Preparation method of grape wine with high anthocyanin content

Abstract

The invention discloses a preparation method of grape wine with high anthocyanin content, and belongs to the technical field of grape wine. The method is used for solving the technical problems of high heavy metal content and low anthocyanin content of the added grape skin in the wine brewing process. The invention relates to a preparation method of wine with high anthocyanin content, which comprises the following steps: synthesizing mesoporous ferroferric oxide inorganic microspheres by adopting a hydrothermal method, and introducing a resin-like structure into the inorganic microspheres to synthesize a hybrid adsorbent with high heavy metal ion adsorption efficiency. Preparing an anthocyanin extracting solution from the grape skin powder; adsorbing the anthocyanin extracting solution by adopting a hybrid adsorbent to obtain an anthocyanin concentrated solution; the composite anthocyanidin microcapsule is synthesized by using surfactant modified dextrin as a wall material and an anthocyanidin concentrated solution as a core material. And blending the adsorbed grape juice, grape skin composite microcapsules, pectinase and saccharomycetes, introducing sulfur dioxide gas, and carrying out culture fermentation to obtain the grape wine with high anthocyanin content.

Description

Technical Field

[0001] The present invention relates to the technical field of wine, and particularly relates to a method for preparing wine with a high anthocyanin content. Background Art

[0002] As an important cash crop, grapes are one of the fruit trees with the widest planting area and the highest yield in the world. Many countries mainly use grapes for winemaking. Wine often contains anthocyanins. As a water-soluble flavonoid compound, anthocyanins can endow wine with unique colors and flavors. In addition, anthocyanins can play an antioxidant role and improve the health care function of wine. However, during the relatively short brewing process of wine, the anthocyanin content produced by the grape juice during the brewing process into wine is relatively low.

[0003] Chinese Patent Application CN101633873A discloses a wine containing procyanidin B2 and a method for preparing the same; in the wine aging process, an appropriate amount of grape seed extract is added to increase the anthocyanin content in the wine. In fact, grape skins also contain a relatively high anthocyanin content. If grape skins can be added during the wine brewing process, the anthocyanins in the grape skins will dissolve into the wine liquid, thereby increasing the anthocyanin content in the wine.

[0004] However, during the cultivation of grapes, the use of fungicides containing heavy metals such as copper not only reduces grape diseases but also introduces a large amount of heavy metal ions. Moreover, heavy metal ions are prone to aggregation and difficult to degrade, thus remaining in the wine for a long time. The above heavy metal ions will not only hinder the wine fermentation process but also have a negative impact on the quality of the wine. Therefore, how to effectively remove heavy metal ions from the raw materials before wine fermentation is a technical problem that needs to be solved urgently. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing wine with a high anthocyanin content, aiming to solve the technical problems of high heavy metal content and low anthocyanin content in the addition of grape skins during the wine brewing process in the prior art.

[0006] The purpose of the present invention can be achieved by the following technical solutions: A method for preparing wine with a high anthocyanin content includes the following steps: S1. Add grape juice, grape skin composite microcapsules, pectinase, and yeast to a fermentation tank, and then introduce sulfur dioxide gas; S2. Carry out culture fermentation in the fermentation tank at a temperature of 18 - 20°C for a duration of 25 - 30 days to obtain wine with a high anthocyanin content.

[0007] An appropriate amount of grape skin composite microcapsules is added during the fermentation process to increase the anthocyanin content in the prepared wine.

