Yellow water fermentation liquor acidification method and application thereof

Abstract

The invention relates to a yellow water fermentation liquor acidification method and application thereof, and the method comprises the following steps: carrying out solid-liquid separation on yellow water fermentation liquor, taking filtrate, and carrying out ultrafiltration to obtain ultrafiltrate; adjusting the concentration of hexanoate in the ultrafiltrate to be 5-10g / L, and then electrolyzing to obtain the acidic yellow water fermentation liquor. According to the method disclosed by the invention, the acid fermentation liquor rich in caproic acid can be obtained by carrying out electrolytic treatment on the yellow water fermentation liquor containing the caproate, and the electrolytic acidification efficiency is improved by regulating and controlling the concentration of the caproate before electrolysis.

Description

Technical Field

[0001] The invention relates to the technical field of winemaking, and in particular to a method for acidifying yellow water fermentation liquid and an application thereof. Background Art

[0002] Yellow water is a byproduct of liquor fermentation, which contains a variety of organic acids, alcohols, sugars, starches and other substances, and has a high utilization value. In traditional winemaking technology, yellow water can be used as bottom pot water for serial distillation to further extract ethanol and some organic acids in the yellow water, but most of the organic acids, sugars and starches in the yellow water are not used efficiently.

[0003] During the liquor brewing process, yellow water submerges the cellar mud, and the microorganisms in the cellar mud can metabolize the starch, sugar, alcohol and organic acid in the yellow water to produce some special compounds, such as butyric acid and caproic acid, which further enrich the flavor of the liquor. Therefore, there are microorganisms in the old cellar mud that can further utilize the yellow water, but they cannot be effectively enriched in the multi-factor environment of brewing.

[0004] After the yellow water is fermented by cellar mud, the solution is neutral. The substances in it are mainly various organic acid salts, such as acetate, caproate, lactate, etc. These salt substances cannot be recycled very well. Among them, caproate is the most important. Caproic acid can be obtained by acidification, and then alcohol and biological enzymes are added for esterification to obtain ethyl caproate, the main flavor substance of Luzhou-flavor liquor.

[0005] Patent document CN202311137724 discloses a method for resource utilization of yellow water fermentation broth and its application, and patent document CN202310096804 discloses a method, product and application for preparing flavored wine by esterification of yellow water fermentation broth. Both of them acidify the yellow water fermentation broth by adding external acids, such as inorganic acids, organic acids, etc. This acidification method not only increases the cost, but also has a low utilization rate of external acid substances, which is not in line with the concept of economic benefits and green production.

[0006] Therefore, a method for acidifying yellow water fermentation liquor without adding exogenous acid is provided, which reduces wine pollution and improves the utilization rate of yellow water fermentation liquor, thereby further brewing high-ester flavored wine with good application prospects. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a method for acidifying yellow water fermentation broth and its application. The present invention can obtain an acidic fermentation broth rich in caproic acid by electrolyzing yellow water fermentation broth containing caproate, and improves the efficiency of electrolytic acidification by regulating the concentration of caproate before electrolysis.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for acidifying yellow water fermentation broth, the method comprising: separating the solid and liquid of the yellow water fermentation broth, taking the filtrate for ultrafiltration to obtain an ultrafiltrate; adjusting the caproate concentration in the ultrafiltrate to 5-10 g / L (for example, it can be 5 g / L, 6 g / L, 7 g / L, 8 g / L, 9 g / L, 10 g / L, etc.), and then performing electrolysis to obtain an acidic yellow water fermentation broth.

[0010] The main substances of the yellow water fermentation liquid used in the present invention are various organic acid salts, such as caproate, lactate, acetate, etc., among which caproate is the most important. In the prior art, an external acid (such as hydrochloric acid, acetic acid, lactic acid, etc.) is usually introduced for acidification to obtain caproic acid, and then esterification is performed to prepare high-ester flavored wine. However, external acid such as hydrochloric acid and acetic acid have the risk of volatilization in the subsequent esterification process, which reduces the quality of subsequent winemaking; and the amount of lactic acid used is large, the hydrogen ion utilization rate is low, and it is difficult to recover, which greatly increases the cost of use.

