CN111718826A

CN111718826A - White spirit decoloring and aging method

Info

Publication number: CN111718826A
Application number: CN202010601942.0A
Authority: CN
Inventors: 马广群
Original assignee: Jiangsu Taolin Wine Co ltd
Current assignee: Jiangsu Taolin Wine Co ltd
Priority date: 2020-06-28
Filing date: 2020-06-28
Publication date: 2020-09-29

Abstract

The invention relates to the technical field of white spirit aging, in particular to a white spirit decoloring and aging method, which comprises the following steps: passing the white spirit not less than 55 vol% obtained by sectional liquor taking through a polyvinylidene fluoride ultrafiltration membrane; aging the white spirit; passing the aged white spirit through a polyvinylidene fluoride ultrafiltration membrane; the polyvinylidene fluoride ultrafiltration membrane is prepared by adding magnetic chitosan and modified bentonite into a polyvinylidene fluoride membrane casting solution through a phase inversion method; and the flux of the polyvinylidene fluoride ultrafiltration membrane is not less than 200L/m²H is used as the reference value. The modified polyvinylidene fluoride ultrafiltration membrane provided by the invention is used for aging after filtering the white spirit raw wine, so that the aging discoloration and yellow discoloration phenomena of the white spirit can be greatly avoided, and the increase of the white spiritThe contents of esters and flavor substances are added, the aging and fragrance effect is obvious, the natural aging period is greatly shortened, and the turnover cost is reduced.

Description

White spirit decoloring and aging method

Technical Field

The invention relates to the technical field of white spirit aging, in particular to a white spirit decoloring and aging method.

Background

The main market mainly has lingering and soft requirements on the taste of white spirit, the white spirit is sweet and palatable, the aftertaste is not lingering, the traditional pursuit of strong fragrance and strong taste of the white spirit is gradually abandoned, the pursuit of consumers on strong fragrance and taste is gradually replaced by soft taste, however, the newly brewed white spirit has very strong taste and pungent irritation, if the pungent smell of the new spirit is not digested after one year or even more than several years of storage and the old spirit is endowed with the taste, the market requirements cannot be met, and the process of storing the new spirit for improving the taste is called aging or aging. The research on the mechanism of natural aging and aging of white spirit is reported in documents as early as 60 years in the 20 th century, at the moment, under the support of national policies, the quality of several famous white spirit brands in China are analyzed, so far, the aging mechanism of the white spirit shares explanations such as association, esterification, oxidation, dissolution and volatilization, and the like, and artificial aging technology developed by applying one or more mechanistic theories appears, and the effect is good and uneven.

On the basis of the discussion of the above mechanisms, scientific research technicians in the liquor brewing industry have created many methods for artificially aging liquor, mainly including physical, chemical, biological and comprehensive aging methods. The physical aging method is mainly to add energy on the wine product by heating, radiation and other methods to accelerate the aging process. There are different methods according to the energy transfer method, and the most typical method is a high temperature heating method. The high temperature can effectively improve the chemical reaction rate in the aging process of the white spirit, is beneficial to the volatilization of volatile components with low boiling points, and finally achieves the aim of accelerating aging. Reports show that the aging degree of the white spirit stored for half a year at 40 ℃ is approximately equal to that of the white spirit stored for 2-3 years at room temperature, the ester content of the white spirit stored for 2 months at 55 ℃ is obviously higher than that of the white spirit stored at room temperature and approximately equal to that of the white spirit stored for 2 years at room temperature, the white spirit stored at high temperature has no obvious reverse reaction within half a year after being recovered to the room temperature, and the taste and the quality of the white spirit are better than those of the white spirit stored for 2 years at room temperature. The chemical aging method is mainly to accelerate the chemical change rate in the white spirit by adding chemical substances, and is mainly divided into an oxidation method and a catalysis method. The oxidation method is to add strong oxidizing substances into the wine body, such as high-purity oxygen and ozone or add strong oxidizing agents such as hydrogen peroxide and potassium permanganate, to accelerate the oxidation rate of the alcohol compounds, thereby achieving the effect of accelerating aging. The biological aging is characterized in that yeast or yeast extract and other biological ripeners are used for catalyzing oxidation and esterification reactions in the white spirit, and the catalytic reactions have obvious specificity. Because the main functional substance in the biological aging method is enzyme, the characteristics of high aging efficiency and low impurity content of the biological aging method are determined by the extremely high catalytic efficiency and substrate specificity of the biological aging method.

For example, the traditional aging process is a Chinese patent with an authorization publication number of CN104479978B, which discloses a white spirit aging accelerator, an aging method and an aging tank, wherein a fibrous iron-loaded attapulgite-based aging accelerator and attapulgite are mixed, granulated and calcined to prepare 10-20-mesh particles as the white spirit aging accelerator for industrial production; the aging accelerator and wine liquid are placed in an aging tank with a jacket according to a certain mass volume ratio, hot water is introduced into the jacket to ensure the aging temperature of 40-60 ℃, and the mixture is intermittently stirred, ventilated and aged for a certain time. Although the wine treated by the method has obvious aging and fragrance effect, harmonious wine body, sweet and mellow taste and clean and cool aftertaste, the color and luster of the white wine can be inevitably damaged due to the adoption of the granular materials and the high-temperature aging acceleration, and the appearance and even the quality of the aged white wine are damaged after the aged white wine turns yellow, so that the approval of consumers is influenced, therefore, the method for aging the white wine with the efficient decoloring function is necessary.

The above background disclosure is only for the purpose of assisting understanding of the inventive concept and technical solutions of the present invention, and does not necessarily belong to the prior art of the present patent application, and should not be used for evaluating the novelty and inventive step of the present application in the case that there is no clear evidence that the above content is disclosed at the filing date of the present patent application.

