Method for reducing content of cyanide and ethyl carbamate in white spirit solid-state distillation

Abstract

The invention discloses a method for reducing the content of cyanide and ethyl carbamate in white spirit solid-state distillation, and belongs to the technical field of solid-state distillation. Based on a unique operation process of a white spirit solid-state distillation process, main operation parameters (steam pressure, retort filling height and auxiliary material ratio) of the process are changed, and the EC content of distilled raw wine can be reduced by 53.94% by reducing the retort filling height; and the cyanide content can be reduced by 36.15% by reducing the input of auxiliary materials. According to the method, the distillation rules of cyanide, EC and flavor components are summarized after the actual production process parameters of the Baijiu are adjusted, and reference and help are provided for balancing the flavor uniqueness and safety of the Baijiu.

Description

Technical Field

[0001] The invention relates to a method for reducing the contents of cyanide and ethyl formate in the solid-state distillation of liquor, and belongs to the technical field of solid-state distillation. Background Art

[0002] Ethyl carbamate (EC) is a safety risk factor widely present in alcoholic beverages and is identified as a Class 2A carcinogen by the International Agency for Research on Cancer (IARC). In recent years, the safety of liquor has received widespread attention from producers and relevant scholars, and the content of EC needs to be strictly controlled. Cyanide is one of the main precursors of EC in distilled liquor. The distillation process is accompanied by the concentration of cyanide and ethanol and the high temperature environment, which is one of the key production links that promotes the conversion of cyanide into EC. Limiting the content of cyanide is also considered an important measure to limit the content of EC in distilled liquor. It can be seen that limiting the distillation of cyanide and EC into the liquor during the solid-state distillation process of liquor will help improve the safety of liquor.

[0003] At present, Western distilled spirits have achieved certain results in the study of regulating cyanide and EC during the distillation process, and have achieved considerable regulation and applied it to actual production by adopting measures such as refined secondary distillation, optimization of still pot materials, and optimization of wine collection. Relevant research on liquor has adopted the method of characterizing dynamic changes and optimizing the wine collection process to limit the distillation of cyanide and EC into the wine body, but this process cannot change the actual distillation amount of cyanide and EC, and has a great impact on the wine yield.

[0004] Other related studies simulated the secondary distillation method of Western liquid distillation, and the removal rate of cyanide and EC can reach more than 90%. At the same time, it also made it difficult for acidic substances to be distilled into the wine, and the total acidity decreased by 93.90%. To a certain extent, it affected the uniqueness and integrity of the flavor of the liquor. The use of chemical reaction method and copper network cyanide research has been certified to effectively reduce the cyanide content in actual production, but it also caused a metallic taste in the wine, and it is not ruled out that Cu 2+ The subsequent impact on the mash.

[0005] Solid-state distillation of liquor is different from Western liquid distillation. It directly puts solid fermentation materials into the retort barrel to form a unique production process of multi-layer concentration by the tower plate effect. It is one of the important links to give liquor its unique flavor. It has high efficiency and heterogeneity of mass transfer and heat transfer. Since solid-state distillation of liquor is accompanied by the distillation of high-concentration ethanol, the mass transfer of the entire system is affected by the "solvent effect", which is complex and difficult to control.

[0006] Therefore, developing a method suitable for solid-state distillation of liquor to reduce cyanide and EC has extremely high practical value and economic value. Summary of the invention

[0007] To solve the above problems, the present invention adjusts the process parameters in the actual production of solid-state distillation of Luzhou-flavor liquor, analyzes the changes in the content of cyanide and EC actually distilled into the liquor body due to changes in different process parameters, and analyzes the main influence of the process parameters after adjustment by characterizing the unit extraction efficiency of cyanide, ethanol and EC under different production conditions. The change rules and influencing factors are analyzed based on the conversion mechanism and the unique mass transfer and heat transfer process of solid-state distillation of liquor. At the same time, attention is paid to the distillate concentration of the main flavor substances of liquor, and the influence of different production parameters on the main flavor substances of liquor is summarized. The control level of cyanide and EC under different production conditions is associated with the impact on flavor. The characteristic control method of solid-state distillation is adopted to provide reference and help for controlling cyanide and EC under the premise of reducing the uniqueness and integrity of liquor flavor.

