White spirit alcoholization aging process and white spirit directional aging process

Abstract

The invention discloses a white spirit alcoholization aging process and a white spirit directional alcoholization process, which comprise the following four steps: S1, a pretreatment step: by taking newly distilled white spirit with the alcoholic strength of 30-65% vol and the total content of foreign flavor substances greater than or equal to 100mg / L as an object, carrying out multi-stage membrane filtration through a pottery jar sheet to obtain pretreated white spirit liquid; s2, a catalytic conversion step: adding a supported metal organic framework-attapulgite composite catalyst into the pretreated wine liquid, carrying out a sealed reaction at 28-36 DEG C for 40-56 h, recovering the catalyst after the reaction, and filtering to obtain a catalytic conversion wine liquid; s3, association induction: transferring the catalytic conversion wine liquid into a temperature control tank, introducing oxygen in a gradient manner, adding an association inducer, and carrying out temperature-controlled standing, so as to obtain a microenvironment regulation wine liquid; and S4, a stabilization step: performing low-temperature plasma treatment on the microenvironment regulation and control liquor, adding a modified molecular sieve for adsorption for 6-10 hours, and filtering to obtain alcoholized liquor with Fe ion content of less than or equal to 60 [mu] g / L and clarity of more than or equal to 99.0%.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to liquor making process, and in particular to a liquor alcoholization aging process and a liquor directional aging process. BACKGROUND

[0002] Liquor aging is a key process for improving the pungent taste of new liquor and improving flavor quality. Natural aging needs 3-5 years, and there are problems such as long cycle, capital accumulation, and large equipment investment. Accelerated aging technology emerges as the times require. Existing accelerated aging methods mainly include physical method, chemical method, biological method and comprehensive method: the physical method (such as high temperature, ultrasonic wave, ultrahigh pressure) accelerates the reaction by external energy, but it is easy to cause the liquor body to be regenerated and heat-sensitive flavor substances to be destroyed; the chemical method (such as single metal ion catalysis, ozone oxidation) has poor catalytic specificity, and part of the catalyst has the risk of exceeding the standard of metal ion dissolution, and the ester hydrolysis and acid generation do not conform to the natural aging rule of "acid increase and ester decrease"; the biological method (such as single lipase, yeast extract) has limited enzymatic efficiency, and it is difficult to realize directional conversion of flavor components; the comprehensive method is a simple superposition of technologies, and lacks component synergistic matching and gradient parameter control, resulting in uneven aging, poor coordination of liquor body, and insufficient stability. SUMMARY

[0003] To at least alleviate the above technical problems, the solution provided by the present application is as follows:

[0004] A liquor alcoholization aging process, which comprises the following four steps:

[0005] S1, a pretreatment step: taking liquor with alcohol content of 30-65%vol and total acid content of ≥100mg / L as the object, and obtaining pretreated liquor after multi-stage membrane filtration;

[0006] S2, a catalytic conversion step: adding Sichuan-made pottery jar pieces into the pretreated liquor, and obtaining catalytic conversion liquor after soaking for seven days;

[0007] S3, an association induction step: connecting the catalytic conversion liquor into a temperature control tank, and introducing oxygen into the gap, and stirring for 30 minutes in the morning and 30 minutes in the afternoon, to obtain microenvironment regulated liquor;

[0008] S4, a stabilization step: transferring the microenvironment regulated liquor into a liquor storage device, and high-temperature aging for 30 days to one year in a high-temperature environment of 35-60℃, to obtain alcoholized and aged liquor, and the material of the liquor storage device is stainless steel or pottery jar.

[0009] A liquor directional aging process, which comprises the following four steps:

[0010] S1, a pretreatment step: taking new distilled liquor with alcohol content of 30-65%vol and total content of impurity substances of ≥100mg / L as the object, and obtaining pretreated liquor after multi-stage membrane filtration;

[0011] S2, catalytic conversion step: the supported metal organic framework-attapulgite composite catalyst is added into the pretreated liquor, and sealed reaction is carried out at 28-36℃ for 40-56h, and after reaction, the catalyst is recovered and filtered to obtain a catalytically converted liquor;

[0012] S3, association induction step: the catalytically converted liquor is transferred into a temperature-controlled tank, oxygen is introduced in gradient, and after the addition of an association inducer, temperature control is carried out and standing is carried out to obtain a microenvironment regulated liquor;

[0013] S4, stabilization step: the microenvironment regulated liquor is treated by low temperature plasma, and then modified molecular sieves are added for adsorption for 6-10h, and after filtration, a matured liquor is obtained, the Fe ion content of which is ≤60μg / L, and the clarity thereof is ≥99.0%.

[0014] Alternatively, the multi-stage membrane filtration is cross-flow filtration through ceramic membranes with pore sizes of 40-60nm, 15-25nm and 3-7nm in sequence, the filtration pressure is 0.2-0.4MPa, and the flow rate is 1.0-1.4m / s, and more than 85% of macromolecular proteins, colloidal impurities and low-boiling-point odor substances are removed. For this reason, in this technical solution, three levels of gradient pore size ceramic membranes are used, from 40-60nm to 3-7nm, the filtration accuracy is gradually refined, which exactly matches the distribution characteristics of different sizes of impurities in the new liquor, can capture macromolecular proteins, colloids and small molecular low-boiling-point odor substances in layers, and finally realizes a removal rate of more than 85%. This gradient design is not a simple superposition of membrane components, but a targeted design based on the size rule of new liquor impurities, which solves the dilemma of "residual odor or flavor loss" in traditional filtration, and provides a cleaner reaction substrate for subsequent composite enzymolysis and catalytic conversion. In addition, the filtration pressure is 0.2-0.4MPa, the flow rate is 1.0-1.4m / s, and the cross-flow filtration mode is combined, which not only avoids the disturbance of high pressure to the liquor system, but also reduces the deposition of impurities on the surface of the filter membrane through reasonable flow rate, reduces the risk of clogging, and guarantees the continuous and stable filtration process. Compared with the traditional filtration parameters which are fuzzy and easily affected by impurities and interrupted, this parameter combination is based on the synergistic optimization of the characteristics of ceramic membranes and the viscosity of liquor, which can efficiently remove impurities while reducing unnecessary loss of flavor substances, and solves the problem of "efficiency and stability cannot be achieved simultaneously" in traditional filtration. Furthermore, by efficiently removing such interfering impurities, the subsequent composite enzyme preparation can more fully act on the flavor precursor substances, and the supported catalyst can more accurately catalyze the ester acid conversion, avoiding the interference of impurities on the reaction.

[0015] Optionally, the preparation method of the supported metal organic framework-attapulgite composite catalyst is mixing Fe-MOF material and acidified attapulgite in a mass ratio of 1:(2-4), dispersing for 10-20 min under ultrasonic of 250-350 W, and drying at 100-120 DEG C for 2-4 h. The Fe-MOF material is Fe-BTC or Fe-MIL-88, and the acidified attapulgite is attapulgite clay treated with 0.5-1.0 mol / L hydrochloric acid, washed to neutral, and dried. For this, the technical scheme of "mixing Fe-BTC or Fe-MIL-88 and acidified attapulgite treated with 0.5-1.0 mol / L hydrochloric acid and washed to neutral in a mass ratio of 1:(2-4), dispersing for 10-20 min under ultrasonic of 250-350 W, and drying at 100-120 DEG C for 2-4 h to prepare a supported composite catalyst" compared with the single metal ion or simple carrier catalyst used in the traditional chemical method: the Fe-MOF material itself has high selectivity for the catalysis of ester hydrolysis and acid generation, the acidified attapulgite can improve the surface activity and adsorption performance after being treated with hydrochloric acid, the two are compounded in a specific ratio and uniformly combined through ultrasonic dispersion, which can not only reduce the dissolution of metal ions by fixing the Fe-MOF on the attapulgite carrier, but also enhance the catalytic targeting of the two for the target flavor components in the liquor, so that the ester-acid conversion is more in line with the "acid increase and ester decrease" rule of natural aging.

[0016] Optionally, the catalyst addition amount in step S2 is 1.0-1.4 g / L, the recovery is performed by magnetic field adsorption for 15-25 min at 0.6-1.0 T, and the recovered catalyst is dried at 100-120 DEG C and can be reused for 2-4 times with a catalytic efficiency of more than 85% of the initial value. For this, the technical scheme of "the catalyst addition amount in step S2 is 1.0-1.4 g / L, the recovery is performed by magnetic field adsorption for 15-25 min at 0.6-1.0 T, and the recovered catalyst is dried at 100-120 DEG C and can be reused for 2-4 times with a catalytic efficiency of more than 85% of the initial value" compared with the traditional chemical method in which the catalyst addition amount is ambiguous, mostly used once or recovered in a complex way (such as filtration, centrifugation) and has low reuse efficiency, the specific catalyst addition amount range can avoid excessive metal ion dissolution caused by excessive use or insufficient catalytic efficiency caused by insufficient use, and meets the needs of liquor catalytic conversion; the magnetic field adsorption recovery method combined with the magnetic properties of the Fe-MOF material is simpler and can reduce catalyst residues and reduce the impact on the coordination of the liquor body, and the design of drying the recovered catalyst for 2-4 times and maintaining a high catalytic efficiency not only reduces catalyst waste and production costs, but also continuously and stably plays a catalytic role and avoids uneven aging caused by catalyst replacement.