Disclosure of Invention

In view of the above, the purpose of the present invention is to provide a method for decoloring and aging white spirit, wherein the modified polyvinylidene fluoride ultrafiltration membrane of the present invention is used for filtering raw white spirit and then aging, so that aging discoloration and white spirit yellowing of white spirit can be greatly avoided, the content of esters and flavor substances can be increased, the aging effect is obvious, the natural aging period can be greatly shortened, and the turnover cost can be reduced.

In order to realize the aim, the invention provides a white spirit decoloring and aging method, which comprises the following steps:

passing the white spirit not less than 55 vol% obtained by sectional liquor taking through a polyvinylidene fluoride ultrafiltration membrane;

-ageing the liquor;

-passing the aged white spirit through a polyvinylidene fluoride ultrafiltration membrane; wherein

The polyvinylidene fluoride ultrafiltration membrane is prepared by adding magnetic chitosan and modified bentonite into a polyvinylidene fluoride membrane casting solution through a phase inversion method; and is

The flux of the polyvinylidene fluoride ultrafiltration membrane is not less than 200L/m²/h。

The method of the invention passes the high-degree white spirit through the polyvinylidene fluoride ultrafiltration membrane with or without pressurization, then the high-degree white spirit is aged and accelerated to ripen according to the method of the prior art, the aged white spirit is further ultrafiltered through the polyvinylidene fluoride ultrafiltration membrane, the white spirit decoloring and aging method has simple process, easily controlled conditions, energy conservation and environmental protection, the extremely short-time accelerated ripening of the strong aromatic white spirit is equivalent to the level of about 1-1.5 years of storage under the common production conditions, the chromatographic framework components of the white spirit have obvious difference compared with the reference spirit which is not decolored and aged, after decoloring and aging, the irritation and the pungency of the original spirit can be greatly reduced, the taste is obviously improved, the content of the four major esters is improved, the aging effect of the white spirit is obvious, the strong aroma is mellow, the taste is cleaner and more refreshing, and the influence of yellowing caused by high-temperature aging on the appearance of the white spirit can be greatly avoided, the excellent appearance of the wine is kept on the basis of reducing the wine storage cost, and the method has very good application and popularization values.

In some preferred embodiments, the white spirit is Luzhou-flavor white spirit or Maotai-flavor white spirit.

In some preferred embodiments, the aging can be performed by aging the white spirit by using the prior art.

In other preferred embodiments, the foregoing aging includes, but is not limited to, the following methods:

performing microwave treatment for 10-15 min at the temperature of 45-50 ℃ and the microwave power of 70-100W; or

And carrying out ultrasonic treatment for 30-35 min at the temperature of 35-40 ℃ and the ultrasonic power of 300-340W. The ageing can obviously accelerate chemical reactions such as oxidation, esterification, condensation and the like in the white spirit, the content of ester substances in the white spirit is obviously increased, the concentration and the proportion of main trace components such as ethyl acetate, ethyl caproate, ethyl lactate, acetic acid, caproic acid and the like are closer to those of natural ageing, in addition, flavor development substances such as propionic acid, valeric acid, caproic acid hexyl ester, ethyl caprate and the like are also generated in the white spirit after ageing, the defects of hot taste, strong irritation, insufficient bouquet, poor mouthfeel and the like of the white spirit are greatly weakened, the pungent taste is removed, the ageing effect is obvious, the aroma is strong, the taste is clear, the spirit is mellow and thick, the spirit body is harmonious, the aroma is increased, the natural ageing period is greatly shortened, and the turnover cost is reduced.

In other preferred embodiments, the magnetic chitosan is prepared by a method comprising the following steps:

1) dissolving hydroxypropyl chitosan in acetic acid solution, and adding Fe³⁺Slowly dripping the mixture into 3-3.5 mol/L sodium hydroxide ethanol solution after stirring for at least 2 hours, stirring and curing for at least 3 hours, and washing the mixture with deionized water to be neutral to obtain chitosan particles;

2) placing the chitosan particles obtained in the step 1) into a sufficient glutaraldehyde aqueous solution, crosslinking for at least 24 hours under stirring, then respectively adding absolute ethyl alcohol and deionized water, then placing into a sufficient amount of deionized water, adjusting the pH of the system to be at least 9.8, adding epoxy chloropropane, heating to 55-58 ℃, activating for at least 5 hours, and washing to be neutral;

3) and (3) placing the particles obtained in the step 2) into sufficient deionized water, adjusting the pH value of the system to be at least 10.2, adding ethylenediamine, heating to 55-58 ℃, reacting for at least 4 hours, washing with deionized water to be neutral, and drying to obtain the catalyst.

In other preferred embodiments, in the step 1) of preparing magnetic chitosan, the substitution degree of hydroxypropyl chitosan is 0.12-0.40, preferably 0.12-0.36, more preferably 0.22-0.36, and most preferably 0.25. The inventor surprisingly found that when the raw material chitosan is substituted by hydroxypropyl with a specific substitution degree, the hydroxypropyl is added into a polyvinylidene fluoride ultrafiltration membrane and the white wine raw wine is filtered, so that Fe in the white wine raw wine is filtered³⁺Realize interception to a great extent and effectively avoid Fe³⁺Resulting in high-temp. white colour change and storage colour change, and at the same time it can adsorb the bad smell of white liquor so as to greatly reduce its contentThe original wine has irritation and pungent taste, and the aged white wine has strong fragrance and long aftertaste.