[0008] The first object of the present invention is to provide a method for reducing the content of harmful substances in the solid-state distillation process of liquor, wherein the harmful substances are one or two of cyanide and ethyl formate; the method comprises:

[0009] The mash is mixed with auxiliary materials in a mass ratio of 100:0.5-5, and solid distillation is carried out under the conditions of a retort height of 50-75 cm and a steam pressure of 0.008-0.032 MPa.

[0010] In one embodiment, the method comprises:

[0011] Mix the fermented grains with auxiliary materials in a mass ratio of 100:3.5-4.5, and perform solid distillation at a retort height of 54-56 cm and a steam pressure of 0.008-0.012 MPa; or,

[0012] Mix the fermented grains with auxiliary materials in a mass ratio of 100:3.5-4.5, and perform solid distillation at a retort height of 68-72 cm and a steam pressure of 0.028-0.032 MPa; or,

[0013] The mash is mixed with auxiliary materials in a mass ratio of 100:0.8-1.2, and solid distillation is carried out under the conditions of a retort height of 68-72 cm and a steam pressure of 0.008-0.012 MPa.

[0014] The second object of the present invention is to provide a method for simultaneously improving the ethanol extraction efficiency and reducing the ethyl formate extraction rate during the solid-state distillation of liquor, the method comprising:

[0015] The fermented grains are mixed with auxiliary materials and distilled in the solid state at a retort height of 50 to 60 cm;

[0016] Optionally, the retort height is 54 to 56 cm.

[0017] In one embodiment, the mass ratio of the fermented grains to the auxiliary materials is 100:3-5;

[0018] Optionally, the mass ratio of the mash to the auxiliary materials is 100:3.5-4.5.

[0019] In one embodiment, the steam pressure of solid state distillation is 0.008 to 0.012 MPa;

[0020] Optionally, the steam pressure is 0.01 MPa.

[0021] The third object of the present invention is to provide a method for simultaneously reducing the extraction efficiency of cyanide and ethyl formate in the solid-state distillation process of liquor, the method comprising:

[0022] The fermented grains and auxiliary materials are mixed in a mass ratio of 100:0.5-2, and solid-state distillation is performed;

[0023] Optionally, the mass ratio of the mash to the auxiliary materials is 100:0.8-1.2.

[0024] In one embodiment, the solid state distillation retort height is 60 to 80 cm;

[0025] Optionally, the solid state distillation retort has a height of 65 to 75 cm.

[0026] In one embodiment, the steam pressure of solid state distillation is 0.008 to 0.012 MPa;

[0027] Optionally, the steam pressure is 0.01 MPa.

[0028] The fourth object of the present invention is to provide a method for simultaneously reducing the extraction efficiency of ethyl formate and increasing the distillation amount of caproic acid during the solid-state distillation of liquor, the method comprising:

[0029] The fermented grains are mixed with auxiliary materials and solid-state distilled under a steam pressure of 0.02 to 0.03 MPa;

[0030] Optionally, the mass ratio of the fermented grains to the auxiliary materials is 100:3.5-4.5;

[0031] Optionally, the solid state distillation retort has a height of 65 to 75 cm.

[0032] A fifth object of the present invention is to provide application of any of the above methods in solid-state distillation of liquor.

[0033] Beneficial effects of the present invention

[0034] (1) Based on the unique operating process of the solid-state distillation process of liquor, this paper changes the main operating parameters of the process (steam pressure, retort height, and auxiliary material ratio). It is found that by reducing the retort height to 55 cm, the EC content of the distilled liquor can be reduced by 53.94%; by reducing the auxiliary materials to 1% w / w, the cyanide content can be reduced by 36.15%; at the same time, the adjustment of the above parameters has little effect on the overall main flavor substances of the liquor.

[0035] (2) The present invention increases the distillation concentration of caproic acid by 64.72% while reducing the EC content by increasing the steam pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The effect of different retort heights on the extraction efficiency of cyanide, ethanol extract and EC;

[0037] Figure 2 The effects of different steam pressures on the extraction efficiency of cyanide, ethanol extracts, and EC;

[0038] Figure 3 The effects of different auxiliary material dosages on the extraction efficiency of cyanide, ethanol extract, and EC;

[0039] Figure 4 The effect of different steamer heights on flavor components;

[0040] Figure 5 The effect of different steam pressures on flavor components;

[0041] Figure 6 The effect of different amounts of auxiliary materials on flavor components. DETAILED DESCRIPTION

[0042] The preferred embodiments of the present invention are described below. It should be understood that the embodiments are for better explaining the present invention and are not used to limit the present invention.