[0011] The present invention can obtain an acidic fermentation broth rich in caproic acid by electrolyzing yellow water fermentation broth containing caproate, and improves the efficiency of electrolytic acidification by regulating the concentration of caproate before electrolysis, solves the problem that the fermentation broth is neutral and cannot be used, and has good application prospects.

[0012] Preferably, the hexanoate concentration in the ultrafiltrate is adjusted by dilution or concentration.

[0013] Preferably, the solid-liquid separation is performed by filtration using a ceramic membrane.

[0014] Preferably, the pore size of the ceramic membrane is 0.8 to 1000 nm, for example, it may be 10 nm, 20 nm, 50 nm, 100 nm, 200 nm, 500 nm, etc.

[0015] Preferably, the membrane material used in the ultrafiltration includes any one of cellulose acetate, cellulose acetate ester, polyethylene, polysulfone or polyamide, or a combination of at least two thereof.

[0016] Preferably, the pore size of the membrane used in the ultrafiltration is 1 to 100 nm, for example, it can be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, etc.

[0017] Preferably, the voltage of the electrolysis is 10-22V, for example, 10V, 12V, 14V, 16V, 18V, 20V, 22V, etc., and the time of the electrolysis is 30-180min, for example, 30min, 60min, 90min, 120min, 150min, 180min, etc.

[0018] Preferably, the equipment used for electrolysis is a bipolar membrane electrodialysis equipment.

[0019] Preferably, the electrolysis further comprises adding an aqueous solution of an electrolysis aid into the polar chamber of the bipolar membrane electrodialysis device.

[0020] Bipolar membrane electrodialysis equipment is a new type of ion exchange composite membrane. It is usually composed of a cation exchange layer (N-type membrane), an interfacial hydrophilic layer (catalytic layer) and an anion exchange layer (P-type membrane). Under the action of a DC electric field, the bipolar membrane can dissociate water, and hydrogen ions and organic weak acid ions are obtained in the acid chambers on both sides of the membrane to form an acid solution, and hydroxide ions and metal ions are obtained in the alkaline chamber to form a by-product alkaline solution.

[0021] The bipolar membrane electrodialysis equipment is divided into an acid chamber, an alkali chamber, an electrode chamber and a salt chamber. The aqueous solution of the electrolytic aid added to the electrode chamber can play the role of conductivity and membrane protection.

[0022] Preferably, the electrolysis aid includes any one of sodium hydroxide or potassium hydroxide or a combination of the two.

[0023] Preferably, in the aqueous solution of the electrolysis aid, the mass percentage of the electrolysis aid is 0.8-1.2%, for example, 0.8%, 0.9%, 1%, 1.1%, 1.2%, etc.

[0024] Preferably, the mass ratio of the ultrafiltrate to the aqueous solution of the electrolysis aid is 1:(0.5-1.5), for example, it can be 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.5, etc.

[0025] Preferably, the method comprises:

[0026] (1) separating the yellow water fermentation liquid from solid and liquid, taking the filtrate and ultrafiltrating it to obtain an ultrafiltrate;

[0027] (2) adjusting the caproate concentration in the ultrafiltrate to 5-10 g / L, placing the ultrafiltrate in the salt chamber of a bipolar membrane electrodialysis device, placing an aqueous solution of an electrolysis aid in the electrode chamber of the bipolar membrane electrodialysis device, and then electrolyzing at 10-22 V for 30-180 min to obtain an acidic yellow water fermentation broth;

[0028] In the aqueous solution of the electrolysis aid, the mass percentage of the electrolysis aid is 0.8-1.2%; the mass ratio of the ultrafiltrate to the aqueous solution of the electrolysis aid is 1:(0.5-1.5).

[0029] In a second aspect, the present invention provides an application of the method for acidifying yellow water fermentation broth according to the first aspect in the preparation of flavored wine.

[0030] Preferably, the application comprises the following steps:

[0031] (1) preparing acidic yellow water fermentation broth by the method for acidifying yellow water fermentation broth described in the first aspect;

[0032] (2) subjecting the acidic yellow water fermentation broth obtained in step (1) to macroporous resin adsorption purification to obtain an eluent;

[0033] (3) subjecting the eluate obtained in step (2) to an esterification reaction to obtain a flavored wine.

[0034] Preferably, after the macroporous resin is adsorbed in step (2), the eluate is obtained by washing with water and desorbing with ethanol.