In other preferred embodiments, in the step 1) for preparing magnetic chitosan, the volume fraction of the acetic acid solution is 2.5-3.0 vol%.

In other preferred embodiments, in the step 1) of preparing magnetic chitosan, Fe³⁺With FeCl₃·6H₂Added in the form of O.

In other preferred embodiments, in the step 1) of preparing magnetic chitosan, hydroxypropyl chitosan and Fe are used³⁺The weight ratio of (A) to (B) is 2.9-3.2: 1.

In other preferred embodiments, in the step 1) for preparing magnetic chitosan, the stirring speed is not lower than 240 r/min.

In other preferred embodiments, in the step 2) of preparing the magnetic chitosan, the amount of glutaraldehyde in the glutaraldehyde aqueous solution is 2.5-4.0 times of the weight of hydroxypropyl chitosan.

In other preferred embodiments, in the step 2) for preparing magnetic chitosan, the stirring speed is not lower than 240 r/min.

In other preferred embodiments, in the step 2) of preparing magnetic chitosan, the anhydrous ethanol and the deionized water are repeatedly washed at least 5 times.

In other preferable embodiments, in the step 2) for preparing the magnetic chitosan, the pH of the system is adjusted by 0.5-2 mol/L sodium hydroxide.

In other preferred embodiments, in the step 2) for preparing the magnetic chitosan, the addition amount of the epichlorohydrin is 7.0 to 8.0 times of the weight of the hydroxypropyl chitosan.

In other preferred embodiments, in the step 2) for preparing magnetic chitosan, the temperature rising rate is 3-5 ℃/min.

In other preferable embodiments, in the step 3) for preparing the magnetic chitosan, the pH of the system is adjusted by 0.5-2 mol/L sodium hydroxide.

In other preferred embodiments, in the step 3) for preparing magnetic chitosan, the addition amount of ethylenediamine is 3.5 to 4.0 times of the weight of hydroxypropyl chitosan.

In other preferred embodiments, in the step 3) for preparing magnetic chitosan, the temperature rising rate is 3-5 ℃/min.

In other preferred embodiments, in the step 3) for preparing magnetic chitosan, drying means vacuum drying at 50-55 ℃ to constant weight.

The magnetic chitosan is prepared according to the method of the invention, firstly, the chitosan is used for coating Fe₃O₄Then, through modification of ethylenediamine, the number of amino groups on the surface of chitosan is increased, the magnetic performance is good, the preparation method is simple to operate, the stability in an acid solution is good, rapid separation can be realized through an external magnetic field, and no secondary pollution is caused; adding into polyvinylidene fluoride ultrafiltration membrane, filtering to obtain raw wine, and adding Fe³⁺Realize interception to a great extent, thereby effectively avoiding fatty acid ester substances and Fe in the solution³⁺The yellowing phenomenon of the white spirit caused by possible complexation reaction enables the white spirit to be transparent and colorless, clean and soft, and can adsorb bad smell in the white spirit base to a certain extent, so that the irritation and the pungency of the base spirit are greatly reduced, and the aged white spirit is thick, fragrant and mellow and has long aftertaste.

In other preferred embodiments, the modified bentonite is prepared by a method comprising the following steps:

1) mixing the nano bentonite with acrylic acid and water to form slurry according to the mass ratio of 4-5: 1: 10-30, uniformly stirring, adding 0.5-1.5% of crosslinking agent N, N-methylene bisacrylamide into the slurry, and continuously stirring for 45-60 min;

2) adding 0.12-0.2% of potassium persulfate into the mixed slurry in the step 1), heating to 72-74 ℃ under stirring, reacting for 2-5 h, cleaning with deionized water, drying and grinding;

3) and 2) adding the powder in the step 2) into a hexadecyl trimethyl ammonium bromide aqueous solution, heating to 55-58 ℃ under stirring, reacting for 1.5-2 h, washing with deionized water, drying, and grinding until the powder passes through a sieve of at least 200 meshes.

In other preferred embodiments, step 1) of preparing the modified bentonite, the nano bentonite has been sieved through a 400 mesh screen.

In other preferred embodiments, the stirring rate in step 1) of preparing the modified bentonite is not less than 300 r/min.

In other preferred embodiments, the stirring rate in step 2) of preparing the modified bentonite is not less than 600 r/min.

In other preferable embodiments, in the step 2) for preparing the modified bentonite, the temperature rise rate is 3-5 ℃/min.

In other preferred embodiments, the step 2) of preparing the modified bentonite comprises drying at a temperature of 100-110 ℃ for at least 5 hours.

In other preferred embodiments, step 2) of preparing the modified bentonite is grinding, meaning grinding to at least 40 mesh.

In other preferred embodiments, the weight ratio of the powder in step 3) and 2) to the cetyl trimethyl ammonium bromide is 1: 0.6-1.5.

In other preferred embodiments, the stirring rate in step 3) of preparing the modified bentonite is not less than 300 r/min.

In other preferable embodiments, in the step 3) of preparing the modified bentonite, the temperature rise rate is 3-5 ℃/min.

In other preferred embodiments, the step 3) of preparing the modified bentonite is drying at a temperature of 100-110 ℃ to a constant weight.

According to the method, after the nano bentonite is modified by using the acrylic acid, when the acrylic acid is polymerized among bentonite layers, the carboxyl of the polymer is in hydrogen bond connection with the hydroxyl of the bentonite, the interlayer structure of the bentonite is more fastened under the condition of not damaging the basic structure of the bentonite, so that the adsorption effect of the nano bentonite is remarkably improved.

