Fermented beverage rich in alpha-ketoglutaric acid and organic acid and preparation method thereof

Abstract

According to the fermented beverage rich in alpha-ketoglutaric acid and organic acid and the preparation method of the fermented beverage, hawthorn fruits are used for preparing 3.5-degree culture wine, the culture wine is rich in amino nitrogen, and rich protein is provided for enrichment of alpha-ketoglutaric acid and organic acid generated through fermentation; acetic acid bacteria are cultured in the culture wine and ignited, mature fermented wine is obtained when the acidity is larger than 3 degrees, the acetic acid bacteria grow into a tricarboxylic acid state when fermentation is vigorous, the acetic acid bacteria are continuously split and grow, and alpha-ketoglutaric acid reaches the enrichment concentration in acetic acid bacteria cells; the method comprises the following steps of: preparing a 3-degree acid stock solution, boiling, evaporating and concentrating the 3-degree acid stock solution to 50% at 60 DEG C through vacuum steam concentration, removing excessive moisture and acidity according to the ratio of naturally proportioned acidity to AKG through concentration evaporation, amplifying the concentration ratio of AKG, and selecting proper concentration acidity to maximize the concentration ratio of AKG when the proper acidity is obtained through blending, so that the concentration ratio of AKG is increased, the concentration ratio of AKG is increased, and the concentration ratio of AKG is increased. Finally, the acidity of the fermented beverage is 0.9-1 degree through blending, and the concentration of the alpha-ketoglutaric acid is 26 mg / L.

Description

Technical Field

[0001] This invention relates to the field of vinegar technology, specifically to a fermented beverage rich in α-ketoglutaric acid and organic acids, and its preparation method. Background Technology

[0002] α-Ketoglutaric acid is one of two ketone-containing derivatives of glutaric acid and is an important biological compound.

[0003] Industrial synthesis of α-ketoglutaric acid typically involves distilling a mixture of triethyl oxaloyl succinate and concentrated hydrochloric acid, making it unsuitable for direct consumption or drinking.

[0004] α-Ketoglutarate is a keto acid product of glutamate deamination and an intermediate product of the tricarboxylic acid (TCA) cycle. During the ethanol fermentation stage of acetic acid fermentation, high concentrations of ethanol and an acidic environment (pH < 4) inhibit key enzymes in the TCA cycle, leading to TCA cycle inhibition. However, during the cell growth stage, the TCA cycle is active, easily producing AKG. Therefore, while acetic acid fermented beverages contain some α-ketoglutarate, the concentration and acidity are insufficient for use or consumption.

[0005] Therefore, there is a need for an acetic acid beverage rich in α-ketoglutarate. Summary of the Invention

[0006] This invention aims to solve the problem of how to enrich α-ketoglutaric acid in fermented beverages, and provides a fermented beverage rich in α-ketoglutaric acid and organic acids and its preparation method. Through fermentation and concentration, α-ketoglutaric acid is enriched while acidity is adjusted to obtain a fermented beverage suitable for drinking that is rich in α-ketoglutaric acid and organic acids.

[0007] This invention provides a fermented beverage rich in α-ketoglutaric acid and organic acids, prepared by liquid fermentation, with an acidity of 0.9 to 1 degree and an α-ketoglutaric acid concentration greater than or equal to 26 mg / L.

