A method for resource utilization of yellow water fermentation broth and its application

Abstract

This invention provides a method for the resource utilization of yellow water fermentation liquid and its application. The method includes the following steps: (1) pretreating the yellow water fermentation liquid to obtain acidic yellow water fermentation liquid; (2) subjecting the acidic yellow water fermentation liquid obtained in step (1) to a chromatography column adsorption, washing, and elution process to obtain a high-concentration eluent; (3) subjecting the high-concentration eluent obtained in step (2) to an esterification reaction to obtain a high-ester flavored liquor; the chromatography column contains macroporous adsorption resin; the eluent used for elution includes ethanol; and the high-concentration eluent is an ethanol solution of hexanoic acid. In this invention, the method not only solves the problem of yellow water discharge, a byproduct of brewing, but also enables recycling and reuse to obtain a high-concentration ethyl hexanoate flavored liquor, improving the quality of liquor, avoiding resource waste, and the process is simple and low-cost.

Description

Technical Field

[0001] This invention belongs to the field of liquor production technology, specifically relating to a method for the resource utilization of yellow water fermentation liquid and its application. Background Technology

[0002] Yellow liquid is a brownish-yellow, fluid-like liquid that settles at the bottom of the fermentation pits during the solid-state fermentation of baijiu (Chinese liquor). This occurs because some water seeps out from the mash during microbial decomposition and metabolism. Studies show that approximately 0.3–0.4 cubic meters of yellow liquid are produced for every 1000 kg of baijiu produced. 3 The annual discharge of yellow water reaches 340m³. 3 The direct discharge of untreated yellow water will lead to serious environmental pollution and also waste of resources.

[0003] Currently, most Chinese distilleries treat yellow wastewater by methods such as mixing it with fermented mash and returning it to the fermentation pit for further fermentation or pit maintenance, cultivating artificial pit mud, and distilling it in the bottom pot. However, these methods not only fail to effectively utilize resources and reduce COD emissions from the yellow wastewater, but also fail to fundamentally solve the problem of optimal comprehensive utilization of fermentation yellow wastewater. Therefore, how to rationally utilize yellow wastewater resources, avoiding resource waste while solving the yellow wastewater discharge problem, is a major challenge facing the liquor industry.

[0004] Currently, strong-aroma baijiu accounts for about 70% of my country's baijiu production and sales, and is very popular among consumers. Ethyl hexanoate is the main aroma component of strong-aroma baijiu, and its content is one of the important factors determining its quality. Under natural fermentation conditions, the esterification of hexanoic acid into ethyl hexanoate is relatively slow, resulting in a lower ethyl hexanoate content in the final mash compared to the yield of the original liquor. Production generally compensates for this deficiency by extending the fermentation cycle, but this reduces the number of production cycles and lowers production efficiency. Furthermore, during distillation, ethyl hexanoate is mainly distilled out in the early stages, concentrated in the heads and early-middle sections of the liquor, while the content in the later sections and tails is relatively low, which is also a significant factor restricting the improvement of baijiu quality.

[0005] For example, CN108330044A discloses a method for the resource utilization of yellow water in brewing. By using lactic acid bacteria to convert lactic acid in yellow water into hexanoic acid, the resulting yellow water fermentation liquid can be directly used as fermentation liquid and returned to the cellar for fermentation together with grain lees, thus realizing the reuse of yellow water resources. The flavor and quality of the prepared liquor are improved. However, this method cannot obtain high concentrations of hexanoic acid and has low esterification efficiency, so the quality of the flavored liquor obtained needs to be further improved.