[0017] Optionally, the gradient oxygen parameters are: the first stage (0-14h) medical grade oxygen concentration 4%-6%, the second stage (14-38h) concentration 1.5%-2.5%, the third stage (38-62h) concentration 0.6%-1.0%; the micro-bubble diameter is 3-12μm, the aeration rate is 0.08-0.12L / (L·h), and the whole process temperature is controlled at 25-31℃. In the present application, the technical scheme of "the gradient oxygen parameters are: the first stage (0-14h) medical grade oxygen concentration 4%-6%, the second stage (14-38h) concentration 1.5%-2.5%, the third stage (38-62h) concentration 0.6%-1.0%, combined with 3-12μm micro-bubbles, 0.08-0.12L / (L·h) aeration rate, and the whole process temperature is controlled at 25-31℃" compared with the traditional single oxygen concentration, no bubble size control, and large temperature fluctuation: the three-stage gradient oxygen concentration design can adapt to the different needs of alcohol aldehyde ester dynamic conversion after catalytic conversion, avoid the local over-oxidation or insufficient reaction caused by traditional single concentration, and make the flavor conversion more consistent with the natural aging law; the micro-bubble combined with the specific aeration rate can improve the uniformity of oxygen and wine, reduce the problem of uneven maturation, and is more conducive to the mild oxidation reaction than the traditional large bubble aeration; the stable temperature control range in the whole process can avoid the damage of high temperature to the heat-sensitive flavor substances, and can better preserve the flavor integrity of the wine body than the traditional oxidation process without precise temperature control.

[0018] Optionally, the association inducer is a compound of glycerol and sorbitol with a mass ratio of 1:(0.8-1.2), and the addition amount is 0.2-0.4g / L; or 0.05-0.1g / L glycerol fatty acid ester is additionally added to synergistically strengthen the hydrogen bond association of ethanol-water molecules. In the present application, the technical scheme of "the association inducer is a compound of glycerol and sorbitol with a mass ratio of 1:(0.8-1.2), and the addition amount is 0.2-0.4g / L, or 0.05-0.1g / L glycerol fatty acid ester is additionally added to synergistically strengthen the hydrogen bond association of ethanol-water molecules" compared with the traditional single use of glycerol, sorbitol and other inducers or no specific ratio scheme, the specific ratio of glycerol and sorbitol can utilize the synergistic effect of the hydrogen bond combination ability of the two, more effectively promote the association of ethanol and water molecules than single inducer, reduce the pungent feeling of free ethanol, and improve the softness of the wine body; the specific addition amount range can avoid the sticky wine body caused by excessive amount or the insufficient association effect caused by insufficient amount, adapt to the component characteristics of the wine after catalytic conversion; the synergistic design of additionally adding glycerol fatty acid ester can further enhance the stability of the association structure, reduce the risk of post-life, and better guarantee the durability of the maturation effect than the traditional single induction scheme.

[0019] Optionally, the low-temperature plasma treatment adopts dielectric barrier discharge mode, power 70-90 W, discharge frequency 0.8-1.2 kHz, treatment time 10-20 min; the modified molecular sieve is 4A molecular sieve modified by 5-10 kGy γ-ray irradiation, the specific surface area is increased by 20-30% after irradiation, the addition amount is 0.4-0.6 g / L, the adsorption temperature is 22-28°C, and the stirring rate is 40-60 r / min.

[0020] Therefore, the technical scheme of "low-temperature plasma treatment adopts dielectric barrier discharge mode, power 70-90 W, discharge frequency 0.8-1.2 kHz, treatment time 10-20 min, modified molecular sieve is 4A molecular sieve modified by 5-10 kGy γ-ray irradiation (the specific surface area is increased by 20-30% after irradiation), addition amount 0.4-0.6 g / L, adsorption temperature 22-28°C, and stirring rate 40-60 r / min" in the application, compared with the single high-temperature treatment, unmodified adsorbent or parameter vague scheme in the traditional stabilization technology: the low-temperature plasma treatment of dielectric barrier discharge mode is more moderate than the traditional high-temperature stabilization process, can strengthen the colloid structure stability of the wine body without destroying the heat-sensitive flavor substances, and reduce the risk of rebirth; the γ-ray irradiation modification increases the specific surface area of the 4A molecular sieve, and the adsorption capacity of the unmodified molecular sieve to residual trace metal ions and small molecule impurity substances is stronger, which can more efficiently control the Fe ion content to be ≤60 μg / L and improve the clarity to ≥99.0% in cooperation with the clear addition amount and adsorption conditions.

[0021] Optionally, it also includes a catalyst regeneration step: the recovered catalyst is soaked and washed in 5%-10% ethanol solution for 1-2 h, and then calcined at 120-150°C for 1-2 h, and the catalytic efficiency after regeneration is maintained at more than 90% of the initial value.

[0022] Optionally, in step S3, sampling and detection are performed every 10-14 h: the acid ester content is detected by gas chromatography, and the characteristic peak intensity of ethanol-water association state at 420 nm is detected by fluorescence spectrum, so as to ensure that the association strength is increased by 30%-40% and the free ethanol content is decreased by 18%-22% before entering step S4.

[0023] Therefore, the technical solution in this application, which involves sampling and testing every 10-14 hours in step S3: detecting the acid ester content by gas chromatography and detecting the intensity of the characteristic peak of the ethanol-water association state at 420 nm by fluorescence spectroscopy, ensuring that the association strength increases by 30%-40% and the free ethanol content decreases by 18%-22% before proceeding to step S4, offers several advantages over traditional aging methods that lack clear process monitoring and rely solely on endpoint sensory evaluation or single-component detection to judge the reaction progress. The timed sampling and testing design is more adaptable to the dynamic characteristics of the wine's association reaction than the traditional "one-size-fits-all" approach, and can promptly avoid problems of insufficient or excessive reaction. The combined detection of gas chromatography and fluorescence spectroscopy focuses on both the proportional changes of acid ester flavor substances and the core physical state of ethanol-water association, providing a more comprehensive approach than traditional single-dimensional detection, and simultaneously ensuring the coordination of the wine's chemical composition and physical structure. Clear quantitative indicators for increased association strength and decreased free ethanol content provide a prerequisite guarantee for consistent quality in subsequent stabilization steps, reducing batch-to-batch quality differences compared to traditional methods without quantitative standards.

[0024] Optionally, in step S4, a 0.20–0.24 μm polytetrafluoroethylene membrane is used for filtration; the final aged liquor has an acetic acid content that is 18%–26% higher than that of new liquor, an hexanoic acid content that is 24%–32% higher, and a total ester content that is 15%–25% lower, achieving the quality of natural aging for more than 3 years.

[0025] Therefore, the technical solution in this application, which states that "in step S4, the filtration uses a 0.20–0.24 μm polytetrafluoroethylene membrane; the final aged liquor has an acetic acid content that is 18%–26% higher than that of new liquor, an hexanoic acid content that is 24%–32% higher, and a total ester content that is 15%–25% lower, achieving the quality of natural aging for more than 3 years," is superior to the traditional aging process that uses diatomaceous earth, ordinary microporous membranes, and other filtration media (with lower precision), lacks quantitative indicators for ester changes, and relies solely on sensory evaluation to determine the degree of aging. The 0.20–0.24 μm polytetrafluoroethylene membrane filtration... With a finer precision than traditional filtration media, it can more efficiently trap tiny particles and trace impurities remaining after adsorption by modified molecular sieves, ensuring greater clarity and stability of the wine compared to traditional filtration. The clearly defined quantitative ranges for increasing acetic acid and hexanoic acid and decreasing esters precisely match the core principle of natural aging: "increasing acidity and reducing fat." Compared to traditional aging methods without quantitative standards, it achieves a more balanced proportion of flavor substances and reduces spiciness. Directly benchmarking the quality of naturally aged wines of 3 years or more, it clearly defines the product quality level and reduces batch-to-batch variations compared to traditional methods that can only vaguely describe the flavor as "close to that of aged wines."

[0026] The four-step targeted aging process for baijiu provided in this application has the following technical advantages, which are explained in detail below:

[0027] I. Shorten the aging period, reduce overall costs, and alleviate the core pain points of natural aging.

[0028] Existing technologies for natural aging require 3-5 years, resulting in significant drawbacks such as long processing times, tied-up capital, and substantial equipment investment. This application utilizes a compact four-step process: pretreatment, catalytic conversion, association induction, and stabilization. Precise parameter matching in each step accelerates the aging process: the pretreatment stage requires only 2-4 hours of enzymatic hydrolysis, the catalytic conversion stage has a reaction time controlled within 40-56 hours, and the subsequent association induction and stabilization steps do not require prolonged settling. The overall process cycle is significantly shorter than the 3-5 years required for natural aging. This short-cycle characteristic greatly reduces the equipment investment required for wine storage and lowers the risk of long-term capital tied up, significantly improving production efficiency and capital turnover compared to the natural aging model.

[0029] II. Optimize catalytic effect and control metal ion dissolution to avoid the drawbacks of chemical catalytic aging.

[0030] Existing chemical aging methods commonly use single-metal ion catalysts, which suffer from poor catalytic specificity, excessive metal ion dissolution, and deviations from the "acid-increase, ester-decrease" principle in ester hydrolysis and acid formation. This application employs a supported metal-organic framework-attapulgite composite catalyst in the catalytic conversion stage. The supported structure facilitates contact between the active components and the target substrates in the wine, enhancing catalytic specificity. Simultaneously, the support's immobilization of the metal active components effectively reduces the dissolution of metal ions into the wine. Combined with mild, sealed reaction conditions of 28–36°C, this process better simulates the natural aging reaction pathway, ensuring that the ester-ester conversion more closely aligns with the natural "acid-increase, ester-decrease" principle. The final product's Fe ion content ≤60 μg / L further demonstrates that this process effectively controls the risk of metal ion dissolution.

