Method for reducing cyanide in the process of moistening grains for making Maotai-flavor liquor

Abstract

The application discloses a method for reducing cyanide in the process of grain moistening of Maotai-flavor liquor, and belongs to the technical field of liquor brewing. 60 Co-gamma ray irradiation and abscisic acid solution treatment are combined to control the content of cyanogenic glycoside in liquor brewing at the source, and the content of cyanogenic glycoside in liquor is significantly reduced from 105221.56 μg / kg of a blank control group to 1395.32±164.29 μg / kg without changing the indexes of quality-related moisture, crude protein, crude fat, total ash, amylose and reducing sugar of sorghum.

Description

Technical Field

[0001] This invention relates to a method for reducing cyanide during the grain moistening process of Maotai-flavor liquor, belonging to the field of liquor brewing technology. Background Technology

[0002] Ethyl carbamate (EC) is a potentially harmful substance formed during the production and storage of alcoholic beverages such as baijiu (Chinese liquor). Due to its potential carcinogenicity, EC has been classified as a Group 2A carcinogen by the International Agency for Research on Cancer (IARC), posing a threat to food safety and consumer health. Therefore, effectively controlling the total EC content in baijiu and other alcoholic beverages has become a crucial technical issue urgently needing to be addressed within the industry.

[0003] Studies have shown that the formation of cyanide glycosides (EC) is related to multiple precursor substances, with cyanide being one of the key precursors. During the brewing process of baijiu (Chinese liquor), especially under high temperature and ethanol conditions, cyanide can be converted into EC. The main source of cyanide is naturally occurring cyanogenic glycosides in the brewing raw materials, particularly high in sorghum and other major brewing ingredients. Research indicates that physical stress (such as crushing and heat treatment) and biological reaction processes (such as moistening and fermentation) experienced by raw materials during processing can promote the hydrolysis of cyanogenic glycosides and the release of cyanide, thereby increasing the risk of EC formation. Therefore, controlling the release and accumulation of cyanide at its source is the key technological bottleneck and fundamental approach to blocking EC production pathways and ensuring the safety of baijiu.

[0004] Currently, to reduce the EC content in baijiu (Chinese liquor), existing technologies are exploring both post-processing and raw material pretreatment stages, but all have significant limitations. For example, post-processing often involves optimizing fermentation parameters, improving distillation processes, or adding adsorbents, but these methods have limited ability to control EC precursors such as cyanide at their source. Some source-level technologies attempt to reduce cyanogenic glycosides by pre-treating brewing raw materials. For instance, while heat treatment can degrade cyanogenic glycosides, it may lead to excessive gelatinization of starch and denaturation of proteins in the raw materials, and damage aromatic precursors crucial to baijiu flavor, negatively impacting subsequent fermentation and the flavor of the final product. Water washing methods have limitations such as cumbersome operation procedures, high water consumption, and unstable cyanogenic glycoside removal, and are prone to causing the loss of water-soluble nutrients and flavor precursors. Adding adsorbents (such as activated carbon and molecular sieves) can adsorb free cyanide, but they are ineffective against structurally stable, unhydrolyzed cyanogenic glycosides, meaning that residual cyanogenic glycosides still pose a risk of continuously releasing cyanide during subsequent fermentation and distillation. In addition, the non-specific adsorption of adsorbents can easily lead to the co-adsorption of flavor substances, resulting in a loss of product quality.

[0005] Of particular note is that grain moistening is a crucial step in the solid-state fermentation of baijiu. This process creates conditions for the activation of endogenous enzymes in the raw materials, the initiation of microorganisms, and the hydrolysis of cyanogenic glycosides. It is also the peak period for the release of cyanide. However, currently, there is a lack of effective bio-regulation measures for the grain moistening stage. Therefore, existing technologies are significantly insufficient in both downstream processing and reducing the potential for cyanide formation at the source, as well as controlling its conversion efficiency during fermentation and distillation. There is an urgent need in this field to develop a new technology that can effectively inhibit the release and conversion of cyanide precursors in the early stages of the brewing process, especially at key points such as raw materials and grain moistening, without affecting the normal fermentation and flavor quality formation of baijiu, and is environmentally friendly and easy to industrially apply. Summary of the Invention

[0006] [Technical Issues]

[0007] There is a lack of existing technologies for reducing the release and transformation of cyanide precursors in baijiu (Chinese liquor) at the source.