[0043] The raw materials, equipment, and detection platform used in the examples are funded by the National Key R&D Program of China “Research and Demonstration of Intelligent Manufacturing Technology for Traditional Brewed Food”, project number (2022YFD2101200).

[0044] Detection Methods

[0045] 1. Determination of cyanide content in cumulative mixed samples by headspace gas chromatography-mass spectrometry

[0046] The method of reference (Determination of cyanide content in liquor by headspace gas chromatography, Journal of Food Safety and Quality, 2019, 10(01): 240-4) was used to pretreat the original liquor sample. The steps are as follows:

[0047] Accurately pipette 0.1 mL of the sample into the headspace bottle, add 0.15 mL of sodium hydroxide solution (1 mg / mL), let it stand for 5 min (to stabilize), add 4.75 mL of ultrapure water, then add 0.1 mL of phosphoric acid solution (1:5, v / v), then add 0.1 mL of chloramine T solution (10 mg / mL), seal the vial with a polytetrafluoroethylene / silicone septum and a screw cap, and shake for 3 min before testing. All analytical samples were performed in triplicate.

[0048] Instrument headspace conditions: headspace equilibrium temperature is 60°C; sampling needle temperature is 65°C; headspace heating time is 10 min, injection interval is 16 min; injection volume is 0.5 mL.

[0049] Instrumental chromatographic conditions: The chromatographic column is a DB-FFAP capillary column (60m×0.25mm×0.25μm); the chromatographic column flow rate is 1.4mL / min; the chromatographic column temperature is 40.0℃. The column oven temperature program is 40℃ for 2min, then rise to 60℃ at a rate of 20℃ / min, and hold for 2min; then rise to 200℃ at a rate of 50℃ / min, and hold for 2min. The injection mode is split (10:1); the injection port temperature is 200℃. The carrier gas is He; the purge flow rate is 3.0mL / min.

[0050] Instrument mass spectrometry conditions: ion source temperature, 230°C; interface temperature, 220°C; solvent delay time, 3 min; scanning ions m / z: 61, 63, 35, 26; quantitative ion m / z: 61.

[0051] Dilute GBW(E)080115 water cyanide component analysis standard substance (50g / mL) to 1g / mL with 0.1% sodium hydroxide solution, and then dilute with water to prepare a series of concentrations of standard solutions. After GC-MS analysis, draw a standard curve with CN-peak area as the horizontal axis and mass concentration as the vertical axis. Quantitative analysis is performed using the external standard method.

[0052] 2. Determination of EC content of cumulative mixed samples by liquid-liquid extraction combined with gas chromatography-mass spectrometry

[0053] The method of reference (Rapid detection and risk assessment of ethyl carbamate in Maotai-flavor liquor; Food Industry, 2021, 42(01): 327-30) was used to pretreat the original liquor sample. The steps are as follows:

[0054] Accurately transfer 2.0 mL of wine sample into a centrifuge tube, then transfer 50 μL (5 μg / mL) of ethyl carbamate internal standard (EC-d5), add 0.5 g NaCl, vortex to dissolve and mix, accurately add 2.0 mL of ethyl acetate, and extract by oscillation for 5 minutes. Take the supernatant, dehydrate with anhydrous sodium sulfate, filter with a 0.22 μm organic filter head, and wait for GC-MS analysis.

[0055] Chromatographic conditions: The chromatographic column was a DB-FFAP capillary column (60m×0.25mm×0.25μm); the injection port temperature was 220℃; the carrier gas was He, purity>99.999%, the flow rate was 1.4mL / min, the injection mode was splitless injection, and the injection volume was 1μL. The column oven temperature program was 50℃ for 2min, increased to 170℃ at a rate of 5℃ / min, and then increased to 230℃ at a rate of 10℃ / min. Mass spectrometry conditions The ion source voltage was 70eV, the ion source temperature was 230℃, the scanning range was m / z: 35-350, and the selected ion monitoring (SIM) mode was used. EC scanning ions m / z: 44, 62 and 89, quantitative ion m / z: 62, EC-d5 scanning ions m / z: 64, 44 and 89, quantitative ion m / z: 64.