[0035] Preferably, the esterification reaction in step (3) comprises mixing the eluate and the biocatalyst, and then performing reduced pressure distillation to obtain the flavored wine.

[0036] Preferably, the biocatalyst comprises immobilized lipase derived from Aspergillus niger.

[0037] Preferably, the amount of the biocatalyst is 1-3% of the mass of the eluent, for example, 1%, 1.5%, 2%, 2.5%, 3%, etc.

[0038] Preferably, the pressure of the reduced pressure distillation is -110 to -90 mbar, for example, -110 mbar, -105 mbar, -100 mbar, -95 mbar, -90 mbar, etc., and the temperature is 50 to 70°C, for example, 50°C, 55°C, 60°C, 65°C, 70°C, etc.

[0039] Preferably, the reduced pressure distillation takes 70-80% of the distillate, for example, 70%, 72%, 74%, 76%, 78%, 80%, etc.

[0040] The present invention further performs an esterification reaction on the acidic fermentation liquid obtained by electrolysis, wherein short-chain organic acids such as caproic acid undergo stronger esterification under the action of a biocatalyst to produce more organic acid ethyl esters, and finally obtains a high-ester flavoring wine through a distillation process. The high-ester flavoring wine prepared by the method has higher total ester content and ethyl caproate content, and the method has a shorter preparation cycle, a higher utilization rate of yellow water as a by-product of winemaking, and a higher fermentation production efficiency, which complies with the energy-saving and green production concept and is beneficial to the protection of the ecological environment.

[0041] Compared with the prior art, the present invention has at least the following beneficial effects:

[0042] The present invention first removes solids and macromolecular substances in the yellow water fermentation liquid, and then adjusts the caproate in the filtrate to a specific concentration for electrolysis treatment to obtain an acidic fermentation liquid rich in caproic acid. The method avoids the introduction of an external acid agent, reduces external acid pollution, and the by-product alkali solution generated during the electrolysis process can be used for pH adjustment in the preparation of the yellow water fermentation liquid, further reducing the production cost. DETAILED DESCRIPTION

[0043] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0044] The source of the yellow water fermentation liquid in the present invention is:

[0045] (1) taking cellar mud, inoculating it into yellow water for fermentation and culturing, and screening a cellar mud functional bacterial liquid with a hexanoate concentration higher than 10 g / L;

[0046] (2) The functional bacterial liquid of the pit mud is inoculated into yellow water for fermentation and cultivation to obtain yellow water fermentation liquid with a caproate concentration of 5-15 g / L.

[0047] Example 1

[0048] This embodiment provides a method for acidifying yellow water fermentation broth, comprising the following steps:

[0049] (1) separating the yellow water fermentation liquid from solid and liquid, taking the filtrate and ultrafiltrating it to obtain an ultrafiltrate;

[0050] (2) Dilute the ultrafiltrate with ultrapure water until the caproate concentration in the ultrafiltrate is 10 g / L, place it in the salt chamber of a bipolar membrane electrodialysis device, place a 1% NaOH aqueous solution in the pole chamber of the bipolar membrane electrodialysis device (the mass ratio of the ultrafiltrate to the 1% NaOH aqueous solution is 1:1.5), and then electrolyze at 22 V for 180 min, mix the solutions in the acid chamber and the salt chamber, and obtain an acidic yellow water fermentation broth.

[0051] Example 2

[0052] This embodiment provides a method for acidifying yellow water fermentation broth, comprising the following steps:

[0053] (1) separating the yellow water fermentation liquid from solid and liquid, taking the filtrate and ultrafiltrating it to obtain an ultrafiltrate;

[0054] (2) Dilute the ultrafiltrate with ultrapure water until the caproate concentration in the ultrafiltrate is 5 g / L, place it in the salt chamber of a bipolar membrane electrodialysis device, place a 1% NaOH aqueous solution in the pole chamber of the bipolar membrane electrodialysis device (the mass ratio of the ultrafiltrate to the 1% NaOH aqueous solution is 1:0.5), and then electrolyze at 10 V for 30 min, mix the solutions in the acid chamber and the salt chamber, and obtain an acidic yellow water fermentation broth.