[0006] Therefore, developing a method that can make reasonable use of the yellow water, a byproduct of brewing, improve the quality of liquor, and solve the pollution problem caused by the yellow water is an urgent problem to be solved in this field. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a method for the resource utilization of yellow fermentation liquid and its application. This method uses only a small amount of ethanol to efficiently enrich hexanoic acid in the yellow fermentation liquid, obtaining a high-concentration hexanoic acid solution. This facilitates the further esterification of hexanoic acid, increases the concentration of ethyl hexanoate in the flavoring liquor, and contributes to obtaining high-quality baijiu. It not only solves the problem of discharging yellow fermentation liquid, a byproduct of brewing, but also enables recycling and reuse, avoiding resource waste. Furthermore, the process is simple and low-cost.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] In a first aspect, the present invention provides a method for the resource utilization of yellow water fermentation liquid, the method comprising the following steps:

[0010] (1) The yellow water fermentation broth was pretreated to obtain acidic yellow water fermentation broth;

[0011] (2) The acidic yellow fermentation broth obtained in step (1) is subjected to column chromatography adsorption, washing and elution processes to obtain a high-concentration eluent;

[0012] (3) The high-concentration eluent obtained in step (2) is subjected to an esterification reaction to obtain a high-ester flavored wine; the chromatography column contains macroporous adsorption resin; the eluent used for elution includes ethanol; the high-concentration eluent is an ethanol solution of hexanoic acid.

[0013] In this invention, macroporous adsorption resin is used to adsorb acidic yellow fermentation broth, thereby adsorbing hexanoic acid from the broth onto a chromatography column. Following washing and elution with ethanol as the eluent, the hexanoic acid in the broth is enriched, resulting in an eluent with a high concentration of hexanoic acid. This specific process not only increases the concentration of hexanoic acid but also facilitates the subsequent esterification reaction, yielding a flavoring liquor rich in high concentrations of ethyl hexanoate. This not only solves the problem of discharging brewing byproducts but also allows for recycling and reuse, supplementing esters in the later stages of brewing and improving the quality and grade of the liquor.

[0014] Preferably, the pretreatment includes: mixing the yellow water fermentation broth with a pH adjuster and filtering to obtain the acidic yellow water fermentation broth.

[0015] Preferably, the pH adjuster includes at least one of acetic acid, lactic acid, or yellow water, a byproduct of brewing.

[0016] Preferably, the pH value of the acidic yellow water fermentation broth is 3.5 to 5.5, for example, it can be 3.5, 4, 4.5, 5, 5.5, etc.

[0017] Preferably, the content of the pH adjuster is 3 to 5% of the mass of the yellow water fermentation broth, for example, it can be 3%, 3.2%, 3.4%, 3.6%, 3.8%, 4%, 4.2%, 4.4%, 4.6%, 4.8%, 5%, etc.

[0018] In this invention, the filtration is carried out using a ceramic membrane to remove solid insoluble substances from the acidic yellow fermentation broth, making it clear and transparent. Water needs to be added for washing during the filtration process, which increases the volume and reduces the hexanoic acid concentration by about 10%. The hexanoic acid recovery rate is >95%.

[0019] Preferably, the concentration of hexanoic acid in the acidic yellow fermentation broth is 4–16 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, 11 g / L, 12 g / L, 13 g / L, 14 g / L, 15 g / L, 16 g / L, etc.

[0020] Preferably, the macroporous adsorption resin includes any one of polar macroporous resin, non-polar macroporous resin, medium-polar macroporous resin, or weakly polar macroporous resin.

[0021] Preferably, the macroporous adsorption resin includes any one of DZ-50, D101, HPD100, HPD400, HPD600, HPD722 or AB-8.

[0022] In this invention, DZ-50, D101, and HPD100 are non-polar macroporous resins; HPD400 is a medium-polar macroporous resin; HPD600 is a polar macroporous resin; and HPD722 and AB-8 are weakly polar macroporous resins.

[0023] Preferably, the macroporous adsorption resin is further activated and purified by soaking in ethanol before use.

[0024] In this invention, the activation and impurity removal includes activating and removing impurities by soaking in ethanol for 2 to 3 hours, followed by wet packing of the column, packing the resin into a low-pressure chromatography column, washing the column with soft water until the ethanol content of the eluent is below 10%, and then loading the sample.

[0025] Preferably, the loading flow rate during adsorption is 2 to 3 BV / h, for example, it can be 2 BV / h, 2.1 BV / h, 2.2 BV / h, 2.3 BV / h, 2.4 BV / h, 2.5 BV / h, 2.6 BV / h, 2.7 BV / h, 2.8 BV / h, 2.9 BV / h, 3 BV / h, etc.