In some preferred embodiments, the polyvinylidene fluoride ultrafiltration membrane is prepared by the following method: respectively adding magnetic chitosan and modified bentonite into the polyvinylidene fluoride membrane casting solution, and preparing the ultrafiltration membrane by a phase inversion method.

In other preferred embodiments, the polyvinylidene fluoride casting solution contains polyvinylidene fluoride, a pore-forming agent and an organic solvent, and the mass ratio of the magnetic chitosan, the modified bentonite to the polyvinylidene fluoride, the pore-forming agent and the organic solvent is as follows: 1: 2.5-4.0: 150-200: 5-50: 400-1000.

In other preferred embodiments, the organic solvent is triethyl phosphate.

In other preferred embodiments, the porogen is PEG-200 or PEG-400.

In other preferred embodiments, the phase inversion method is by dip-precipitation phase inversion method by knife-coating a polyvinylidene fluoride casting solution onto a flat plate.

In other preferred embodiments, the polyvinylidene fluoride ultrafiltration membrane is prepared by a method comprising the following steps:

1) adding magnetic chitosan and modified bentonite into triethyl phosphate, performing ultrasonic dispersion for at least 2 hours, adding polyvinylidene fluoride powder, heating to 82-85 ℃, stirring for at least 24 hours, then adding a pore-forming agent, continuously stirring for at least 24 hours to form a uniform and stable casting solution, and placing the casting solution in a vacuum drying oven at 75-80 ℃ for vacuum defoaming for 3-4 hours;

2) using an Elcometer4340 type film scraping machine, setting the temperature to be 80 ℃, adjusting the index of a scraper to be 200 mu m, casting the casting solution on a clean glass plate, and forming a film by using an immersion precipitation phase inversion method, wherein the air evaporation time is 5-10 s, and the coagulation bath temperature is 15-20 ℃;

3) soaking the wet film obtained in the step 2) in absolute ethyl alcohol for at least 5h, then transferring and placing the wet film in a normal hexane solution for at least 3h, taking out the wet film, and naturally airing the wet film to obtain the nano-silver zinc oxide.

In other preferred embodiments, in the step 1) of preparing the polyvinylidene fluoride ultrafiltration membrane, ultrafiltration is performedThe ultrasonic frequency of sound dispersion is 50-80 KHz, and the ultrasonic intensity is 0.6-0.8W/cm²。

In other preferred embodiments, in the step 1) of preparing the polyvinylidene fluoride ultrafiltration membrane, the temperature rise rate is 3 to 5 ℃/min.

In other preferred embodiments, in the step 1) of preparing the polyvinylidene fluoride ultrafiltration membrane, the stirring speed is 240 to 600 r/min.

The method of the invention adds the magnetic chitosan and the modified bentonite into the polyvinylidene fluoride casting solution for casting film, the film can be prepared according to the existing production line, no additional production line is needed, the final product polyvinylidene fluoride ultrafiltration film has equivalent tensile strength and elongation at break, and the final product polyvinylidene fluoride ultrafiltration film has the tensile strength of not less than 200L/m²The flux of/h ensures the smooth passing of the white spirit, has stronger adsorption effect on furan compounds and pyran compounds containing oxygen heterocycles and carbonyl compounds with stronger polarity such as acetic acid hum in the white spirit raw spirit, is favorable for preventing aging and discoloration caused by the compounds, and in addition, the doped and modified polyvinylidene fluoride ultrafiltration membrane can also be used for preventing Fe in the white spirit raw spirit³⁺Realize interception to a great extent, thereby effectively avoiding fatty acid ester substances and Fe in the solution³⁺The white spirit yellowing phenomenon caused by possible complexation reaction can adsorb bad smell in the white spirit raw wine to a certain extent, so that the irritation and pungency of the raw wine are greatly reduced, the aged white spirit is transparent, colorless, clean, soft, mellow and long in aftertaste, and is assisted with microwave aging or ultrasonic aging, the aging is accelerated for a very short time by the method of the invention, the aging is equivalent to the level of about 1-1.5 years under the common production condition, the aging effect is obvious, the natural aging period is greatly shortened, and the turnover cost is reduced.

The invention also provides application of the white spirit decoloring and aging method in white spirit production.

The invention has the beneficial effects that:

1) adding magnetic chitosan into polyvinylidene fluoride ultrafiltration membrane, filtering the wine base, and adding Fe in the wine base³⁺Realize interception to a great extent, thereby effectively avoiding fatty acid esters in the fatty acid esterSubstance and Fe³⁺The possible complexation reaction causes the yellowing phenomenon of the white spirit, so that the white spirit is transparent, colorless, clean, soft and soft;

2) after the raw material chitosan is subjected to hydroxypropyl substitution with a specific substitution degree, the raw material chitosan is added into a polyvinylidene fluoride ultrafiltration membrane and the white wine raw wine is filtered, so that Fe in the white wine raw wine can be removed³⁺The method has the advantages that the method can realize interception to a great extent, and can adsorb bad smell in the white spirit base liquor to a certain extent, so that the irritation and the pungency of the base liquor are greatly reduced, and the aged white spirit is strong in aroma and mellow and has long aftertaste;

3) after the modified bentonite is added into the polyvinylidene fluoride ultrafiltration membrane, the permeability and the hydrophilicity of the polyvinylidene fluoride ultrafiltration membrane are favorably improved, and the modified bentonite has stronger adsorption on oxygen heterocyclic-containing furan compounds, pyran compounds and carbonyl compounds with stronger polarity such as acetic acid hum possibly due to the strengthening of the adsorption, so that the aging and the color change caused by the compounds are possibly caused;

4) the method of the invention adds the magnetic chitosan and the modified bentonite into the polyvinylidene fluoride casting solution for casting film, the film can be prepared according to the existing production line, no additional production line is needed, the final product polyvinylidene fluoride ultrafiltration film has equivalent tensile strength and elongation at break, and the final product polyvinylidene fluoride ultrafiltration film has the tensile strength of not less than 200L/m²The flux of the/h ensures the smooth passing of the white spirit;

5) after the polyvinylidene fluoride ultrafiltration membrane is used for filtering and aging the white spirit raw wine, the aging discoloration and the yellowing of the white spirit can be greatly avoided, the white spirit is colorless, clear and transparent, the aging is accelerated for a short time to be equivalent to the level of about 1-1.5 years under the common production condition, the aging effect is obvious, the natural aging period is greatly shortened, and the turnover cost is reduced.

