A preparation process of a new type of Dornfelter sparkling grape juice

Abstract

The invention relates to a preparation process of a novel Danfit sparkling grape juice, and belongs to the technical field of grape juice preparation. Fully mature, brightly colored, non-rotten and pesticide-free Danfit grape fruits are selected, rinsed in clean water, dried and then the fruit stems are removed; the grapes are crushed after being quickly frozen at low temperature, and the pulp after low-temperature immersion is squeezed using a press to make all the juice flow out; the squeezed juice is first filtered with a filter screen, then put into a sterilized container, a clarifier is added, and naturally clarified at low temperature; the upper clarified liquid is taken and finely filtered through a modified microfiltration membrane; the sugar-acid ratio of the grape juice is adjusted and then homogenized, and then rapidly cooled after ultra-high temperature instantaneous sterilization; the sterilized grape juice is cooled and added to a soda mixer, filled with carbon dioxide, and then poured into a sterilized glass bottle, and sealed and packaged; the novel Danfit sparkling grape juice prepared by the invention contains a high level of proanthocyanidins.

Description

Technical Field

[0001] The invention relates to the technical field of grape juice preparation, in particular to a preparation process of a novel Dornfelder sparkling grape juice. Background Art

[0002] Dornfelder Sparkling Grape Juice is a beverage rich in carbon dioxide bubbles made from Dornfelder grapes. Dornfelder grapes are a popular red grape variety in Germany, which was bred through hybridization in 1956. Its skin is dark in color, rich in phenolic substances, and high in sugar content. The wine brewed from it is dark in color, with appropriate acidity, and has the aroma of fruits such as plums, cherries, blackberries, and flowers, and sometimes you can feel the coolness of mint.

[0003] A Chinese patent application with publication number CN110403109A discloses a method for preparing sparkling grape juice. The main differences from the traditional preparation method are: first, the grapes are frozen and soaked, which is conducive to extracting various nutrients in the grapes; second, the addition of spirulina can significantly improve the nutritional value of the grape juice; third, the grape juice is soaked at low temperature, ultraviolet sterilization is used during disinfection, and the bubbling step is also processed at low temperature, which can reduce the damage to aromatic substances during the preparation process and enhance the aroma of the grape juice.

[0004] The Chinese patent application with publication number CN1033236A discloses a process for producing grape juice, wherein the grapes are picked, removed from the buds and impurities, washed, crushed and destemmed, pulped, colored, centrifuged, enzyme precipitated, degummed, decalcified, finely filtered, sterilized, and finally bottled to form the finished product.

[0005] The Chinese patent application with publication number CN105838532A discloses a processing technology for a grape juice wine beverage, which belongs to the field of grape wine making technology, including material selection, preparation of grape wine, preparation of grape juice, addition of fruit juice and blending of grape juice wine beverage in proportion.

[0006] The content of proanthocyanidins in the grape juice prepared by the above patents and prior art is relatively low. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a novel process for preparing Dornfelde sparkling grape juice, comprising the following steps: S1 Raw material selection: Choose fully ripe, brightly colored, free of rot and pesticide residues. S2 flushing and stem removal: Rinse: Rinse the selected grapes in clean water to remove dirt, impurities and residual pesticides on the surface; Destemming: Remove the fruit stems after drying; S3 Crushing and Pressing: Freeze immersion: The grapes are quickly frozen at -25~-30℃ and then crushed, using ice crystals to destroy the cell structure and perform low-temperature immersion treatment; Squeezing: Use a squeezer to squeeze the soaked pulp 3-8 times to make all the juice flow out; S4 Filtration Clarification: Coarse filtration: The squeezed juice is first filtered through a strainer to remove impurities such as peel, seeds and pulp from the juice; Clarification: put the coarsely filtered juice into a sterilized container, add 1-5% of the juice mass of clarifier to help the fine particles in the juice settle; then let the juice stand at low temperature for a period of time to make the juice clarify naturally; Fine filtration: Take the upper clarified liquid, pass it through a modified microfiltration membrane to further remove impurities in the juice, and filter it to obtain clear and transparent grape juice; S5 adjusts the sugar-acid ratio: Adjust the sugar-acid ratio to (13-15):1 to make the taste of the juice more balanced and palatable; S6 homogenization sterilization: Homogenization: homogenize the juice with adjusted sugar-acid ratio; Sterilization: Use ultra-high temperature instantaneous sterilization method, and then quickly cool to 30-40℃ within 10-20s; S7 Low Temperature Carbonation: The sterilized grape juice is cooled to 0-5℃, then added to a soda mixer and charged with carbon dioxide to form uniform and fine bubbles in the juice under saturated state; S8 bottling packaging: The Dornfelter sparkling grape juice filled with carbon dioxide is poured into sterilized glass bottles and sealed and packaged; the packaged products are stored and transported at a low temperature of 2-6°C; The modified microfiltration membrane is prepared by reacting a microfiltration membrane, rapeseed polyphenols and cysteine ​​to obtain a polyphenol microfiltration membrane, and then subjecting the membrane to plasma treatment.