[0008] This invention provides a method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids, comprising the following steps: S1. Mix water in a mass ratio of (2~4):(1~1.5) with fresh hawthorn fruit after washing and removing the pits, boil it, cool it, and then filter it by plate and frame pressing. Then add rock sugar to the filtrate to obtain the filtered hawthorn liquid. The total acid content of the filtered hawthorn extract was 6.0~7.0 g / L, the total sugar content was greater than or equal to 13%, the total hawthorn flavonoid content was greater than or equal to 210 mg / 100 ml, and the amino nitrogen content was greater than or equal to 0.18 g / 100 ml. S2. Add 0.2% by weight of yeast (Baijiu King) to the filtered hawthorn liquid, and ferment it in an alcohol tank to obtain hawthorn wine with an alcohol content of 6.0°~7.0°. S3. Dilute the hawthorn wine with membrane-filtered water to an alcohol content of 3.5 degrees and introduce it into a fruit vinegar generator. Then add acetic acid bacteria and continuously replenish the fermentation wine until the acidity reaches 3 degrees. Then divide it to obtain fermented liquid vinegar. During the growth of acetic acid bacteria, α-ketoglutaric acid is enriched. The α-ketoglutaric acid content of the fermented liquid vinegar is greater than 66 mg / L and the acidity is 3.0°~3.5°. S4. Inject the fermented liquid vinegar into the vacuum chamber, and use a vacuum pump to continuously reduce the vacuum level of the vacuum chamber while simultaneously heating with steam to bring the fermented liquid vinegar to a boil at a temperature below 60°C and maintain the boiling point. The concentration ratio is 50%, and the concentration of α-ketoglutaric acid is greater than or equal to 130 mg / L, thus obtaining a fermentation concentrate rich in α-ketoglutaric acid. S5. Dilute the acidity of the α-ketoglutaric acid-rich fermentation concentrate to 0.9-1 degrees using membrane filtration, add honey, and then bottle to obtain a fermented beverage rich in α-ketoglutaric acid and organic acids.

[0009] The method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids according to the present invention, in a preferred embodiment, includes the following steps in step S1: S11. Mix water in a mass ratio of (2~4):(1~1.5) with fresh hawthorn fruit after washing and removing the pits. Simmer over low heat until it becomes a porridge-like consistency. Let it stand and cool to room temperature to obtain hawthorn fruit pulp. S12. Cool to room temperature to obtain cooled hawthorn pulp; S13. After cooling, the hawthorn pulp is filtered by plate and frame filter press to separate the hawthorn liquid and hawthorn residue. 50-mesh polypropylene filter cloth can be selected in combination with diatomaceous earth filter media for filtration. S14. Add 7% to 10% by mass of rock sugar to the filtrate, stir well, and obtain the filtered hawthorn liquid. The filtered hawthorn extract contained a total acid of ≥6.0 g / L, a total sugar of ≥13%, a total hawthorn flavonoid of ≥210 mg / 100 ml, and an amino nitrogen of ≥0.18 g / 100 ml.

[0010] In the preferred embodiment of the method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids according to the present invention, the fermentation time in the alcohol tank in step S2 is 12 days.

[0011] In the preferred embodiment of the method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids described in this invention, in step S3, the operating temperature of the fruit vinegar generator is 28 degrees Celsius, and the acetic acid bacteria are Hu Niang 1.01 strain and Zhongke AS.4.01 strain. Fermented liquid vinegar can be obtained by dividing the product after 7 days of fermentation. Acidity should be tested starting from day 4. When the acidity exceeds 2 degrees, fermentation should continue for another day before dividing. When dividing, first collect 30-40L, and then add an equal amount of hawthorn wine diluted to 3.5 degrees. On day 7, acidity should be tested daily, and the product should be divided and replenished as needed.

[0012] The method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids according to the present invention, in a preferred embodiment, includes the following steps in step S4: S41. Inject fermented liquid vinegar into the vacuum chamber and close the valve; S42. Turn on the vacuum pump to evacuate the vacuum chamber. The vacuum level will continue to decrease. Stop evacuating when the vacuum level drops from 0.04MPa to 0.08MPa. While vacuuming, steam is turned on to heat the concentrate. When the vacuum reaches 0.04 MPa, the temperature is adjusted to 40℃. S43. When the vacuum degree reaches 0.08MPa, the fermented liquid vinegar boils at 60℃. At this time, keep the vacuum pump running and adjust the steam valve to keep the concentrate in a normal boiling state. S44. Continuous concentration: When 150 kg of white vinegar is produced, the concentration ends, and a fermentation concentrate rich in α-ketoglutaric acid is obtained.

