阅读说明：本技术 橡木风味的白酒及其制备方法 (Oak-flavored white spirit and preparation method thereof ) 是由 杨粟平 李勇 侯长军 霍丹群 张宿义 杨平 周军 黄锐 于 2021-09-16 设计创作，主要内容包括：本发明公开了一种橡木风味的白酒及其制备方法,属于生物工程领域、食品领域、发酵工程领域。橡木风味的白酒,用橡木代替10-50％质量的糠壳参与发酵得到,其主要原料的质量比为高粱∶打量水∶糠壳∶橡木屑∶大曲粉＝8-12∶2-4∶1∶1∶2-4,本发明的白酒制备工艺在酿造时特别添加了Fe-(3)O-(4)纳米粒子,所述Fe-(3)O-(4)纳米粒子为粒径为10-50nm的Small-Fe-(3)O-(4)、粒径为250-450nm的Big-Fe-(3)O-(4)、粒径为50-100nm的组氨酸修饰His-Fe-(3)O-(4)中任意一种。采用本发明方法酿造的白酒,酒体更加柔和、丰满、具有结构感,可有效解决现有白酒酿造工艺中糠壳给酒体带来异杂味的问题。(The invention discloses an oak-flavored white spirit and a preparation method thereof, belonging to the fields of bioengineering, food and fermentation engineering. The oak flavor liquor is obtained by fermenting oak instead of 10-50% of bran shells, and the mass ratio of the main raw materials is sorghum, equivalent water, bran shells, oak dust and Daqu powder is 8-12: 2-4: 1: 2-4 3 O 4 Nanoparticles of said Fe 3 O 4 The nanoparticles are Small-Fe with particle diameter of 10-50nm 3 O 4 Big-Fe with particle size of 250-450nm 3 O 4 Histidine modified His-Fe with particle size of 50-100nm 3 O 4 Any one of them. The white spirit brewed by the method has softer and fuller wine body and structural sense, and can effectively solve the problem that the bran shells bring different foreign flavors to the wine body in the traditional white spirit brewing process.)

1. The oak-flavored white spirit is characterized in that: oak is used to replace 10-50% of bran hull to ferment.

2. The oak flavored liquor of claim 1, wherein: the mass ratio of the main raw materials is sorghum, water, bran shells, oak dust and Daqu powder is 8-12: 2-4: 1: 2-4.

3. The oak flavored liquor of claim 2, wherein: the raw material also comprises Fe₃O₄Nanoparticles of said Fe₃O₄The mass ratio of the nano particles to the main raw materials is 1: 24000-26000.

4. The oak flavored liquor of claim 3, wherein: said Fe₃O₄The nano particles are: Small-Fe with grain diameter of 10-50nm₃O₄Big-Fe with particle size of 250-450nm₃O₄Histidine modified His-Fe with particle size of 50-100nm₃O₄Any one of them.

5. The preparation method of the oak-flavored liquor is characterized by comprising the following steps of:

a. pretreatment: steaming bran shell and oak dust with particle size of 6-20 mesh at 95-100 deg.C for 30-40min, spreading, and cooling;

b. pasting: moistening sorghum and gelatinizing with 95-100 deg.C steam;

c. and c, adding the sorghum gelatinized in the step b into the weighed water according to the mass ratio of the sorghum to the weighed water to the bran shells, the oak chips and the Daqu powder of 8-12: 2-4: 1: 2-4, spreading and cooling to 25-35 ℃, adding the bran shells, the oak chips and the Daqu powder pretreated in the step a, uniformly mixing to obtain a mixture, and fermenting to obtain the white wine with the oak flavor.

6. The method of preparing oak-flavored liquor according to claim 5, wherein the method comprises the steps of: in the step b, the grain moistening is to mix sorghum and water with the temperature of 80-90 ℃ according to the mass ratio of 4-6: 2-4, and the temperature is kept for 150 min.

7. The method of preparing oak-flavored liquor according to claim 5, wherein the method comprises the steps of: in step c, Fe is added before fermentation₃O₄The nano particles and the mixture are uniformly mixed according to the mass ratio of 1: 24000-26000.