[0008] [Technical Solution]

[0009] To address the aforementioned problems, this invention proposes a technical solution that combines raw material irradiation treatment with the spraying of abscisic acid (ABA) solution during the grain moistening stage. This invention reduces the content of EC precursors in baijiu (Chinese liquor) through synergistic irradiation and ABA treatment, thereby improving the overall efficiency of EC precursor regulation in baijiu.

[0010] On one hand, the present invention provides a method for reducing the content of strychnine in baijiu (Chinese liquor), the method comprising the following steps:

[0011] (1) Irradiate the sorghum raw material to obtain irradiated sorghum raw material;

[0012] (2) Use the irradiated sorghum raw material to brew liquor, and spray abscisic acid solution onto the irradiated sorghum raw material during the grain moistening step of liquor brewing.

[0013] In one embodiment of the present invention, the irradiation treatment employs... 60 Co-γ rays.

[0014] In one embodiment of the present invention, the absorbed dose of the irradiation treatment is 1 to 10 kGy.

[0015] Preferably, the absorbed dose of the irradiation treatment is 1 to 5 kGy.

[0016] In one embodiment of the present invention, the grain moistening step includes adding water 1 to 5 times. After each addition of water, the temperature is controlled to drop to 40 to 45°C, and an abscisic acid solution with a concentration of 50 to 100 μmol / L is sprayed, followed by continuous stacking and cultivation.

[0017] Preferably, the grain moistening step includes adding water three times.

[0018] In one embodiment of the present invention, the solvent for the abscisic acid solution is water.

[0019] In one embodiment of the present invention, the amount of abscisic acid solution added each time, based on the dry weight of the sorghum raw material, is (0.5~1.5)×10. -7 molABA / kg sorghum.

[0020] Preferably, the amount of abscisic acid solution added is 1×10⁻⁶. -7 molABA / kg sorghum.

[0021] In one embodiment of the present invention, the grain moistening step includes: adding water three times at a water temperature of 95℃ to 98℃, with the water amounts accounting for 34%, 12%, and 10% of the total mass of the sorghum, respectively; the interval between the first and second water addition operations is 80 to 100 minutes, and the interval between the second and third water addition operations is 300 to 400 minutes.

[0022] In one embodiment of the present invention, the mixture is stirred immediately after each addition of water, and additional stirring is performed at 20-24 hours and 35-40 hours after the first addition of water.

[0023] In one embodiment of the present invention, the total duration of the grain moistening step is 50 to 70 hours.

[0024] In one embodiment of the present invention, the sorghum includes Hongyingzi, Nuoliang No. 1, Jiliang No. 2, S&WTanami, or Langnuohong No. 19.

[0025] On the other hand, the present invention also provides a method for brewing baijiu (Chinese liquor). After processing using the above method, the process of steaming grains, spreading and cooling, mixing with yeast, fermentation and distillation is continued, and the content of strychnine in the resulting liquor is significantly reduced.

[0026] In one embodiment of the present invention, the liquor is a sauce-flavored liquor.

[0027] The present invention also provides a type of liquor prepared according to the above method.

[0028] The present invention also provides the application of the method for reducing the content of strychnine in baijiu in the baijiu brewing process.

[0029] [Beneficial Effects]

[0030] This invention pretreats sorghum, the raw material for brewing, with gamma-ray irradiation and applies abscisic acid solution during a key step in the brewing process (the grain moistening stage). This invention utilizes physical pretreatment (1-5 kGy) 60The combination of Co-γ ray irradiation and biochemical regulation (50-100 μmol / L abscisic acid solution) controls the content of cyanogenic glycosides in baijiu brewing at the source. Without changing the six key chemical components related to sorghum quality (moisture, crude protein, crude fat, total ash, amylose and reducing sugar), the content of cyanogenic glycosides in baijiu is significantly reduced from 105221.56 μg / kg in the blank control group to 1395.32±164.29 μg / kg. Attached Figure Description

[0031] Figure 1 The graph shows the effect of different treatments on the content of styracin.

[0032] Figure 2 The graph shows the effect of irradiation at doses of 0.2–30 kGy on the content of sphagnum motrin.

[0033] Figure 3 The graph shows the effect of using 50–1000 μM ABA alone on the content of stigmosiderin.

[0034] Figure 4 Scanning electron microscope images of sorghum starch structure after different treatments. Detailed Implementation

[0035] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explanation of the present invention and are not intended to limit the present invention.