[0031] Third, achieve gradient regulation and synergistic effects to solve the coordination problem of comprehensive detoxification method.

[0032] Existing technologies for accelerated aging often involve the simple superposition of techniques, lacking synergistic component ratios and gradient parameter control, resulting in uneven maturation, poor wine body harmony, and insufficient stability. This application overcomes this bottleneck through two key design steps: First, the association induction stage employs a gradient oxygenation method. Compared to non-gradient oxygen supply, gradient changes can more gently regulate the wine's microenvironment, avoiding excessive or insufficient local oxidation and making the maturation process more uniform. Second, synergistic effects are formed between each step. Membrane filtration in the pretreatment stage removes impurities, providing a clean matrix for subsequent catalysis; the products of catalytic conversion provide the reaction basis for association induction; and low-temperature plasma and modified molecular sieve adsorption in the stabilization stage further optimize the wine's structure. This synergistic and gradient design significantly improves the wine's body harmony and reduces the problem of uneven maturation.

[0033] IV. Enhance the stability of the wine and preserve its flavor integrity, overcoming the shortcomings of physical aging methods.

[0034] Existing technologies employ physical aging methods (such as high temperature and ultrasound) to accelerate the reaction through external energy, but these methods are prone to causing wine degradation and damage to heat-sensitive flavor compounds. This application utilizes low-temperature plasma treatment combined with modified molecular sieve adsorption in the stabilization stage. The low-temperature conditions effectively reduce the loss of heat-sensitive flavor compounds, and compared to high-temperature physical methods, they are more conducive to preserving the original flavor integrity of the wine. Simultaneously, the adsorption effect of the modified molecular sieve removes unstable components from the wine, and combined with the stable wine structure formed in the previous processes, significantly reduces the risk of wine degradation. The final product's clarity of ≥99.0% also proves that this process effectively improves wine stability and clarity.

[0035] V. Adapt to the characteristics of specific raw materials to improve the applicability and specificity of the process.

[0036] Existing accelerated aging technologies have poor adaptability to raw materials and are difficult to accurately control for different types of new liquor. This application specifically targets newly distilled strong-aroma or sauce-aroma baijiu with an alcohol content of 30-65% vol and a total content of off-flavor substances ≥100 mg / L. The multi-stage membrane filtration in the pretreatment stage can specifically remove some off-flavor substances from this type of new liquor. The parameters of subsequent steps are also matched with the component characteristics of this type of new liquor, making the process more targeted to the target raw materials and more effectively improving the spiciness and flavor quality of this type of new liquor.

[0037] Specifics and implementation methods

[0038] The core innovation of this invention lies in constructing a system of "attapulgite catalytic conversion - gradient micro-oxygen association induction - low-temperature plasma - modified molecular sieve synergistic stabilization". By accurately controlling the ratio of each component and process parameters, the directional conversion of flavor components and the stability of the liquor structure can be achieved.

[0039] Therefore, in the specific embodiments of this application, eight core embodiments (covering different raw materials, different combinations of process parameters, catalyst regeneration, industrial pilot production, etc.) and six comparative examples (covering physical methods, chemical methods, comprehensive methods and natural aging in the prior art) are provided for comprehensive comparison from multiple dimensions such as physicochemical indicators, sensory evaluation, stability, production cost, and production cycle, so as to provide an exemplary explanation of the solution of the present invention.

[0040] The raw materials used are described as follows: Raw material 1: Newly distilled baijiu, purchased from a winery in Yibin, Sichuan Province, with an alcohol content of 52% vol (tested by distillation method according to GB / T10345-2022), a total content of off-flavor substances (hydrogen sulfide + acrolein + methyl mercaptan) of 118 mg / L (tested by headspace solid phase microextraction-gas chromatography-mass spectrometry according to GB / T39126-2020), a total acid content of 0.82 g / L, a total ester content of 2.85 g / L, and a sensory score of 62 points (out of 100 points, evaluation criteria: appearance 20 points, aroma 35 points, taste 35 points, style 10 points). Raw Material 2: Newly distilled sauce-aroma baijiu, purchased from a distillery in Zunyi, Guizhou Province, with an alcohol content of 53% vol, total content of off-flavor substances (hydrogen sulfide + acrolein + furfural) of 106 mg / L, total acid content of 1.05 g / L, total ester content of 3.12 g / L, and a sensory score of 65 points. Raw Material 3: Newly distilled strong-aroma baijiu (for comparison with low off-flavors), purchased from a distillery in Luzhou, Sichuan Province, with an alcohol content of 50% vol, total content of off-flavor substances of 102 mg / L, total acid content of 0.78 g / L, total ester content of 2.76 g / L, and a sensory score of 63 points.

[0041] The core reagents used are described below: Supported catalyst raw material: Fe-MOF material: Fe-BTC (CAS No.: 70942-33-7), a product of Nanjing Pioneer Nanomaterials Technology Co., Ltd., with a specific surface area of ​​1400 / 1600 m². 2 / g, pore size 1.2 / 1.5nm, purity ≥98%; Fe-MIL-88 (CAS No.: 105046-72-2), product of Shanghai Maclean Biochemical Technology Co., Ltd., specific surface area 1200 / 1400m² 2 / g, pore size 1.0 / 1.3nm, purity ≥97%. Attapulgite clay: supplied by a mine in Xuyi, Jiangsu Province. The main components, as determined by X-ray fluorescence spectrometry, are SiO2 68.5%, Al2O3 11.2%, MgO 8.3%, and Fe2O3 2.1%. It is pulverized through a 200-mesh sieve and dried to a moisture content ≤5% for later use. Hydrochloric acid: analytical grade, concentration 36%–38%, product of Sinopharm Chemical Reagent Co., Ltd., used for acidification treatment of attapulgite clay. Association inducers: Glycerol: analytical grade, purity ≥99.5%, product of Sinopharm Chemical Reagent Co., Ltd.; Sorbitol: food grade, purity ≥99.0%, product of Shandong Futian Pharmaceutical Co., Ltd.; Glyceryl fatty acid ester: food grade, purity ≥98%, product of Guangzhou Jiadelai Biochemical Technology Co., Ltd., model GMS-90. Modified molecular sieve raw material: 4A molecular sieve: product of Tianjin Nankai Catalyst Factory, particle size 100 mesh, specific surface area 250-280 m² 2 / g, static water adsorption capacity ≥21% (25℃, relative humidity 50%), dried to moisture content ≤3% for use. γ-ray irradiation source: Cobalt-60 irradiation device, provided by Jiangsu Provincial Institute of Atomic Medicine, irradiation dose error ≤±5%, irradiation ambient temperature 20~25℃.

[0042] Other auxiliary reagents are described as follows: Medical-grade oxygen: purity ≥99.99%, product of Suzhou Jinhong Gas Co., Ltd.; Analytical-grade ethanol: purity ≥99.7%, product of Sinopharm Chemical Reagent Co., Ltd., used for catalyst regeneration; Polytetrafluoroethylene membrane: pore size 0.20μm, 0.22μm, 0.24μm, product of Shanghai Anpu Experimental Technology Co., Ltd., hydrophilic, maximum withstand pressure 0.3MPa.

[0043] The raw material pretreatment method is described as follows: Preparation of acidified attapulgite clay: Take 10 kg of natural attapulgite clay, add 50 L of 0.8 mol / L hydrochloric acid solution, stir and soak at room temperature for 2 h, stirring once every 20 min (stirring rate 50 r / min). After soaking, wash repeatedly with deionized water until the pH of the filtrate is 7.0 (pH meter model Mettler FE28), then place it in a forced-air drying oven at 110℃ for 4 h, pulverize and pass through a 200 mesh sieve, seal and store for later use. The specific surface area was determined to be 185 m² by the BET method. 2 / g. Preparation of modified molecular sieve: 5 kg of 4A molecular sieve was placed in a cobalt-60 irradiation device and irradiated at a dose of 8 kGy and room temperature. After irradiation, the specific surface area was measured to be 320 m². 2 / g (23% higher than before irradiation), static water adsorption capacity ≥24%, sealed and dried for later use.

[0044] The models and operating parameters of the experimental equipment used are described below:

[0045] Example

[0046] Catalytic conversion: 50g of Fe-BTC material and 150g of acidified attapulgite (mass ratio 1:3) were weighed, 500mL of deionized water was added, and the mixture was ultrasonically dispersed at 300W for 15min, dried at 110℃ for 3h, and pulverized through a 180-mesh sieve to obtain 192g of composite catalyst. 57.6g of the catalyst (addition amount 1.2g / L) was added to the pretreated wine, the reaction vessel was sealed, and a constant temperature water bath shaker was placed in it. The temperature was set at 32℃ and the shaking rate at 80r / min, and the reaction was carried out for 48h. After the reaction was completed, the reaction vessel was placed in a 0.8T electromagnetic adsorption device for 20min to adsorb the catalyst and recover 55.8g (recovery rate 96.9%). The wine was filtered through a 200-mesh filter to obtain 47.5L of catalytically converted wine.

[0047] Association induction: The catalytically converted wine was transferred to a 100L temperature-controlled tank, and a microbubble generator was installed. The bubble diameter was set to 8μm and the aeration rate to 0.1L / (L·h). Medical-grade oxygen was introduced in three stages: 5% oxygen concentration in the first stage (0-14h), 2.0% oxygen concentration in the second stage (14-38h), and 0.8% oxygen concentration in the third stage (38-60h). The temperature was controlled at 28℃ throughout the process. At 14h, 14.25g of glycerol-sorbitol compound inducing agent (1:1) (addition amount 0.3g / L) was added, and the mixture was allowed to stand for another 60h. Samples were taken every 14h during this period to obtain 47L of microenvironment-controlled wine.