[0008] Furthermore, the low-temperature immersion temperature is 1-3°C and the time is 12-24 hours.

[0009] Furthermore, the clarifier is gelatin or pectinase.

[0010] Furthermore, the low-temperature standing time is 24-48 hours.

[0011] Furthermore, the ultra-high temperature instantaneous sterilization method has a temperature of 130-140°C and a time of 3-5s.

[0012] Furthermore, the carbon dioxide filling amount is 2-2.5 times the volume of the grape juice.

[0013] Furthermore, the specific preparation method of the modified microfiltration membrane is: A1 Preparation of polyphenol microfiltration membrane: According to weight, 100-140 parts of microfiltration membrane, 5-10 parts of rapeseed polyphenol, 2-5 parts of cysteine, and 2-4 parts of sodium bicarbonate are added to 1000-1200 parts of water, stirred at 65-75° C. for 100-150 minutes, taken out and dried to obtain a polyphenol microfiltration membrane; A2 Plasma Treatment: The polyphenol microfiltration membrane obtained in step A1 is placed in a radio frequency plasma treatment instrument, and nitrogen is used as a plasma gas source; first, the vacuum degree in the reaction chamber is evacuated to 10-20Pa, and then nitrogen is introduced into the reaction chamber at a flow rate of 30-50sccm. After stabilization for 5-10 minutes, the power is adjusted to 80-120W for 5-15 minutes, during which the pressure in the reaction chamber is controlled at 50-100Pa; after the treatment, the plasma generator and the nitrogen inlet valve are closed, and the vacuum is continued for 5-10 minutes, and finally air is slowly introduced to restore the pressure to normal pressure to obtain a modified microfiltration membrane.

[0014] Furthermore, the microfiltration membrane is selected from one of CA microfiltration membranes 11104-013N, 11104-025N, 11106-013N, and 11106-025N.

[0015] Reaction mechanism: Cysteine ​​contains a sulfhydryl group (-SH), and rapeseed polyphenols have an olefin group. Under the conditions of step A1, the sulfhydryl hydrogen dissociates into a sulfhydryl radical (-S ), attacks the carbon-carbon double bond of rapeseed polyphenol, the π bond opens, the sulfur free radical combines with one carbon atom, and the hydrogen atom combines with another carbon atom, so that rapeseed polyphenol is grafted onto cysteine ​​and finally onto the surface of the microfiltration membrane. Sodium bicarbonate may adjust the pH and assist the reaction, and the microfiltration membrane is used as a reaction carrier.

[0016] Compared with the prior art, the novel preparation process of Dornfelde sparkling grape juice of the present invention has the following significant effects: 1. The present invention adopts the freezing immersion technology. By crushing the grapes after low-temperature quick freezing, using ice crystals to destroy the cell structure, combined with low-temperature immersion, the release efficiency of polyphenols and volatile aroma components in the peel can be significantly improved, and the layered sense of fruit aroma can be enhanced.

[0017] 2. The present invention adopts ultra-high temperature instantaneous sterilization technology, which can kill microorganisms while retaining nutrients and flavors to the maximum extent; through rapid heating and cooling, the negative impact of long-term high temperature on the color and taste of the juice is avoided.