8. The method of preparing oak-flavored liquor according to claim 7, wherein the method comprises the steps of: said Fe₃O₄The nano particles are: Small-Fe with grain diameter of 10-50nm₃O₄Big-Fe with particle size of 250-450nm₃O₄Histidine modified His-Fe with particle size of 50-100nm₃O₄Any one of them.

9. Big-Fe according to claim 4 or 8₃O₄The preparation method is characterized by comprising the following steps: completely dissolving ferric chloride and trisodium citrate in ethylene glycol according to the mass ratio of 13: 4: 440: 24, adding sodium acetate, violently stirring until the mixture is uniformly mixed, transferring the mixture into an autoclave, heating for 10 hours at 200 ℃, washing a product with ethanol, and drying to obtain Big-Fe₃O₄。

10. His-Fe according to claim 4 or 8₃O₄The preparation method is characterized by comprising the following steps: ferric chloride hexahydrateThe preparation method comprises the following steps of dissolving ferric chloride hexahydrate in ethylene glycol completely at a mass ratio of 4: 220: 18: 5, adding sodium acetate and histidine, stirring vigorously to mix uniformly, carrying out ultrasonic treatment on the mixture for 10-15 minutes, transferring the mixture into a reactor, heating at 200 ℃ for 12 hours, washing the product with ethanol, and drying to obtain His-Fe₃O₄。

Technical Field

The invention belongs to the fields of bioengineering, food and fermentation engineering, and particularly relates to oak-flavored white spirit and a preparation method thereof.

Background

Chinese white spirit has a long history and a plurality of varieties, and different fragrance types are formed due to different process flows and raw materials. Most of the brewing raw materials of the white spirit mainly comprise grains rich in starch, wherein sorghum, rice, sticky rice and corn are the main raw materials for brewing the white spirit. The bran husk is rich in cellulose and lignin, has low contents of fat and protein, has a stable fiber structure and a large specific surface area, is used as a main auxiliary material for producing the Luzhou-flavor liquor, and is an indispensable solid filling agent and loosening agent in Chinese liquor brewing, particularly Luzhou-flavor liquor brewing. The bran shell provides a loose space for the metabolism succession of microbial communities in the fermentation of the fermented grains, and provides a loose mass transfer space for the efficient extraction and concentration of ethanol and trace aroma components in the fermented grains at the distillation end. Because the bran shells contain a large amount of bran flavor, mud fishy smell and other foreign flavors to influence the sensory evaluation of wine, the pretreatment and the dosage of the bran shells are very important in the brewing production process. At present, aiming at reducing the foreign flavor brought to the wine body by the bran shells and not reducing the function of the bran shells, the method mainly optimizes the conditions of bran shell raw material quality control and bran steaming mode, and has large operation limitation and single effect.

CN110591871A patent of 12 months and 20 days in 2019 discloses a white spirit wine base with oak components, which consists of oak pieces, carotene, mogroside, xylitol, lactose and white spirit. Also provides a preparation method of the white spirit base with oak components, which comprises the steps of baking oak pieces until the oak pieces are dark brown and have intense oak taste; placing processed oak pieces and Chinese liquor into oak barrel, adding carotene, mogroside, xylitol and lactose, and sealing and storing at room temperature for over one week to obtain Chinese liquor with oak components.

CN112159744A patent of 1 month and 1 day 2021 discloses a flavoring wine with oak fragrance, its preparation method and flavoring white wine.

The two methods for preparing the white spirit with oak flavor only adopt a process of soaking oak by using the white spirit so as to obtain certain flavor components, the white spirit prepared by the method has single flavor substance, and the obtained oak white spirit system is uneven. Therefore, it is necessary to research a new brewing process of white spirit with oak flavor for improving the bran shell odor.

Disclosure of Invention

The invention aims to solve the technical problem that bran shells bring foreign flavor to wine bodies in the existing white wine brewing process.