[0048] Stabilization: The microenvironment-controlled liquor was introduced into the plasma reaction chamber, with a power of 80W, a discharge frequency of 1.0kHz, and a treatment time of 15min. Then it was transferred to an adsorption tank, where 23.5g of modified molecular sieve (addition amount 0.5g / L) was added, the stirring rate was 50r / min, and the adsorption was carried out at 25℃ for 8h. Finally, it was filtered through a 0.22μm polytetrafluoroethylene membrane to obtain 46.5L of aged liquor (total loss 7%).

[0049] The test results are as follows:

[0050] Physicochemical indicators: alcohol content 51.8% vol, Fe ion content 32 μg / L, clarity 0.4 NTU, acetic acid content 0.39 g / L (47.6% higher than the original spirit), hexanoic acid content 0.34 g / L (54.5% higher), total esters 1.82 g / L (36.1% lower), total off-flavors 3.2 mg / L (removal rate 97.4%), free ethanol content decreased by 20.5%, and ethanol-water association strength (characteristic peak intensity at 420 nm) increased by 35.3%.

[0051] Sensory evaluation: Appearance 19.2 points, Aroma 32.5 points, Taste 33.1 points, Style 9.2 points, Total score 94.0 points. The evaluation description is "colorless and transparent, with a pure and rich cellar aroma, a harmonious and full-bodied taste, smooth and mellow, clean and sweet aftertaste, reaching the quality of strong-aroma baijiu that has been naturally aged for more than 3 years".

[0052] Example 1: Sauce-flavored Baijiu (raw material 2) + compound enzyme 1:0.6 + Fe-MIL-88 catalyst + glycerol-sorbitol (1:0.8) + glycerol fatty acid ester

[0053] Pretreatment: 50L of raw material 2 was filtered through a ceramic membrane (pressure 0.25MPa, flow rate 1.1m / s) to collect 48.2L of wine; 3.0g (0.06g / L) of compound enzyme preparation (1:0.6) was added, enzymatic hydrolysis was carried out at 40℃ for 2h, inactivation was carried out at 70℃ for 25min, and then cooled to 22℃ to obtain 47.8L of pretreated wine.

[0054] Catalytic conversion: Fe-MIL-88 and acidified attapulgite were mixed at a ratio of 1:2, ultrasonically dispersed at 250W for 20 min, and dried at 100℃ for 4 h to prepare the catalyst; 47.8 g (1.0 g / L) of catalyst was added to the pretreated wine, and the reaction was carried out at 28℃ with shaking for 40 h. The catalyst was recovered by adsorption under a 0.6T magnetic field for 25 min, and 47.2 L of catalytically converted wine was obtained by filtration.

[0055] Association induction: microbubble diameter 5μm, aeration rate 0.08L / (L·h), three-stage oxygen concentrations of 4%, 1.5%, and 0.6%, temperature controlled at 25℃; after 14h, 9.44g (0.2g / L) of glycerol-sorbitol (1:0.8) and 3.78g (0.08g / L) of glycerol fatty acid ester were added, and the mixture was allowed to stand for 62h to obtain 46.8L of microenvironment-regulated wine.

[0056] Stabilization: Plasma power 70W, time 10min, 23.4g (0.4g / L) of modified molecular sieve, adsorption at 22℃ for 6h, filtration through 0.20μm membrane, to obtain 46.2L of aged baijiu.

[0057] The test results are as follows:

[0058] Physicochemical indicators: Fe ion content 28 μg / L, clarity 0.3 NTU, acetic acid content 0.42 g / L (increased by 18.2%), hexanoic acid content 0.31 g / L (increased by 24.1%), total esters 2.64 g / L (decreased by 15.3%), off-flavor removal rate 97.7%, association strength increased by 30.2%, and free ethanol decreased by 18.1%.

[0059] Sensory evaluation: Total score 92.5 points, the evaluation description is "rich and pure soy sauce aroma, accompanied by caramel and aged aroma, smooth and harmonious body, no spiciness or off-flavors, reaching the quality of soy sauce aroma baijiu that has been naturally aged for more than 3 years".

[0060] Example 2: Strong-aroma Baijiu (raw material 3) + compound enzyme 1:1.0 + Fe-BTC catalyst + glycerol-sorbitol (1:1.2)

[0061] Pretreatment: 50L of raw material 3 was filtered through a ceramic membrane (pressure 0.35MPa, flow rate 1.3m / s) to collect 48.3L of wine; 5.0g (0.10g / L) of compound enzyme preparation (1:1.0) was added, enzymatic hydrolysis was carried out at 50℃ for 4h, inactivation was carried out at 80℃ for 15min, and then cooled to 28℃ to obtain 47.9L of pretreated wine.

[0062] Catalytic conversion: Fe-BTC was mixed with acidified attapulgite at a ratio of 1:4, ultrasonically dispersed at 350W for 10 min, and dried at 120℃ for 2 h to prepare the catalyst; 67.1 g (1.4 g / L) of catalyst was added, and the reaction was carried out at 36℃ with shaking for 56 h. The catalyst was then recovered by adsorption under a 1.0T magnetic field for 15 min and filtered to obtain 47.3 L of catalytically converted wine.

[0063] Association induction: microbubble diameter 12μm, aeration rate 0.12L / (L·h), three-stage oxygen concentrations of 6%, 2.5%, and 1.0%, temperature controlled at 31℃; 18.9g (0.4g / L) of glycerol-sorbitol (1:1.2) was added after 14h, and the mixture was allowed to stand for 60h to obtain 46.9L of microenvironment-regulated wine.

[0064] Stabilization: Plasma power 90W, time 20min, modified molecular sieve 28.1g (0.6g / L), adsorption at 28℃ for 10h, filtration through 0.24μm membrane, to obtain 46.3L of aged baijiu.

[0065] The test results are as follows:

[0066] Physicochemical indicators: Fe ion content 35 μg / L, clarity 0.5 NTU, acetic acid content 0.39 g / L (increased by 26.0%), hexanoic acid content 0.33 g / L (increased by 32.0%), total esters 1.87 g / L (decreased by 25.0%), off-flavor removal rate 96.9%, association strength increased by 40.0%, and free ethanol decreased by 22.0%.

[0067] Sensory evaluation: Total score 93.2 points, the evaluation description is "full cellar aroma, mellow body, delicate taste, long aftertaste, which is in line with the style of strong aroma baijiu that has been naturally aged for more than 3 years".

[0068] Example 3: Catalyst Reuse (Catalyst Recovery in Example 1)

[0069] 55.8 g of the catalyst recovered in Example 1 was dried at 110 °C for 3 h and then reused in the catalytic conversion step of 50 L of feedstock 1 according to the process parameters of Example 1. The catalyst was used a second, third, and fourth time, and the catalytic effect was recorded each time. The results are as follows: Second use: Acetic acid increase rate 20.5% (initial 22.1%), hexanoic acid increase rate 26.5% (initial 28.2%), catalytic efficiency maintained at 92.8% of the initial value, Fe ion content 34 μg / L. Third use: Acetic acid increase rate 19.1%, hexanoic acid increase rate 24.8%, catalytic efficiency 86.4%, Fe ion content 36 μg / L. Fourth use: Acetic acid increase rate 17.8%, hexanoic acid increase rate 23.1%, catalytic efficiency 80.5% (lower than the 85% specified in claim 5). The catalyst can be reused 3 times, and the first 3 uses all meet the requirements of claim 5, reducing production costs.

[0070] Example 4: Catalyst Regeneration (Catalyst after 3 uses in Example 4)

[0071] Regeneration treatment: Take 50g of the catalyst used 3 times in Example 4, add 500mL of 5% ethanol solution, soak and wash for 1.5h (stir once every 30min), filter, rinse 3 times with deionized water, dry at 110℃ for 2h, transfer to muffle furnace and calcine at 130℃ for 1.5h to obtain 48.5g of regenerated catalyst (recovery rate 97%).

[0072] Regenerated catalyst was used for the catalytic conversion of 50 L of feedstock 1 according to the parameters of Example 1, and the catalytic effect was tested. The test results are as follows: catalytic effect: acetic acid enhancement rate 21.8% (close to 22.1% of fresh catalyst), hexanoic acid enhancement rate 27.8% (fresh catalyst 28.2%), and the catalytic efficiency recovered to 98.6% of the initial value. Physicochemical indicators: Fe ion content 30 μg / L, with a deviation of ≤3% from the result of fresh catalyst treatment, proving that the regeneration step was effective.

[0073] Example 5: Low oxygen concentration adjustment (third stage oxygen concentration 0.7%) + inducer addition of 0.25 g / L

[0074] Association induction: In the third stage, the oxygen concentration was 0.7%, the inducer dosage was 0.25 g / L, and other parameters were the same as in Example 1. The raw material was 50 L of raw material 2. The test results are as follows: Physicochemical indicators: Fe ion content 29 μg / L, acetic acid increase rate 20.3%, hexanoic acid increase rate 26.7%, esters decrease 18.5%; Sensory evaluation: Total score 92.8 points, good body coordination, and no excessive oxidation off-flavors.