[0036] The methods involved in the following embodiments:

[0037] 1. LC-MS / MS method for quantifying stigmosiderin

[0038] The following steps were taken to pretreat the raw wine sample according to the national standard GB / T 42113-2022, "Determination of Cyanobacterial Glycosides in Agricultural Products by Liquid Chromatography-Tandem Mass Spectrometry":

[0039] (1) Extraction:

[0040] Weigh 1g of sample (accurate to 0.1mg) into a 15mL centrifuge tube, add 3mL of 80% methanol aqueous solution, vortex for 15s, sonicate for 15min, and immediately centrifuge at 4200r / min for 10min. Collect all supernatant. Add 3mL of 80% methanol aqueous solution to the residue again, extract and centrifuge under the above conditions, combine the two extracts into a 10mL volumetric flask, add water to the mark, mix well, and wait for purification.

[0041] (2) Purification:

[0042] Connect the activated solid-phase extraction column to a solid-phase extraction apparatus (N-vinylpyrrolidone and divinylbenzene copolymer packed column (200 mg / 6 mL)). Transfer the crude extract prepared in (1) into the extraction column. After all the sample solution has flowed through the column, discard the eluent. Rinse the column with 2 mL of water and dry it completely, discarding the eluent. Elute the column with 3 mL of 30% methanol-acetonitrile solution, eluting in fractions of 1 mL at a flow rate of 1 mL / min, collecting all the eluent. Dry the eluent with nitrogen (40 °C) and redissolve it with 1 mL of 10% methanol-water solution. Filter through a 0.22 μm filter membrane for liquid chromatography-tandem mass spectrometry determination.

[0043] Instrument LC conditions:

[0044] Chromatographic column: Cis (50 mm × 2.1 mm, 1.8 μm) column, or equivalent; column temperature: 30 °C; mobile phase A: 0.1% formic acid aqueous solution; mobile phase B: acetonitrile. Flow rate: 0.2 mL / min; injection volume: 10 μL.

[0045] The elution conditions were as follows: 0-0.5 min, 2% B; 0.5-3.0 min, 2-7% B; 3.0-7.5 min, 7-40% B; 7.5-8 min, 40-90% B; 8-10 min, 90% B; 10-13 min, 90-2% B.

[0046] Instrument MS conditions:

[0047] ESI ion source, positive ion mode.

[0048] The capillary voltage was set to 3.5kV, the cone voltage to 20V, the collision energy to 12V, the source temperature to 120℃, the desolventizing temperature to 300℃, the desolventizing gas flow rate to 700L / h, the cone gas flow rate to 50L / h, and the collision gas flow rate to 0.15mL / min.

[0049] The MS detector was set to MRM mode, with m / z 334.1→145 and 334.1→185.1 selected as the qualitative ion pair for stigmosiderin and m / z 334.1→185.1 selected as the quantitative ion pair.

[0050] 2. Separation of starch

[0051] Sorghum starch was extracted using the method described by Sakshi Singh et al. (Gamma Irradiation-Induced Structural Modification of Sorghum Flour and Its Impact on the Physicofunctional, Rheological, and Thermal Properties of Extracted Starch, https: / / doi.org / 10.1155 / 2024 / 2228239). 100g of sorghum was ground into powder and mixed with 200mL of deionized water containing 0.1% NaOH, then passed through a 100-mesh sieve. The mixture was centrifuged at 6000rpm for 30min to remove the yellow fraction. The residue was then washed with double-distilled water; the white residue after six washes was the starch. The starch was then dried in an oven at 40℃ for 24h, and subsequently stored in a refrigerator at 4℃ for further analysis.

[0052] 3. Morphological characteristics

[0053] Scanning electron microscopy was used to analyze the morphological characteristics of sorghum starch granules after the grain soaking process in different treatment groups (JSM-7500, Joel Ltd, Tokyo, Japan). Starch samples were adhered to a circular aluminum rod using double-sided tape and covered with a thin layer of gold foil.

[0054] 4. Determination of chemical composition content

[0055] The moisture content of sorghum starch was determined by the direct drying method in the national standard GB 5009.3-2016.

[0056] Determination of crude protein using the Kjeldahl method as specified in GB 5009.5-2016;

[0057] GB 5009.6-2016, Soxhlet extraction method for the determination of crude fat;

[0058] The determination of total ash content by carbonization and ashing method as specified in GB 5009.4-2016;

[0059] Enzymatic determination of amylose in GB / T15683-2008;

[0060] GB5009.7-2016 specifies the direct titration method for the determination of reducing sugars.