[0056] Standard curve: EC and EC-d5 standards were diluted to a concentration of 1.0 mg / mL with chromatographic methanol, and then gradiently diluted with 60% vol ethanol aqueous solution to prepare a series of standard solutions. GC-MS analysis was performed in the same manner as for wine samples. The standard curve was drawn with the ratio of the peak area of ​​EC to the internal standard EC-d5 as the abscissa and the ratio of the mass concentration as the ordinate.

[0057] 3. Direct injection combined with gas chromatography-hydrogen flame ionization detector to quantitatively accumulate the main aroma components of mixed samples

[0058] GC-FID analysis was performed on an Agilent 7890A gas chromatograph equipped with a hydrogen flame ionization detector, and the chromatographic column was a CP-WAX 57CB column (50m×0.25mm×0.20μm, Agilent). 1mL of the diluted wine sample was placed in a 2mL screw-top sample bottle, and 50μL of mixed internal standards (tert-amyl alcohol, 111.04mg / L; n-amyl acetate, 125.50mg / L; 2-ethylbutyric acid, 102.57mg / L) was added, then sealed with a hollow screw cap equipped with a PTFE / silicone rubber septum, shaken well, and 1μL was injected.

[0059] The chromatographic conditions were as follows: the column oven was equilibrated at an initial temperature of 35°C for 5 min, then heated to 100°C at 4°C / min, maintained for 2 min, then heated to 150°C at 8°C / min, and finally heated to 200°C at 15°C / min, maintained for 25 min. The GC inlet temperature was 250°C, the injection mode was split mode, and the split ratio was 20:1. The temperature program was carried out in constant flow mode, the carrier gas was high-purity helium (purity>99.9995%), and the flow rate was 1 mL / min. The FID detector temperature was 250°C.

[0060] Drawing of standard curve: This study used the internal standard-standard curve method for quantitative analysis. 1g / L lactic acid was added to a 50%vol ethanol-water solution to prepare the matrix solution for the standard curve. According to the characteristics of the compound to be tested and its detection method, several mixed standard stock solutions were prepared. A certain amount of the standard of the compound to be tested was dissolved in the matrix solution to prepare a high-concentration standard stock solution. The standard stock solution was then diluted step by step with the matrix solution to prepare a series of standard solutions with concentration gradients, requiring at least 6 concentration gradients. Each standard solution sample was analyzed according to the above-mentioned sample detection method. The mass concentration ratio and peak area ratio of the standard to be tested and the internal standard were used as the horizontal and vertical coordinates to draw the standard curve of each analyte.

[0061] 4. Calculation method

[0062] EC extraction efficiency is as follows:

[0063]

[0064] F is the unit extraction efficiency; C is the mass concentration of the target substance, μg / L; V is the cumulative volume of the mixed wine sample, L; M is the weight of the input mash, kg.

[0065] Flavor distillate concentration:

[0066]

[0067] V1 is the converted volume, L; V2 is the cumulative mixed sample volume, L; C2 is the cumulative alcohol content of the mixed wine sample, %.

[0068] Example 1

[0069] 1. The existing distillation method has the following steps:

[0070] Take the mash, add 4% of the weight of the mash (rice husk) as auxiliary material, and mix well; fill the retort at a height of 70 cm and distill at a steam pressure of 0.01 MPa until the wine is completely extracted.

[0071] 2. A method for reducing the content of harmful substances in solid-state distillation of liquor by reducing the height of the retort, the steps are as follows:

[0072] Take the mash, add 4% of the weight of the mash (rice husk) as auxiliary material, and mix well; fill the retort at a height of 55 cm and distill at a steam pressure of 0.01 MPa until the wine is completely extracted.

[0073] 3. A method for reducing the content of harmful substances in solid-state distillation of liquor by increasing steam pressure, comprising the steps of:

[0074] Take the mash, add 4% of the weight of the mash (rice husk) as auxiliary material, and mix well; fill the retort at a height of 70 cm and distill at a steam pressure of 0.03 MPa until the wine is completely extracted.

[0075] 4. A method for reducing the content of harmful substances in solid-state distillation of liquor by reducing the amount of auxiliary materials added, comprising the steps of:

[0076] Take the mash, add 1% of the weight of the mash (rice husk) as auxiliary material, and mix well; fill the retort at a height of 70 cm and distill at a steam pressure of 0.01 MPa until the wine is completely extracted.