[0075] Catalytic conversion: 1152g (1.2g / L) of catalyst prepared by Fe-BTC and acidified attapulgite in a 1:3 ratio was reacted in an industrial-grade shaking reactor at 32℃ for 48h. The catalyst was recovered using a 0.8T electromagnetic adsorption device, and 950L of catalytically converted wine was obtained by filtration. Association induction: An industrial-grade microbubble generator (bubble diameter 10μm, aeration rate 0.1L / (L·h)) was used, with three stages of oxygen concentrations of 5%, 2.0%, and 0.8%, and the temperature was controlled at 28℃. 285g (0.3g / L) of inducer was added, and the mixture was allowed to stand for 60h to obtain 940L of microenvironment-controlled wine.

[0076] Stabilization: Industrial plasma equipment (power 10kW) was used to treat for 15 min, 470g of modified molecular sieve (0.5g / L) was used, adsorption was carried out at 25℃ for 8 h, and filtration was performed through a 0.22μm membrane to obtain 935L of aged baijiu (total loss 6.5%).

[0077] The test results are as follows:

[0078] Physicochemical indicators: Fe ion content 35 μg / L, clarity 0.5 NTU, acetic acid enhancement rate 46.8%, hexanoic acid enhancement rate 53.2%, esters decreased by 35.8%, off-flavor removal rate 97.2%; Sensory evaluation: total score 93.2 points, deviation from laboratory-scale results ≤1%; Production cost: 68% lower than natural aging, production cycle 8 days (natural aging 3 years), proving industrialization feasibility.

[0079] Comparative Example

[0080] Comparative Example 1: Single Fe 3+ Catalysis (chemical method, existing technology)

[0081] 50L of raw material 1, with the addition of ferric sulfate to make Fe 3+ The concentration was 50 μg / L, and the mixture was allowed to stand at 28℃ for 48 hours before filtration and testing. The results are as follows: Physicochemical indicators: Acetic acid increase rate 18.5%, hexanoic acid increase rate 20.3%, ester decrease 12.1%, Fe ion content 48 μg / L, off-flavor removal rate 72.3%; Sensory evaluation: Total score 75.3 points, evaluation description: "Imbalanced ester-acid ratio, slight metallic taste, poor stability, reversion after 3 months"; Defects: Poor catalytic targeting, off-flavors, insufficient stability.

[0082] Comparative Example 2: High-Temperature Accelerated Aging (Physical Method, Existing Technology)

[0083] 50L of raw material 1 was left to stand at a constant temperature of 60℃ for 30 days, and then tested after natural cooling. The test results are as follows: Physicochemical indicators: acetic acid increase rate 22.1%, hexanoic acid increase rate 24.6%, esters decrease 18.5%, off-flavor removal rate 80.5%; Sensory evaluation: total score 78.6 points, evaluation description "insufficient aged aroma, some heat-sensitive aroma substances are destroyed, and are prone to reversion"; Defects: long cycle (30 days), damage to flavor substances, poor stability.

[0084] Comparative Example 3: Ultrasonic + Ozone Combined Catalysis (Combined Method, Existing Technology)

[0085] 50L of raw material 1 was treated with ultrasound at 20kHz for 1 hour, followed by ozone treatment at 5mg / L for 30 minutes. After standing at 25℃ for 15 days, the results were tested. The results are as follows: Physicochemical indicators: Acetic acid increased by 25.3%, hexanoic acid increased by 28.5%, esters decreased by 22.3%, and off-flavor removal rate was 85.7%; Sensory evaluation: Total score 82.1 points, evaluation description: "Excessive ozone oxidation, partial aroma decomposition, and slightly bland taste"; Defects: Uncontrollable oxidation, flavor damage, and the treatment period is still relatively long (15 days).

[0086] Comparative Example 4: Naturally Aging (Blank Control)

[0087] 50L of raw material 1 was left to stand at room temperature (20-25℃) in the dark for 3 years before direct testing. The test results are as follows: Physicochemical indicators: Acetic acid increase rate 45.2%, hexanoic acid increase rate 51.3%, ester content decrease 33.5%, Fe ion content 25μg / L, off-flavor removal rate 96.8%; Sensory evaluation: Total score 93.5 points, evaluation description "harmonious flavor, natural aged aroma, but the cycle is too long"; Defects: The 3-year cycle resulted in significant capital tied up and substantial equipment investment.

[0088] Comparative Example 5: Variant of the present invention without the complex enzyme (lacking essential technical features)

[0089] The compound enzyme preparation in Example 1 was removed, while all other process parameters remained identical. The test results are as follows: Physicochemical indicators: Acetic acid increase rate 15.7%, hexanoic acid increase rate 18.9%, ester decrease 12.4%, off-flavor removal rate 82.3%; Sensory evaluation: Total score 81.2 points, evaluation description: "Residual spiciness, insufficient ester conversion, poor body harmony"; Defects: This demonstrates that the compound enzyme is a necessary technical feature for achieving targeted hydrolysis; its absence prevents the achievement of the expected results.

[0090] Test Method Description Example

[0091] 5.1 Determination of ester content (GC-FID method)

[0092] 5.1.1 Sample pretreatment: Take 10 mL of wine sample, add 0.1 mL of internal standard n-amyl acetate (concentration 1.0 mg / mL), dilute with anhydrous ethanol to 20 mL, vortex for 1 min, let stand for 5 min, and then take the supernatant for injection.

[0093] 5.1.2 Chromatographic conditions: DB-WAX column (30m×0.25mm×0.25μm), column temperature program: initial 40℃ for 2 min, increase to 200℃ at 5℃ / min and hold for 10 min; injection port temperature 230℃, split ratio 10:1; detector temperature 250℃; carrier gas nitrogen (purity ≥99.999%), flow rate 1.0 mL / min; injection volume 1 μL.

[0094] 5.1.3 Quantitative method: Internal standard method; standard curves were plotted for target compounds such as acetic acid, hexanoic acid, ethyl acetate, and ethyl hexanoate; linear correlation coefficient R0 was calculated. 2 ≥0.999, recovery rate 95%~105%, relative standard deviation (RSD) ≤3%.

[0095] 5.2 Determination of Fe ion content (ICP-MS method)

[0096] 5.2.1 Sample pretreatment: Take 20 mL of wine sample, add 2 mL of superior pure nitric acid, microwave digest (50℃ for 5 min → 100℃ for 5 min → 150℃ for 10 min → 180℃ for 20 min), cool and then make up to 50 mL with ultrapure water, and filter through a 0.22 μm filter membrane.

[0097] 5.2.2 Instrument parameters: RF power 1550W, sampling depth 8mm, carrier gas flow rate 1.0L / min, auxiliary gas flow rate 0.8L / min, nebulization chamber temperature 2℃, internal standards Ge and In (concentration 10μg / L).

[0098] 5.3 Detection of ethanol-water association strength (fluorescence spectroscopy): excitation wavelength 280 nm, emission wavelength range 300-500 nm, slit width 5 nm, scanning speed 240 nm / min, 1 cm quartz cuvette; the association strength is characterized by the ratio of the peak intensity at 420 nm (associated state) to that at 307 nm (free state), the larger the ratio, the stronger the association.

[0099] 5.4 Sensory evaluation method: Blind evaluation process: Sample coding → equilibration at 25℃ for 30 min → evaluation in random order → rinsing mouth with water for 1 min interval → scoring in four dimensions → removing extreme values ​​and taking the average value.

[0100] The comparison of test results is explained below:

[0101] 6.1 Comparison of Physicochemical Indicators

[0102]

[0103] 6.2 Overall Performance Comparison

[0104]

[0105] In this application, the requirements for raw material quality control are as follows:

[0106] Baijiu raw materials: The total content of off-flavor substances must be ≥100mg / L. If the alcohol content deviates from 50-55% vol, it should be diluted with purified water or diluted with distilled alcohol. Catalyst: Fe-MOF purity ≥97%. Acidified attapulgite must be washed to neutral, as residual hydrochloric acid will cause the acidity of the liquor to be too high.

[0107] In this application, the requirements for process operation are as follows:

[0108] Membrane filtration: Backwash every 2 hours (pressure 0.4 MPa, 5 min) to avoid membrane clogging; Catalytic conversion: The reaction vessel is well sealed to prevent oxygen from entering and causing Fe... 2+After oxidation and catalyst recovery, timely drying (100-120℃) is necessary to prevent mold growth. Gradient oxygenation: Real-time monitoring using an online dissolved oxygen detector ensures an oxygen concentration deviation of ≤±0.2%; otherwise, over- or under-oxidation may occur. Plasma treatment: The wine temperature is controlled to ≤30℃, with continuous cooling in the cooling jacket to prevent high temperatures from damaging aroma compounds.

[0109] In this application, the safety and environmental protection requirements are as follows: Safety: Ensure proper insulation protection during plasma treatment, keep away from fire sources when washing the catalyst with ethanol, and avoid proximity to electronic equipment during magnetic field adsorption. Environmental Protection: Regenerate the catalyst after reusing it three times to reduce solid waste; discharge the washing wastewater after neutralization (pH=7), in compliance with GB8978-1996 standards.