The technical scheme adopted by the invention for solving the technical problems is as follows: the oak flavor liquor is obtained by fermenting oak instead of 10-50% of bran hull.

The oak flavor white spirit has the main raw materials with the mass ratio of sorghum, water, bran shells, oak dust and Daqu powder being 8-12: 2-4: 1: 2-4.

Further, the raw material also comprises Fe₃O₄Nanoparticles of said Fe₃O₄The mass ratio of the nano particles to the main raw materials is 1: 24000-26000.

Fe as described above₃O₄The nano particles are: Small-Fe with grain diameter of 10-50nm₃O₄Big-Fe with particle size of 250-450nm₃O₄Histidine with particle size of 50-100nmModified His-Fe₃O₄Any one of them.

The preparation method of the oak-flavored liquor comprises the following steps:

a. pretreatment: steaming bran shell and oak dust with particle size of 6-20 mesh at 95-100 deg.C for 30-40min, spreading, and cooling;

b. pasting: moistening sorghum and gelatinizing with 95-100 deg.C steam;

c. and c, adding the sorghum gelatinized in the step b into the weighed water according to the mass ratio of the sorghum to the weighed water to the bran shells, the oak chips and the Daqu powder of 8-12: 2-4: 1: 2-4, spreading and cooling to 25-35 ℃, adding the bran shells, the oak chips and the Daqu powder pretreated in the step a, uniformly mixing to obtain a mixture, and fermenting to obtain the white wine with the oak flavor.

In the step b, the grain moistening is to mix the sorghum and water with the temperature of 80-90 ℃ according to the mass ratio of 4-6: 2-4, and keep the temperature for 120-150 min.

In the step b, the gelatinization time is 35-45 min.

In the above step c, Fe is added before fermentation₃O₄The nano particles and the mixture are uniformly mixed according to the mass ratio of 1: 24000-26000.

Fe as described above₃O₄The nano particles are: Small-Fe with grain diameter of 10-50nm₃O₄Big-Fe with particle size of 250-450nm₃O₄Histidine modified His-Fe with particle size of 50-100nm₃O₄Any one of them.

The above Big-Fe₃O₄The preparation method comprises the following steps: completely dissolving ferric chloride and trisodium citrate in ethylene glycol according to the mass ratio of 13: 4: 440: 24, adding sodium acetate, violently stirring until the mixture is uniformly mixed, transferring the mixture into a high-pressure kettle, heating for 10 hours at 200 ℃, washing a product with ethanol, and drying to obtain the Big-Fe with the particle size of 250-450nm₃O₄。

Further, the vigorous stirring time is 30-40 min.

Furthermore, the autoclave is a stainless steel autoclave with a Teflon lining, and the drying temperature is 55-65 ℃.

The above His-Fe₃O₄The preparation method comprises the following steps: completely dissolving ferric chloride hexahydrate in ethylene glycol according to the mass ratio of 4: 220: 18: 5, adding sodium acetate and histidine, violently stirring until the mixture is uniformly mixed, then carrying out ultrasonic treatment on the mixture for 10-15 minutes, transferring the mixture into a reactor, heating the mixture at 200 ℃ for 12 hours, washing the product with ethanol, and drying to obtain histidine-modified His-Fe with the particle size of 50-100nm₃O₄。

Further, the vigorous stirring time is 30-40 min.

Further, the reactor is a polytetrafluoroethylene reactor, and the drying temperature is 55-65 ℃.

The invention has the beneficial effects that: the invention provides a white spirit with oak flavor. The oak component has 24% -30% lignin, 41% -44% cellulose, 21% -25% hemicellulose and a small amount of lipid, and has similarity with the component structure of the bran shell. The process for preparing the white spirit is a solid brewing method, and based on the brewing process of the traditional Chinese white spirit, oak replaces part of bran shells to participate in the brewing of the white spirit, so that the support and interface action of the whole fermentation space can be ensured, the fermented grains have proper porosity and oxygen content, and the normal operation of distillation and fermentation is facilitated; the unique oak flavors such as coconut flavor, woody flavor and the like of roasted almonds are given to the white spirit, the mellow feeling of the white spirit body is enhanced, and the typical flavor characteristics of the Chinese white spirit are not influenced.