The invention adopts the technical scheme for achieving the purpose, makes up the defects of the prior art, and has reasonable design and convenient operation.

Drawings

The foregoing and/or other objects, features, advantages and embodiments of the invention will be more readily understood from the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic diagram of the modification step of hydroxypropyl chitosan by ethylenediamine according to the present invention;

FIG. 2 is a schematic diagram showing the contents of some metal ions in the decolorized and aged white spirit according to the present invention;

FIG. 3 is a schematic diagram showing the results of the comparison of the color comparison ratio of the decolorized and aged white spirit of the present invention to an ethanol solution at 363nm wavelength.

Detailed Description

Those skilled in the art can appropriately substitute and/or modify the process parameters to implement the present disclosure, but it is specifically noted that all similar substitutes and/or modifications will be apparent to those skilled in the art and are deemed to be included in the present invention. While the products and methods of making described herein have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and modifications in the products and methods of making described herein may be made and utilized without departing from the spirit and scope of the invention.

Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The present invention uses the methods and materials described herein; other suitable methods and materials known in the art may be used. The materials, methods, and examples described herein are illustrative only and are not intended to be limiting. All publications, patent applications, patents, provisional applications, database entries, and other references mentioned herein, and the like, are incorporated by reference herein in their entirety. In case of conflict, the present specification, including definitions, will control.

All percentages, parts, ratios, etc., are by weight unless otherwise indicated; additional instructions include, but are not limited to, "wt%" means weight percent, "mol%" means mole percent, "vol%" means volume percent.

When an amount, concentration, or other value or parameter is given as either a range, preferred range or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5(1 to 5)" is described, the described range is understood to include ranges of "1 to 4(1 to 4)", "1 to 3(1 to 3)", "1 to 2(1 to 2) and 4 to 5(4 to 5)", "1 to 3(1 to 3) and 5", and the like. Where numerical ranges are described herein, unless otherwise stated, the ranges are intended to include the endpoints of the ranges, and all integers and fractions within the ranges.

When the term "about" is used to describe a numerical value or an end point value of a range, the disclosure should be understood to include the specific value or end point referred to.

Furthermore, "or" means "or" unless expressly indicated to the contrary, rather than "or" exclusively. For example, condition a "or" B "applies to any of the following conditions: a is true (or present) and B is false (or not present), a is false (or not present) and B is true (or present), and both a and B are true (or present).

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are intended to mean no limitation on the number of occurrences (i.e., occurrences) of the element or component. Thus, "a" or "an" should be understood to include one or at least one and the singular forms of an element or component also include the plural unless the singular is explicitly stated.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation. The use of the phrase "comprising one of the elements does not exclude the presence of other like elements in the process, method, article, or apparatus that comprises the element.

The materials, methods, and examples described herein are illustrative only and not intended to be limiting unless otherwise specified. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

The present invention is described in detail below.

Example 1:

the embodiment provides a method for decoloring and aging newly brewed white spirit, which specifically comprises the following steps:

s1 preparation of magnetic chitosan:

1.1) hydroxypropyl chitosan (weight average molecular weight of about 120000, degree of deacetylation 93%) with substitution degree of 0.25 is dissolved in sufficient 3.0 vol% acetic acid solution according to hydroxypropyl chitosan and Fe³⁺Adding FeCl into the solution in a weight ratio of 3.2:1₃·6H₂O, stirring for 2 hours at the speed of 300r/min, slowly dripping the mixture into 3.5mol/L sodium hydroxide ethanol solution, continuously stirring and solidifying the mixture for 3 hours, and washing the mixture to be neutral by deionized water to obtain chitosan particles;

1.2) placing the chitosan particles obtained in the step 1.1) into sufficient glutaraldehyde aqueous solution, wherein the weight of glutaraldehyde is 3.5 times of that of hydroxypropyl chitosan, crosslinking for 24 hours under stirring at 300r/min, washing for 5 times by using absolute ethyl alcohol and deionized water respectively, then placing into sufficient deionized water, adjusting the pH of the system to 9.8 by using 1mol/L sodium hydroxide solution, adding epoxy chloropropane of which the weight is 7.8 times of that of hydroxypropyl chitosan, heating to 55 ℃ at 5 ℃/min, activating for 5 hours, and washing to neutrality;

1.3) putting the particles obtained in the step 1.2) into sufficient deionized water, adjusting the pH of the system to 10.5 by using 1mol/L sodium hydroxide solution, adding ethylenediamine with the weight being 4 times that of hydroxypropyl chitosan, heating to 55 ℃ at the speed of 5 ℃/min, reacting for 4 hours, washing to be neutral by using the deionized water, and drying in vacuum at the temperature of 50 ℃ to constant weight to obtain the chitosan nanoparticle.