[0110] To accurately select the key parameter combinations affecting the aging effect in this process and improve the efficiency of ester-ester conversion and the overall quality of the wine, based on the process parameter ranges in previous examples (compound enzyme ratio 1:0.6:1:1.0, catalyst addition 1.0-1.4 g / L, gradient oxygen concentration 4%-6% / 1.5%-2.5% / 0.6%-1.0%, plasma treatment time 10-20 min), L9 (3 4 An orthogonal array design experiment was conducted. Using "acetic acid enhancement rate (%, reflecting acid enhancement effect, the higher the better)," "hexanoic acid enhancement rate (%, a core flavor indicator for strong aroma, the higher the better)," "sensory score (points, overall quality, the higher the better)," and "production cycle (d, efficiency indicator, the shorter the better)" as evaluation indicators, four core process parameters were selected as experimental factors, each with three levels, as detailed below:

[0111] I. Orthogonal Experimental Design

[0112] 1. Experimental factors and level settings

[0113] Raw material 1 (freshly distilled strong-aroma baijiu, alcohol content 52% vol, off-flavor substances 118 mg / L) was selected as the uniform experimental raw material. The equipment parameters were the same as in Example 1 (ceramic membrane filtration pressure 0.3 MPa, flow rate 1.2 m / s; catalytic reaction temperature 32℃; association induction temperature control 28℃; modified molecular sieve adsorption for 8 h), with only the following four factors adjusted:

[0114]

[0115] 2.L9(3 4 Orthogonal Experiment Tables and Results

[0116] The process was executed using an orthogonal array combination. 50L of raw material 1 was taken from each experimental group. The data for the test indicators (acetic acid / hexanoic acid enhancement rate was determined according to GB / T 10345-2022, and sensory evaluation was performed using a four-dimensional blind evaluation method) are as follows:

[0117]

[0118] II. Range Analysis (Intuitive Analysis Method)

[0119] By calculating the mean (K1 = mean of level 1, K2 = mean of level 2, K3 = mean of level 3) and range (R = max(K1,K2,K3) - min(K1,K2,K3)) of the indicators at different levels of each factor, the significance of the factor's influence on the indicator is determined (the larger the R value, the more significant the influence). The results are as follows:

[0120] 1. Range analysis of acetic acid enhancement rate index

[0121]

[0122] 2. Range analysis of hexanoic acid enhancement rate index

[0123]

[0124] 3. Range analysis of sensory rating indicators

[0125]

[0126] 4. Range analysis of production cycle indicators

[0127]

[0128] III. Derivation and Verification of Optimal Parameter Combination

[0129] 1. Derivation of the theoretical optimal combination

[0130] Considering the optimal levels and significant impact of the four indicators (prioritizing "high ester content improvement rate + high sensory score + short production cycle"):

[0131] Key influencing factors (A, C): A2 (1:0.8 compound enzyme) resulted in the highest increase in acetic acid / hexanoic acid ratio and sensory score, while C2 (5% / 2.0% / 0.8% oxygen concentration) balanced the oxidation intensity (avoiding excessive oxidation of C3 that could lead to flavor incompatibility).

[0132] Secondary factors (B, D): B2 (1.2 g / L catalyst) balances catalytic efficiency and Fe ion dissolution (Fe ion concentration of B2 in Example 1 is 32 μg / L ≤ 60 μg / L), while D2 (15 min plasma treatment) is optimal in terms of stability and flavor retention.

[0133] The final theoretically optimal combination is A2B2C2D2: complex enzyme ratio 1:0.8, catalyst addition 1.2 g / L, three-stage oxygen concentration 5% / 2.0% / 0.8%, and plasma treatment time 15 min.

[0134] 2. Optimal Combination Verification Experiment

[0135] The aging process of 50L raw material 1 was performed according to parameters A2B2C2D2, and the results are as follows:

[0136]

[0137] Verification conclusion: The optimal combination improved the acetic acid / hexanoic acid ratio by 0.6%-1.1% compared to the highest value in the orthogonal experiment, improved the sensory score by 0.5 points, shortened the production cycle by 1 day compared to Example 1, and met the requirements for Fe ion content and clarity, proving that this combination is the optimal process parameter.

[0138] 3. Explanation of the Influence Patterns of Factors

[0139] Gradient oxygen concentration: C2 (5% / 2.0% / 0.8%), high oxygen in the early stage accelerates the conversion of alcohol → aldehyde → acid, medium oxygen in the middle stage promotes the balance of ester and acid, and low oxygen in the later stage avoids the accumulation of aldehydes (such as acetaldehyde). It is better than C1 (too low oxygen concentration) for insufficient reaction and C3 (too high oxygen concentration) for excessive oxidation (aggravated ester hydrolysis).

[0140] Catalyst addition amount: When B2 (1.2 g / L) is added, the active sites of the Fe-MOF / acidified attapulgite composite catalyst are in full contact with the wine, and the catalytic efficiency for hexanoic acid formation is the highest; B1 (1.0 g / L) has insufficient activity, and although B3 (1.4 g / L) has improved activity, the risk of Fe ion dissolution increases (in Experiment 3, Fe ion concentration was 34 μg / L, close to B2's 32 μg / L, and the cost increased).

[0141] Plasma treatment time: During D2 (15 min), the dielectric barrier discharge mode can fully enhance the colloidal stability of the wine and avoid the damage to heat-sensitive aroma substances (such as slight degradation of ethyl hexanoate) caused by insufficient treatment during D1 (10 min) (clarity 0.4 NTU) and high temperature during D3 (20 min).

[0142] IV. Summary of the Value of Orthogonal Experiments

[0143] Parameter optimization: Determine the optimal range of core parameters to provide a precise control basis for industrial production (e.g., compound enzyme formulation should preferably be 1:0.8±0.05, and oxygen concentration deviation should be ≤±0.2%).

[0144] Improved performance: Compared with the original Example 1, the optimal combination shortens the production cycle by 12.5%, increases the acetic acid / hexanoic acid ratio by 1.1%-1.2%, and further optimizes sensory quality;

[0145] Cost control: The catalyst addition of 1.2g / L can avoid waste caused by excessive use, and the catalyst cost is reduced by 14.3% compared with B3 (1.4g / L), which is in line with the technical advantage of "low-cost industrialization".

[0146] In summary, the comparative examples of the present invention, compared with the prior art, have significant technical advantages in terms of ester conversion, odor removal, stability, and production cycle.

[0147] In addition, this application also provides a process for aging and maturing baijiu (Chinese liquor), which includes the following four steps:

[0148] S1 Pretreatment Step: Taking a new type of baijiu with an alcohol content of 30-65% vol and a total acid content ≥100 mg / L as the target, the pretreatment liquid is obtained after multi-stage membrane filtration.

[0149] S2 catalytic conversion steps: Add the fired clay cloud pieces to the pretreatment solution and soak for seven days to obtain the catalytic conversion solution;

[0150] S3 association induction step: The catalytic conversion liquid is connected to a temperature-controlled tank, and oxygen is introduced intermittently. Oxygen is introduced and stirred for 30 minutes in the morning and 30 minutes in the afternoon to obtain a microenvironment-controlled wine.

[0151] S4 Stabilization Step: The microenvironment-controlled liquor is transferred to a storage container and aged at a high temperature of 35℃-60℃ for 30 days to one year to obtain a mature and mellow liquor. The storage container is made of stainless steel or ceramic jar.

[0152] In the above embodiments of this application, aging at a high temperature of 30-65 vol for 30 days to one year is used instead of the natural aging of 3-5 years, shortening the aging cycle and reducing investment in storage equipment and long-term capital tied up. Fired clay cloud-shaped sheets are used as the catalytic material, without the addition of artificial metal ion catalysts, avoiding the risk of excessive metal ion leaching. Simultaneously, the natural properties of clay are adapted to the flavor transformation of baijiu, enhancing the targeted catalysis. Through the design of "intermittent oxygen introduction + timed oxygen introduction and stirring (30 minutes each in the morning and afternoon)" in S3, the microenvironment of the liquor is regularly regulated, replacing simple technology stacking and avoiding uneven aging problems. The range of raw materials is expanded to "baijiu with an alcohol content of 30-65% vol and a total acid content ≥100 mg / L," covering a wider alcohol range and improving the process's adaptability to different types of new baijiu.

[0153] The following detailed description of the aging process of Baijiu (Chinese liquor) in this application is based on specific embodiments. The raw materials, equipment and testing methods involved are all conventional choices in the relevant technical field. Unless otherwise stated, they all comply with national standards. Those skilled in the art can adjust and adapt the parameters according to actual production needs.

[0154] I. Raw Materials and Equipment Description

[0155] 1. Characteristics of core raw materials

[0156] Baijiu (Chinese liquor): Base liquors of different aroma types and alcohol contents were selected, all meeting the requirements of alcohol content of 30-65% vol and total acid content ≥100 mg / L. The total acid content was determined by potentiometric titration in GB / T 10345-2022 "Analytical Methods for Baijiu". Luzhou clay cloud-shaped tea leaves from Sichuan: Made from high-quality local Luzhou clay, fired at 1200℃, with dimensions of 5cm × 8cm × 0.5cm, porosity of 35-40%, and naturally containing Fe. 2 +、Cu 2 +、Mn 2 + and other catalytically active metal ions were purchased from a ceramic materials factory in Luzhou.

[0157] 2. Main Equipment Parameters

[0158] Multi-stage membrane filtration system: Contains three ceramic membrane modules with pore sizes of 1μm, 0.2μm, and 0.05μm respectively, operating pressure 0.3-0.5MPa, and membrane material Al2O3. Temperature control tank: 500L capacity, temperature control accuracy ±1℃, equipped with an aeration device and mechanical stirrer, stirring speed 0-200r / min. Storage containers: 304 stainless steel tank (1000L capacity) and ceramic jar (50L capacity, traditional Luzhou ceramic jar, micropore size 0.02-0.05μm / s). Detection equipment: Gas chromatography-mass spectrometry (GC-MS), automatic potentiometric titrator, spectrophotometer. II. Specific Implementation Methods

[0160] Example 1

[0161] 1. S1 Pretreatment Step: Select 1000L of a light-aroma type of baijiu with an alcohol content of 50% vol and a total acid content of 120mg / L, and pass it into a multi-stage membrane filtration system. Control the operating pressure at 0.4MPa, and filter it sequentially through 1μm, 0.2μm, and 0.05μm ceramic membranes to remove impurities, colloids, and large molecular proteins with a particle size ≥0.05μm from the baijiu. Collect 985L of the pretreated liquid after filtration.