Meanwhile, the invention adds Fe specially during brewing₃O₄Nanoparticles of Fe₃O₄The nano particles have the advantages of conductivity, low toxicity, high surface area and the like, can be used as an electron acceptor to improve the electron transfer rate in a system, enhance the gas-liquid mass transfer coefficient and the microbial metabolism process in the system and accelerate the anaerobic fermentation rate. By Fe₃O₄The nanoparticles and oak act synergistically to participate in the whole solid-state fermentation process of Chinese liquor, and perform substance exchange under the action of microbial community in the system, and the metabolism of the microbes makes oakSubstances which are difficult to extract and decompose in the wood participate in the reaction, so that the unique flavor of the white spirit is given. Compared with other processes for soaking oak by using liquor to obtain certain flavor components, the oak liquor obtained by the method is more balanced in system, more consistent in expression of flavor substances, and more in trace flavor substances obtained by microbial treatment.

The invention constructs a novel method for brewing the white spirit with the combination of Chinese flavor and western flavor, and the white spirit brewed by the method is softer and plump in body and has structural sense; various aromatic components contained in the oak are dissolved in the liquor, so that the Chinese white liquor has an extra elegant style; the invention not only ensures the obvious flavor characteristics of the traditional brewed white spirit, reduces the evil and foreign flavor brought by bran shells, but also combines the unique flavor of foreign liquor, and provides a first opportunity for further expanding the world market for the Chinese white spirit.

Drawings

FIG. 1 shows the contents of starch and reducing sugar in fermented grains of group A according to the present invention;

FIG. 2 shows the contents of starch and reducing sugar in fermented grains of group B according to the present invention;

FIG. 3 is a graph of the relative proportions of the aldol phenol species in example A, B set in accordance with the invention;

FIG. 4 is a group hierarchical clustering and heatmap visualization, in accordance with an embodiment of the present invention;

FIG. 5 is a B-group hierarchical clustering and heatmap visualization, in accordance with an embodiment of the present invention;

FIG. 6 shows the total alcohol and total ester contents of A, B wine samples according to example of the present invention;

FIG. 7 shows the total aldehyde and total phenol content in A, B group of wine samples according to the present invention.

Detailed Description

The technical solution of the present invention can be specifically implemented as follows.

The oak flavor liquor is obtained by fermenting oak instead of 10-50% of bran hull.

In order to obtain the white spirit with the optimal oak flavor, the white spirit with the oak flavor is preferably prepared by mixing the main raw materials of sorghum in a mass ratioThe weight ratio of water, bran shell, oak dust and Daqu powder is 8-12: 2-4: 1: 2-4, its raw material also includes Fe₃O₄Nanoparticles of said Fe₃O₄The mass ratio of the nano particles to the main raw material is 1: 24000-26000, and the Fe₃O₄The nano particles are: Small-Fe with grain diameter of 10-50nm₃O₄Big-Fe with particle size of 250-450nm₃O₄Histidine modified His-Fe with particle size of 50-100nm₃O₄Any one of them.

The preparation method of the oak-flavored liquor comprises the following steps:

a. pretreatment: steaming bran shell and oak dust with particle size of 6-20 mesh at 95-100 deg.C for 30-40min, spreading, and cooling;

b. pasting: moistening sorghum and gelatinizing with 95-100 deg.C steam;

c. and c, adding the sorghum gelatinized in the step b into the weighed water according to the mass ratio of the sorghum to the weighed water to the bran shells, the oak chips and the Daqu powder of 8-12: 2-4: 1: 2-4, spreading and cooling to 25-35 ℃, adding the bran shells, the oak chips and the Daqu powder pretreated in the step a, uniformly mixing to obtain a mixture, and fermenting to obtain the white wine with the oak flavor.