[0013] In a preferred embodiment of the method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids according to the present invention, the amount of fermented liquid vinegar added in step S41 is 300 kg. Before concentration, the acidity of the fermented liquid vinegar was 3.1° and the AKG content was 66.52 mg / L. After concentration in step S43, the acidity of the α-ketoglutaric acid-rich fermented concentrate was 4.5° and the AKG content was 137.8 mg / L. The acidity of the concentrated white vinegar was 1.8°.

[0014] The present invention provides a method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids. In a preferred embodiment, in step S5, 12.5% ​​honey is added during preparation, the beverage is then bottled into 25ml PP bottles and sterilized to obtain a fermented beverage rich in α-ketoglutaric acid and organic acids.

[0015] The present invention has the following advantages: (1) In the preparation of filtered hawthorn liquid, the acidity is adjusted to 6.0~7.0 by adding rock sugar to provide a suitable amino nitrogen concentration. The filtered hawthorn liquid is used to make a cultured wine with a temperature of 6.0°~7.0°, which is rich in amino nitrogen, provides rich protein for the fermentation to produce α-ketoglutarate and organic acid enrichment, and can also prevent spoilage and preserve quality, which is beneficial to production. (2) Acetic acid bacteria used in the production of α-ketoglutaric acid are cultured in the culture wine. When the acidity is greater than 3 degrees, mature fermented wine is obtained. When the fermentation is vigorous, the acetic acid bacteria enter the tricarboxylic acid state. The acetic acid bacteria continuously divide and grow. The organic acids formed by α-ketoglutaric acid and the tricarboxylic acid cycle reach an enriched concentration in the acetic acid bacteria cells. As the number of bacteria reaches 10 8 / ml, fermentation ends; by dividing the fermentation broth over time, the acetic acid acidity reaches 3.0°~3.5° and is accumulated. At this time, the concentration of α-ketoglutarate is 66.52mg / L.

[0016] (3) The original solution with an acidity of 3.0°~3.5° was concentrated by vacuum steam concentration at 60°C to 50% of the original volume before concentration. The ratio of acidity to AKG in a natural proportion was removed by concentration and evaporation to eliminate excess water and acidity, thereby increasing the concentration ratio of AKG. By selecting a suitable concentration acidity, the concentration ratio of AKG was maximized when the acidity was adjusted to a suitable level, further increasing the concentration of α-ketoglutarate. After concentration, the acidity reached 4.5° and the concentration of α-ketoglutarate reached more than 130mg / L, thus obtaining the original solution before preparation.

[0017] (4) Finally, the acidity of the fermented beverage is adjusted to 0.9~1 degrees, and the concentration of α-ketoglutarate is approximately 26 mg / L. This invention, through fermentation and concentration, enriches α-ketoglutarate and organic acids while adjusting the acidity to obtain a fermented beverage suitable for drinking that is rich in α-ketoglutarate and organic acids. Attached Figure Description

[0018] Figure 1 A diagram showing a fermented beverage rich in α-ketoglutaric acid and organic acids and its preparation method; Figure 2 This is a schematic diagram illustrating the fermentation acidity, fermentation temperature, and AKG content of a fermented beverage rich in α-ketoglutaric acid and organic acids, and its preparation method. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Example 1

[0020] like Figure 1 As shown, a fermented beverage rich in α-ketoglutaric acid and organic acids and its preparation method are disclosed. This example uses fermentation at degree 3 as an example: S1. Production of fermented wine: Hawthorn fruit is used to make 6-degree wine, with an amino nitrogen content of 0.18g / 100ml.

[0021] The specific preparation method is as follows: S1. Boiling hawthorn fruit puree: This includes the following steps: S11. Mix 3 kg of water with 1 kg of fresh hawthorn fruit, simmer over low heat with stirring until it becomes a porridge-like consistency, let it cool to room temperature, and obtain hawthorn fruit puree; S12, Cool down to room temperature.