S2 preparation of modified bentonite:

2.1) mixing the nano bentonite which is sieved by a 400-mesh sieve with acrylic acid and water according to the mass ratio of 4:1:30 to form slurry, uniformly stirring at 600r/min, adding 1% of cross-linking agent N, N-methylene bisacrylamide of the slurry, and continuously stirring for 60 min;

2.2) adding 0.15 percent of potassium persulfate into the mixed slurry in the step 2.1), heating to 72 ℃ at the speed of 5 ℃/min under stirring at 600r/min, reacting for 4h, washing with deionized water, drying for 5h at 100 ℃, and grinding until the mixture is sieved by a 40-mesh sieve;

2.3) adding the powder obtained in the step 2.2) into a hexadecyl trimethyl ammonium bromide aqueous solution, wherein the weight ratio of the powder to the hexadecyl trimethyl ammonium bromide is 1:1.2, heating to 56 ℃ at the speed of 5 ℃/min under the stirring of 300r/min for reaction for 2h, washing with deionized water, drying at the temperature of 105 ℃ to constant weight, and grinding until the weight is 240-mesh.

S3 preparation of a polyvinylidene fluoride ultrafiltration membrane:

3.1) adding 1g of magnetic chitosan and 3.5g of modified bentonite into 600g of triethyl phosphate at 60KHz and 0.65W/cm²Performing ultrasonic dispersion for 2h, adding 160g of polyvinylidene fluoride powder, heating to 85 ℃ at the speed of 5 ℃/min, stirring for 24h at the speed of 360r/min, adding 20g of PEG-200, continuously stirring for 24h to form a uniform and stable casting solution, and placing the casting solution in a vacuum drying oven at the temperature of 80 ℃ for vacuum defoaming for 4 h;

3.2) using an Elcometer4340 type film scraping machine, setting the temperature to be 80 ℃, adjusting the index of a scraper to be 200 mu m, casting the casting solution on a clean glass plate, forming a film by using an immersion precipitation phase inversion method, wherein the air evaporation time is 5s, and the coagulation bath temperature is 20 ℃;

3.3) soaking the wet film obtained in the step 3.2) in absolute ethyl alcohol for 5 hours, then transferring and placing the film in a normal hexane solution for 3 hours, taking out the film and naturally drying the film to obtain the nano-silver zinc oxide film.

S4 decoloring and aging:

4.1) passing 60 vol% of newly brewed strong aromatic Chinese spirits through a polyvinylidene fluoride ultrafiltration membrane;

4.2) aging the white spirit in the step 4.1) for 15min at the temperature of 50 ℃ and the microwave power of 80W;

4.3) passing the white spirit aged in the step 4.2) through a polyvinylidene fluoride ultrafiltration membrane to obtain the finished product.

Example 2:

this example provides another method for decoloring and aging freshly brewed white spirit, which comprises the same steps as example 1, except that chitosan (weight-average molecular weight 120000, deacetylation degree 93%) is used instead of hydroxypropyl chitosan with substitution degree of 0.25 to prepare magnetic chitosan in this example.

Example 3:

this example provides another method for decoloring and aging freshly brewed white spirit, which comprises the following steps that are substantially the same as those in example 1, except that the substitution degree of hydroxypropyl chitosan in this example is 0.07.

Example 4:

this example provides another method for decolorizing and aging freshly brewed white spirit, which comprises the following steps that are substantially the same as those in example 1, except that the substitution degree of hydroxypropyl chitosan in this example is 0.32.

Example 5:

this example provides another method for decolorizing and aging freshly brewed white spirit, which comprises the following steps that are substantially the same as those in example 1, except that the substitution degree of hydroxypropyl chitosan in this example is 0.46.

Example 6:

this example provides another method for decolorizing and aging freshly brewed white spirit, which comprises the following steps that are substantially the same as those in example 1, except that the substitution degree of hydroxypropyl chitosan in this example is 0.55.

Example 7:

this example provides another method for decoloring and aging freshly brewed white spirit, which includes steps substantially the same as those in example 1, except that the chitosan particles in step 1.2) are used as magnetic chitosan in this example, that is, the magnetic chitosan in this example is added to a polyvinylidene fluoride casting solution without being modified by ethylenediamine to prepare an ultrafiltration membrane, and the freshly brewed white spirit is subjected to decoloring and aging according to the other steps the same as those in example 1.

Example 8:

this example provides another method for decoloring and aging freshly brewed white spirit, which includes steps substantially the same as those in example 1, except that hydroxypropyl chitosan with a substitution degree of 0.25 without any modification is added to the polyvinylidene fluoride casting solution instead of magnetic chitosan to prepare an ultrafiltration membrane, and the freshly brewed white spirit is subjected to decoloring and aging according to the other steps similar to those in example 1.

Example 9:

this example provides another method for decoloring and aging freshly brewed white spirit, which includes steps substantially the same as those in example 1, except that in this example, the 400-mesh-screened nano bentonite is added to the polyvinylidene fluoride casting solution without any modification to prepare an ultrafiltration membrane, and the freshly brewed white spirit is subjected to decoloring and aging according to the other steps the same as those in example 1.

Example 10:

the embodiment provides another method for decoloring and aging newly brewed white spirit, which has the same specific steps as those in embodiment 1, except that magnetic chitosan is not added to the polyvinylidene fluoride casting solution in the embodiment.

Example 11:

this example provides another method for decoloring and aging freshly brewed white spirit, which has the same specific steps as example 1, except that no modified bentonite is added to the polyvinylidene fluoride casting solution of this example.

Example 12:

the embodiment provides another method for decoloring and aging freshly brewed white spirit, which has the specific steps basically the same as those in embodiment 1, and the difference is that in the decoloring and aging step of the embodiment, the freshly brewed white spirit is not filtered by a polyvinylidene fluoride ultrafiltration membrane before aging.

