CN109593627B

CN109593627B - Electric field strengthening brewing process of sea-buckthorn and Chinese wolfberry health-care fruit wine

Info

Publication number: CN109593627B
Application number: CN201910128896.4A
Authority: CN
Inventors: 贺丹; 王福鑫; 刘双
Original assignee: Cardenburg Wine China Co ltd
Current assignee: Zebra Tongda Anhui Technology Co ltd
Priority date: 2019-02-21
Filing date: 2019-02-21
Publication date: 2021-10-22
Anticipated expiration: 2039-02-21
Also published as: CN109593627A

Abstract

The invention discloses an electric field strengthening brewing process of sea-buckthorn and Chinese wolfberry health care fruit wine, which comprises the following process flows of raw material pretreatment, enzymolysis, component adjustment, yeast cell immobilization, electric field strengthening alcohol fermentation, clarification, filtration sterilization, aging acceleration and filling, wherein the sea-buckthorn and Chinese wolfberry mixed fruit juice is fermented into low-alcohol-degree fruit wine by utilizing immobilized saccharomyces cerevisiae and adopting an electric field strengthening liquid fermentation mode, and then the sea-buckthorn and Chinese wolfberry health care fruit wine beverage is obtained through subsequent treatment. The adaptation period after inoculation of the immobilized yeast is short, the total fermentation time can be saved, the immobilized yeast can be reused, the complicated operations of re-inoculation of each batch, sterilization of a fermentation tank and the like in intermittent fermentation are omitted, the production cost is reduced, and the production efficiency is improved; the electric field reinforced liquid fermentation technology can promote the growth and metabolism of yeast cells, solve the problems of low alcohol production rate, low conversion rate and long fermentation period, can also obviously improve the quality of fruit wine, and has wide practicability.

Description

Electric field strengthening brewing process of sea-buckthorn and Chinese wolfberry health-care fruit wine

Technical Field

The invention relates to an electric field enhanced brewing process of sea-buckthorn and Chinese wolfberry health care fruit wine, belonging to the field of food processing.

Background

Seabuckthorn is a plant of the genus hippophae of the family elaeagnus, also known as hippophae rhamnoides, yellow thorn, sour thorn, black thorn, sour soup, sea buckthorn and the like, and the fruit of seabuckthorn is a small berry containing nutritional ingredients such as vitamin C, vitamin E, carotenoid, amino acid, unsaturated fatty acid, flavonoid compounds, phospholipid compounds, sterol compounds, trace elements, proteins and the like, wherein the contents of vitamin C and vitamin E are in the head of all fruits and vegetables, and the seabuckthorn is called 'vitamin treasure house'. The seabuckthorn fruit has outstanding edible and medicinal values, can enhance the immunity of a human body, reduce blood pressure, reduce cholesterol and relieve angina attack after being eaten frequently, can also prevent and treat coronary atherosclerotic heart disease, has the functions of eliminating phlegm, relieving cough and asthma and treating chronic tracheitis, and can also treat gastric ulcer, duodenal ulcer, dyspepsia and other diseases. In China, the planting area of the sea buckthorn is quite wide, but the picking period of the sea buckthorn fruits is short and not easy to store, the market is limited by seasons, people can hardly taste the fresh sea buckthorn fruits all the year round, the sea buckthorn fruits are small, the taste is sour, and the sea buckthorn fruits cannot be accepted by all people when being directly eaten.

The medlar is a plant of medlar of solanaceae, the fruit of the medlar is also called medlar, red eardrop and beet, is a famous and precious traditional Chinese medicine material in China and abroad, is listed as a top-grade product as early as Shennong herbal classic, is called as 'light body and not old, cold and summer heat resistant after long-time taking, has the efficacy of delaying senility and resisting aging', and is also called 'charpy'. The medlar has various health care efficacies and is a medicine and food dual-purpose food approved by the Ministry of health. The medlar contains rich medlar polysaccharide, amino acid, betaine, zeaxanthin, baccatin, beta-carotene, vitamin E, flavone and other nutrient components, and has multiple effects of resisting oxidation, resisting aging, resisting tumor, regulating immunity, lowering blood pressure, lowering blood sugar, lowering blood fat and the like. However, fresh medlar is not easy to store, and is usually stored after being dried and aired, and phenomena of insect growth, mildew, color change and the like often occur due to the influence of environmental conditions.