[0022] S13. The cooled hawthorn pulp is subjected to plate and frame filter press to separate the hawthorn liquid and hawthorn residue. During filtration, 50-mesh polypropylene filter cloth can be selected in combination with diatomaceous earth filter media to obtain the filtered hawthorn liquid. S14. Add rock sugar at 8% and stir well.

[0023] Test indicators for filtered hawthorn extract: Total acid: 8.0 g / L; total sugar: 13%; total hawthorn flavonoids: 280 mg / 100 ml; amino nitrogen: 0.18 g / 100 ml; S2, Inoculate with yeast. Continuously inoculate with 0.2% of the Baijiu King yeast, for a total of 132 grams.

[0024] Alcoholic fermentation. The mixture was transferred to an alcohol tank and fermented for 12 days. Alcohol content: 6.5% (V / V), amino nitrogen content: 0.18g / 100ml.

[0025] Step S3 includes the following steps: Acetic acid liquid fermentation 1. Liquid separation preparation.

[0026]

[0027] The total acidity of the fermented liquid vinegar product is 3.1°. Test results: Total acid: 3.1g / 100ml, AKG (α-ketoglutarate): 66.52mg / L Step S4 concentration includes the following steps: Equipment: Vacuum concentrator S41. Inject concentrated liquid into the vacuum chamber, typically 300 kg. Close the valve.

[0028] S42. Turn on the vacuum pump to evacuate the vacuum chamber. The vacuum level in the vacuum chamber will continuously decrease, starting from 0.04 MPa and stopping at 0.08 MPa.

[0029] When starting the vacuum process, simultaneously turn on the steam to heat the concentrate. Pay attention to the steady and continuous increase of the concentrate temperature. When the vacuum level reaches 0.04 MPa, monitor the concentrate temperature and appropriately increase it to 40 degrees Celsius.

[0030] S43. When the vacuum degree reaches 0.08MPa, the concentrate boils at 60 degrees. At this time, keep the vacuum pump running and adjust the steam valve to keep the concentrate in a normal boiling state.

[0031] S44. Continuous concentration: Concentration ends when 150 kg of white vinegar is produced.

[0032] Liquid before concentration: Acidity: 3.1°. AKG: 66.52 mg / L Concentrated liquid: 4.5° AKG: 137.8 mg / L Concentrated white vinegar: Acidity: 1.8° S5. Dilute the 4.5° acidity with membrane-filtered water to 0.9-1°, and add 12.5% ​​honey for a suitable drinking product. After bottling into 25ml PP bottles, sterilize and set, to obtain a fermented beverage rich in α-ketoglutaric acid and organic acids, with an acidity of 0.9-1° and an AKG (α-ketoglutaric acid) concentration of 25mg / L.

[0033] like Figure 2 As shown in the experimental data of acetic acid bacteria fermentation, it can be seen that whether it is solid-state fermentation or liquid-state fermentation, the acidity of the fermentation broth can represent the degree of fermentation. Therefore, the proportion of AKG produced by acetic acid bacteria in the tricarboxylic acid cycle during the division growth (growth period, about 7 days) is positively correlated with acidity. According to actual measurements, their relationship can generally be expressed by a positive correlation function: y (acidity) = 0.04679x (where y is acidity and x is AKG concentration, mg / L).

[0034] Note: The acidity has not been concentrated during the brewing process. Generally, solid-state fermentation requires 30% aging for natural concentration, which increases the acidity by about 0.3.

[0035] During the cell growth stage, the TCA cycle is active, making it easy to produce AKG. Once the acetic acid bacteria have stabilized fermentation, the TCA cycle is inhibited. Therefore, controlling the fermentation stage is crucial to obtaining high AKG production.