[0061] The raw materials used in the following examples:

[0062] The sorghum raw materials used in this study were sourced from a sauce-flavored liquor production enterprise in Jiangsu Province, and all were newly purchased brewing-specific varieties in 2025.

[0063] All samples were sealed and stored at 4°C after sampling to ensure their stability.

[0064] Abscisic acid was purchased from Yuan Ye Company. The abscisic acid was dissolved in water to prepare a working solution.

[0065] Unless otherwise specified, the solvent used in the solutions mentioned in the examples and comparative examples is water; and the operating conditions without a specific temperature refer to room temperature (20-30°C).

[0066] Example 1: 5 kGy irradiation combined with 50 μM ABA treatment group

[0067] 1. Pretreatment of brewing raw materials: 500g of red sorghum samples from the same batch were selected and subjected to gamma-ray pretreatment. (Using...) 60 The sample was irradiated using a Co radioactive source at a dose of 5 kGy. After irradiation, the raw material was sealed and stored away from light until it was ready for use in grain conditioning.

[0068] 2. The grain soaking process is strictly operated according to the simulated process parameters, and ABA treatment is carried out simultaneously during the grain soaking process:

[0069] (1) First addition of water: Add 95℃ hot water to the sorghum, the amount of water is 34% of the total mass of the sorghum, and immediately stir manually. When the temperature drops to 40℃, spray 1.0 mL of 50μM abscisic acid solution (ABA) evenly on the sample surface. Then, pile the sample in a tray lined with absorbent sponges to simulate the actual mountain-like structure and place it in a 40℃ constant temperature box for continuous stacking culture.

[0070] (2) Second water addition: 90 min after the first water addition, add 95℃ hot water to the sorghum, the amount of water added is 12% of the total mass of the sorghum, and immediately stir manually. When the temperature drops to 40℃, spray 1.0 mL of 50 μM ABA solution evenly on the sample surface. Then pile the sample in a tray lined with absorbent sponges to simulate the actual mountain-like structure, and place it in a 40℃ constant temperature box for continuous stacking culture.

[0071] (3) Third water addition: 360 min after the second water addition, add 95℃ hot water to the sorghum, the amount of water added is 10% of the total mass of the sorghum, and immediately stir manually. When the temperature drops to 40℃, spray 1.0 mL of 50μM ABA solution evenly on the sample surface. Then pile the sample in a tray lined with absorbent sponges to simulate the actual hill-like structure. Place it in a 40℃ constant temperature incubator for continuous stacking culture until the grain is moistened. The whole process takes 54 h.

[0072] The mixture was stirred again at 24 and 36 hours after the first water injection.

[0073] After the culture was completed, 30g of material was randomly collected from the sample, with 6 replicates per group. The samples were immediately frozen and stored at -80℃ for subsequent extraction and determination of stigmosiderin.

[0074] This invention achieves a significant reduction in the content of strychnine in baijiu raw materials by combining low-dose gamma-ray irradiation (5 kGy) with spraying of a low-concentration abscisic acid solution (ABA, 50 μM).

[0075] The experimental results showed that the average content of stigmosiderin in the combined treatment group was 1395.32±164.29μg / kg.

[0076] Comparative Example 1: Grain-moistened control group (blank treatment)

[0077] A 500g sample of red sorghum that had not undergone any irradiation or chemical treatment was selected and directly treated using a simulated grain-moistening process:

[0078] (1) First addition of water: Add 95℃ hot water to the sorghum, the amount of water is 34% of the total mass of the sorghum, stir manually immediately, then pile the sample in a tray lined with absorbent sponges to simulate the actual mountain-like structure, and place it in a 40℃ constant temperature box for continuous stacking culture.

[0079] (2) Second water addition: 90 minutes after the first water addition, add 95℃ hot water to the sorghum, the amount of water added is 12% of the total mass of the sorghum, and immediately stir manually. Then, pile the sample in a tray lined with absorbent sponges to simulate the actual mountain-like structure, and place it in a 40℃ constant temperature box for continuous stacking culture.

[0080] (3) Third water addition: 360 minutes after the second water addition, add 95℃ hot water to the sorghum, the amount of water added is 10% of the total mass of the sorghum, and immediately stir manually. Then, pile the sample in a tray lined with absorbent sponges to simulate the actual mountain-like structure, and place it in a 40℃ constant temperature box for continuous stacking culture until the grain is moistened. The whole process takes 54 hours.