[0018] 3. The present invention adopts low-temperature carbonation technology and injects carbon dioxide under low-temperature environment, so that the juice forms uniform and dense bubbles under saturation state; by controlling the amount of carbon dioxide filling, the aroma escape caused by high-temperature carbonation can be avoided, and the bubbles can reduce the masking of the original flavor of the juice.

[0019] 4. Pigment removal: The modified microfiltration membrane grafted with rapeseed polyphenols has active groups such as phenolic hydroxyl groups, which adsorb pigments (such as anthocyanins) in grape juice through hydrogen bonds and π-π stacking, thereby removing them and making the original juice clear and transparent.

[0020] 5. Retention of other impurities: The microfiltration membrane screens by pore size, and the active groups of rapeseed polyphenols are adsorbed by hydrogen bonds and electrostatic effects to remove impurities such as particles, microorganisms, proteins, polysaccharides, etc., thereby improving the purity and clarity of the original juice.

[0021] 6. Selective separation: The modified microfiltration membrane has different effects on impurities. Strong impurities (pigments, proteins, etc.) are easier to remove, and small molecule effective ingredients such as flavor substances and vitamins in the original juice are well retained, thus maintaining the flavor and nutrition of the original juice.

[0022] 7. The novel Dornfelter sparkling grape juice prepared by the present invention contains a relatively high level of proanthocyanidins, so that the Dornfelter sparkling grape juice has certain anti-oxidation and anti-aging effects. DETAILED DESCRIPTION

[0023] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a detailed description in combination with embodiments and comparative examples: 1. Proanthocyanidin content test: high performance liquid chromatography was used for determination.

[0024] 2. Total colony count test: refer to GBT4789.21-2003 Food Hygiene Microbiology Inspection Frozen Printed Materials and Beverage Inspection Standards for testing.

[0025] 3. Clarity test: 50 people were randomly invited to rate the clarity of the new Danfelt sparkling grape juice, and the average of the scores was taken for statistics; the full score was 10 points.

[0026] Example 1: A novel process for preparing Dornfit sparkling grape juice, the operating steps of which are as follows: S1 Raw material selection: Choose fully ripe, brightly colored, free of rot and pesticide residues. S2 flushing and stem removal: Rinse: Rinse the selected grapes in clean water to remove dirt, impurities and residual pesticides on the surface; Destemming: Remove the fruit stems after drying; S3 Crushing and Pressing: Freeze maceration: The grapes are quickly frozen at -25°C and then crushed, using ice crystals to destroy the cell structure and perform low-temperature maceration. Pressing: Use a press to press the soaked pulp three times to make all the juice flow out; S4 Filtration Clarification: Coarse filtration: The squeezed juice is first filtered through a strainer to remove impurities such as peel, seeds and pulp from the juice; Clarification: put the coarsely filtered juice into a sterilized container and add 1% of the juice mass of a clarifier to help the fine particles in the juice settle; then let the juice stand at low temperature for a period of time to clarify the juice naturally; Fine filtration: Take the upper clarified liquid, pass it through a modified microfiltration membrane to further remove impurities in the juice, and filter it to obtain clear and transparent grape juice; S5 adjusts the sugar-acid ratio: Adjust the sugar-acid ratio to 13:1 to make the juice taste more balanced and palatable; S6 homogenization sterilization: Homogenization: homogenize the juice with adjusted sugar-acid ratio; Sterilization: Use ultra-high temperature instantaneous sterilization method, and then quickly cool to 30℃ within 10s; S7 Low Temperature Carbonation: The sterilized grape juice is cooled to 5°C, then added to a soda mixer and charged with carbon dioxide to form uniform and fine bubbles in the juice under saturated state; S8 bottling packaging: The carbon dioxide-filled Danfit sparkling grape juice is poured into sterilized glass bottles and sealed; the packaged products are stored and transported at a low temperature of 6°C.

[0027] The low-temperature immersion is carried out at a temperature of 1° C. and for 12 hours.

[0028] The clarifier is gelatin.

[0029] The low-temperature standing time is 24 hours.

[0030] The ultra-high temperature instantaneous sterilization method has a temperature of 130° C. and a time of 3 seconds.

[0031] The carbon dioxide filling amount is twice the volume of the grape juice.