[0036] The following is a rough ranking of the concentrations of intermediate carboxylic acids in the tricarboxylic acid cycle in the mitochondrial matrix of prokaryotic cells: 1. Malic acid (Malate) - Highest concentration 2. Citric acid 3. Succinate 4. Isocitrate 5. Fumaric acid or fumarate 6. α-Ketoglutarate 7. Succinyl-CoA - Extremely low concentration 8. Oxaloacetate (OAA) - Lowest concentration The above-mentioned organic acids are enriched using the same process as AKG.

[0037] One of the technical features of this solution is the implementation of a concentration process. The ratio of naturally proportional acidity to AKG is concentrated and evaporated to remove excess acidity, thereby increasing the concentration ratio of AKG. By selecting an appropriate concentration acidity, the concentration ratio of AKG is maximized when the appropriate acidity is achieved.

[0038] Comparison with Option 1: Steps S1 and S2 are the same as in this embodiment. The preparation of liquid separation during acetic acid liquid fermentation in step S3 is shown in the table below:

[0039] Compared to Scheme 1, the fermented liquid vinegar product has a 6° alcohol content and the following test indicators: total acid: 6.1g / 100ml, AKG (α-ketoglutarate) concentration: 121.74mg / L; Then, step S4 is performed for concentration. After concentration, the acidity is 8.5° and the AKG content is 242 mg / L. Then, step S5 is performed for blending. After blending, the acidity is the same as in this example.

[0040] Comparison with Option Two: Similar to Comparative Scheme 1, after steps S1 and S2, step S3 is performed to ferment to 6°. Step S4 is skipped for concentration, and step S5 is performed directly. The acidity after blending is the same as in this embodiment.

[0041] The comparison results of the three schemes are shown in the table below:

[0042] From the above results, we can conclude that: Compared with this embodiment, the first scheme fermented to 6° and then concentrated and blended, resulting in a higher dilution ratio during blending. Although the AKG index is not much different from that of this embodiment, the concentration caused a great waste of other beneficial components in the liquid fermented vinegar.

[0043] Compared with Comparative Scheme 1, Scheme 2 showed a significant difference in AKG concentration due to the absence of concentration in step S4; Conclusion: This embodiment has the best overall effect.

[0044] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A fermented beverage rich in α-ketoglutaric acid and organic acids, characterized in that: Prepared by liquid fermentation, with an acidity of 0.9-1 degree and an α-ketoglutaric acid concentration greater than or equal to 26 mg / L.

2. The method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids according to claim 1, characterized in that: Includes the following steps: S1. Mix water in a mass ratio of (2~4):(1~1.5) with fresh hawthorn fruit after washing and removing the pits, boil it, cool it, and then filter it by plate and frame pressing. Then add rock sugar to the filtrate to obtain the filtered hawthorn liquid. The total acid content of the filtered hawthorn liquid is 6.0~7.0 g / L, the total sugar content is greater than or equal to 13%, the total hawthorn flavonoid content is greater than or equal to 210 mg / 100 ml, and the amino nitrogen content is greater than or equal to 0.18 g / 100 ml. S2. Add 0.2% by weight of yeast (Baijiu King) to the filtered hawthorn liquid, and ferment it in an alcohol tank to obtain hawthorn wine with an alcohol content of 6.0°~7.0°. S3. Dilute the hawthorn wine with membrane filtered water to an alcohol content of 3.5 degrees and introduce it into a fruit vinegar generator. Add acetic acid bacteria and continuously replenish the fermented wine until the acidity reaches 3 degrees. Then, divide the wine to obtain fermented liquid vinegar. The fermented liquid vinegar has an α-ketoglutaric acid content greater than 66 mg / L and an acidity of 3.0°~3.5°. S4. The fermented liquid vinegar is injected into a vacuum chamber. The vacuum degree of the vacuum chamber is continuously reduced by a vacuum pump, while steam heating is performed to make the fermented liquid vinegar boil at a temperature below 60°C and maintain it. The concentration ratio is 50%, and the concentration of α-ketoglutaric acid is greater than or equal to 130 mg / L, thus obtaining a fermentation concentrate rich in α-ketoglutaric acid. S5. Dilute the acidity of the α-ketoglutaric acid-rich fermentation concentrate to 0.9-1 degrees using membrane filtration, add honey, and then bottle to obtain the fermented beverage rich in α-ketoglutaric acid and organic acids.