The fruit wine is fermented wine with low alcohol content prepared by using fresh fruit or fruit juice as raw material and through sugar regulation, acid regulation and other technological processes. The alcohol content in the fruit wine is lower than that of white wine, grape wine and the like, generally ranges from 5% to 10%, the alcohol content is slightly higher than that of the grape wine by about 14%, and the proper drinking of the fruit wine can promote the metabolism and blood circulation of organisms, so that the effects of stabilizing blood pressure, preventing arteriosclerosis and the like are achieved. Therefore, the sea-buckthorn and the medlar are made into the fruit wine by a certain brewing process, the fruit wine is easy to store, can well keep the nutritional ingredients of the fruit wine, has a certain health-care function, integrates sanitation, nutrition, health care and safety, and can be eaten for a long time. At present, the fruit wine market in China still has the problems of few varieties, low yield, small production scale, low quality and the like, and a certain consumption scale is not formed. Along with the increasing living standard of people, the health attention of people is gradually strengthened, so the share of health care consumption in the market is increased, and the fruit wine beverage with the health care function gradually draws the attention of people. In future, with the gradual deepening of people's understanding of health-care fruit wine, the fruit wine becomes a new economic growth point and has huge development prospect.

The fruit resources and varieties in China are rich, in recent years, due to policy support, a plurality of fruit wine manufacturers appear in succession, but the scale of the fruit wine production enterprises is small, so that the technical equipment for producing the fruit wine is far away from the operation level requirement of modernization, the fruit wine production can be still simply and mechanically operated, the production efficiency is low, the product quality cannot be guaranteed, brand products cannot be molded, and the industrial advantage cannot be formed to strengthen the production. The fermentation process in the fruit wine brewing process is one of key technical links, but in the prior art, the problems of incomplete control of fermentation conditions, low utilization rate of strains, slow alcohol generation rate, low conversion rate, long fermentation period and the like exist. Therefore, for brewing the fruit wine, the process conditions need to be continuously optimized, and meanwhile, a plurality of advanced technologies at home and abroad are adopted to improve the process level of the fruit wine production in China so as to promote the fruit wine industry to develop towards the large-scale and modernized direction.

Disclosure of Invention

Aiming at some problems in the prior fruit wine brewing technology, the invention provides an electric field strengthening brewing process of sea-buckthorn and Chinese wolfberry health care fruit wine by introducing an immobilized cell technology, so that the problems of low generation rate, low conversion rate and long fermentation period in the alcohol fermentation process are solved, the production efficiency of enterprises can be improved, and the production cost is reduced.

The invention is realized by the following technical scheme:

an electric field strengthening brewing process of sea-buckthorn medlar health care fruit wine is characterized in that the process flow comprises the following steps:

(1) pretreatment of raw materials: selecting fresh and mature fructus Hippophae and fructus Lycii, removing secondary fruit and bad fruit, cleaning with clear water, respectively placing cleaned fresh fruit in pulping machine, adding 3 times of water, and pulping for about 1min to obtain fructus Hippophae pulp and fructus Lycii pulp;

(2) enzymolysis: respectively adding 0.1-0.2% of complex enzyme into the sea buckthorn fruit pulp and the medlar fruit pulp, performing enzymolysis for 2-3 h at 50 ℃, inactivating enzyme for 15-20 min at 65 ℃, cooling and filtering;

(3) component adjustment: mixing the sea buckthorn juice and the medlar juice according to a certain proportion, adding glucose and sucrose to adjust the concentration of soluble solids so that the initial sugar degree reaches 20-22%, adding sodium citrate to adjust the pH value so that the pH value reaches 3.7-4.3, and then adding 0.04-0.06% of ascorbic acid and 0.9-1.1% of glutathione;