In order to provide water required by fermentation of the sorghum raw material, remove partial tannin and other substances in the sorghum and improve the liquor quality, preferably, in the step b, the grain moistening is to mix the sorghum and water at 80-90 ℃ according to the mass ratio of 4-6: 2-4, and keep the temperature for 120-150 min; the gelatinization time is 35-45 min.

In order to promote the exchange of substances by the microbial community in the system and to allow substances in the oak wood which are difficult to leach and decompose to participate in the reaction, it is preferable that Fe is added before fermentation in the step c₃O₄The nano particles and the mixture are uniformly mixed according to the mass ratio of 1: 24000-26000.

Fe as described above₃O₄The nano particles are: Small-Fe with grain diameter of 10-50nm₃O₄Big-Fe with particle size of 250-450nm₃O₄Histidine modified His-Fe with particle size of 50-100nm₃O₄Any one of them.

The above Big-Fe₃O₄The preparation method comprises the following steps: completely dissolving ferric chloride and trisodium citrate in ethylene glycol according to the mass ratio of 13: 4: 440: 24, adding sodium acetate, violently stirring until the mixture is uniformly mixed, transferring the mixture into a high-pressure kettle, heating for 10 hours at 200 ℃, washing a product with ethanol, and drying to obtain the Big-Fe with the particle size of 250-450nm₃O₄。

For better experimental results, it is therefore preferred that the vigorous stirring time is 30-40 minutes, the autoclave is a stainless steel autoclave lined with Teflon and the drying temperature is 55-65 ℃.

The above His-Fe₃O₄The preparation method comprises the following steps: completely dissolving ferric chloride hexahydrate in ethylene glycol according to the mass ratio of 4: 220: 18: 5, adding sodium acetate and histidine, violently stirring until the mixture is uniformly mixed, then carrying out ultrasonic treatment on the mixture for 10-15 minutes, transferring the mixture into a reactor, heating the mixture at 200 ℃ for 12 hours, washing the product with ethanol, and drying to obtain histidine-modified His-Fe with the particle size of 50-100nm₃O₄。

For better experimental results, it is therefore preferred that the vigorous stirring time is 30 to 40 minutes, the reactor is a polytetrafluoroethylene reactor, and the drying temperature is 55 to 65 ℃.

The technical solution and effects of the present invention will be further described below by way of practical examples.

Examples

(1)Fe₃O₄Synthesis of NPs

①Small-Fe₃O₄: obtained by market purchase.

②Big-Fe₃O₄: 0.65g of ferric chloride and 0.20g of trisodium citrate are completely dissolved in 20mL of ethylene glycol, then 1.20g of sodium acetate are added and stirred vigorously for 30 minutes. The mixture was transferred to a 50ml teflon lined stainless steel autoclave, heated at 200 ℃ for 10h, the product washed three times with ethanol and dried at 60 ℃ for future use.

③His-Fe₃O₄: 0.82g of ferric chloride hexahydrate was completely dissolved in 40mL of ethylene glycol, followed by the addition of 3.6g of sodium acetate and 1g of histidine and vigorous stirring for 30 minutes, followed by sonication for 10 minutes, the mixture was transferred to a 50mL polytetrafluoroethylene reactor, heated at 200 ℃ for 12h, the product washed three times with ethanol and dried at 60 ℃ until use.

Small-Fe obtained in the above₃O₄，Big-Fe₃O₄，His-Fe₃O₄0.16g of each of the solutions was weighed and added to 16mL of distilled water, respectively, to obtain a stock solution having a concentration of 10 mg/mL.

(2) Pretreatment and gelatinization of materials

Oak pretreatment: pulverizing oak with high speed Chinese medicinal pulverizer, and sieving with 20 mesh (0.85mm) sieve to obtain oak dust. Steaming oak dust in 100 deg.C steam pot for 30min to reduce foreign flavor in oak, spreading, air drying, and cooling.

Pretreating bran shells: steaming bran shell in 100 deg.C steam pot for 30min to remove furfural and other foreign flavor, spreading, air drying, and cooling.

