentation to obtain an acetic acid fermentation product, wherein the acetic acid fermentation includes a first stage at 30° C. for 20-30 days and a second stage at 25° C. for 40-50 days; Adding 3-8% honey, 6-9% maltose, and 0.05-0.1% trehalose to the acetic acid fermentation product to adjust the sugar content to obtain a crude product; The crude product was sterilized by ultrasonic sterilization (800-1000W, 15-30 minutes) combined with ultraviolet irradiation (200-300J / m 2 ) After sterilization, filling is carried out to obtain the blueberry mulberry vinegar product.

2. The method for preparing blueberry mulberry vinegar according to claim 1, wherein: The blueberry juice accounts for 50%, the mulberry juice accounts for 30%, the lily juice accounts for 10%, the honey accounts for 5%, and the maltose accounts for 5%.

3. The method for preparing blueberry mulberry vinegar according to claim 1, wherein: During the secondary fermentation stage of the residue, 25°Bx sugar water is added, and the amount of sugar water added is 50% of the weight of the residue.

4. The method for producing blueberry mulberry vinegar according to claim 1, wherein: The acetic acid bacteria is the Shanghai Niang 1.01 strain, and the inoculation amount is 8-10% of the volume of the fermentation liquid.

5. The method for preparing blueberry mulberry vinegar according to claim 1, wherein: The production method further comprises: The mixed pulp is pre-boiled and sterilized by boiling at 100° C. for 45-55 minutes, and then 0.1% pectinase is added and enzymolysis is performed at 45° C. for 1 hour.

6. The method for making blueberry mulberry vinegar according to claim 1, wherein: During the sugar content adjustment stage, 3-5% wolfberry juice is added and mixed with the crude product simultaneously.

7. The method for making blueberry mulberry vinegar according to claim 1, wherein: The parameters of the ultrasonic sterilization are 900W, 20 minutes, and the ultraviolet dose is 250J / m 2 .

8. The method for making blueberry mulberry vinegar according to claim 1, wherein: During the acetic acid fermentation stage, the temperature is dynamically adjusted through online pH monitoring, and when the pH is ≤3.5, it is switched to low-temperature fermentation at 25°C.

9. The method for making blueberry mulberry vinegar according to claim 1, wherein: The honey is acacia honey, and the maltose is oligosaccharide with a DE value of 10-15.

10. The method for making blueberry mulberry vinegar according to claim 1, wherein: The anthocyanin content of the blueberry mulberry vinegar product is ≥120 mg / 100 mL, and the pH value is 3.2-3.5.

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