[0081] The mixture was stirred again at 24 and 36 hours after the first water injection.

[0082] After the culture was completed, 30g of material was randomly collected from the sample, with 6 replicates per group. The samples were immediately frozen and stored at -80℃ for subsequent extraction and determination of stigmosiderin.

[0083] The test results showed that the concentration of styracin in the control group (containing styracin) was approximately 105221.56 μg / kg, which was used as the baseline reference. Figure 1 ).

[0084] Comparative Example 2: Individually treated groups irradiated with different doses (γ-rays)

[0085] 500g of the same batch of red sorghum were subjected to gamma-ray irradiation at different dose levels: 0.2, 1, 5, 10, 20, and 30 kGy. The irradiation source was... 60 Co radioactive source. The processed samples were treated according to the grain-moistening process and then sampled for testing;

[0086] The specific steps are as follows:

[0087] 1. Pretreatment of brewing raw materials: 500g of red sorghum samples from the same batch were selected and subjected to gamma-ray pretreatment. (Using...) 60 The samples were irradiated with a Co radioactive source at doses of 0.2, 1, 5, 10, 20, and 30 kGy. After irradiation, the raw materials were sealed and stored away from light until use during the grain conditioning process.

[0088] 2. The grain soaking process is strictly operated according to the simulated process parameters:

[0089] (1) First addition of water: Add 95℃ hot water to the sorghum, the amount of water is 34% of the total mass of the sorghum, stir manually immediately, then pile the sample in a tray lined with absorbent sponges to simulate the actual mountain-like structure, and place it in a 40℃ constant temperature box for continuous stacking culture.

[0090] (2) Second water addition: 90 minutes after the first water addition, add 95℃ hot water to the sorghum, the amount of water added is 12% of the total mass of the sorghum, and immediately stir manually. Then, pile the sample in a tray lined with absorbent sponges to simulate the actual mountain-like structure, and place it in a 40℃ constant temperature box for continuous stacking culture.

[0091] (3) Third water addition: 360 minutes after the second water addition, add 95℃ hot water to the sorghum, the amount of water added is 10% of the total mass of the sorghum, and immediately stir manually. Then, pile the sample in a tray lined with absorbent sponges to simulate the actual mountain-like structure, and place it in a 40℃ constant temperature box for continuous stacking culture until the grain is moistened. The whole process takes 54 hours.

[0092] The mixture was stirred again at 24 and 36 hours after the first water injection.

[0093] After the culture was completed, 30g of material was randomly collected from the sample, with 6 replicates per group. The samples were immediately frozen and stored at -80℃ for subsequent extraction and determination of stigmosiderin.

[0094] The test results are shown in Table 1.

[0095] Table 1. Effects of individual irradiation treatment on the content of stigmosiderin in Baijiu (Chinese liquor)

[0096] 0.2 <![CDATA[113040.35±503.35 a ]]> 1 <![CDATA[100438.71±577.35 b ]]> 5 <![CDATA[34783.13±532.57 c ]]> 10 <![CDATA[1438.24±164.29 d ]]> 20 <![CDATA[1671.99±157.74 d ]]> 30 <![CDATA[1605.32±109.08 d ]]>

[0097] As shown in Table 1, compared with the results of Example 1 (1395.32±164.29 μg / kg), the combined use of radiation and ABA was more effective in reducing the content of styracin in baijiu (Chinese liquor) in the 5 kGy treatment group alone (34783.13±532.57 μg / kg). There was no significant difference in the 10–30 kGy groups, indicating that the regulatory effect reached a plateau and could not achieve the effect of the combined treatment group in Example 1. Figure 2 ).

[0098] Comparative Example 3: Grain moistening spray treatment groups with different concentrations of ABA

[0099] 500g of unirradiated red sorghum from the same batch was selected and treated with ABA aqueous solutions of 50, 100, 200, 500, and 1000 μmol / L, respectively. Standard grain soaking and stacking cultivation were then performed, and samples were taken for analysis.

[0100] The specific steps are as follows:

[0101] (1) First addition of water: Add 95℃ hot water to the sorghum, the amount of water is 34% of the total mass of the sorghum, and immediately stir manually. When the temperature drops to 40℃, spray 1.0 mL of ABA solution (concentrations of 50, 100, 200, 500, and 1000 μmol / L) evenly on the sample surface. Then, pile the sample in a tray lined with absorbent sponges to simulate the actual hill-like structure and place it in a 40℃ constant temperature incubator for continuous stacking culture.