Weighing 500g of sorghum by using a balance, putting the sorghum into a beaker, adding 300mL of hot water (85 ℃) for grain moistening, and keeping for 140 min; after the grain moistening is finished, the sorghum is placed into a steamer to be gelatinized by steam with the temperature of 100 ℃, and the gelatinization is kept for 40 min.

(3)Fe₃O₄Brewing white spirit with nano particles

Adding 100mL of water into gelatinized sorghum, spreading and cooling to 30 ℃, then adding 100g of pretreated bran shells and 100g of Daqu powder, stirring uniformly to form a mixture, and then carrying out the following steps:

and ANC group: weighing 200g of the mixture and putting the mixture into a 250mL fermentation tank;

group A1: aspirate 800. mu.L of Small-Fe at 10mg/mL₃O₄Mixing with 200g of the mixture, and loading into a 250mL fermentation tank;

group A2: absorb 800 mu L of 10mg/mL Big-Fe₃O₄Mixing with 200g of the mixture, and loading into a 250mL fermentation tank;

group A3: aspirate 800. mu.L of 10mg/mL His-Fe₃O₄Mix well with 200g of the mixture and load into a 250mL fermentor.

And (4) putting the fermentation tank into an incubator for fermentation for 28 days.

(4) Oak and Fe₃O₄Brewing white spirit with nano particles

Adding 100mL of water into gelatinized sorghum, spreading and cooling to 30 ℃, adding 50g of pretreated bran shells, 50g of pretreated oak chips and 100g of yeast powder, uniformly stirring to form a mixture, and then carrying out the following steps:

BNC group: weighing 200g of the mixture and putting the mixture into a 250mL fermentation tank;

group B1: aspirate 800. mu.L of Small-Fe at 10mg/mL₃O₄Mixing with 200g of the mixture, and loading into a 250mL fermentation tank;

group B2: absorb 800 mu L of 10mg/mL Big-Fe₃O₄Mixing with 200g of the mixture, and loading into a 250mL fermentation tank;

group B3: aspirate 800. mu.L of 10mg/mL His-Fe₃O₄Mix well with 200g of the mixture and load into a 250mL fermentor.

And (4) putting the fermentation tank into an incubator for fermentation for 28 days.

(5) Detection of the results of the experiment

Physicochemical analysis and detection are carried out on fermented grains after fermentation of group A, and the contents of starch and reducing sugar in the fermented grains are shown in figure 1; after the fermentation of group B, the contents of starch and reducing sugar in fermented grains are shown in FIG. 2.

As can be seen from FIGS. 1 and 2, the starch content of fermented grains A3 was the lowest, while the starch content of fermented grains A1 and ANC was higher, indicating that His-Fe₃O₄The addition of the material is beneficial to the utilization of starch; the starch content in the fermented grains of the BNC group added with the oak chips is higher than that of the ANC group, which shows that the addition of the oak chips weakens the utilization of the starch in the fermented grains; the B1 group had the lowest starch content, indicating Small-Fe₃O₄The co-fermentation of the material and the oak dust can promote the utilization of starch.

② the acidity of the fermented grains after the fermentation is finished is detected by phenolphthalein neutralization titration, and the result is shown in table 1.

TABLE 1 acidity (mmol/g)

	NC	1	2	3
					Fe3O4(A)	0.109	0.1	0.097	0.093
Fe3O4+ oak chip (B)	0.078	0.095	0.081	0.074

As is clear from Table 1, the acidity of fermented grains A1, A2 and A3 was lower than that of the fermented grains ANC group, indicating that Fe₃O₄The addition of the nano material can reduce the acidity in the fermented grains; the group B added with oak dust can obviously show that the acidity of the fermented grains is lower than that of the group A, which indicates that the oak and the Fe are all₃O₄The nanometer material can promote the conversion of acid in wine and further reduce the acid content.