(4) yeast cell immobilization: after the saccharomyces cerevisiae strain is subjected to propagation culture, yeast cells are obtained through centrifugal separation and are resuspended in sterile water to prepare a bacterial suspension; preparing a mixed solution consisting of polyvinyl alcohol, sodium alginate and polyvinylpyrrolidone, heating and stirring the mixed solution in a water bath kettle at about 100 ℃ to be in a uniform state, standing and cooling the mixed solution, mixing the mixed solution cooled to below 30 ℃ with the bacterial suspension according to a volume ratio of 1:1, uniformly stirring the mixed solution, pouring the mixed solution into a culture dish, freezing the mixed solution in a refrigerator with the thickness of 3-4 mm for 12 hours at-20 ℃, unfreezing the mixed solution at 4 ℃ for 12 hours, freezing and unfreezing the mixed solution for 3 times, cutting the frozen and unfrozen mixed solution into small blocks with the thickness of 4-5 mm, and fully cleaning the small blocks with sterile water for later use;

(5) electric field enhanced alcohol fermentation: sterilizing the mixed fruit juice obtained in the step (3) in an airlift fermentation tank at 70-75 ℃ for 10min, cooling to room temperature, inoculating immobilized saccharomyces cerevisiae in an aseptic operation mode, uniformly stirring for alcoholic fermentation, controlling the fermentation temperature at 23-25 ℃, controlling the dissolved oxygen at 2-4 mg/L, starting electric field strengthening treatment after fermenting for 11-15 h, wherein the electrode material is a graphite electrode, the electric field action strength is 150V/m, electrifying for 2h in the same time period every day, the total fermentation time is 4-6 d, and the alcoholic strength reaches 8.2-8.5% vol;

(6) clarification, filtration and sterilization: discharging the fermentation liquor into an aseptic container, slowly adding a chitosan solution with the concentration of 2-2.5% under continuous stirring, standing at 24-28 ℃ for 5-6h to obtain clear liquor, and filtering and sterilizing the liquor by using an ultrafiltration membrane;

(7) aging and filling: and (3) carrying out aging acceleration on the filtrate by adopting an ultrahigh pressure technology, wherein the pressure is 200-300 MPa, and the time is 35-45 min, canning the obtained wine liquid in a vacuum sterile environment, and obtaining the finished product of the sea-buckthorn and Chinese wolfberry health-care fruit wine after the canning is qualified through inspection.

The complex enzyme in the step (2) comprises 5 parts of pectinase, 2 parts of cellulase and 1 part of tannase.

The ratio of the seabuckthorn fruit juice to the medlar fruit juice in the step (3) is 3: 2.

The proliferation culture method in the step (4) comprises the following steps: and inoculating the saccharomyces cerevisiae strain into a sterile YPD liquid culture medium, and carrying out shake culture in a shaking table at the temperature of 28 ℃ and at the speed of 150r/min for 48-72 h.

The centrifugation parameters in the step (4) are as follows: the rotating speed is 8000r/min, and the time is 5 min.

The mass concentration of polyvinyl alcohol, the mass concentration of sodium alginate and the mass concentration of polyvinylpyrrolidone in the mixed solution in the step (4) are respectively 8%, 1% and 1.5%.

The inoculation amount of the immobilized yeast in the step (5) is 0.6-0.8%.

The operation of filtering and sterilizing by the ultrafiltration membrane in the step (6) is as follows: and filtering the liquor through an ultrafiltration membrane with the aperture of 0.45 mu m under the pressure of 8-10 MPa to obtain filtrate.

In the step (5), after the fermentation liquor meets the alcoholic strength requirement, the fermentation liquor is discharged through the filter screen, the immobilized saccharomyces cerevisiae is still kept in the fermentation tank, the next batch of sterilized mixed juice is added into the fermentation tank for electric field enhanced alcoholic fermentation, and the immobilized saccharomyces cerevisiae can be recycled by about 30 batches.