[0077] Comparative Example 1

[0078] Raising the retort loading height comprises the following steps:

[0079] Take the mash, add 4% of the weight of the mash (rice husk) as auxiliary material, and mix well; fill the retort at a height of 85 cm and distill at a steam pressure of 0.01 MPa until the wine is completely extracted.

[0080] Comparative Example 2

[0081] Increasing the steam pressure comprises the steps of:

[0082] Take the mash, add 4% of the weight of the mash (rice husk) as auxiliary material, and mix well; fill the retort at a height of 70 cm and distill at a steam pressure of 0.02 MPa until the wine is completely extracted.

[0083] Comparative Example 3

[0084] Increasing the amount of excipients, including steps:

[0085] Take the mash, add 7% of the weight of the mash (rice husk) as auxiliary material, and mix well; fill the retort at a height of 70 cm and distill at a steam pressure of 0.01 MPa until the wine is completely extracted.

[0086] Example 2

[0087] The wine samples obtained by distillation in Example 1 and Comparative Examples 1 to 3 were taken for quality testing.

[0088] 1. Ethanol distillation detection

[0089] Table 1 Ethanol distillate and alcohol content

[0090]

[0091] As one of the most basic extracting substances in liquor, ethanol is volatile and relatively stable, and exhibits a relatively stable extraction effect under various conditions. The results show that the control process parameters are adjusted within a very reasonable range in actual production, which has little effect on the ethanol extraction rate, that is, the control scheme in Example 1 has little effect on the wine yield in actual production, and the economic cost is objective. Taking the wine yield as the measurement standard meets the production needs of the winery.

[0092] 2. Cyanide, ethanol, and EC extraction efficiency testing

[0093] (1) Effect of retort height on extraction efficiency of cyanide, ethanol and EC

[0094] Take the wine samples obtained by distillation of 1 and 2 in Example 1 and Comparative Example 1, and test the extraction efficiency of cyanide, ethanol and EC. The results are as follows: Figure 1 And as shown in Table 2.

[0095] The results showed that with the increase of the retort height, the cyanide extraction efficiency showed an insignificant downward trend, from 17.24μg / kg to 15.61μg / kg; the ethanol extraction efficiency showed a more obvious downward trend than cyanide, from 66.98g / kg to 55.12g / kg; the EC extraction efficiency increased significantly with the increase of the retort height, from 0.61μg / kg to 3.19μg / kg.

[0096] The retort height affects the mass transfer distance and time between the components and the solid material. Ethanol and cyanide are volatile in themselves, and a higher solid material mass transfer distance has no significant effect on the mass transfer process of the two. The low volatility of EC allows it to have a more stable mass transfer effect at a higher retort height system (85 cm), thereby improving the extraction efficiency of EC.

[0097] Therefore, reducing the retort height can significantly reduce the EC extraction efficiency.

[0098] (2) Effect of steam pressure on the extraction efficiency of cyanide, ethanol and EC

[0099] Take the wine samples obtained by distillation of 1 and 3 in Example 1 and Comparative Example 2, and test the extraction efficiency of cyanide, ethanol and EC. The results are as follows: Figure 2 And as shown in Table 2.

[0100] The results showed that with the increase of steam pressure, the extraction efficiency of cyanide and ethanol showed an insignificant downward trend, the cyanide extraction efficiency decreased from 23.32μg / kg to 20.77μg / kg; the ethanol extraction efficiency decreased from 64.08g / kg to 54.57g / kg; the EC extraction efficiency showed a clear downward trend, the extraction efficiency decreased from 3.86μg / kg to 1.32μg / kg.

[0101] Cyanide will form EC with high concentration ethanol in the distillation process, but due to the low conversion rate, the distillation amount of cyanide in the solid distillation process is mainly affected by the mass transfer process. Compared with cyanide, EC is more affected by chemical conversion and is less volatile. In the process of increasing steam pressure, the distillation rate of each component is accelerated, resulting in a decrease in the reaction time of cyanide and ethanol, and the generated EC is also reduced.

[0102] Therefore, increasing the steam pressure can reduce the extraction and conversion of EC.

[0103] (3) Effect of auxiliary material addition on the extraction efficiency of cyanide, ethanol and EC

[0104] Take the wine samples obtained by distillation of Example 1, 4 and Comparative Example 5, and test the extraction efficiency of cyanide, ethanol and EC. The results are as follows: Figure 3 And as shown in Table 2.