[0055] Example 3

[0056] This embodiment provides a method for acidifying yellow water fermentation broth, comprising the following steps:

[0057] (1) separating the yellow water fermentation liquid from solid and liquid, taking the filtrate and ultrafiltrating it to obtain an ultrafiltrate;

[0058] (2) Dilute the ultrafiltrate with ultrapure water to a caproate concentration of 8 g / L, place it in the salt chamber of a bipolar membrane electrodialysis device, place a 1% KOH aqueous solution in the pole chamber of the bipolar membrane electrodialysis device (the mass ratio of the ultrafiltrate to the 1% NaOH aqueous solution is 1:1), and then electrolyze at 18 V for 120 min, mix the solutions in the acid chamber and the salt chamber, and obtain an acidic yellow water fermentation broth.

[0059] Comparative Example 1

[0060] This comparative example provides a method for acidifying yellow water fermentation broth, which differs from Example 1 only in that step (2) does not involve electrolysis, but uses hydrochloric acid to adjust the pH of the system to 4 to obtain acidic yellow water fermentation broth.

[0061] Comparative Example 2

[0062] This comparative example provides a method for acidifying yellow water fermentation broth, which differs from Example 1 only in that step (2) does not perform electrolysis, and lactic acid is used to adjust the pH of the system to 4 to obtain acidic yellow water fermentation broth (lactic acid content 50 g / L, caproic acid content 10 g / L).

[0063] Comparative Example 3

[0064] This comparative example provides a method for acidifying yellow water fermentation broth, which differs from Example 1 only in that step (2) adjusts the caproate concentration in the ultrafiltrate to 3 g / L.

[0065] Comparative Example 4

[0066] This comparative example provides a method for acidifying yellow water fermentation broth, which differs from Example 1 only in that step (2) adjusts the caproate concentration in the ultrafiltrate to 16 g / L.

[0067] Test Example 1

[0068] The acidification conditions of the yellow water fermentation broth in the methods provided in Examples 1-3 and Comparative Examples 1-4 are shown in Table 1.

[0069] Table 1

[0070] Grouping Acidity Hexanoate utilization / % Example 1 9.1 95.2 Example 2 8.5 92.6 Example 3 8.9 93.4 Comparative Example 1 8.5 91.3 Comparative Example 2 9.2 90.5 Comparative Example 3 10.5 71.4 Comparative Example 4 6.8 75.2

[0071] The test results show that:

[0072] (1) It can be seen from Examples 1 to 3 that the present invention can achieve acidification of yellow water fermentation broth by electrolysis, and can also achieve good acidification effect under the premise of avoiding the introduction of external acid.

[0073] (2) By comparing Example 1 with Comparative Example 2, it can be seen that the addition amount of lactic acid for acidification is nearly 5% (volume ratio), the lactic acid content obtained in the acidified solution is much higher than that of caproic acid, the hydrogen ion utilization rate is low, and the recovery is difficult, which increases the preparation cost;

[0074] It can be seen from the comparison between Example 1 and Comparative Examples 3-4 that, due to the limited solubility of caproic acid in water, which is about 10-15 g / L, when the concentration of caproate is too high, the excess caproic acid generated in the electrolysis cannot be dissolved, and will float on the aqueous solution in a stratified manner with the system, which not only reduces the utilization rate of caproic acid, but also adsorbs on the membrane device to cause damage to the device; and when the concentration of caproate is too low, the obtained caproic acid concentration is low and the cost is too high; the present invention can improve the utilization rate of caproic acid by adjusting the concentration of caproic acid in the ultrafiltrate.

[0075] Application Example 1

[0076] This application example provides a method for preparing flavored wine, comprising the following steps:

[0077] (1) The acidic yellow water fermentation broth obtained in Example 1 was subjected to macroporous resin adsorption purification, and an eluent was obtained after washing with water and desorption with ethanol;

[0078] (2) The eluate was mixed with immobilized lipase derived from Aspergillus niger (Qingdao Weilan Biotechnology Co., Ltd., the amount used was 2% of the mass of the eluate) at room temperature for 3 hours to obtain an esterified liquid; the esterified liquid was subjected to reduced pressure distillation at 60°C and -100 mbar, and the first 80% volume of the distillate was taken to obtain a flavored wine, in which the content of ethyl hexanoate was 52 g / L.