Example 13:

the embodiment provides another method for decoloring and aging newly brewed white spirit, which has the specific steps basically the same as those in embodiment 1, and the difference is that the decoloring and aging step in the embodiment is to perform ultrasonic aging treatment on the white spirit in step 4.1) for 30min at the temperature of 40 ℃ and the ultrasonic power of 320W.

Example 14:

the embodiment provides another method for decoloring and aging freshly brewed white spirit, which has the specific steps basically the same as those in embodiment 1, and the difference is that in the decoloring and aging step of the embodiment, the freshly brewed white spirit is not filtered by a polyvinylidene fluoride ultrafiltration membrane after being aged.

Experimental example 1:

the performance of each polyvinylidene fluoride ultrafiltration membrane in examples 1 to 11 was tested according to the following methods:

A. and (3) testing mechanical strength: respectively cutting the dry film into 2.0cm multiplied by 5.0cm, respectively fixing two ends of the film on a tensile machine to enable the sample to be in a natural tensile state, setting the tensile speed of the tensile machine to be 10mm/min, respectively repeating 5 times on each ultrafiltration membrane, averaging the results, and calculating the tensile strength and the elongation at break by using the following formulas (1) to (2):

wherein, in the formula (1), σ t is a tensile strength (MPa), F is a maximum load (N), b is a film width (mm), and d is a film thickness (mm);

in the formula (2), t is elongation at break (%), Δ x is the length (mm) of the film stretched at the moment of breaking during stretching, and L₀Is the initial length (mm) of the film.

B. And (3) detecting the water flux: at 25 ℃, pre-pressing the membrane for 30min at 0.2MPa, measuring the volume of penetrating fluid per minute at 0.1MPa, and calculating the water flux, wherein the calculation formula is shown as a formula (3):

wherein, in the formula (3), J is the water flux (L/m)²V is permeate volume (L) and A is effective membrane area (m)²) And t is the filtration time (h).

The statistical results are shown in table 1.

TABLE 1 film Properties

Example group	Tensile Strength (MPa)	Elongation at Break (%)	Water flux (L/m)²/h)
				Example 1	3.16	53.52	232.85
Example 2	2.24	42.17	200.33
				Example 3	3.08	50.22	222.07
Example 4	3.01	50.88	216.04
				Example 5	2.95	48.63	213.37
Example 6	2.99	49.91	220.06
				Example 7	2.33	43.69	201.98
Example 8	2.21	43.30	207.41
				Example 9	2.57	46.18	223.05
Example 10	1.86	42.91	183.69
				Example 11	2.05	46.29	191.84

As can be seen from table 1 above, the polyvinylidene fluoride ultrafiltration membranes in

preferred embodiments

1 and 4 of the present application have excellent mechanical strength and pure water flux, and it can also be seen that the addition of magnetic chitosan and modified bentonite has important significance for the mechanical strength and water flux of the ultrafiltration membrane, and in addition, incomplete modification with chitosan that is not hydroxypropyl-substituted or hydroxypropyl chitosan can cause significant influence on the mechanical strength and water flux of the final ultrafiltration membrane.

Experimental example 2:

according to GB/T10345-2007 white spirit analysis method, 5 professional wine evaluators were organized to conduct sensory evaluation and scoring on freshly brewed white spirit base (group O), white spirit (groups 1-14) which had been subjected to decolorization and aging in examples 1-14, and white spirit (group C) which had been naturally aged for 16 months, and the average value was taken, and the statistical results are shown in Table 2.

TABLE 2 sensory evaluation and Scoring

As can be seen from Table 2, the original wine has heavy flavor, insufficient bouquet, spicy flavor, strong impurity flavor and strong mouthfeel due to non-aging, the new wine is faded after being naturally aged for 16 months, the strong flavor is mellow and soft, the taste is sweet and clean, but the color is light yellow, the texture is strong, and compared with the natural aging white wine which is aged for 16 months in the

preferred embodiments

1, 4 and 13, the white wine has excellent flavor characteristics and quality scores, and the evaluation is almost the same as that of the natural aging white wine which is aged for 16 months. In addition, it can be seen from table 2 that, compared to the above preferred embodiment of the present application, when no magnetic chitosan is added to the polyvinylidene fluoride ultrafiltration membrane component and hydroxypropyl chitosan is not completely modified, the aging effect on the white wine base is slightly insufficient, the new wine taste and the foreign taste are slightly remained, and the wine aroma is insufficient.

Experimental example 3:

according to GB/T10345-2007 white spirit analysis method, quantitative detection of flavor substance content (mg/L) was performed on freshly brewed white spirit base (group O), white spirit (groups 1-14) which had been subjected to decolorization and aging in examples 1-14, and white spirit (group C) which had been naturally aged for 16 months, respectively, and the detection results are shown in tables 3 and 4.

TABLE 3 flavor content 1

Note: "/" indicates no detection.

TABLE 4 flavor content 2

Note: "/" indicates no detection.

As can be seen from tables 3 and 4, in

preferred embodiments

1, 4 and 13 of the present application, the white spirit has higher content of four major esters and total esters after being treated by the modified polyvinylidene fluoride ultrafiltration membrane and being aged, and meanwhile, compared with the original white spirit, the white spirit has a new content of flavor-producing substances such as hexyl hexanoate, ethyl decanoate, propionic acid, valeric acid and the like, and the contents of main esters, alcohols and acids thereof are all equivalent to the content of the white spirit naturally aged for 16 months. Meanwhile, the change of the components of the modified polyvinylidene fluoride ultrafiltration membrane, particularly when magnetic chitosan or modified bentonite is not added, the comprehensive flavor substance content, particularly the content of tetraesters, of the white spirit obtained by aging is reduced to different degrees from the content of other flavor substances, and the like, and the obvious aging effect can be achieved after the modified polyvinylidene fluoride ultrafiltration filtration white spirit raw spirit is aged by microwave or ultrasonic assisted aging and the white spirit is filtered and aged again and is aged by very short time.