[0102] (2) Second water addition: 90 min after the first water addition, add 95℃ hot water to the sorghum, the amount of water added is 12% of the total mass of the sorghum, and immediately stir manually. When the temperature drops to 40℃, spray 1.0 mL of ABA solution (concentration is the same as in step (1)) evenly on the sample surface. Then, pile the sample in a tray lined with absorbent sponges to simulate the actual mountain-like structure and place it in a 40℃ constant temperature box for continuous stacking culture.

[0103] (3) Third water addition: 360 min after the second water addition, add 95℃ hot water to the sorghum, the amount of water added is 10% of the total mass of the sorghum, and immediately stir manually. When the temperature drops to 40℃, spray 1.0 mL of ABA solution (concentration is the same as in step (1)) evenly on the sample surface. Then pile the sample in a tray lined with absorbent sponges to simulate the actual hill-like structure. Place it in a 40℃ constant temperature box for continuous stacking culture until the grain is moistened. The whole process takes 54 h.

[0104] The mixture was stirred again at 24 and 36 hours after the first water injection.

[0105] After the culture was completed, 30g of material was randomly collected from the sample, with 6 replicates per group. The samples were immediately frozen and stored at -80℃ for subsequent extraction and determination of stigmosiderin.

[0106] The test results are shown in Table 2.

[0107] Table 2. Effects of ABA treatment alone on the content of stigmosiderin in Baijiu.

[0108] 50 <![CDATA[22249.13±503.32 a ]]> 100 <![CDATA[9245.87±199.15 b ]]> 200 <![CDATA[5345.24±141.89 c ]]> 500 <![CDATA[5285.57±103.20 c ]]> 1000 <![CDATA[5405.89±208.17 c ]]>

[0109] As shown in Table 2, compared with the results of Example 1 (1395.32±164.29 μg / kg), the 50 μM ABA treatment group alone (22249.13±503.32 μg / kg) showed that the combined use of radiation and ABA was more effective in reducing the content of styracin in baijiu. There was no significant difference in the 200–1000 μM ABA groups, indicating that the regulatory effect reached a plateau and could not achieve the effect of the combined treatment group in Example 1. Using higher concentrations of ABA treatment might affect the flavor of the baijiu product. Figure 3 ).

[0110] Example 2: Scanning electron microscopy observation of the structure of sorghum starch under different treatment methods

[0111] To investigate the effects of different treatment methods on the microstructure of sorghum, the raw material for liquor, after the grain soaking process, samples were selected from Example 1, Comparative Example 1, and Comparative Example 2, and their morphology was analyzed by scanning electron microscopy (SEM).

[0112] The control group and two treatment groups were set up as follows:

[0113] Control group of grains moistened (no pretreatment was performed, only standard grain moistening operation was performed) (Comparative Example 1);

[0114] High-dose single irradiation group (raw sorghum treated with 10kGy γ-rays and then moistened) (10kGy group in Comparative Example 2);

[0115] Combined treatment group (raw sorghum was irradiated with 5 kGy γ rays and sprayed with 50 μM ABA solution during grain moistening operation) (Example 1).

[0116] Immediately after the grain soaking is completed, samples from each group are collected and processed as follows:

[0117] (1) Starch extraction: Refer to the method of "Starch Separation" (Marcu, D., Damian, G., Cosma, C., & Cristea, V. (2013). Gamma radiation effects on seed germination, growth and pigment content, and ESR study of induced free radicals in maize (Zea mays). JBiol Phys, 39(4), 625-634. https: / / doi.org / 10.1007 / s10867-013-9322-z);

[0118] (2) Freeze-drying: Pre-freeze at -80℃ for 12 hours, then dry in a vacuum freeze dryer for 24 hours;

[0119] (3) Spraying: The dried sample powder is uniformly fixed on the SEM sample holder and then subjected to metal spraying.

[0120] (4) Scanning observation: Using a field emission scanning electron microscope with an accelerating voltage of 5kV and a magnification of 2000×, the surface morphology and structural integrity of starch granules were observed.

[0121] The results are as follows Figure 4 As shown, the analysis is as follows:

[0122] (1) Control group of grain moistening: The starch granules have a smooth and flat surface, regular shape, uniform particle size, dense arrangement of granules and intact edges;

[0123] (2) High-dose irradiation group: The starch granule structure was damaged, and the surface showed wrinkling, holes and fragmentation, indicating that high-dose irradiation caused serious damage to the cell structure.