[0032] The specific preparation method of the modified microfiltration membrane is: A1 Preparation of polyphenol microfiltration membrane: 100 g of microfiltration membrane, 5 g of rapeseed polyphenols, 2 g of cysteine, and 2 g of sodium bicarbonate were added to 1000 g of water, stirred at 65° C. for 100 minutes, and then taken out and dried to obtain a polyphenol microfiltration membrane; A2 Plasma Treatment: The polyphenol microfiltration membrane obtained in step A1 is placed in a radio frequency plasma treatment instrument, and nitrogen is used as a plasma gas source; first, the vacuum degree in the reaction chamber is evacuated to 10Pa, and then nitrogen is introduced into the reaction chamber at a flow rate of 30sccm. After stabilization for 5 minutes, the power is adjusted to 80W for 5 minutes, during which the pressure in the reaction chamber is controlled at 50Pa; after the treatment, the plasma generator and the nitrogen inlet valve are closed, and the vacuum is continued for 5 minutes. Finally, air is slowly introduced to restore the pressure to normal pressure to obtain a modified microfiltration membrane.

[0033] The microfiltration membrane is selected from CA microfiltration membrane 11104-013N.

[0034] Example 2: A novel process for preparing Dornfit sparkling grape juice, the operating steps of which are as follows: S1 Raw material selection: Choose fully ripe, brightly colored, free of rot and pesticide residues. S2 flushing and stem removal: Rinse: Rinse the selected grapes in clean water to remove dirt, impurities and residual pesticides on the surface; Destemming: Remove the fruit stems after drying; S3 Crushing and Pressing: Freeze maceration: The grapes are quickly frozen at -28°C and then crushed, using ice crystals to destroy the cell structure and perform low-temperature maceration. Pressing: Use a press to press the soaked pulp 5 times to make all the juice flow out; S4 Filtration Clarification: Coarse filtration: The squeezed juice is first filtered through a strainer to remove impurities such as peel, seeds and pulp from the juice; Clarification: put the coarsely filtered juice into a sterilized container and add 3% of the juice mass of a clarifier to help the fine particles in the juice settle; then let the juice stand at low temperature for a period of time to clarify the juice naturally; Fine filtration: Take the upper clarified liquid, pass it through a modified microfiltration membrane to further remove impurities in the juice, and filter it to obtain clear and transparent grape juice; S5 adjusts the sugar-acid ratio: Adjust the sugar-acid ratio to 14:1 to make the juice taste more balanced and palatable; S6 homogenization sterilization: Homogenization: homogenize the juice with adjusted sugar-acid ratio; Sterilization: Ultra-high temperature instantaneous sterilization method is used, and then rapidly cooled to 35°C within 15 seconds; S7 Low Temperature Carbonation: The sterilized grape juice is cooled to 3°C, then added to a soda mixer and charged with carbon dioxide to form uniform and fine bubbles in the juice under saturated state; S8 bottling packaging: The carbon dioxide-filled Danfit sparkling grape juice is poured into sterilized glass bottles and sealed; the packaged products are stored and transported at a low temperature of 4°C.

[0035] The temperature of the low-temperature immersion is 2° C. and the time is 16 hours.

[0036] The clarifier is gelatin.

[0037] The low-temperature standing time is 32 hours.

[0038] The ultra-high temperature instantaneous sterilization method has a temperature of 135° C. and a time of 4 seconds.

[0039] The carbon dioxide filling amount is 2.1 times the volume of the grape juice.

[0040] The specific preparation method of the modified microfiltration membrane is: A1 Preparation of polyphenol microfiltration membrane: 110 g of microfiltration membrane, 6 g of rapeseed polyphenols, 3 g of cysteine, and 3 g of sodium bicarbonate were added to 1050 g of water, stirred at 68° C. for 110 minutes, and then taken out and dried to obtain a polyphenol microfiltration membrane; A2 Plasma Treatment: The polyphenol microfiltration membrane obtained in step A1 is placed in a radio frequency plasma treatment instrument, and nitrogen is used as a plasma gas source; the vacuum degree in the reaction chamber is first evacuated to 13Pa, and then nitrogen is introduced into the reaction chamber at a flow rate of 40sccm. After stabilization for 6 minutes, the power is adjusted to 90W for 8 minutes, during which the pressure in the reaction chamber is controlled at 60Pa; after the treatment, the plasma generator and the nitrogen inlet valve are closed, and the vacuum is continued for 6 minutes. Finally, air is slowly introduced to restore the pressure to normal pressure to obtain a modified microfiltration membrane.