Experimental example 4:

according to the prior art, the metal ion content detection is respectively carried out on the original liquor (group O) of the newly brewed white spirit, the white spirit (group 1-14) which is decolorized and aged in the examples 1-14 and the white spirit (group C) which is naturally aged for 16 months, and the detection results are shown in figure 2. As can be seen from FIG. 2, the raw wine of the newly brewed white spirit contains higher Fe³⁺、Pb²⁺、Cu²⁺And Mn²⁺In particular Fe³⁺The content is very high, and according to the existing theory and the corresponding Fe of the white spirit aged for 16 months naturally³⁺The content and color development of Fe³⁺The content is in direct proportion to the yellowing of the white spirit; as can also be seen from figure 2, after the modified polyvinylidene fluoride ultrafiltration membrane is treated before and after microwave aging or ultrasonic aging, the content Pb of metal ions in the white spirit can be remarkably reduced²⁺、Cu²⁺And Mn²⁺In particular Fe³⁺The content of heavy metal ions in the white spirit is reduced effectively, the phenomenon that the heavy metal ions of the white spirit exceed the standard due to the raw material end, the storage vessel section, the transfer section and the like is avoided, the high-temperature color change and the storage color change of the white spirit can be reduced greatly, the appearance and the impression of the white spirit are improved, and the white spirit is accepted by consumers.

Experimental example 5:

comparing the colors of the freshly brewed white spirit base (group O), the white spirit (group 1-14) which is decolorized and aged in the examples 1-14 and the white spirit (group C) which is naturally aged for 16 months, wherein the specific method comprises the following steps: 30.0mL of each sample was accurately pipetted into a 50mL colorimetric cylinder, and the colorimetric results were shown in FIG. 3, where an ethanol solution (30 mL of a 60 vol% ethanol solution) was used as a control at a wavelength of 363 nm. As can be seen from FIG. 3, compared with the original liquor of the newly brewed liquor, the liquor after being naturally aged for 16 months has a darker color, and the aging is promoted while the modified polyvinylidene fluoride of the application is used for filtering, so that the color of the liquor can be greatly reduced, the aging and color change of the liquor and the yellowing of the liquor can be effectively avoided, the liquor is colorless, clear and transparent, the aging effect is obvious, the natural aging period is greatly shortened, and the turnover cost is reduced.

Conventional techniques in the above embodiments are known to those skilled in the art, and therefore, will not be described in detail herein.

In view of the numerous embodiments of the present invention, the experimental data of each embodiment is huge and is not suitable for being listed and explained herein one by one, but the contents to be verified and the final conclusions obtained by each embodiment are close. Therefore, the contents of the verification of the respective examples are not described herein, and the excellent points of the present invention will be described only by representative examples 1 to 14 and experimental examples 1 to 5.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

While the above detailed description has shown, described, and pointed out novel features as applied to various embodiments, it will be understood that various omissions, substitutions, and changes in the form and details of the device or method illustrated may be made without departing from the spirit of the disclosure. In addition, the various features and methods described above may be used independently of one another, or may be combined in various ways. All possible combinations and sub-combinations are intended to fall within the scope of the present disclosure. Many of the embodiments described above include similar components, and thus, these similar components are interchangeable in different embodiments. While the invention has been disclosed in the context of certain embodiments and examples, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and obvious modifications and equivalents thereof. Accordingly, the invention is not intended to be limited by the specific disclosure of preferred embodiments herein.

Claims

1. A white spirit decoloring and aging method is characterized by comprising the following steps:

-ageing the liquor;

2. The method of claim 1, wherein: the aging comprises the following steps:

And carrying out ultrasonic treatment for 30-35 min at the temperature of 35-40 ℃ and the ultrasonic power of 300-340W.

3. The method according to claim 1 or 2, characterized in that: the magnetic chitosan is prepared by a method comprising the following steps:

4. The method of claim 3, wherein: the substitution degree of the hydroxypropyl chitosan is 0.12-0.40, preferably 0.12-0.36, more preferably 0.22-0.36, and most preferably 0.25.

5. The method according to claim 3 or 4, characterized in that: hydroxypropyl chitosan and Fe³⁺The weight ratio of (A) to (B) is 2.9-3.2: 1.

6. The method according to any one of claims 1 to 5, wherein: the modified bentonite is prepared by a method comprising the following steps:

7. The method according to any one of claims 1 to 5, wherein: the polyvinylidene fluoride ultrafiltration membrane is prepared by the following method: respectively adding magnetic chitosan and modified bentonite into the polyvinylidene fluoride membrane casting solution, and preparing the ultrafiltration membrane by a phase inversion method.

8. The method of claim 7, wherein: the polyvinylidene fluoride casting solution contains polyvinylidene fluoride, a pore-forming agent and an organic solvent, and the mass ratio of the magnetic chitosan, the modified bentonite to the polyvinylidene fluoride, the pore-forming agent and the organic solvent is as follows: 1: 2.5-4.0: 150-200: 5-50: 400-1000.

9. The method of claim 8, wherein: the polyvinylidene fluoride ultrafiltration membrane is prepared by the following steps:

10. Use of a liquor decolorization and aging method according to any one of claims 1 to 9 in liquor production.