Compared with the prior art, the invention has the advantages that:

1. the invention utilizes the immobilized saccharomyces cerevisiae to carry out alcohol fermentation, the growth dead time of yeast cells after inoculation is short, the cell density is high, the activity can be kept for a long time, the fermentation process is stable, and the product is easy to separate and purify; the immobilized yeast can be repeatedly used for about 30 batches, so that the repeated operations of cleaning, sterilizing, inoculating and the like of equipment are reduced, the fermentation period is shortened, the pollution probability can be reduced, the utilization rate of the equipment is improved, the production efficiency is greatly improved, and the production cost is reduced.

2. The invention applies the electric field strengthening liquid state fermentation technology to the brewing process of the fruit wine, the electric field treatment with proper strength can promote the growth and the propagation of yeast cells, greatly increase the yeast quantity, improve the metabolism rate of the yeast cells, promote the generation of beneficial secondary metabolites, and solve the problems of low generation rate, low conversion rate and long fermentation period in the alcohol fermentation process.

3. The method adopts an ultrafiltration membrane technology to filter and sterilize the wine liquid, adopts an ultrahigh pressure technology to age the wine liquid, reduces the loss of nutrient components and shortens the aging time compared with the traditional high-temperature sterilization technology and natural aging.

4. The brewing process of the fruit wine is reasonable in design and environment-friendly, the nutritional ingredients of the sea buckthorn and the medlar are greatly reserved, so that the produced fruit wine has high nutritional value and a strong health-care function, and the development and utilization approaches of the sea buckthorn and the medlar are widened.

Drawings

FIG. 1 shows the effect of initial brix on wine fermentation;

FIG. 2 shows the effect of immobilized yeast inoculum size on fruit wine fermentation;

FIG. 3 shows the effect of fermentation temperature on fruit wine fermentation;

FIG. 4 shows the effect of the strength of the electric field on the fermentation of fruit wine;

FIG. 5 shows the analysis of the recycling effect of immobilized yeast.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

All the raw and auxiliary materials, reagents, instruments and equipment selected for use in the present invention are well known in the art and are not intended to limit the practice of the present invention, and other reagents and equipment known in the art may be used in the practice of the following embodiments of the present invention.

Example 1

An electric field strengthening brewing process of sea-buckthorn medlar health care fruit wine comprises the following steps:

(2) enzymolysis: respectively adding 0.1-0.2% of complex enzyme in mass fraction into the sea buckthorn fruit pulp and the medlar fruit pulp, wherein the complex enzyme comprises 5 parts of pectinase, 2 parts of cellulase and 1 part of tannase, performing enzymolysis for 2-3 h at 50 ℃, inactivating enzyme for 15-20 min at 65 ℃, cooling and filtering;

(3) component adjustment: mixing fructus Hippophae juice and fructus Lycii juice at a ratio of 3:2, adding glucose and sucrose to adjust soluble solid concentration to make initial sugar degree reach 21%, adding sodium citrate to adjust pH to make pH reach 4.0, and adding 0.05% ascorbic acid and 1.0% glutathione;

(4) yeast cell immobilization: inoculating Saccharomyces cerevisiae strain (active dry yeast, purchased from Angel Yeast Co., Ltd.) into sterile YPD liquid culture medium, shake culturing at 28 deg.C in 150r/min shaking table for 72h, separating by centrifugation (rotation speed 8000r/min, time 5 min) to obtain yeast cells, and suspending in sterile water to obtain bacterial suspension; preparing a mixed solution with the mass concentration of 8% of polyvinyl alcohol, 1% of sodium alginate and 1.5% of polyvinylpyrrolidone, heating and stirring the mixed solution in a water bath kettle at about 100 ℃ to be uniform, standing and cooling the mixed solution, mixing the mixed solution cooled to below 30 ℃ with the bacterial suspension according to the volume ratio of 1:1, uniformly stirring the mixed solution, pouring the mixed solution into a culture dish with the thickness of 3-4 mm, freezing the mixed solution in a refrigerator at-20 ℃ for 12h, then unfreezing the mixed solution at 4 ℃ for 12h, freezing and unfreezing the mixed solution for 3 times, cutting the frozen and unfrozen mixed solution into small blocks with the thickness of 4-5 mm, and fully cleaning the small blocks with sterile water for later use;