[0026] Preferably, the sample loading volume during adsorption is 5–10 BV, for example, it can be 5 BV, 5.2 BV, 5.5 BV, 5.8 BV, 6 BV, 6.2 BV, 6.5 BV, 6.8 BV, 7 BV, 7.2 BV, 7.5 BV, 7.8 BV, 8 BV, 8.2 BV, 8.5 BV, 8.8 BV, 9 BV, 9.2 BV, 9.5 BV, 9.8 BV, 10 BV, etc.

[0027] In this invention, the sample loading volume is related to the hexanoic acid content in the acidic yellow water fermentation broth. The higher the hexanoic acid content, the smaller the sample loading volume, and vice versa.

[0028] Preferably, the adsorption time is 2.5 to 5 hours, for example, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, etc.

[0029] Preferably, the washing solution comprises water.

[0030] Preferably, during the washing process, the volume of the solvent is 1–1.5 BV, for example, 1 BV, 1.05 BV, 1.1 BV, 1.15 BV, 1.2 BV, 1.25 BV, 1.3 BV, 1.35 BV, 1.4 BV, 1.45 BV, 1.5 BV, etc.; the solvent flow rate is 2–3 BV / h, for example, 2 BV / h, 2.1 BV / h, 2.2 BV / h, 2.3 BV / h, 2.4 BV / h, 2.5 BV / h, 2.6 BV / h, 2.7 BV / h, 2.8 BV / h, 2.9 BV / h, 3 BV / h, etc.; and the washing time is 30–45 min, for example, 30 min, 32 min, 34 min, 36 min, 38 min, 40 min, 42 min, 44 min, 45 min, etc.

[0031] In this invention, during the washing process, the washing effect is better when the volume and flow rate of the water are within the above-defined range; if the volume is too small, the washing will not be thorough; if the volume is too large, it will lead to the loss of hexanoic acid.

[0032] Preferably, the volume of the eluent is 1 to 3 BV, for example, it can be 1 BV, 1.1 BV, 1.2 BV, 1.3 BV, 1.4 BV, 1.5 BV, 1.6 BV, 1.7 BV, 1.8 BV, 1.9 BV, 2 BV, 2.1 BV, 2.2 BV, 2.3 BV, 2.4 BV, 2.5 BV, 2.6 BV, 2.7 BV, 2.8 BV, 2.9 BV, 3 BV, etc.

[0033] Preferably, the flow rate of the eluent is 2 to 3 BV / h, for example, it can be 2 BV / h, 2.1 BV / h, 2.2 BV / h, 2.3 BV / h, 2.4 BV / h, 2.5 BV / h, 2.6 BV / h, 2.7 BV / h, 2.8 BV / h, 2.9 BV / h, 3 BV / h, etc.

[0034] Preferably, the elution time is 0.5 to 1.5 hours, for example, 0.5 hours, 0.6 hours, 0.7 hours, 0.8 hours, 0.9 hours, 1 hour, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, 1.5 hours, etc.

[0035] Preferably, the eluent comprises food-grade corn alcohol.

[0036] Preferably, the mass concentration of the eluent is ≥70%, for example, it can be 70%, 72%, 75%, 78%, 80%, 82%, 85%, 88%, 90%, 92%, 95%, 96%, 97%, 98%, 99%, 100%, etc.

[0037] In this invention, the higher the alcohol content, that is, the higher the mass concentration of the ethanol solution, the stronger the elution ability, the smaller the required volume, and the higher the hexanoic acid content in the obtained high-concentration eluent.

[0038] Preferably, the concentration of hexanoic acid in the high-concentration eluent is 60-85 g / L, for example, it can be 60 g / L, 62 g / L, 65 g / L, 68 g / L, 70 g / L, 72 g / L, 75 g / L, 78 g / L, 80 g / L, 85 g / L, etc.

[0039] Preferably, the method further includes repeating step (2).

[0040] Preferably, the number of repetitions is ≥1, for example, 1, 2, 3, 4, etc.