[0105] The results showed that with the increase of auxiliary material input, the extraction efficiency of cyanide, ethanol and EC showed a significant upward trend. The extraction efficiency of cyanide increased from 10.46μg / kg to 20.35μg / kg; the extraction efficiency of ethanol increased from 81.10g / kg to 112.81g / kg; the extraction efficiency of EC increased from 1.25μg / kg to 5.22μg / kg.

[0106] The input of auxiliary materials enhances the looseness and porosity of solid materials, so that the mass transfer effect of most components of liquor solid distillation is enhanced with the increase of auxiliary materials. The increase of auxiliary materials makes cyanide, ethanol and EC have better mass transfer effect, and the extraction efficiency of the three is enhanced, among which the increase of EC extraction efficiency is the most obvious. It may be because the extraction effect of the two reaction precursors, cyanide and ethanol, is more ideal, resulting in an increase in the reaction intensity of conversion to EC, which leads to more significant physical extraction effect and chemical conversion effect of EC with the input of auxiliary materials, so that the extraction efficiency of EC increases most significantly.

[0107] Therefore, reducing the input of auxiliary material ratio can also limit the extraction effect of cyanide and EC.

[0108] Table 2 Extraction effects of cyanide and EC

[0109]

[0110] Note: Superscript a, b, c indicate significance, and different superscripts indicate significant differences.

[0111] 3. Flavor component detection

[0112] (1) The influence of the filling height on the flavor of wine

[0113] Take the wine samples obtained by distillation of 1 and 2 in Example 1 and Comparative Example 1, and detect the flavor components in the wine samples. The results are as follows: Figure 4 shown.

[0114] The results show that with the increase of the retort height, the concentrations of ethyl acetate and caproic acid show a significant increasing trend, with ethyl acetate increasing from 212.53 mg / L to 321.10 mg / L; caproic acid increasing from 693.81 mg / L to 1122.08 mg / L. The rising and falling trends of the concentration changes of other components are not obvious.

[0115] It can be seen that lowering the height of the steamer can have a smaller impact on the distillation concentration of liquor flavor components.

[0116] (2) Effect of vapor pressure on wine flavor

[0117] Take the wine samples obtained by distillation of 1 and 3 in Example 1 and Comparative Example 2, and detect the flavor components in the wine samples. The results are as follows: Figure 5 shown.

[0118] The results show that with the increase of steam pressure, the distillate concentrations of ethyl acetate, ethyl lactate, acetic acid and caproic acid show an upward trend. The change trend of ethyl butyrate is not significant, and the distillate concentrations of ethyl caproate and butyric acid show a downward trend. Among them, the concentration of caproic acid increases significantly when the steam pressure is increased from 0.01MPa to 0.02MPa, from 178.59mg / L to 598.46mg / L. Butyric acid shows a significant downward trend, from 432.02mg / L to 236.50mg / L; the concentration changes of the other components with the adjustment of steam pressure are relatively stable.

[0119] It can be seen that adjusting the steam pressure has little effect on the flavor of the wine.

[0120] (3) Effect of the amount of auxiliary materials added on the flavor of wine

[0121] Take the wine samples obtained by distillation of 1 and 4 in Example 1 and Comparative Example 3, and detect the flavor components in the wine samples. The results are as follows: Figure 6 shown.

[0122] The results showed that with the addition of auxiliary materials, the distillate concentration of hexanoic acid showed a downward trend, from 769.72 mg / L to 288.39 mg / L. The concentrations of other flavor components showed an upward trend to a certain extent, among which the changes of acetic acid and butyric acid were more significant, with acetic acid increasing from 2542.66 mg / L to 3746.34 mg / L; butyric acid increased from 90.88 mg / L to 223.06 mg / L.

[0123] It can be seen that reducing the input of auxiliary materials can effectively limit the distillation of cyanide and EC into the wine, increase the hexanoic acid content, and reduce the acetic acid and butyric acid contents.

[0124] (4) Total amount of esters, alcohols and acids

[0125] The main flavor components of liquor are an important part of the characteristic flavor system of liquor. This paper analyzes the influence of different process parameters on the concentration of the main flavor components of the cumulative mixed sample. According to the types of flavor substances, the flavor integrity is evaluated after adjusting different parameters according to the change trend and significance of ester compounds, alcohol compounds, and acid compounds, and the total acid, total ester, and total alcohol of the liquor sample are used to show the overall impact on the flavor.