[0124] (3) Combined treatment group: The surface of starch granules was slightly rough, and some granules showed slight deformation, but the overall outline was clear and the structure was intact. No obvious collapse or breakage was observed, indicating that the combined treatment of low-dose irradiation and ABA had little impact on the raw material structure.

[0125] The results showed that high-dose gamma-ray treatment significantly damaged the starch structure in sorghum raw materials, potentially negatively impacting the activity of subsequent saccharifying enzymes and the fermentation process. Therefore, even though high-dose gamma-ray treatment can reduce stigmosiderin in finished baijiu, it is not suitable for use in the preparation of finished baijiu. The combined treatment method proposed in this invention, however, achieves control over stigmosiderin content while preserving the integrity of the starch structure to the greatest extent possible, demonstrating the technical advantage of combining irradiation and ABA application in controlling toxicity and reducing cyanide while protecting the quality of raw materials.

[0126] Example 3: Effects of combined treatment group on the structure and chemical composition of raw sorghum

[0127] To further verify the protective effect of the combined treatment process (5kGy irradiation + 50μM ABA) on the quality of baijiu raw materials, sorghum samples from the combined treatment group (Example 1) and the sorghum control group (Comparative Example 1) after the grain soaking process were selected for the following analysis:

[0128] Table 3 Sample Quality Testing Methods

[0129]

[0130]

[0131] The results are shown in Table 4.

[0132] Table 4 Chemical Composition Results

[0133] Moisture (%) 12.40±0.06 12.39±0.07 -0.08％ Crude protein (%) 8.49±0.18 8.33±0.19 -1.88％ Crude fat (%) 1.13±0.05 1.04±0.05 -7.96％ Total ash content (%) 0.78±0.06 0.81±0.07 3.85％ Amylose (%) 16.10±0.05 16.05±0.04 -0.31％ Reducing sugar (%) 7.12±0.02 7.18±0.01 0.84％

[0134] As shown in Table 4, after the raw sorghum treated with 5kGy γ-rays combined with 50μM ABA was subjected to a grain-moistening simulation treatment, the six key chemical components (including moisture, crude protein, crude fat, total ash, amylose and reducing sugar) showed slight changes compared with the grain-moistening control group, but none of them reached the level of statistical significance (p>0.05).

[0135] The following conclusions can be drawn from the data analysis:

[0136] (1) The contents of main components such as moisture and amylose are basically the same;

[0137] (2) Crude protein and crude fat decreased slightly, while total ash and reducing sugar increased slightly;

[0138] The results showed that the fluctuation range of the six key chemical components for sorghum quality was within ±8%, which falls within the common physiological response range during grain moistening and irradiation treatments. The combined treatment scheme proposed in this invention can effectively reduce sorghum glycosides while maintaining the stability of the nutritional and structural components of sorghum raw materials, demonstrating good component protection capabilities and practicality for production.

[0139] Example 4: Effects on different sorghum varieties

[0140] In this embodiment, Nuoliang No. 1, Jiliang No. 2, S&W Tanami (Australian sorghum), and Langnuohong No. 19 were selected as raw materials and prepared using the process described in Example 1. The results are shown in Table 5.

[0141] Table 5. Effects of combined irradiation and ABA on different sorghum varieties.

[0142]

[0143] The results in Table 5 show that the combined treatment of irradiation and ABA with different varieties of sorghum can reduce the content of sorghum glycosides.

[0144] Comparative Example 4: Ultrasonic treatment as an alternative to irradiation treatment

[0145] To investigate the effects of different physical methods on sorghum raw materials, an experiment was conducted to replace irradiation with ultrasonic treatment, including ultrasonic treatment alone and a combination of ultrasonic treatment and ABA.

[0146] Sonic treatment alone: ​​40kHz, 200W for 30min (water bath controlled <30℃);

[0147] Ultrasound and ABA combined group: 40kHz, 200W treatment for 30min (water bath controlled <30℃) + 50μM ABA;

[0148] The remaining steps are the same as in Example 1.

[0149] The results are shown in Table 6.

[0150] Table 6

[0151]

[0152] As can be seen from Table 6, neither ultrasound treatment alone nor in combination with ABA can achieve the same effect as the irradiation combined with ABA treatment group.