[0162] 2. S2 Catalytic Conversion Step: Add 5% of the wine mass of clay cloud pieces (50kg in total) to the pretreatment liquid, and statically soak at room temperature for 7 days. During this period, gently turn the clay cloud pieces once a day. After soaking, filter to remove the clay cloud pieces and obtain 980L of catalytic conversion liquid.

[0163] 3. S3 Association Induction Step: The catalytic conversion solution was transferred to a temperature-controlled tank, and the tank temperature was set to 25°C. Medical-grade pure oxygen (purity ≥99.5%) was intermittently introduced. Oxygen was introduced and stirred for 30 minutes at 9:00 AM and 30 minutes at 3:00 PM. The oxygen introduction rate was 0.3 L / (min·L of wine), and the stirring speed was 80 r / min. After the procedure, 978 L of microenvironment-controlled wine was obtained.

[0164] 4. S4 Stabilization Step: The microenvironment-controlled liquor is transferred to a ceramic jar, sealed, and placed in a constant-temperature aging chamber. The ambient temperature is controlled at 45℃, and the liquor is aged at high temperature for 30 days. After aging, a sample is taken for testing, yielding 970L of aged and matured white liquor.

[0165] Example 2

[0166] 1. S1 Pretreatment Step: Select 800L of rice-aroma type new baijiu with an alcohol content of 30% vol and a total acid content of 150mg / L, filter it through a multi-stage membrane filtration system (operating pressure 0.3MPa), and collect 788L of pretreated liquid.

[0167] 2. S2 Catalytic Conversion Step: Add 4% of Sichuan Longchang clay cloud slices (32kg) by weight of the wine, soak at room temperature for 7 days, and obtain 782L of catalytic conversion liquid after filtration.

[0168] 3. S3 association induction steps: The temperature of the temperature control tank was 28℃, the oxygenation rate was 0.25L / (min·L wine), and oxygenation and stirring were carried out for 30 minutes each at 10:00 am and 4:00 pm. The stirring speed was 60r / min, and 780L of microenvironment-controlled wine was obtained.

[0169] 4. S4 Stabilization Step: Transfer to a 304 stainless steel tank, seal, and age at 55℃ for 180 days to obtain 770L of aged baijiu.

[0170] Example 3

[0171] 1. S1 Pretreatment Step: Select 1200L of a new type of soy sauce-flavored liquor with an alcohol content of 65% vol and a total acid content of 105 mg / L, filter it through a multi-stage membrane filtration system (operating pressure 0.5 MPa), and collect 1175L of pretreated liquid.

[0172] 2. S2 Catalytic Conversion Step: Add 6% of Sichuan Longchang clay cloud slices (70.5kg) by weight of the wine, soak at room temperature for 7 days, and filter to obtain 1168L of catalytic conversion liquid.

[0173] 3. S3 association induction steps: The temperature of the temperature control tank was 22℃, the oxygenation rate was 0.35L / (min·L wine), and oxygenation and stirring were carried out for 30 minutes each at 8:00 am and 2:00 pm. The stirring speed was 100r / min, and 1165L of microenvironment-controlled wine was obtained.

[0174] 4. S4 Stabilization Step: Transfer to a ceramic jar, seal, and age at 35℃ for 365 days to obtain 1150L of aged baijiu.

[0175] III. Effect Testing and Results

[0176] 1. Testing Method

[0177] Physicochemical properties: Total acid and total ester content were determined according to GB / T 10345-2022; acetaldehyde, methanol, and fusel oil content were determined by GC-MS; clarity was determined by spectrophotometer at a wavelength of 600 nm.

[0178] Sensory evaluation: Seven national first-class baijiu judges conducted blind evaluations according to GB / T 23545-2021 "Sensory Evaluation Methods for Baijiu", scoring from four dimensions: color, aroma, taste, and style (out of 100 points).

[0179] 2. Test Results

[0180]

[0181] 3. Results Analysis

[0182] Physicochemical indicators: Compared with the raw material liquor, the total ester content of the aged liquor in the three examples was significantly increased (by 74%-95%), and the content of irritating substances such as acetaldehyde, methanol, and fusel oil was significantly reduced (acetaldehyde decreased by more than 40%). The clarity was ≥99.0%, which meets the physicochemical requirements of high-quality liquor.

[0183] Sensory evaluation: The aged baijiu is slightly yellow and bright (aged in ceramic jars) or clear and transparent (aged in stainless steel tanks). It has a harmonious and rich aroma, the spiciness has disappeared, the taste is mellow and smooth, and the aftertaste is long. The sensory quality is significantly improved compared to the raw baijiu.

[0184] Process adaptability: Example 1 uses medium alcohol content and short-cycle aging in ceramic jars, resulting in the best overall quality; Example 2 is suitable for low-alcohol baijiu and stainless steel tank storage, meeting the needs of large-scale production; Example 3 is for high-alcohol sauce-flavored baijiu, with a richer flavor after long-cycle aging, proving that this process can cover different raw material characteristics and production scenarios.

[0185] 1000L of the same raw material baijiu as in Example 1 was selected and directly put into a ceramic jar. It was naturally aged at room temperature (15-25℃) for 2 years. The test results showed that the total ester content was 2.95g / L, the acetaldehyde content was 25.3mg / L, and the sensory score was 85.7 points. Although the quality was improved, the aging period was 24 times that of Example 1 of this application, and the conversion efficiency of key flavor substances and sensory experience were lower than those of the process in this application.

[0186] To further clarify the impact of key parameters on the aging effect of this baijiu aging process and to screen the optimal parameter combination, L9(3) was adopted. 4 An orthogonal array design experiment was conducted, using "total ester content (g / L, reflecting flavor richness, the higher the better)" and "aging period (days, reflecting efficiency, the shorter the better)" as evaluation indicators. Four core process parameters were selected as experimental factors, each with three levels, as detailed below:

[0187] I. Orthogonal Experimental Design

[0188] 1. Experimental factors and level settings

[0189]

[0190] 2.L9(3 4 Orthogonal Experiment Tables and Results

[0191] The same raw material baijiu (a light-aroma baijiu with an alcohol content of 50% vol and a total acid content of 120 mg / L) as in Example 1 was selected. 500 L of raw material was used for each experiment. The process was executed according to the orthogonal array parameters. The total ester content (GB / T 10345-2022) and aging period were tested (with a sensory score ≥90 as the endpoint). The results are as follows:

[0192]

[0193]

[0194] II. Range Analysis (Intuitive Analysis Method)

[0195] By calculating the mean (K1, K2, K3) and range (R = max(K1, K2, K3) - min(K1, K2, K3)) of the indicators at different levels of each factor, the significance of the factor's influence on the indicator is determined (the larger the R value, the more significant the influence). The results are as follows:

[0196] 1. Range analysis of total ester content index

[0197]

[0198] 2. Range analysis of mature cycle indicators

[0199]

[0200] III. Verification and Analysis of Optimal Parameter Combinations

[0201] 1. Derivation of the theoretical optimal combination

[0202] Considering the optimal levels and significance of the two indicators, priority should be given to ensuring "high total ester content + short aging period":

[0203] Total esters preferred: B2 (5% clay), D3 (55℃), A2 (0.4MPa), C2 / C3 (0.3-0.35L / (min·L)); Cycle preferred: C3 (0.35L / (min·L)), B2 / B3 (5%-6% clay), D3 (55℃), A2 / A3 (0.4-0.5MPa); The theoretically optimal combination derived from comprehensive deduction is A2B2C3D3: membrane filtration pressure 0.4MPa, clay cloud addition 5%, oxygenation rate 0.35L / (min·L), aging temperature 55℃.

[0204] 2. Optimal Combination Verification Experiment

[0205] The process was executed according to parameters A2B2C3D3, and 500L of raw liquor was used. The results are as follows:

[0206] Total ester content: 3.92 g / L (1.8% higher than the highest value of 3.85 g / L in the orthogonal experiment); aging period: 26 days (7.1% shorter than the shortest period of 28 days in the orthogonal experiment); sensory score: 94.0 points (color 19.5 points, aroma 34.2 points, taste 33.8 points, style 16.5 points); other indicators: acetaldehyde content 15.2 mg / L (a decrease of 59.5%), clarity 99.9%, both better than all orthogonal experiment groups.

[0207] 3. Explanation of the Influence Patterns of Factors

[0208] The amount of clay flakes added (with the most significant impact): catalytic activity is optimal at a 5% addition level – Fe in the clay. 2 +、Cu 2 + It can promote the conversion of alcohol → aldehyde → acid → ester. Excess (6%) will adsorb some esters, resulting in a decrease in total esters. Insufficient (4%) will result in low catalytic efficiency and a longer cycle. Oxygenation rate: 0.35L / (min·L) is moderate oxidation - it can provide sufficient oxygen source for ester synthesis, while avoiding excessive oxidation to generate off-flavor substances such as aldehydes, shortening the cycle while ensuring flavor harmony. Aging temperature: 55℃ accelerates molecular motion - promotes hydrogen bonding between ethanol and water molecules, accelerates the transesterification reaction, shortens the cycle by 25.6% compared to 35℃, and does not cause ester hydrolysis (due to the directional inhibition of hydrolysis by clay catalysis). Membrane filtration pressure: 0.4MPa balances efficiency and retention - too low a pressure (0.3MPa) cannot completely remove colloidal impurities and interferes with catalysis; too high a pressure (0.5MPa) will retain some small molecule flavor precursors, and the total esters will decrease slightly.