(5) electric field enhanced alcohol fermentation: sterilizing the mixed fruit juice obtained in the step (3) in an airlift fermentation tank at 70-75 ℃ for 10min, cooling to room temperature, inoculating immobilized saccharomyces cerevisiae in an aseptic operation mode, wherein the inoculation amount is 0.7%, uniformly stirring for alcohol fermentation, controlling the fermentation temperature at 24 ℃, controlling the dissolved oxygen content at 3mg/L, starting electric field strengthening treatment after fermenting for 13h, wherein the electrode material is a graphite electrode, the electric field action strength is 150V/m, electrifying for 2h in the same time period every day, the total fermentation time is 5d, and the alcoholic strength reaches 8.2-8.5% vol;

(6) clarification, filtration and sterilization: discharging the fermentation liquor into an aseptic container, slowly adding a chitosan solution with the concentration of 2-2.5% under continuous stirring, standing at 24-28 ℃ for 5-6h to obtain clear liquor, and filtering and sterilizing the liquor by an ultrafiltration membrane with the pore diameter of 0.45 mu m under the condition that the pressure is 8-10 MPa to obtain filtrate;

(7) aging and filling: aging the filtrate under 250MPa for 40min under ultrahigh pressure, canning the obtained wine liquid under vacuum sterile environment, and inspecting to obtain fructus Hippophae and fructus Lycii health fruit wine;

(8) and (3) determination: the alcohol content and sensory score of the finished product of the sea-buckthorn and Chinese wolfberry health-care fruit wine are measured, and the sensory score standard is shown in the following table 1.

Example 2 Effect of initial sugar content on fruit wine fermentation

On the basis of example 1, the initial sugar degrees in step (3) were set to 15%, 17%, 19%, 21% and 23%, respectively, and the final finished wine was subjected to alcoholic strength and sensory score measurements, and the results are shown in fig. 1. As can be seen from figure 1, with the increase of the initial sugar degree, the alcoholic strength and sensory score of the finished fruit wine show the tendency of increasing first and then decreasing, when the initial sugar degree is 21%, the quality of the finished fruit wine is the best, at the moment, the alcoholic strength is 8.36%, the sensory score is 80.1%, and probably because the saccharomyces cerevisiae takes sugar as a raw material to perform growth metabolism and generate flavor substances such as alcohol, lipid and the like, the alcoholic strength and flavor of the fruit wine can be gradually improved with the increase of the initial sugar content, when the initial sugar content exceeds a certain range, the growth metabolism of the saccharomyces cerevisiae can be inhibited, and further the alcoholic strength and sensory score of the fruit wine are reduced, so that 21% is the best initial sugar degree.

Example 3 Effect of immobilized Yeast inoculum size on fruit wine fermentation

The results of alcoholic strength and sensory score measurements on the final finished fruit wine were carried out on the immobilized yeast strains in step (5) set at 0.3%, 0.5%, 0.7%, 0.9% and 1.1% on the basis of example 1, and are shown in FIG. 2. As can be seen from the figure 2, the alcoholic strength of the finished fruit wine is gradually improved with the increase of the inoculation amount of the immobilized yeast, when the inoculation amount is 0.7%, the alcoholic strength reaches 8.42%, and then the alcoholic strength is not greatly changed with the increase of the inoculation amount; the sensory score of the fruit wine shows a tendency of ascending first and then descending along with the increase of the inoculation amount, when the inoculation amount is 0.7%, the sensory score reaches 81.7 minutes and is obviously superior to other inoculation amounts, which is probably because the fermentation speed of the fruit wine is slow and the fermentation is incomplete when the inoculation amount is low, thereby affecting the alcoholic strength and the flavor; when the inoculation amount is too high, more fusel is left to influence the taste of the fruit wine and reduce sensory score, so that 0.7 percent of the inoculation amount is the optimal immobilized yeast inoculation amount.