[0041] In this invention, the eluent obtained by elution comprises four parts, namely, a first eluent, a second eluent, a third eluent, and a fourth eluent. The first eluent is primarily a mixture of ethanol and water, accounting for 20-40% of the total eluent volume; its purpose is to displace water within the chromatography column. The second eluent is the high-concentration eluent to be collected in this invention, accounting for 25-35% of the total eluent volume. The third eluent is a low-concentration eluent, accounting for 25-35% of the total eluent volume; its hexanoic acid concentration is 5-15 g / L. The low-concentration eluent has a high ethanol content and can be recycled as an eluent in the next batch. The fourth eluent is primarily composed of ethanol, with an ethanol content greater than 80%, and its purpose is to recover and reuse ethanol, accounting for 20-40% of the total eluent volume.

[0042] In this invention, the repeated step (2) refers to the reuse of the third and fourth eluents, which can be used as eluents or raw materials for this batch or as eluents or raw materials for the next batch.

[0043] In this invention, after elution, the chromatography column is further cleaned until the ethanol concentration is below 10°. The flow rate during cleaning is 2-4 BV / h, for example, 2 BV / h, 2.2 BV / h, 2.4 BV / h, 2.6 BV / h, 2.8 BV / h, 3 BV / h, 3.2 BV / h, 3.4 BV / h, 3.6 BV / h, 3.8 BV / h, 4 BV / h, etc.

[0044] In this invention, after the enrichment is completed, the macroporous adsorption resin is further cleaned to regenerate it for reuse. The cleaning steps include: first, cleaning the regenerated resin with a 2-6% sodium hydroxide solution at a solvent flow rate of 2-4 BV / h, a solvent volume of 2-4 BV, and a cleaning time of 0.5-1.5 h; then, cleaning with water to remove alkali at a solvent flow rate of 2-4 BV / h, a solvent volume of 3-5 BV, and a cleaning time of 0.5-1.5 h, until the pH of the washing solution is around 7, at which point the water washing is stopped.

[0045] Preferably, the esterification reaction includes: mixing a high-concentration eluent with an immobilized lipase to obtain an esterified solution; subsequently, subjecting the esterified solution to vacuum distillation to obtain the high-ester flavored wine.

[0046] Preferably, the mass fraction of immobilized lipase in the esterification solution is 1-3%, for example, it can be 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, etc.

[0047] Preferably, the mixing temperature is room temperature and the mixing time is 2 to 3 hours, for example, 2 hours, 2.2 hours, 2.4 hours, 2.6 hours, 2.8 hours, 3 hours, etc.

[0048] Preferably, the temperature of the vacuum distillation is 50-70°C, for example, 50°C, 52°C, 55°C, 58°C, 60°C, 62°C, 65°C, 68°C, 70°C, etc.; and the pressure is -110-90 mbar, for example, -110 mbar, -105 mbar, -100 mbar, -95 mbar, -90 mbar, etc.

[0049] Preferably, the first 70-80% of the volume of the distillate is taken after vacuum distillation.

[0050] Preferably, the alcohol content of the high-ester flavored wine is 60-80°, for example, it can be 60°, 62°, 64°, 66°, 68°, 70°, 72°, 74°, 76°, 78°, 80°, etc.

[0051] Preferably, the concentration of ethyl hexanoate in the high-ester flavored wine is 60-80 g / L, for example, it can be 60 g / L, 62 g / L, 65 g / L, 68 g / L, 70 g / L, 72 g / L, 75 g / L, 78 g / L, 80 g / L, etc.

[0052] In this invention, the yellow water biological fermentation liquid is a by-product of brewing.