3. The method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids according to claim 2, characterized in that: Step S1 includes the following steps: S11. Mix water in a mass ratio of (2~4):(1~1.5) with fresh hawthorn fruit after washing and removing the pits. Simmer over low heat until it becomes a porridge-like consistency. Let it stand and cool to room temperature to obtain hawthorn fruit pulp. S12. Cool to room temperature to obtain cooled hawthorn pulp; S13. The cooled hawthorn pulp is subjected to plate and frame filter press to separate the hawthorn liquid and hawthorn residue. During filtration, 50-mesh polypropylene filter cloth can be selected in combination with diatomaceous earth filter media. S14. Add 7% to 10% by mass of rock sugar to the filtrate, stir well, and obtain the filtered hawthorn liquid. The filtered hawthorn liquid has a total acid content greater than or equal to 6.0 g / L, a total sugar content greater than or equal to 13%, a total hawthorn flavonoid content greater than or equal to 210 mg / 100 ml, and an amino nitrogen content greater than or equal to 0.18 g / 100 ml.

4. The method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids according to claim 2, characterized in that: In step S2, the fermentation time in the alcohol tank is 12 days.

5. The method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids according to claim 2, characterized in that: In step S3, the operating temperature in the fruit vinegar generator is 28 degrees Celsius, and the acetic acid bacteria are Hu Niang 1.01 strain and Zhongke AS.4.01 strain; The fermented liquid vinegar can be obtained by fermentation for 7 days. Acidity should be tested starting from day 4. When the acidity exceeds 2 degrees, fermentation should continue for another day before division. When dividing, first collect 30-40L, and then add an equal amount of hawthorn wine diluted to 3.5 degrees. On day 7, acidity should be tested daily, and division and liquid replenishment should be carried out accordingly. α-Ketoglutarate is enriched during the growth of acetic acid bacteria.

6. The method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids according to claim 2, characterized in that: Step S4 includes the following steps: S41. Inject the fermented liquid vinegar into the vacuum chamber and close the valve; S42. Turn on the vacuum pump to evacuate the vacuum chamber. The vacuum level will continue to decrease. Stop evacuating when the vacuum level drops from 0.04MPa to 0.08MPa. While vacuuming, steam is turned on to heat the concentrate. When the vacuum reaches 0.04 MPa, the temperature is adjusted to 40℃. S43. When the vacuum degree reaches 0.08MPa, the fermented liquid vinegar boils at 60°C. At this time, the vacuum pump is kept running and the steam valve is adjusted to keep the concentrate in a normal boiling state. S44. Continuous concentration: When 150 kg of white vinegar is produced, the concentration ends, and the fermentation concentrate rich in α-ketoglutaric acid is obtained.

7. The method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids according to claim 6, characterized in that: In step S41, the amount of fermented liquid vinegar added is 300 kg; The acidity of the fermented liquid vinegar before concentration was 3.1°, and the AKG content was 66.52 mg / L; after concentration in step S43, the acidity of the fermented concentrate rich in α-ketoglutaric acid was 4.5°, the AKG content was 137.8 mg / L, and the acidity of the concentrated white vinegar was 1.8°.

8. The method for preparing a fermented beverage rich in α-ketoglutaric acid and organic acids according to claim 2, characterized in that: In step S5, after adding 12.5% ​​honey during preparation, the mixture is bottled into 25ml PP bottles and then sterilized to obtain the fermented beverage rich in α-ketoglutaric acid and organic acids.

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