Example 4 Effect of fermentation temperature on fruit wine fermentation

The final wine products were measured for alcohol content and sensory score by setting the fermentation temperature in step (5) to 20 ℃, 22 ℃, 24 ℃, 26 ℃ and 28 ℃ respectively, based on example 1, and the results are shown in fig. 3. As can be seen from figure 3, the alcoholic strength and sensory score of the finished fruit wine show a tendency of increasing first and then decreasing with the increase of the fermentation temperature, when the fermentation temperature is 24 ℃, the quality of the finished fruit wine is the best, the alcoholic strength is 8.39%, the sensory score is 79.8 min, which is probably because the fermentation temperature can influence the growth and metabolism rate of yeast; when the temperature is too low, the yeast grows and metabolizes slowly, so that the alcoholic strength and the mouthfeel of the fruit wine are influenced; when the temperature is too high, the yeast grows and metabolizes too vigorously, so that the saccharides are not completely converted into alcohol, the alcoholic strength is reduced, and the quality of the fruit wine is further influenced, therefore, the optimal fermentation temperature is 24 ℃.

EXAMPLE 5 Effect of the intensity of the electric field on the fermentation of fruit wine

In addition to example 1, the strengths of the electric field applied in step (5) were set to 100V/m, 150V/m, 200V/m, 250V/m and 300V/m, respectively, and the final wine product was subjected to alcoholic strength and sensory score measurements without electric field strengthening treatment (0V/m) as a control, and the results are shown in FIG. 4. As can be seen from figure 4, when the strength of the electric field is 100V/m, 150V/m and 200V/m, the alcoholic strength and sensory score of the finished fruit wine are both higher than those of the control group, and when the strength of the electric field is 150V/m, the quality of the finished fruit wine is the best, at the moment, the alcoholic strength is 8.45 percent, and the sensory score is 80.7 minutes; when the electric field strength is 250V/m and 300V/m, the alcoholic strength and sensory score of the finished fruit wine are lower than those of the control group. The reason is probably that the influence of different electric field action strengths on yeast growth and metabolism is different, the proper electric field action strength can promote yeast cell growth and propagation, the yeast quantity is greatly increased, the yeast cell metabolism rate can be improved, and the generation of beneficial secondary metabolites is promoted, and the excessively high electric field action strength can inhibit the yeast cell growth and metabolism and is not beneficial to fruit wine fermentation, so that the electric field action strength of 150V/m is the optimal electric field action strength.

Example 6 analysis of Recycling Effect of immobilized Yeast

On the basis of the example 1, when the fermentation liquor in the step (5) meets the alcoholic strength requirement, the fermentation liquor is discharged through a filter screen, the immobilized saccharomyces cerevisiae still remains in the fermentation tank, the next batch of sterilized mixed fruit juice is added into the fermentation tank for carrying out electric field enhanced alcoholic fermentation, 40 batches are recycled in this way, and the alcoholic strength and sensory score of the final fruit wine products of 10 th, 20 th, 30 th and 40 th batches are respectively measured by taking the example 1 as a control group, and the result is shown in fig. 5. As can be seen from figure 5, when 30 batches of the immobilized yeast are recycled, the alcoholic strength of the finished fruit wine is 8.30%, the sensory score is 79.9, the alcoholic strength of the finished fruit wine is reduced compared with that of a control group, but the alcoholic strength of the finished fruit wine still can reach the alcoholic strength standard, and when 40 batches of the immobilized yeast are recycled, the alcoholic strength of the finished fruit wine is 8.05%, and the alcoholic strength of the finished fruit wine cannot reach the standard, so that the immobilized yeast can be recycled for about 30 batches.

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable to various fields of endeavor for which the invention may be embodied with additional modifications as would be readily apparent to those skilled in the art, and the invention is therefore not limited to the details given herein and to the embodiments shown and described without departing from the generic concept as defined by the claims and their equivalents.