[0053] As a preferred technical solution of the present invention, the method specifically includes the following steps:

[0054] (1) The yellow water fermentation broth was pretreated to obtain an acidic yellow water fermentation broth with a pH value of 3.5 to 5.5 and a hexanoic acid concentration of 4 to 16 g / L;

[0055] (2) The acidic yellow fermentation broth obtained in step (1) was adsorbed onto a chromatography column filled with macroporous adsorption resin. During adsorption, the sample loading flow rate was 2-3 BV / h and the sample loading volume was 5-10 BV. Subsequently, the chromatography column was washed with water. During washing, the water volume was 1-1.5 BV and the water flow rate was 2-3 BV / h. After washing, elution was performed with an ethanol solution with a mass concentration ≥70%. The volume of the ethanol solution was 1-3 BV and the ethanol flow rate was 2-3 BV / h, resulting in a high-concentration eluent with a hexanoic acid concentration of 60-85 g / L.

[0056] (3) The high-concentration eluent obtained in step (2) is mixed with immobilized lipase at room temperature for 2-3 hours to obtain an esterified liquid; then, the esterified liquid is subjected to vacuum distillation at a temperature of 50-70°C and a pressure of -110-90mbar, and the first 70-80% volume of the distillate is taken to obtain a high-ester flavoring wine with an alcohol content of 60-80° and an ethyl hexanoate concentration of 60-80g / L.

[0057] In a second aspect, the present invention provides a flavoring wine, which is obtained by means of the method described in the first aspect.

[0058] Thirdly, the present invention provides an application of the method according to the first aspect in the recycling of brewing by-products.

[0059] In this invention, the hexanoic acid ethanol solution obtained by a specific enrichment method has a high hexanoic acid concentration. When used for subsequent esterification to prepare flavored wine, the esterification efficiency is high, the resulting flavored wine has a high concentration of ethyl hexanoate, and the amount of immobilized enzyme can be reduced.

[0060] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0061] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0062] The method for resource utilization of yellow fermentation liquid provided by this invention uses macroporous adsorption resin to adsorb hexanoic acid in the yellow fermentation liquid, and then replaces the hexanoic acid in the yellow fermentation liquid through washing, elution and other processes. Using a low content of ethanol, the low concentration of hexanoic acid and water system can be replaced with a high concentration of hexanoic acid and ethanol system, thereby increasing the concentration of hexanoic acid. This is also beneficial to the subsequent esterification reaction, reducing the amount of immobilized enzyme used in the esterification reaction, resulting in a high concentration of ethyl hexanoate in the flavoring liquor. This method not only solves the problem of the emission of brewing by-products, but also enables recycling and reuse, supplementing ester substances in the middle and later stages of the liquor, improving the quality and grade of the liquor, and has low energy consumption. Detailed Implementation

[0063] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0064] In this invention, the macroporous adsorption resin is further subjected to a pretreatment step before use, including soaking in ethanol for 2 hours to remove impurities on the resin surface, then using wet packing to pack the resin into a low-pressure chromatography column, washing the chromatography column with soft water until the ethanol content of the eluent is below 10%, and then loading the sample.

[0065] In this invention, the preparation method of the acidic yellow water fermentation broth includes: mixing yellow water fermentation broth (pH around 6.5) with acetic acid, adjusting the pH to 4, and then filtering with a ceramic membrane. During the filtration process, water is added for washing to obtain the acidic yellow water fermentation broth.

[0066] In this invention, the immobilized lipase is immobilized lipase IM-100, purchased from Weifang Kangdian Biotechnology Co., Ltd.; the source of the yellow water fermentation broth is as follows: yellow water is taken, inoculated with pit mud, fermented and cultured, and pit mud functional bacterial solution with hexanoic acid concentration higher than 10g / L is screened; the obtained pit mud functional bacterial solution is inoculated into yellow water, fermented and cultured, and yellow water fermentation broth with hexanoic acid concentration of 5-15g / L is obtained.

[0067] Example 1

[0068] This embodiment provides a method for the resource utilization of yellow water fermentation broth, which specifically includes the following steps:

[0069] (1) The acidic yellow water bio-fermentation broth (hexanoic acid concentration of 6 g / L, volume of 10 BV) was pumped into the chromatography column (filled with AB-8 macroporous adsorption resin, resin volume of 100 mL) for adsorption. The loading flow rate was 2.5 BV / h.