③ taking 50g of fermented grains out of the fermentation tanks of the group A and the group B, adding 100mL of I-grade water for mixing, putting into a distillation flask for distilling to obtain 50mL of wine. And (3) analyzing volatile flavor substances in the wine by adopting a headspace solid-phase microextraction-gas mass spectrometry (HS-SPME-GC/MS) method for the distilled wine sample, and performing semi-quantification on the flavor substances in the wine by using 2-octanol as an internal standard. The relative proportions of the aldol phenols in the various wine samples were analyzed and the results are shown in figure 3.

As can be seen from FIG. 3, the addition of Fe alone₃O₄For the A group of the nano particles, the proportion of alcohol substances in the A1 and A3 groups is as high as 85 percent; the proportion of the phenolic substances in A2 and A3 is more than 2 percent; the proportion of esters in ANC and A2 is higher. And adding oak dust and Fe₃O₄The B group of the nano particles is obviously different from the A group, and the relative proportion of alcohol substances in B1 and B2 is high; the proportion of esters and phenols in B3 can reach up to 19% and 5%, and the proportion of alcohols is the lowest; the proportion of aldehydes in BNC is highest. Analysis of groups A and B gives, Small-Fe₃O₄Big-Fe which inhibits the conversion of alcohols to esters₃O₄Capable of converting alcohols into phenols, His-Fe₃O₄Conversion of energetic aldehydes to phenols; the added oak dust can convert alcohol into ester and acid, and convert aldehyde into phenol.

Thus, it was confirmed that oak and Fe₃O₄The nanometer particles can generate more kinds of flavor substances in the liquor under the synergistic effect, so that the liquor is plump.

And fourthly, measuring the volatile flavor substances of the wines by using an HS-SPME-GC/MS method, carrying out hierarchical clustering and heat map visualization by analyzing the relation between the types and the contents of the flavor substances in different samples, wherein the A group result is shown in figure 4, and the B group result is shown in figure 5.

As can be seen from FIG. 4, the ANC samples in group A were classified individually, while A1, A2 and A3 were classified as a group, indicating that the aroma components in ANC were compared with Fe₃O₄The nanoparticles differ significantly in the groups a1, a2 and A3. The aroma components in the wine are classified into four types, wherein the I type substance has higher ANC content, and mainly comprises ester substances (ethyl caprylate, diethyl azelate) and acids (n-decanedioic acid)Acids, octanoic acid), n-octanol and small amounts of aldehydes, phenols; the content of class II substances in A2 and A3 is high, and the class II substances mainly comprise octyl alcohol and furfuryl aldehyde, wherein the content of esters (ethyl butyrate, isobutyl acetate and ethyl cinnamate) in A3 is high; the III substances are higher in A1 and A3, mainly comprise higher fatty acid esters, phenols (guaiacol) and other flavor substances, wherein the higher alcohol (heptanol) is high in A1 and ANC; the IV substances are mainly contained in A1 and A2, and comprise typical Chinese liquor flavor substances such as ethyl esters (ethyl acetate, ethyl lactate, ethyl palmitate, ethyl linoleate and the like), lower alcohols (ethanol and the like), aldehydes (acetaldehyde and the like), acids (acetic acid), phenols (4-ethylphenol) and the like. The alcohol and ester contents in the ANC group are far lower than that of the ANC group added with Fe₃O₄Set of nanoparticles, description of Fe₃O₄Has promoting effect on the generation of alcohol and ester in the fermentation of Chinese liquor.

