Method for removing cyanide and reducing ethyl carbamate in strong-flavor liquor during distillation

Abstract

The present application provides a method for removing cyanide and reducing ethyl carbamate in strong-flavor liquor during distillation, which comprises: taking fermented grains as raw materials, and performing membrane filtration on wine steam before the wine steam enters a condensing device during distillation of the fermented grains to obtain liquor after condensation of the filtered wine steam; the membrane used for filtration comprises a base film and a coating attached to the surface of the base film, and the coating comprises PEG-NH2 modified nano-silver. The above method can greatly reduce the content of ethyl carbamate in liquor, and can also remove cyanide to some extent, and has little effect on the organoleptic effect of the liquor.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of liquor brewing, in particular to a method for removing cyanide and ethyl carbamate in strong-flavor liquor during distillation. BACKGROUND

[0002] Ethyl carbamate (EC) is also known as urethane, which is a kind of pollutant naturally produced in the fermentation and storage process of food, and alcoholic beverages are the main source of dietary intake of ethyl carbamate, which is listed as a 2A carcinogen by the International Agency for Research on Cancer. The research on EC in wine products at home and abroad mainly occurred before 1992, and mainly concentrated in foreign countries. Canada formulated the limit standard of ethyl carbamate in various alcoholic beverages in 1985. The research on controlling the EC content of wine products in China did not really start until 2006. On the one hand, it is difficult to ensure the flavor quality of traditional wine products and control the EC content in the process of continuing the traditional brewing process. On the other hand, there is no limit standard for EC in wine products in China, and there is no safety evaluation of the EC content in the process of wine product processing and sales, which leads to the late start of systematic research on the control of EC in wine products. Since 2011, the research on the control of EC in wine products has gradually increased. According to the analysis of the literature reports in recent years, the precursor substances of EC in liquor mainly include urea, citrulline and cyanide, which are mainly generated by the reaction of precursor cyanide and ethanol during the storage stage.

[0003] Therefore, the maximum removal of cyanide and ethyl carbamate during the brewing stage of liquor can effectively reduce the generation of ethyl carbamate during the aging process of liquor and reduce the quality risk of liquor. SUMMARY

[0004] Therefore, the present application provides a method for removing cyanide and reducing ethyl carbamate in strong-flavor liquor during distillation, which aims to remove or reduce the ethyl carbamate and the main precursor of ethyl carbamate, cyanide, in the wine steam during the distillation stage of wine dregs, so as to improve the wine quality and ensure the quality safety of liquor.

[0005] The technical scheme of the present application is realized as follows: the present application provides a method for removing cyanide and reducing ethyl carbamate in strong-flavor liquor during distillation, which comprises the following steps:

[0006] The wine dregs are used as raw materials, and the wine steam is subjected to membrane filtration treatment before entering the condensing equipment during the distillation of wine dregs to obtain liquor after condensation of the filtered wine steam; the membrane for filtration comprises a base film and a coating layer attached to the surface of the base film, and the coating layer comprises PEG-NH2 modified nano-silver.

[0007] In some embodiments, the average particle size of the PEG-NH2 modified nano-silver is 5-20 nm.

[0008] In some embodiments, the PEG-NH2 modified nano-silver is purchased from Xi'an Qiyue Biology.

[0009] In some embodiments, the coating further comprises modified zeolite.

[0010] In some embodiments, the preparation method of the modified zeolite comprises: dissolving cetyltrimethylammonium chloride in water to obtain a modified aqueous solution, heating the zeolite to 100℃, holding for 10-30 s, then naturally cooling, soaking the cooled zeolite in the modified aqueous solution, ultrasonic treatment for 10 min, and filtering and drying to obtain the modified zeolite.

[0011] In some embodiments, the base membrane is a ceramic membrane or a polymer membrane, and the pore size of the base membrane is 50-200 nm.

[0012] In some embodiments, during the filtration process, the vacuum degree on the permeation side of the membrane is -0.05 MPa.

[0013] In some embodiments, the preparation method of the coating comprises: mixing the functional components such as PEG-NH2 modified nano-silver and / or modified zeolite with pore-forming agents, binders, dispersants and solvents, then coating on the surface of the base membrane, and drying to obtain the coating, wherein the mass ratio of each component is: PEG-NH2 modified nano-silver and / or modified zeolite: pore-forming agent: binder: dispersant: solvent = 50:10:5:3:20.

[0014] In the above examples, the pore-forming agent is ammonium bicarbonate, the binder is carboxymethyl cellulose, the dispersant is polyacrylic acid, and the solvent is ethanol.

[0015] In some embodiments, when both PEG-NH2 modified nano-silver and modified zeolite are present, the mass ratio of PEG-NH2 modified nano-silver to modified zeolite is 1:1.