[0153] Comparative Example 5: Pulsed electric field as an alternative to irradiation treatment

[0154] To investigate the effects of different physical methods on sorghum raw materials, a group was set up to use pulsed electric fields to replace irradiation, including a group using pulsed electric fields alone and a group using pulsed electric fields in combination with ABA.

[0155] Single pulse electric field: Applying a pulse electric field with a field strength of 5 kV / cm for 60 minutes

[0156] The combined use of pulsed electric field and ABA: 60 min of pulsed electric field with a field strength of 5 kV / cm + 50 μM ABA;

[0157] The remaining steps are the same as in Example 1.

[0158] The results are shown in Table 7.

[0159] Table 7

[0160]

[0161] As can be seen from Table 7, neither a single pulsed electric field nor its combination with ABA can achieve the same effect as the combination of irradiation and ABA.

[0162] Comparative Example 6: Jasmonic acid replacing ABA

[0163] To investigate the effects of different compounds on sorghum raw materials, we set up groups that used jasmonic acid to replace ABA, including jasmonic acid alone and a combination of irradiation and jasmonic acid.

[0164] Jasmonic acid alone: ​​100 μmol / L jasmonic acid solution;

[0165] The combined irradiation and jasmonic acid group: 5 kGy irradiation + 100 μmol / L jasmonic acid solution;

[0166] The remaining steps are the same as in Example 1.

[0167] The results are shown in Table 8.

[0168] Table 8

[0169]

[0170] As can be seen from Table 8, neither jasmonic acid nor the combination of jasmonic acid and irradiation can achieve the same effect as the combination of irradiation and ABA.

[0171] Comparative Example 7: Ferulic Acid Replacing ABA

[0172] To investigate the effects of different compounds on sorghum raw materials, we set up groups that used ferulic acid to replace ABA, including ferulic acid alone and a combination of irradiation and ferulic acid.

[0173] Ferulic acid alone: ​​100 ppm ferulic acid solution;

[0174] Irradiation and ferulic acid combined group: 5 kGy irradiation + 100 ppm ferulic acid solution;

[0175] The remaining steps are the same as in Example 1.

[0176] The results are shown in Table 9.

[0177] Table 9

[0178]

[0179] As can be seen from Table 9, neither ferulic acid nor the combination of ferulic acid and irradiation can achieve the same effect as the combination of irradiation and ABA.

[0180] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A method for reducing the content of glutenin in baijiu (Chinese liquor), characterized in that, The method includes the following steps: (1) Irradiate the sorghum raw material to obtain irradiated sorghum raw material; Among them, irradiation treatment adopts 60 The absorbed dose of Co-γ rays irradiation treatment is 1~10 kGy; (2) Use the irradiated sorghum raw material to brew liquor, and spray abscisic acid solution onto the irradiated sorghum raw material in the grain moistening step of liquor brewing. The grain moistening step includes adding water three times at a water temperature of 95℃~98℃. After each addition of water, the temperature is controlled to drop to 40~45℃, and a 50~100 μmol / L abscisic acid solution is sprayed. The grain is then continuously piled up for cultivation. Based on the dry weight of the sorghum raw material, the amount of abscisic acid solution added for each spraying is (0.5~1.5)×10. -7 mol ABA / kg sorghum; The grain moistening process includes: adding water three times, with the water amount accounting for 34%, 12%, and 10% of the total mass of sorghum, respectively; the interval between the first and second water addition operations is 80-100 minutes, and the interval between the second and third water addition operations is 300-400 minutes; Stir immediately after each addition of water, and then stir again at 20-24 hours and 35-40 hours after the first addition of water.

2. The method according to claim 1, characterized in that, The absorbed dose of the irradiation treatment is 1~5 kGy.

3. The method according to claim 1, characterized in that, The solvent for abscisic acid solution is water.

4. The method according to claim 1, characterized in that, The amount of abscisic acid solution added is 1×10 -7 molABA / kg sorghum.

5. The method according to claim 1, characterized in that, The sorghum varieties include Hongyingzi, Nuoliang No. 1, Jiliang No. 2, S&W Tanami, or Langnuohong No.

19.

6. A method for brewing baijiu (Chinese white liquor), characterized in that, After processing using any one of the methods described in claims 1 to 5, the grain is then steamed, spread out to dry, mixed with koji, fermented, and distilled.

7. The liquor prepared according to claim 6.

8. The application of the method according to any one of claims 1 to 5 in the field of liquor brewing technology.

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