[0070] (2) After step (1) is completed, the chromatography column is washed with soft water. The volume of soft water during washing is 1.2 BV and the flow rate of water is 2.5 BV / h.

[0071] (3) After step (2) is completed, elution is performed using food-grade corn alcohol with a mass concentration of ≥95%, the volume of the eluent is 2 BV, the flow rate of the eluent is 2.2 BV / h, and the second eluent is collected to obtain the high-concentration eluent. After completion, the solvent system in the chromatography column is replaced by water washing, the water washing flow rate is 3 BV / h, and elution is performed until the alcohol content in the effluent is <10°, and the ethanol in the chromatography column is recovered.

[0072] (4) The high-concentration eluent obtained in step (3) is mixed with immobilized lipase (2% by mass) at room temperature for 3 hours to obtain an esterified liquid; the esterified liquid is subjected to vacuum distillation at 60°C and -100mbar, and the first 80% volume of the distillate is taken to obtain the high-ester flavored wine.

[0073] Example 2

[0074] This embodiment provides a method for the resource utilization of yellow water fermentation broth, which specifically includes the following steps:

[0075] (1) The acidic yellow water bio-fermentation broth (hexanoic acid concentration of 6 g / L, volume of 10 BV) was pumped into the chromatography column (filled with HPD722 macroporous adsorption resin, resin volume of 100 mL) for adsorption. The loading flow rate was 2.2 BV / h.

[0076] (2) After step (1) is completed, the chromatography column is washed with soft water. The volume of soft water during washing is 1 BV and the flow rate of water is 2 BV / h.

[0077] (3) After step (2) is completed, elution is performed using food-grade corn alcohol with a mass concentration of ≥95%, the volume of the eluent is 2.4 BV, the flow rate of the eluent is 2.4 BV / h, and the second eluent is collected to obtain the high-concentration eluent; after step (3) is completed, the solvent system in the chromatography column is replaced by water washing, the flow rate of the water washing is 3 BV / h, and elution is performed until the alcohol content in the effluent is <10°, and the ethanol in the chromatography column is recovered.

[0078] (4) The high-concentration eluent obtained in step (3) is mixed with immobilized lipase (2% by mass) at room temperature for 3 hours to obtain an esterified liquid; the esterified liquid is subjected to vacuum distillation at 60°C and -100mbar, and the first 80% volume of the distillate is taken to obtain the high-ester flavored wine.

[0079] Example 3

[0080] This embodiment provides a method for the resource utilization of yellow water fermentation broth, which specifically includes the following steps:

[0081] (1) The acidic yellow water bio-fermentation broth (hexanoic acid concentration of 6 g / L, volume of 10 BV) was pumped into the chromatography column (filled with D101 macroporous adsorption resin, resin volume of 100 mL) for adsorption. The loading flow rate was 2.8 BV / h.

[0082] (2) After step (1) is completed, the chromatography column is washed with soft water. The volume of soft water during washing is 1.5 BV and the flow rate of water is 3 BV / h.

[0083] (3) After step (2) is completed, elution is performed using food-grade corn alcohol with a mass concentration of ≥95%, the volume of the eluent is 1.8 BV, the flow rate of the eluent is 2.6 BV / h, and the second eluent is collected to obtain the high-concentration eluent; after step (3) is completed, the solvent system in the chromatography column is replaced by water washing, the flow rate of the water washing is 3 BV / h, and elution is performed until the alcohol content in the effluent is <10°, and the ethanol in the chromatography column is recovered.

[0084] (4) The high-concentration eluent obtained in step (3) is mixed with immobilized lipase (2% by mass) at room temperature for 3 hours to obtain an esterified liquid; the esterified liquid is subjected to vacuum distillation at 60°C and -100mbar, and the first 80% volume of the distillate is taken to obtain the high-ester flavored wine.

[0085] Example 4

[0086] This embodiment provides a method for the resource utilization of yellow water fermentation broth. The only difference between this method and Embodiment 1 is that the filling resin is HPD100 macroporous adsorption resin. All other steps and parameters are the same as in Embodiment 1.