[0209] IV. Conclusions of Orthogonal Experiments

[0210] The key influencing factors of this process, ranked by the combined effect of total esters and aging period, are: clay flake addition > oxygenation rate > aging temperature > membrane filtration pressure. Recommended industrial-scale parameters are: membrane filtration pressure 0.4-0.5 MPa, clay flake addition 5%-5.5%, oxygenation rate 0.3-0.35 L / (min·L), and aging temperature 45-55℃. Within this range, a total ester content ≥3.7 g / L + aging period ≤30 days can be achieved, representing an efficiency improvement of over 24 times compared to traditional natural aging. Orthogonal experimental data validated the controllability and optimization potential of the process parameters, providing precise parameter adjustment guidelines for different production scales and meeting the requirements of "clear process parameters and repeatable verification of effects."

[0211] This application utilizes the synergistic effects of multi-stage membrane filtration to remove impurities, catalytic conversion with clay cloud sheets, flavor reconstruction induced by intermittent oxygenation, and stabilization through high-temperature aging to significantly shorten the aging period while ensuring the quality of the liquor. Furthermore, the process is simple, the raw materials are readily available, and the operation is controllable, making it suitable for liquor production enterprises of different sizes.

[0212] This application provides two solutions: "Directed Aging Process for Baijiu" and "Aging Process for Baijiu". The core purpose is to provide complementary aging technology options for different raw material characteristics, production conditions, cost budgets, and quality requirements in baijiu production scenarios, ensuring the universality and practicality of the solutions. The specific adaptation logic is as follows:

[0213] 1. Adaptable to the application requirements of different raw materials:

[0214] The targeted aging process focuses on "newly distilled baijiu with an alcohol content of 50-55% vol and a total content of off-flavors ≥100mg / L," providing precise aging solutions for new baijiu with high off-flavors and specific aroma types and alcohol content ranges. The mellowing aging process expands the applicable raw materials to "new baijiu with an alcohol content of 30-65% vol and a total acid content ≥100mg / L," without limiting the aroma type, covering a wide alcohol content range from as low as 25% vol to as high as 70% vol. It can meet the aging needs of non-strong / sauce-aroma baijiu and new baijiu with special alcohol content, filling the raw material compatibility gap of the targeted aging process.

[0215] 2. Matching the technical complexity and cost budget of different production scenarios:

[0216] The directional aging process employs sophisticated technologies such as supported metal-organic framework-attapulgite composite catalysts and low-temperature plasma treatment. It requires specialized equipment (such as electromagnetic adsorption devices and plasma reaction chambers), and the catalyst is recyclable and regenerable. It is more suitable for large-scale production scenarios with certain technical capabilities that pursue "short cycle (a few days), high quality, and precise flavor control" (such as high-end product production lines of large wineries). In contrast, the mellowing aging process uses "Sichuan Longchang fired clay cloud pieces" as a natural catalyst material, supported catalysts, and specialized precision equipment. The process steps are simple (only multi-stage membrane filtration + soaking + intermittent oxygenation + high-temperature aging), resulting in lower production costs and a lower operating threshold. It is more suitable for small and medium-sized wineries, start-ups, and other production scenarios with "diverse raw material types, limited budgets, and a pursuit of process simplicity."

[0217] 3. Meet different quality targets and production cycle requirements:

[0218] The directional aging process aims to achieve "Fe ion ≤ 60μg / L, clarity ≥ 99.0%, and quality equivalent to natural aging for more than 3 years," emphasizing "short cycle, high quality, and standardization" to address the demands of high-end baijiu for consistent and efficient aging quality. Meanwhile, the mellowing aging process focuses on "simplified procedures and compatibility with a broad range of raw materials," achieving aging through "30 days to one year of high-temperature aging at 35℃-60℃." Although its cycle is slightly longer than the directional aging process, it does not require stringent control of physicochemical indicators, making it more suitable for mass-market baijiu production that has relatively relaxed requirements for aging cycles and emphasizes "basic flavor improvement (reducing spiciness) and controllable costs."

[0219] In summary, the two solutions are complementary designs for different raw materials, different production conditions, and different quality requirements: the targeted aging process focuses on "precision, efficiency, and high quality" and is suitable for high-end and large-scale production; the mellowing aging process focuses on "broad spectrum, simplicity, and low cost" and is suitable for mass-market and flexible production, together covering the diverse needs in the aging of baijiu.

Claims

1. A process for aging and maturing baijiu (Chinese white liquor), characterized in that, It includes the following four steps: S1 Pretreatment Step: Taking baijiu with an alcohol content of 30% to 65% vol and a total acid content ≥100 mg / L as the target, the pretreated liquid is obtained after multi-stage membrane filtration; S2 catalytic conversion step: Add the fired ceramic jar pieces to the pretreatment solution and soak for 7 days to obtain the catalytic conversion solution; S3 association induction step: The catalytic conversion liquid is connected to a temperature-controlled tank, and oxygen is introduced intermittently. Oxygen is introduced and stirred for 30 minutes in the morning and 30 minutes in the afternoon to obtain a microenvironment-controlled wine. S4 Stabilization Step: The microenvironment-controlled liquor is transferred to a storage container and aged at a high temperature of 35℃-60℃ for 30 to 365 days to obtain a mature and mellow liquor. The storage container is made of stainless steel or ceramic jar.

2. A targeted aging process for baijiu (Chinese liquor), characterized in that, It includes the following four steps: S1. Pretreatment step: Using newly distilled baijiu with an alcohol content of 30% to 65% vol and a total content of off-flavor substances ≥100 mg / L as the subject, the pretreated liquor is obtained after multi-stage membrane filtration. S2. Catalytic conversion step: The supported metal-organic framework-attapulgite composite catalyst is added to the pretreated wine liquid and reacted in a sealed manner at 28-36℃ for 40-56h. After the reaction, the catalyst is recovered and filtered to obtain the catalytically converted wine liquid. S3. Association Induction Step: The catalytically converted wine is transferred to a temperature-controlled tank, oxygen is introduced in a gradient, an association inducer is added, and the wine is allowed to stand at a controlled temperature to obtain a microenvironment-regulated wine. S4. Stabilization step: After the microenvironment-controlled liquor is treated with low-temperature plasma, it is adsorbed by modified molecular sieve for 6-10 hours, and then filtered to obtain aged white liquor with Fe ion content ≤60μg / L and clarity ≥99.0%.

3. The directional aging process for baijiu as described in claim 2.

4. The directional aging process for baijiu according to claim 2, characterized in that, The multi-stage membrane filtration involves sequential cross-flow filtration through ceramic membranes with pore sizes of 40–60 nm, 15–25 nm, and 3–7 nm, with a filtration pressure of 0.2–0.4 MPa and a flow rate of 1.0–1.4 m / s, removing more than 85% of macromolecular proteins, colloidal impurities, and low-boiling-point off-flavor substances.

5. The directional aging and maturation process for baijiu according to claim 2, characterized in that, The preparation method of the supported metal-organic framework-attapulgite composite catalyst is as follows: Fe-MOF material and acidified attapulgite are mixed at a mass ratio of 1:(2-4), ultrasonically dispersed at 250-350W for 10-20 min, and then dried at 100-120℃ for 2-4 h; the Fe-MOF material is Fe-BTC or Fe-MIL-88, and the acidified attapulgite is attapulgite clay that has been treated with 0.5-1.0 mol / L hydrochloric acid, washed to neutral, and then dried.

6. The directional aging and maturation process for baijiu according to claim 2, characterized in that, In step S2, the catalyst addition amount is 1.0-1.4 g / L. The recovery is carried out by magnetic field adsorption at 0.6-1.0T for 15-25 min. After recovery, it can be reused 2-4 times after drying at 100-120℃. When reused, the catalytic efficiency is maintained at more than 85% of the initial value.

7. The directional aging process for baijiu according to claim 2, characterized in that, The parameters for the gradient oxygen introduction are as follows: first stage (0-14h) medical-grade oxygen concentration 4%-6%, second stage (14-38h) concentration 1.5%-2.5%, third stage (38-62h) concentration 0.6%-1.0%; microbubble diameter 3-12μm, aeration rate 0.08-0.12L / (L·h), and temperature controlled at 25-31℃ throughout the process.

8. The directional aging process for baijiu according to claim 2, characterized in that, The association inducer is a compound of glycerol and sorbitol in a mass ratio of 1:(0.8-1.2), with an addition amount of 0.2-0.4 g / L; or an additional 0.05-0.1 g / L of glycerol fatty acid ester is added to synergistically enhance the hydrogen bond association of ethanol-water molecules.

9. The directional aging process for baijiu according to claim 2, characterized in that, The low-temperature plasma treatment adopts a dielectric barrier discharge mode with a power of 70-90W, a discharge frequency of 0.8-1.2kHz, and a treatment time of 10-20min. The modified molecular sieve is a 4A molecular sieve modified by irradiation with 5-10kGy γ-rays, which increases the specific surface area by 20%-30% after irradiation. The addition amount is 0.4-0.6g / L, the adsorption temperature is 22-28℃, and the stirring rate is 40-60r / min.

10. The directional aging and maturation process for baijiu according to claim 2, characterized in that, It also includes a catalyst regeneration step: the recovered catalyst is soaked and washed in a 5% to 10% ethanol solution for 1 to 2 hours, and then calcined at 120 to 150°C for 1 to 2 hours. After regeneration, the catalytic efficiency remains above 90% of the initial value.

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