[0008] Further, the preparation method of the grape skin composite microcapsule comprises the following steps: A1. Add cellulase and grape skin powder into an acidified ethanol solution, mix well, and treat at 45 - 55°C with 200 - 500W for 40 - 50 min to obtain an anthocyanin extract; mix the anthocyanin extract with a hybrid adsorbent, stand for adsorption, filter, and obtain the adsorbed anthocyanin extract; centrifuge and rotary evaporate the adsorbed anthocyanin extract to concentrate it to 1 / 3 - 1 / 2 of the original volume to obtain an anthocyanin concentrate; A2. Add dextrin into an ethanol aqueous solution, heat to 45 - 55°C and stir until the dextrin is completely dissolved to obtain a dextrin solution; add dodecyl trimethyl ammonium bromide to the dextrin solution, stir, and then concentrate at 80 - 85°C until crystals precipitate to obtain a supersaturated modified dextrin solution; add the anthocyanin concentrate and an emulsifier to the modified dextrin solution, stir, homogenize, and emulsify to obtain an emulsion; A3. Extrude the emulsion into isopropanol to obtain a crude product; then separate, dry, and pulverize the crude product to synthesize the grape skin composite microcapsule.

[0009] The dextrin solution physically adsorbs the surfactant dodecyl trimethyl ammonium bromide to obtain a modified dextrin solution; dextrin, as a coating material, dehydrates and hardens and then coats the surface of the anthocyanin concentrate to form a crude product. Using the modified dextrin solution as the wall material and the anthocyanin concentrate as the core material, the grape skin composite microcapsule is synthesized by the extrusion method.

[0010] Further, in step A1, the preparation method of the acidified ethanol solution is: add citric acid to a 55 - 65%wt ethanol solution to adjust the pH of the ethanol solution to 4 - 6 to prepare the acidified ethanol solution; the preparation method of the grape skin powder is: freeze - dry the grape skin, pulverize and sieve it to prepare the grape skin powder; the dosage ratio of the acidified ethanol solution, cellulase, and grape skin powder is 200 mL: 1 - 3 g: 20 - 30 g; the centrifugation speed is 3000 - 5000 r / min and the centrifugation time is 5 - 10 min.

[0011] Further, in step A2, the concentration of the ethanol aqueous solution is 40 - 50%wt, the dosage ratio of dextrin and ethanol is 5 - 10 g: 200 mL; the dosage ratio of the dextrin solution and dodecyl trimethyl ammonium bromide is 200 mL: 3 - 5 g; the dosage ratio of the modified dextrin solution, anthocyanin concentrate, and emulsifier is 20 - 30 mL: 5 - 10 mL: 1 - 3 g; the homogenization temperature is 40 - 60°C and the homogenization pressure is 20 - 40 MPa; the emulsification speed is 2000 - 3000 r / min and the emulsification time is 3 - 5 min.

[0012] Further, in step A3, the mass ratio of the emulsion to isopropanol is 1 - 2:10.

[0013] Further, in step A1, the preparation method of the hybrid adsorbent includes the following steps: B1. Ferric chloride hexahydrate is dissolved in ethylene glycol, and then polyvinylpyrrolidone is added. The mixture is heated and reacted at 55 - 65 °C for 1 - 2 h, and then urea is added and stirred for 30 - 50 min to obtain a mixture. The mixture is reacted at 200 - 220 °C for 10 - 12 h, and the solid product is collected. The solid product is subjected to post - process treatment to synthesize mesoporous iron oxide nanoparticles. When synthesizing mesoporous iron oxide nanoparticles by hydrothermal method, an appropriate amount of urea is added. Urea decomposition can produce carbon dioxide gas, thus forming tiny bubbles in the mixture, and then forming a mesoporous structure in the synthesized mesoporous iron oxide nanoparticles.

[0014] B2. Ascorbic acid is added to deionized water and stirred until completely dissolved to obtain a solution A. Allyl alcohol polyoxyethylene ether is added to deionized water, and then sodium persulfate is added and mixed evenly to obtain a reaction solution. The solution A is added dropwise to the reaction solution and mesoporous iron oxide nanoparticles are added to obtain a reaction system. Ascorbic acid and allyl alcohol polyoxyethylene ether are used as polymerization monomers, and are added to the surface and inside of the mesoporous iron oxide nanoparticles to obtain iron oxide modified with organic functional groups, which is the synthesized hybrid adsorbent.

[0015] B3. The reaction system is reacted at 70 - 80 °C for 1 - 2 h, then heated to 85 - 95 °C and reacted for 2 - 3 h, and then boiled at 95 - 100 °C for 4 - 6 h, and then filtered to obtain a composite solid. The composite solid is subjected to post - process treatment to synthesize a copolymer hybrid adsorbent.