[0041] The microfiltration membrane is selected from CA microfiltration membrane 11104-025N.

[0042] Example 3: A novel process for preparing Dornfit sparkling grape juice, the steps of which are as follows: S1 Raw material selection: Choose fully ripe, brightly colored, free of rot and pesticide residues. S2 flushing and stem removal: Rinse: Rinse the selected grapes in clean water to remove dirt, impurities and residual pesticides on the surface; Destemming: Remove the fruit stems after drying; S3 Crushing and Pressing: Freeze maceration: The grapes are quickly frozen at -29°C and then crushed, using ice crystals to destroy the cell structure and perform low-temperature maceration. Pressing: Use a press to press the soaked pulp 7 times to make all the juice flow out; S4 Filtration Clarification: Coarse filtration: The squeezed juice is first filtered through a strainer to remove impurities such as peel, seeds and pulp from the juice; Clarification: put the coarsely filtered juice into a sterilized container and add 4% of the juice mass of a clarifier to help the fine particles in the juice settle; then let the juice stand at low temperature for a period of time to clarify the juice naturally; Fine filtration: Take the upper clarified liquid, pass it through a modified microfiltration membrane to further remove impurities in the juice, and filter it to obtain clear and transparent grape juice; S5 adjusts the sugar-acid ratio: Adjust the sugar-acid ratio to 14:1 to make the juice taste more balanced and palatable; S6 homogenization sterilization: Homogenization: homogenize the juice with adjusted sugar-acid ratio; Sterilization: Ultra-high temperature instantaneous sterilization method is used, and then rapidly cooled to 35°C within 15 seconds; S7 Low Temperature Carbonation: The sterilized grape juice is cooled to 2°C, then added to a soda mixer and charged with carbon dioxide to form uniform and fine bubbles in the juice under saturated state; S8 bottling packaging: The carbon dioxide-filled Danfit sparkling grape juice is poured into sterilized glass bottles and sealed; the packaged products are stored and transported at a low temperature of 3°C.

[0043] The low-temperature immersion is carried out at a temperature of 2° C. and for 20 hours.

[0044] The clarifier is pectinase.

[0045] The low-temperature standing time is 43h.

[0046] The ultra-high temperature instantaneous sterilization method has a temperature of 135° C. and a time of 4 seconds.

[0047] The carbon dioxide filling amount is 2.4 times the volume of the grape juice.

[0048] The specific preparation method of the modified microfiltration membrane is: A1 Preparation of polyphenol microfiltration membrane: 130 g of microfiltration membrane, 8 g of rapeseed polyphenols, 4 g of cysteine, and 3 g of sodium bicarbonate were added to 1150 g of water, stirred at 73° C. for 140 minutes, and then taken out and dried to obtain a polyphenol microfiltration membrane; A2 Plasma Treatment: The polyphenol microfiltration membrane obtained in step A1 is placed in a radio frequency plasma treatment instrument, and nitrogen is used as a plasma gas source; the vacuum degree in the reaction chamber is first evacuated to 18Pa, and then nitrogen is introduced into the reaction chamber at a flow rate of 45sccm. After stabilization for 8 minutes, the power is adjusted to 110W for 13 minutes, during which the pressure in the reaction chamber is controlled at 90Pa; after the treatment, the plasma generator and the nitrogen inlet valve are closed, and the vacuum is continued for 8 minutes. Finally, air is slowly introduced to restore the pressure to normal pressure to obtain a modified microfiltration membrane.

[0049] The microfiltration membrane is selected from CA microfiltration membrane 11106-013N.