As can be seen from fig. 5, in the group B to which oak chips were added, the samples B1 and B2 were classified into one group and the BNC group and B3 were classified into one group according to the flavor of each group, indicating that the fragrance difference between the groups B1 and B2 and the groups BNC and B3 was significant. The flavors in the samples were divided into four broad categories. The content of the I-type substances in the group B1 is high, and the I-type substances mainly comprise aldehydes (furfural, octyl aldehyde, benzaldehyde and the like), tridecanol and phenol; the class II substances are also highest in the group B1, second in the group B2 and lowest in BNC, and mainly comprise typical white spirit flavors (ethyl caproate and ethyl lactate) and oak flavors (whiskey lactone) and other ethyl esters, acids (acetic acid), a small amount of alcohols, aldehydes, furan (2-pentylfuran), ketone (3-octen-2-one) and the like; the III substances are mainly concentrated in groups B2 and B3, and mainly comprise aldehydes (acetaldehyde), esters (isoamyl lactate), alcohols (ethanol) and the like; the IV substances are concentrated in B3, and BNC is the second time, and mainly comprises fatty acid esters (ethyl oleate, ethyl linolenate) and ethyl acetate, phenols (guaiacol, phenol and the like), a small amount of fatty acids (linoleic acid), aldehydes (valeraldehyde), alcohols (phenethyl alcohol, heptanol) and the like.

According to the statistics of experimental data, the types of the flavor substances in the group A are 54, the types of the flavor substances in the group B added with the oak are 76, and the more types are mainly esters and aldehydes, so that the flavor of the white spirit is obviously enhanced by adding the oak, and the white spirit is more mellow.

After fermenting for 28 days, total alcohol content and total ester content in A, B groups of samples are analyzed and are shown in figure 6; A. the contents of total aldehydes and total phenols in group B are shown in FIG. 7.

As can be seen from FIG. 6, the total alcohol content (123.9. mu.g/mL) and total ester content (34.1. mu.g/mL) of ANC in the control group were the lowest among all samples, and the total alcohol content (844.7. mu.g/mL) and total ester content (148.2. mu.g/mL) of A1 were the highest, about 5.8 times and 3.3 times the ANC group, respectively, indicating the addition of Fe₃O₄The nanoparticles can effectively promote the efficiency of alcohol and ester production in the fermentation process, wherein Small-Fe₃O₄The most efficient is facilitated. In group B, the total alcohol content (443.2. mu.g/mL) and total ester content (58.9. mu.g/mL) of group B3 were the highest, increased by 44.3% and 54.8% respectively over group BNC, the total ester content (35.7. mu.g/mL) was the lowest in group B2, and the total alcohol content (258.9. mu.g/mL) was the lowest in group B1, indicating His-Fe in the presence of oak₃O₄The best effect is achieved on alcohol production and ester production. For the absence of Fe₃O₄For the nano particle ANC group and the BNC group, the total alcohol and ester contents of the BNC group are higher than those of the ANC group, which shows that the alcohol and ester contents in the wine are increased by adding the oak.

As can be seen from FIG. 7, A1 was highest in the total aldehyde content (19.054. mu.g/mL) of group A, which was about 5.4 times that of group ANC; group B1 highest in total aldehyde content (22.265 μ g/mL) in group B, about 4.5 times that of group BNC; the total phenol content of the A3 in the A group is highest (14.772 mug/mL), which is 51.6 percent higher than that of the BNC group; group B3 contained the highest total phenol content (18.517. mu.g/mL) in group B, which was about 2 times that of group BNC. Illustrating Small-Fe₃O₄Has promoting effect on the generation of aldehydes, His-Fe₃O₄Has effect in promoting generation of phenols. Comparison of ANC and BNC shows that the addition of oak promotes the generation of aldehydes in a fermentation system, reduces the content of phenolic substances and reduces the foreign flavor of wine body pathogens.

In conclusion, the preparation method of the invention uses Fe₃O₄The nanoparticles and oak act synergistically to participate in the whole solid-state fermentation process of Chinese liquor, and exchange substances under the action of microbial community in the system, and the metabolism of the microorganisms makesSubstances which are difficult to extract and decompose in the oak participate in the reaction, so that the liquor is endowed with unique flavor. The white spirit brewed by the method is softer and plump in body and has structural sense; various aromatic components contained in the oak are dissolved in the liquor, so that the Chinese white liquor has an extra elegant style; the invention not only ensures the obvious flavor characteristics of the traditional brewed white spirit, reduces the evil and foreign flavor brought by bran shells, but also combines the unique flavor of foreign liquor, and provides a first opportunity for further expanding the world market for the Chinese white spirit.