[0079] Comparative application example 1

[0080] This comparative application example provides a method for preparing a flavored wine, which differs from Application Example 1 only in that in step (1), the acidic yellow water fermentation liquid prepared in Comparative Example 1 is used for subsequent operations, and the content of ethyl hexanoate in the obtained flavored wine is 45 g / L, and the content of chloride ions is 53 ppm.

[0081] It can be seen from Application Example 1 that the acidification method of the yellow water fermentation broth provided by the present invention can be further applied to the preparation of high-ester flavored wine.

[0082] Through the comparison between Application Example 1 and Comparative Application Example 1, it can be seen that although the use of hydrochloric acid to acidify the yellow water fermentation liquid reduces the cost of external acid, due to the volatility of hydrochloric acid, it is easy to remain in the wine in the later esterification process, significantly reducing the quality of the flavored wine.

[0083] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for acidifying yellow water fermentation broth, characterized in that: The method comprises: separating the solid and liquid of the yellow water fermentation liquid, taking the filtrate for ultrafiltration to obtain the ultrafiltrate; adjusting the caproate concentration in the ultrafiltrate to 5-10 g / L, and then performing electrolysis to obtain the acidic yellow water fermentation liquid.

2. The method according to claim 1, characterized in that The membrane material used in the ultrafiltration includes any one or a combination of at least two of cellulose acetate, cellulose acetate ester, polyethylene, polysulfone or polyamide; Preferably, the pore size of the membrane used in the ultrafiltration is 1 to 100 nm.

3. The method according to claim 1 or 2, characterized in that: The voltage of the electrolysis is 10 to 22 V, and the time of the electrolysis is 30 to 180 min.

4. The method according to any one of claims 1 to 3, characterized in that: The equipment used for electrolysis is a bipolar membrane electrodialysis equipment; Preferably, the electrolysis further comprises adding an aqueous solution of an electrolysis aid into the polar chamber of the bipolar membrane electrodialysis device; Preferably, the electrolysis aid comprises any one of sodium hydroxide or potassium hydroxide or a combination of the two; Preferably, in the aqueous solution of the electrolysis aid, the mass percentage of the electrolysis aid is 0.8 to 1.2%; Preferably, the mass ratio of the ultrafiltrate to the aqueous solution of the electrolysis aid is 1:(0.5-1.5).

5. The method according to any one of claims 1 to 4, characterized in that: The method comprises: (1) separating the yellow water fermentation liquid from solid and liquid, taking the filtrate and ultrafiltrating it to obtain an ultrafiltrate; (2) adjusting the caproate concentration in the ultrafiltrate to 5-10 g / L, placing the ultrafiltrate in the salt chamber of a bipolar membrane electrodialysis device, placing an aqueous solution of an electrolysis aid in the electrode chamber of the bipolar membrane electrodialysis device, and then electrolyzing at 10-22 V for 30-180 min to obtain an acidic yellow water fermentation broth; In the aqueous solution of the electrolysis aid, the mass percentage of the electrolysis aid is 0.8-1.2%; the mass ratio of the ultrafiltrate to the aqueous solution of the electrolysis aid is 1:(0.5-1.5).

6. Use of the method for acidifying yellow water fermentation liquid according to any one of claims 1 to 5 in preparing flavored wine.

7. The use according to claim 6, characterized in that: The application comprises the following steps: (1) Acidic yellow water fermentation broth is prepared by the method for acidifying yellow water fermentation broth according to any one of claims 1 to 5; (2) subjecting the acidic yellow water fermentation broth obtained in step (1) to macroporous resin adsorption purification to obtain an eluent; (3) subjecting the eluate obtained in step (2) to an esterification reaction to obtain a flavored wine.

8. The use according to claim 7, characterized in that: After the macroporous resin is adsorbed in step (2), the eluent is obtained by washing with water and desorbing with ethanol.

9. The use according to claim 7 or 8, characterized in that: The esterification reaction in step (3) comprises mixing the eluate and the biocatalyst, and then performing reduced pressure distillation to obtain flavored wine; Preferably, the biocatalyst comprises immobilized lipase derived from Aspergillus niger; Preferably, the amount of the biocatalyst used is 1-3% of the mass of the eluent.

10. The use according to claim 9, characterized in that: The pressure of the reduced pressure distillation is -110 to -90 mbar, and the temperature is 50 to 70°C; Preferably, the reduced pressure distillation takes the first 70-80% of the distillate.