[0050] Example 4: A novel process for preparing Dornfit sparkling grape juice, the operating steps of which are as follows: S1 Raw material selection: Choose fully ripe, brightly colored, free of rot and pesticide residues. S2 flushing and stem removal: Rinse: Rinse the selected grapes in clean water to remove dirt, impurities and residual pesticides on the surface; Destemming: Remove the fruit stems after drying; S3 Crushing and Pressing: Freeze maceration: The grapes are quickly frozen at -30°C and then crushed, using ice crystals to destroy the cell structure and perform low-temperature maceration. Pressing: Use a press to press the soaked pulp 8 times to make all the juice flow out; S4 Filtration Clarification: Rough filtration: The squeezed juice is first filtered through a filter to remove impurities such as peels, seeds and pulp in the juice; Clarification: The juice after rough filtration is placed in a sterilized container, and 1-5% of the juice mass of a clarifier is added to help the fine particles in the juice to precipitate; then the juice is allowed to stand at low temperature for a period of time to clarify the juice naturally; Fine filtration: Take the upper clarified liquid, pass it through a modified microfiltration membrane to further remove impurities in the juice, and filter it to obtain clear and transparent grape juice; S5 adjusts the sugar-acid ratio: Adjust the sugar-acid ratio to 15:1 to make the juice taste more balanced and palatable; S6 homogenization sterilization: Homogenization: homogenize the juice with adjusted sugar-acid ratio; Sterilization: Ultra-high temperature instantaneous sterilization method is used, and then rapidly cooled to 35°C within 15 seconds; S7 Low Temperature Carbonation: The sterilized grape juice is cooled to 0℃, then added to a soda mixer and charged with carbon dioxide to form uniform and fine bubbles in the juice under saturated state; S8 bottling packaging: The carbon dioxide-filled Danfit sparkling grape juice is poured into sterilized glass bottles and sealed; the packaged products are stored and transported at a low temperature of 2°C.

[0051] The temperature of the low-temperature immersion is 3° C. and the time is 24 hours.

[0052] The clarifier is pectinase.

[0053] The low-temperature standing time is 48 hours.

[0054] The ultra-high temperature instantaneous sterilization method has a temperature of 140° C. and a time of 5 seconds.

[0055] The carbon dioxide filling amount is 2.5 times the volume of the grape juice.

[0056] The preparation method of the modified microfiltration membrane is: A1 Preparation of polyphenol microfiltration membrane: 140 g of microfiltration membrane, 10 g of rapeseed polyphenols, 5 g of cysteine, and 4 g of sodium bicarbonate were added to 1200 g of water, stirred at 75° C. for 150 minutes, taken out and dried to obtain a polyphenol microfiltration membrane; A2 Plasma Treatment: The polyphenol microfiltration membrane obtained in step A1 is placed in a radio frequency plasma treatment instrument, and nitrogen is used as a plasma gas source; the vacuum degree in the reaction chamber is first evacuated to 20Pa, and then nitrogen is introduced into the reaction chamber at a flow rate of 50sccm. After stabilization for 10 minutes, the power is adjusted to 120W for 15 minutes, during which the pressure in the reaction chamber is controlled at 100Pa; after the treatment, the plasma generator and the nitrogen inlet valve are closed, and the vacuum is continued for 10 minutes. Finally, air is slowly introduced to restore the pressure to normal pressure to obtain a modified microfiltration membrane.

[0057] The microfiltration membrane is selected from CA microfiltration membrane 11106-025N.

[0058] Comparative Example 1: The microfiltration membrane is not modified, and the rest is the same as in Example 1.

[0059] Comparative Example 2: rapeseed polyphenols were not added, and the other aspects were the same as those of Example 1.

[0060] Comparative Example 3: No cysteine ​​was added, and the rest was the same as in Example 1.

[0061] Table 1: Test results of various embodiments and comparative examples

[0062] Through the data analysis of the above embodiments and comparative examples, the novel Dornfelde sparkling grape juice prepared by the present invention contains a relatively high level of proanthocyanidins, so that the Dornfelde sparkling grape juice has certain anti-oxidation and anti-aging effects.