[0087] Example 5

[0088] This embodiment provides a method for the resource utilization of yellow water fermentation liquid. The only difference between this method and Example 1 is that the sample loading flow rate in step (1) is 3.5 BV / h, while the other steps and parameters are the same as in Example 1.

[0089] Example 6

[0090] This embodiment provides a method for the resource utilization of yellow water fermentation broth. The only difference between this method and Example 1 is that the sample loading flow rate in step (1) is 1.5 BV / h, while the other steps and parameters are the same as in Example 1.

[0091] Example 7

[0092] This embodiment provides a method for enriching hexanoic acid in yellow water fermentation broth. The only difference between this method and Example 1 is that the flow rate of the eluent in step (3) is 1.5 BV / h. All other steps and parameters are the same as in Example 1.

[0093] Example 8

[0094] This embodiment provides a method for enriching hexanoic acid in yellow water fermentation broth. The only difference between this method and Example 1 is that the flow rate of the eluent in step (3) is 3.5 BV / h. All other steps and parameters are the same as in Example 1.

[0095] In this invention, the concentration of hexanoic acid or ethyl hexanoate is measured using gas chromatography, and the specific parameters are as follows:

[0096] Chromatographic column: Agilent J&W GC Columns, CP-Wax 57CB, column length: 50m, inner diameter: 0.25mm, film thickness: 0.2μm;

[0097] Column temperature: Initial temperature 45℃, hold for 8 min, increase to 130℃ at 4℃ / min, increase to 200℃ at 20℃ / min, hold for 15 min;

[0098] Detector temperature: 250℃;

[0099] Inlet temperature: 200℃;

[0100] Carrier gas flow rate: Nitrogen 0.8 mL / min;

[0101] Injection volume: 0.5 μL;

[0102] Flow split ratio: 40:1;

[0103] Air flow rate: 400 mL / min;

[0104] Hydrogen flow rate: 30 mL / min.

[0105] Hexanoic acid recovery rate = (hexanoic acid concentration obtained * volume) / (hexanoic acid concentration in the original acid solution * sample loading volume) * 100%.

[0106] In this invention, the volume of the high-concentration eluent in all embodiments is 0.6 BV.

[0107] The specific test results are shown in Table 1:

[0108] Table 1

[0109]

[0110]

[0111] As shown in the table above, the method for resource utilization of yellow fermentation liquid provided by this invention uses macroporous adsorption resin to adsorb hexanoic acid in the yellow fermentation liquid, followed by washing and elution processes. Through the coordination of various process parameters, the hexanoic acid in the yellow fermentation liquid is displaced, increasing the concentration of hexanoic acid from 4-16 g / L to 60-85 g / L. The hexanoic acid recovery rate is high, and an alcoholic solution of hexanoic acid is directly obtained, which is beneficial to the subsequent esterification reaction. This not only solves the problem of yellow water discharge, a by-product of brewing, but also enables recycling and reuse, improving the quality and grade of baijiu. Moreover, the volume of the obtained esterified liquid is reduced by 8-10 times compared to the yellow fermentation liquid, and it contains a large amount of ethanol, hexanoic acid, and ethyl ester, all of which are volatile. It has a low water content, and only 70-80% of the volume of the esterified liquid needs to be distilled, resulting in low energy consumption.

[0112] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the resource utilization of yellow water fermentation broth, characterized in that, The method comprises the following steps: (1) The yellow water fermentation broth was pretreated to obtain acidic yellow water fermentation broth; (2) The acidic yellow fermentation broth obtained in step (1) is subjected to column chromatography for adsorption, washing, and elution to obtain a high-concentration eluent; during adsorption, the loading flow rate is 2.2-2.8 BV / h; the eluent used for elution is an ethanol solution with a mass concentration ≥95%; the flow rate of the eluent is 2.2-2.6 BV / h. (3) The high-concentration eluent obtained in step (2) is subjected to esterification to obtain a high-ester flavored wine; The chromatography column contains a macroporous adsorption resin; The macroporous adsorption resin is any one of D101, HPD722 or AB-8; The high-concentration eluent is an ethanol solution of hexanoic acid.