[0016] In some embodiments, the present application also provides a distillation device, comprising a wine retort, a filter membrane and a condenser, the gas outlet of the wine retort is communicated with the gas inlet of the condenser, and the filter membrane is arranged between the gas outlet of the wine retort and the condenser.

[0017] The present application has the following beneficial effects compared with the prior art:

[0018] The present application directly filters the liquor steam in the distillation link by adding a filter membrane between the wine retort and the condenser, thereby greatly reducing the content of ethyl carbamate in the filtered liquor, and when the modified zeolite used in the present application is further included in the coating of the membrane, the cyanide can be completely removed, and since the cyanide is a precursor of the ethyl carbamate generated in the later period, after the scheme is adopted, the ethyl carbamate will not increase substantially during the later aging. The method does not have any effect on the flavor of the liquor, and does not need to be distilled twice, greatly reducing the energy consumption, and simplifying the subsequent impurity removal process of the liquor body, reducing the production cost, and the operation is also simpler. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the application belong. If the definitions set forth in this section are contrary to or otherwise inconsistent with the definitions set forth in the patents, patent applications, published patent applications, and other publications that are herein incorporated by reference, the definitions set forth in this section are preferred.

[0021] The methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents and instruments used are conventional materials, reagents and instruments in the art unless otherwise specified, and can be obtained by commercial channels by those skilled in the art.

[0022] When a range, a preferred range, or other values or parameters are expressed in a range format, it is to be understood that the description is for the full range as well as for any sub-ranges within the range. For example, where a range of "1 to 5" is described, it is to be understood that this description applies to the full range as well as to the sub-ranges "1 to 4," "1 to 3," "1 to 2," "1 to 2," and "4 to 5," "1 to 3 and 5," etc. Where a range of values is provided, it is intended to include all values between the upper and lower limits of the range, unless the context clearly indicates otherwise. In the application description and in the claims, range limitations can be combined and / or interchanged, unless the context clearly indicates otherwise. Such ranges are intended to include the endpoints of the range, unless the context clearly indicates otherwise.

[0023] Select one pit two canteen middle layer of fermented grains mixed, then divided into six, the following examples and comparative examples of raw materials fermented grains are selected from the six fermented grains

[0024] Example 1

[0025] Coating preparation:

[0026] Respectively take 50g PEG-NH2 modified nano-silver (average particle size 10nm), 10g ammonium bicarbonate, 5g carboxymethyl cellulose, 3g polyacrylic acid and 20g ethanol, mixed uniformly to obtain coating slurry.

[0027] Film preparation:

[0028] The above coating slurry is uniformly coated on the surface of the alumina ceramic membrane (membrane pore size is 100nm), and then dried at 70℃ to constant weight, to obtain a membrane with coating.

[0029] The wine retort is heated to 75℃, and the generated wine vapor is passed through the membrane into the condenser for condensation. The cooling medium temperature in the condenser is-20℃, and the vacuum degree in the space between the condenser and the membrane is-0.05MPa. The condensate is cut off and the body of the wine is retained.

[0030] Example 2

[0031] Modified zeolite preparation:

[0032] Dissolve 10g cetyltrimethylammonium chloride in 100ml water to obtain a modified aqueous solution; heat the zeolite to be modified to 100℃, and keep it at this temperature for 20s, then naturally cool it. The cooled zeolite is soaked in the modified aqueous solution while being ultrasonically treated for 10min. After filtration and drying, the modified zeolite is obtained. The modified zeolite is crushed to an average particle size of 5μm.

[0033] Coating preparation:

[0034] Respectively take 25g PEG-NH2 modified nano-silver (average particle size 10nm), 25g modified zeolite powder, 10g ammonium bicarbonate, 5g carboxymethyl cellulose, 3g polyacrylic acid and 20g ethanol, mixed uniformly to obtain coating slurry.

[0035] Film preparation:

[0036] The above coating slurry is uniformly coated on the surface of the alumina ceramic membrane (membrane pore size is 100nm), and then dried at 70℃ to constant weight, to obtain a membrane with coating.

[0037] The wine retort is heated to 75℃, the generated wine vapor is passed through the membrane into the condenser for condensation, the cooling medium temperature in the condenser is -20℃, the vacuum degree in the space between the condenser and the membrane is -0.05MPa, the head and tail of the condensed wine liquid are removed, and the wine body is reserved.

[0038] Example 3

[0039] Modified zeolite preparation:

[0040] Dissolve 10g of cetyltrimethylammonium chloride in 100ml of water to obtain a modified aqueous solution; heat the zeolite to be modified to 100℃, heat treatment for 20s, then naturally cool, soak the cooled zeolite in the modified aqueous solution, and ultrasonic treatment for 10min, filter and dry to obtain modified zeolite, and crush the modified zeolite to an average particle size of 5μm.

[0041] Coating preparation:

[0042] Respectively take 50g of modified zeolite powder, 10g of ammonium bicarbonate, 5g of carboxymethyl cellulose, 3g of polyacrylic acid and 20g of ethanol, mix uniformly to obtain a coating slurry.