[0126] Three batches of mash were prepared (for detecting the effects of different steam pressures, retort heights and auxiliary material ratios on the total amount of flavor substances). The total amount of esters, alcohols and acids in the distilled liquor samples were detected according to the methods of Example 1 and Comparative Examples 1 to 3. The results are shown in Table 3.

[0127] Table 3 Total amount of esters, alcohols and acids

[0128]

[0129] Note: Superscript a, b, c indicate significance, and different superscripts indicate significant differences.

[0130] The results show that, compared with increasing the retort height (85cm), lowering the retort height (55cm) has no significant effect on the overall flavor content of liquor; appropriately increasing the steam pressure (0.02, 0.03MPa) has little effect on the overall flavor of liquor, and both can be used as control measures in actual production; and adjusting the auxiliary material ratio has a relatively greater impact on the overall flavor of liquor compared with the above two parameters. According to the significance analysis, reducing the amount of auxiliary materials has no significant effect on the flavor substances, while increasing the amount of auxiliary materials will have a greater impact on the flavor substances.

[0131] The above results show that lowering the retort height, increasing the steam pressure and reducing the amount of auxiliary materials have limited effects on the actual distillate fractions and are feasible in actual production.

[0132] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for reducing the content of harmful substances in the solid-state distillation process of liquor, characterized in that: The harmful substance is one or both of cyanide and ethyl carbamate; the method comprises: The mash is mixed with auxiliary materials in a mass ratio of 100:0.5-5, and solid distillation is carried out under the conditions of a retort height of 50-75 cm and a steam pressure of 0.008-0.032 MPa.

2. The method according to claim 1, characterized in that The method comprises: Mix the fermented grains with auxiliary materials in a mass ratio of 100:3.5-4.5, and perform solid distillation at a retort height of 54-56 cm and a steam pressure of 0.008-0.012 MPa; or, Mix the fermented grains with auxiliary materials in a mass ratio of 100:3.5-4.5, and perform solid distillation at a retort height of 68-72 cm and a steam pressure of 0.028-0.032 MPa; or, The mash is mixed with auxiliary materials in a mass ratio of 100:0.8-1.2, and solid distillation is carried out under the conditions of a retort height of 68-72 cm and a steam pressure of 0.008-0.012 MPa.

3. A method for simultaneously improving the ethanol extraction efficiency and reducing the ethyl formate extraction rate in the solid-state distillation process of liquor, characterized in that: The method comprises: The fermented grains are mixed with auxiliary materials and distilled in the solid state at a retort height of 50 to 60 cm; Optionally, the retort height is 54 to 56 cm.

4. The method according to claim 3, characterized in that The mass ratio of fermented grains to auxiliary materials is 100:3-5; Optionally, the mass ratio of the mash to the auxiliary materials is 100:3.5-4.

5.

5. The method according to claim 3, characterized in that: The steam pressure of solid distillation is 0.008~0.012MPa; Optionally, the steam pressure is 0.01 MPa.

6. A method for simultaneously reducing the extraction efficiency of cyanide and ethyl formate in the solid-state distillation process of liquor, characterized in that: The method comprises: The fermented grains and auxiliary materials are mixed in a mass ratio of 100:0.5-2, and solid-state distillation is performed; Optionally, the mass ratio of the mash to the auxiliary materials is 100:0.8-1.

2.

7. The method according to claim 6, characterized in that The height of the retort for solid-state distillation is 60 to 80 cm; Optionally, the solid state distillation retort has a height of 65 to 75 cm.

8. The method according to claim 6, characterized in that The steam pressure of solid distillation is 0.008~0.012MPa; Optionally, the steam pressure is 0.01 MPa.

9. A method for simultaneously reducing the extraction efficiency of ethyl formate and increasing the distillation amount of caproic acid during the solid-state distillation of liquor, characterized in that: The method comprises: The fermented grains are mixed with auxiliary materials and solid-state distilled under a steam pressure of 0.02 to 0.03 MPa; Optionally, the mass ratio of the fermented grains to the auxiliary materials is 100:3.5-4.5; Optionally, the solid state distillation retort has a height of 65 to 75 cm.

10. Use of the method according to any one of claims 1 to 9 in the solid-state distillation of liquor.

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