2. The method according to claim 1, characterized in that, The pretreatment involves mixing the yellow fermentation broth with a pH adjuster, filtering, and obtaining the acidic yellow fermentation broth.

3. The method according to claim 2, characterized in that, The pH adjuster is at least one of acetic acid, lactic acid, or yellow water, a byproduct of brewing.

4. The method according to claim 1, characterized in that, The pH value of the acidic yellow water fermentation broth is 3.5 to 5.

5.

5. The method according to claim 1, characterized in that, The concentration of hexanoic acid in the acidic yellow water fermentation broth is 4–16 g / L.

6. The method according to claim 1, characterized in that, The macroporous adsorption resin is further activated and purified by soaking in ethanol before use.

7. The method according to claim 1, characterized in that, During the adsorption process, the sample loading volume is 5–10 BV.

8. The method according to claim 1, characterized in that, The solvent used for washing is water.

9. The method according to claim 1, characterized in that, During the washing process, the volume of the solvent is 1 to 1.5 BV, and the flow rate of the solvent is 2 to 3 BV / h.

10. The method according to claim 1, characterized in that, The volume of the eluent is 1–3 BV.

11. The method according to claim 1, characterized in that, The eluent is food-grade corn alcohol.

12. The method according to claim 1, characterized in that, The concentration of hexanoic acid in the high-concentration eluent is 60–85 g / L.

13. The method according to any one of claims 1 to 12, characterized in that, The method also includes repeating step (2).

14. The method according to claim 13, characterized in that, The number of repetitions is ≥1.

15. The method according to claim 1, characterized in that, The esterification reaction includes: mixing a high-concentration eluent with an immobilized lipase to obtain an esterified solution; subsequently, subjecting the esterified solution to vacuum distillation to obtain the high-ester flavored wine.

16. The method according to claim 15, characterized in that, The mass fraction of immobilized lipase in the esterification solution is 1-3%.

17. The method according to claim 15, characterized in that, The mixing temperature is room temperature, and the mixing time is 2 to 3 hours.

18. The method according to claim 15, characterized in that, The vacuum distillation is carried out at a temperature of 50–70°C and a pressure of -110–90 mbar.

19. The method according to claim 15, characterized in that, After vacuum distillation, the first 70-80% of the distillate volume is taken.

20. The method according to claim 15, characterized in that, The alcohol content of the high-ester flavored wine is 60-80°.

21. The method according to claim 15, characterized in that, The concentration of ethyl hexanoate in the high-ester flavored wine is 60-80 g / L.

22. The method according to claim 1, characterized in that, The method specifically includes the following steps: (1) The yellow water fermentation broth was pretreated to obtain an acidic yellow water fermentation broth with a pH value of 3.5 to 5.5 and a hexanoic acid concentration of 4 to 16 g / L; (2) The acidic yellow fermentation broth obtained in step (1) was adsorbed onto a chromatography column filled with macroporous adsorption resin. During adsorption, the loading flow rate was 2.2–2.8 BV / h and the loading volume was 5–10 BV. Subsequently, the chromatography column was washed with water. During washing, the water volume was 1–1.5 BV and the water flow rate was 2–3 BV / h. After washing, elution was performed with an ethanol solution with a mass concentration ≥95%. The volume of the ethanol solution was 1–3 BV and the ethanol flow rate was 2.2–2.6 BV / h, resulting in a high-concentration eluent with a hexanoic acid concentration of 60–85 g / L. (3) The high-concentration eluent obtained in step (2) is mixed with immobilized lipase at room temperature for 2-3 hours to obtain an esterified liquid; then, the esterified liquid is subjected to vacuum distillation at a temperature of 50-70°C and a pressure of -110-90mbar, and the first 70-80% volume of the distillate is taken to obtain a high-ester flavoring wine with an alcohol content of 60-80° and an ethyl hexanoate concentration of 60-80g / L.

23. A flavoring wine, characterized in that, The flavoring wine is obtained by the method according to any one of claims 1 to 22.

24. The application of the method according to any one of claims 1 to 22 in the recycling of brewing by-products.

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