Claims

1. An electric field strengthening brewing process of sea-buckthorn medlar health care fruit wine is characterized in that the process flow comprises the following steps:

(1) pretreatment of raw materials: selecting fresh and mature fructus Hippophae and fructus Lycii, removing secondary fruit and bad fruit, cleaning with clear water, respectively placing cleaned fresh fruit in pulping machine, adding 3 times of water, and pulping for 1min to obtain fructus Hippophae pulp and fructus Lycii pulp;

(2) enzymolysis: respectively adding 0.1-0.2% of complex enzyme into the sea buckthorn fruit pulp and the medlar fruit pulp, performing enzymolysis for 2-3 h at 50 ℃, inactivating enzyme for 15-20 min at 65 ℃, cooling and filtering; the compound enzyme comprises 5 parts of pectinase, 2 parts of cellulase and 1 part of tannase;

(4) yeast cell immobilization: after the saccharomyces cerevisiae strain is subjected to propagation culture, yeast cells are obtained through centrifugal separation and are resuspended in sterile water to prepare a bacterial suspension; preparing a mixed solution consisting of polyvinyl alcohol, sodium alginate and polyvinylpyrrolidone, heating and stirring the mixed solution in a water bath kettle at 100 ℃ to be in a uniform state, then placing the mixed solution for cooling, mixing the mixed solution cooled to below 30 ℃ with bacterial suspension according to a volume ratio of 1:1, uniformly stirring the mixed solution, then pouring the mixed solution into a culture dish, freezing the mixed solution in a refrigerator at the temperature of-20 ℃ for 12 hours, then unfreezing the mixed solution at the temperature of 4 ℃ for 12 hours, freezing and unfreezing the mixed solution for 3 times, cutting the frozen and unfrozen mixed solution into small blocks with the size of 4-5 mm, and fully cleaning the small blocks with sterile water for later use;

2. The electric field strengthening brewing process of the sea buckthorn and medlar health care fruit wine according to claim 1, wherein the ratio of the sea buckthorn juice to the medlar juice in the step (3) is 3: 2.

3. The electric field enhanced brewing process of the sea buckthorn medlar health care fruit wine according to claim 1, wherein the propagation culture method in the step (4) comprises the following steps: and inoculating the saccharomyces cerevisiae strain into a sterile YPD liquid culture medium, and carrying out shake culture in a shaking table at the temperature of 28 ℃ and at the speed of 150r/min for 48-72 h.

4. The electric field enhanced brewing process of the sea buckthorn medlar health care fruit wine according to claim 1, wherein the parameters of centrifugation in the step (4) are as follows: the rotating speed is 8000r/min, and the time is 5 min.

5. The electric field strengthening brewing process of the sea buckthorn and wolfberry health care fruit wine as claimed in claim 1, wherein the mass concentration of the polyvinyl alcohol, the mass concentration of the sodium alginate and the mass concentration of the polyvinylpyrrolidone in the mixed solution of the step (4) are respectively 8%, 1% and 1.5%.

6. The electric field enhanced brewing process of the sea buckthorn medlar health care fruit wine according to claim 1, wherein the inoculation amount of the immobilized saccharomyces cerevisiae in the step (5) is 0.6-0.8%.

7. The electric field strengthening brewing process of the sea buckthorn and medlar health care fruit wine according to claim 1, wherein the operation of filtering and sterilizing by the ultrafiltration membrane in the step (6) is as follows: and filtering the liquor through an ultrafiltration membrane with the aperture of 0.45 mu m under the pressure of 8-10 MPa to obtain filtrate.

8. The electric field enhanced brewing process of the sea buckthorn and medlar health care fruit wine as claimed in claim 1, wherein in the step (5), after the fermentation liquor reaches the alcohol degree requirement, the fermentation liquor is discharged through a filter screen, the immobilized saccharomyces cerevisiae is still kept in the fermentation tank, the next batch of sterilized mixed fruit juice is added into the fermentation tank for electric field enhanced alcohol fermentation, and the immobilized saccharomyces cerevisiae can be reused for 30 batches.