[0063] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A novel process for preparing Dornfeld sparkling grape juice, characterized in that: The following steps are involved: S1 Raw material selection: Choose fully ripe, brightly colored, free of rot and pesticide residues. S2 flushing and stem removal: Rinse: Rinse the selected grapes in clean water to remove dirt, impurities and residual pesticides on the surface; Destemming: Remove the fruit stems after drying; S3 Crushing and Pressing: Freeze immersion: The grapes are quickly frozen at -25~-30℃ and then crushed, using ice crystals to destroy the cell structure and perform low-temperature immersion treatment; Squeezing: Use a squeezer to squeeze the soaked pulp 3-8 times to make all the juice flow out; S4 Filtration Clarification: Coarse filtration: The squeezed juice is first filtered through a strainer to remove impurities such as peel, seeds and pulp from the juice; Clarification: put the coarsely filtered juice into a sterilized container and add 1-5% of the juice mass of a clarifier to help the fine particles in the juice settle; Then let the juice stand at low temperature for a while to make the juice clarify naturally; Fine filtration: Take the upper clarified liquid, pass it through a modified microfiltration membrane to further remove impurities in the juice, and filter it to obtain clear and transparent grape juice; S5 adjusts the sugar-acid ratio: Adjust the sugar-acid ratio to (13-15):1 to make the taste of the juice more balanced and palatable; S6 homogenization sterilization: Homogenization: homogenize the juice with adjusted sugar-acid ratio; Sterilization: Use ultra-high temperature instantaneous sterilization method, and then quickly cool to 30-40℃ within 10-20s; S7 Low Temperature Carbonation: The sterilized grape juice is cooled to 0-5℃, then added to a soda mixer and charged with carbon dioxide to form uniform and fine bubbles in the juice under saturated state; S8 bottling packaging: The Dornfelter sparkling grape juice filled with carbon dioxide is poured into sterilized glass bottles and sealed and packaged; the packaged products are stored and transported at a low temperature of 2-6°C; The modified microfiltration membrane is prepared by reacting a microfiltration membrane, rapeseed polyphenols and cysteine ​​to obtain a polyphenol microfiltration membrane, and then subjecting the membrane to plasma treatment.

2. The preparation process of a novel Dornfelde sparkling grape juice according to claim 1, characterized in that: The temperature of the low-temperature immersion is 1-3°C and the time is 12-24 hours.

3. The preparation process of a novel Dornfit sparkling grape juice according to claim 1, characterized in that: The clarifier is gelatin or pectinase.

4. The preparation process of a novel Dornfelde sparkling grape juice according to claim 1, characterized in that: The low-temperature standing time is 24-48h.

5. The preparation process of a novel Dornfelde sparkling grape juice according to claim 1, characterized in that: The ultra-high temperature instantaneous sterilization method has a temperature of 130-140° C. and a time of 3-5 seconds.

6. The preparation process of a novel Dornfelde sparkling grape juice according to claim 1, characterized in that: The carbon dioxide filling amount is 2-2.5 times the volume of the grape juice.

7. The preparation process of a novel Dornfelde sparkling grape juice according to claim 1, characterized in that: The specific preparation method of the modified microfiltration membrane is: A1 Preparation of polyphenol microfiltration membrane: According to weight, 100-140 parts of microfiltration membrane, 5-10 parts of rapeseed polyphenol, 2-5 parts of cysteine, and 2-4 parts of sodium bicarbonate are added to 1000-1200 parts of water, stirred at 65-75° C. for 100-150 minutes, taken out and dried to obtain a polyphenol microfiltration membrane; A2 Plasma Treatment: The polyphenol microfiltration membrane obtained in step A1 is placed in a radio frequency plasma treatment instrument, and nitrogen is used as a plasma gas source; first, the vacuum degree in the reaction chamber is evacuated to 10-20Pa, and then nitrogen is introduced into the reaction chamber at a flow rate of 30-50sccm. After stabilization for 5-10 minutes, the power is adjusted to 80-120W for 5-15 minutes, during which the pressure in the reaction chamber is controlled at 50-100Pa; after the treatment, the plasma generator and the nitrogen inlet valve are closed, and the vacuum is continued for 5-10 minutes, and finally air is slowly introduced to restore the pressure to normal pressure to obtain a modified microfiltration membrane.

8. The process for preparing the novel Dornfelde sparkling grape juice according to claim 7, characterized in that: The microfiltration membrane is selected from one of CA microfiltration membranes 11104-013N, 11104-025N, 11106-013N, and 11106-025N.

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