[0043] Membrane preparation:

[0044] Uniformly coat the above coating slurry on the surface of the alumina ceramic membrane (membrane pore size is 100nm), then dry at 70℃ to constant weight to obtain a membrane with coating.

[0045] The wine retort is heated to 75℃, the generated wine vapor is passed through the membrane into the condenser for condensation, the cooling medium temperature in the condenser is -20℃, the vacuum degree in the space between the condenser and the membrane is -0.05MPa, the head and tail of the condensed wine liquid are removed, and the wine body is reserved.

[0046] Comparative Example 1

[0047] An alumina ceramic membrane with a membrane pore size of 100nm is used.

[0048] The wine retort is heated to 75℃, the generated wine vapor is passed through the membrane into the condenser for condensation, the cooling medium temperature in the condenser is -20℃, the vacuum degree in the space between the condenser and the membrane is -0.05MPa, the head and tail of the condensed wine liquid are removed, and the wine body is reserved.

[0049] Comparative Example 2

[0050] The wine retort is heated to 75℃, the generated wine vapor is directly passed into the condenser for condensation, the cooling medium temperature in the condenser is -20℃, the head and tail of the condensed wine liquid are removed, and the wine body is reserved.

[0051] Comparative Example 3

[0052] Coating preparation:

[0053] 50 g of zeolite powder (average particle size 5 μm), 10 g of ammonium bicarbonate, 5 g of carboxymethyl cellulose, 3 g of polyacrylic acid and 20 g of ethanol were weighed respectively, and after being mixed uniformly, a coating slurry was obtained.

[0054] Membrane preparation:

[0055] The above coating slurry was uniformly coated on the surface of an alumina ceramic membrane (membrane pore size 100 nm), and then dried at 70 DEG C to constant weight, to obtain a membrane with a coating.

[0056] The wine retort was heated to 75 DEG C, and the generated wine vapor was passed through the membrane into the condenser for condensation, the cooling medium temperature in the condenser was -20 DEG C, and the vacuum degree in the space between the condenser and the membrane was -0.05 MPa. The head and tail of the condensed wine were removed, and the body of the wine was retained.

[0057] The wine body obtained in the above examples and comparative examples was subjected to related substance detection and sensory evaluation, and the obtained wine body was subjected to high temperature condition accelerated simulation storage for one year, and the accelerated wine body was subjected to related substance detection, to obtain the results shown in the following table:

[0058]

[0059] From the above data, it is not difficult to see that after the distillation treatment of the fermented grains by the gaseous wine membrane process of the present application, the content of ethyl carbamate is greatly reduced, and when the modified zeolite is present in the membrane, the content of cyanide is greatly reduced, and when the modified zeolite and PEG-NH2 modified nano-silver are present in the membrane at the same time, the removal effect of cyanide and ethyl carbamate is greatly improved, cyanide can be completely removed, a small amount of ethyl carbamate is left, and the influence on the flavor of the wine is small.

[0060] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for removing cyanide and reducing ethyl carbamate in strong-aroma baijiu during distillation, characterized in that, Includes the following steps: Using fermented mash as raw material, during the distillation of the mash, the alcohol vapor is subjected to membrane filtration before entering the condensation equipment. The filtered alcohol vapor is then condensed to obtain baijiu (Chinese white liquor). The filtration membrane consists of a base membrane and a coating attached to the surface of the base membrane. The coating includes PEG-NH2 modified silver nanoparticles. The membrane preparation method includes: Preparation of modified zeolites: 10g of hexadecyltrimethylammonium chloride was dissolved in 100ml of water to obtain a modified aqueous solution; the zeolite to be modified was heated to 100℃ and kept at that temperature for 20s, then cooled naturally. The cooled zeolite was then immersed in the modified aqueous solution and ultrasonically treated for 10min. After filtration, it was dried to obtain the modified zeolite. The modified zeolite was then pulverized to an average particle size of 5μm. Coating preparation: Weigh out 25g of PEG-NH2 modified silver nanoparticles with an average particle size of 10nm, 25g of modified zeolite powder, 10g of ammonium bicarbonate, 5g of carboxymethyl cellulose, 3g of polyacrylic acid and 20g of ethanol, respectively, and mix them evenly to obtain the coating slurry. Membrane preparation: The above coating slurry was uniformly applied to the surface of an alumina ceramic film with a pore size of 100 nm, and then dried at 70°C to constant weight to obtain a film with a coating.

2. The method for removing cyanide and reducing ethyl carbamate in strong-aroma baijiu during distillation as described in claim 1, characterized in that, During the filtration process, the vacuum level on the permeate side of the membrane is -0.05 MPa.

3. The method for removing cyanide and reducing ethyl carbamate in strong-aroma baijiu during distillation as described in claim 1, characterized in that, The condensing medium temperature is -20℃.

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