[0016] Further, in step B1, the dosage ratio of ferric chloride hexahydrate, ethylene glycol and polyvinylpyrrolidone is 2.7 - 5.4 g:30 - 50 mL:0.3 - 0.5 g.

[0017] Further, in step B2, the dosage ratio of ascorbic acid, deionized water and sodium persulfate is 1.8 - 3.6 g:20 - 30 mL; the dosage ratio of allyl alcohol polyoxyethylene ether, deionized water and sodium persulfate is 10 - 15 g:200 - 300 mL:0.2 - 0.4 g; the dosage ratio of the reaction solution, solution A and mesoporous iron oxide nanoparticles is 210 - 310 g:20 - 30 mL:3 - 10 g.

[0018] Further, in step S1, the dosage ratio of the grape juice, the grape skin composite microcapsules, pectinase, yeast, and the introduced SO2 is 500 mL: 20 - 40 g: 0.025 - 0.05 mg: 15 - 25 mL: 25 - 30 mL.

[0019] The present invention has the following beneficial effects: 1. When preparing wine in the present invention, a hybrid adsorbent is pre - used to adsorb the raw grape juice to remove the heavy metal elements contained in the grape juice; when synthesizing the magnetite nano - microspheres by the hydrothermal method, a small amount of urea is added to expand the pore structure volume of the synthesized nano - microspheres, obtaining magnetite nano - microspheres with a large number of pores and a large specific surface area. The surface of the magnetite particles of the above - mentioned nanoparticles is a hollow outer shell, and the internal has a mesoporous structure, and the size of the mesoporous structure is controlled at the nanoscale; the synthesized mesoporous magnetite is used as a carrier, which has a larger specific surface area to adsorb organic substances. Then, by a polymerization method, ascorbic acid and allyl alcohol polyoxyethylene ether are used as monomers to introduce a resin - like structure into the above - mentioned inorganic microspheres, enhancing the adsorption capacity of the hybrid adsorbent. The present invention can effectively remove heavy metal elements such as copper ions contained in the wine by using only a small amount of the hybrid adsorbent, thereby improving the beneficial effect of the prepared wine on the human body.

[0020] 2. The adsorbed grape juice is added with relevant auxiliaries such as pectinase and yeast, and an appropriate amount of grape skin composite microcapsules is added, and through the fermentation process, finally, wine with a high anthocyanin content is obtained. The present invention uses grape skin extract as a raw material to synthesize an anthocyanin concentrate; by the extrusion method, using modified dextrin as the wall material and the anthocyanin concentrate as the core material, composite anthocyanin microcapsules are synthesized. The above - mentioned dextrin is modified by the surfactant dodecyl trimethyl ammonium bromide, thereby further enhancing its oxygen - barrier effect, reducing the inactivation rate of the core - material anthocyanin concentrate and improving the encapsulation rate of anthocyanin, thereby preparing composite anthocyanin microcapsules with a high anthocyanin content and good slow - release efficiency. During the fermentation process, the wine added with the composite anthocyanin microcapsules always maintains a high anthocyanin content. In addition, the composite anthocyanin microcapsules can be used as a color developer to adjust the color of the wine body, enriching the taste and quality of the wine. Detailed implementation manners

[0021] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention.

[0022] In Example 1 of the present invention, the grapes were purchased from Shandong Yiqi Fruit Industry Co., Ltd., and the variety was Kyoho grapes; the structural formula of allyl alcohol polyoxyethylene ether used in Examples 2-4 of the present invention was CH2=CHCH2-(OCH2CH2)n-OH, where n was 45 and the hydroxyl value was 28 mgKOH / g, and it was purchased from Hai'an Petrochemical Factory in Jiangsu Province; the ferric chloride hexahydrate used in Examples 2-4 of the present invention was purchased from Langfang Qianyao Technology Co., Ltd.; the cellulase used in Examples 5-7 of the present invention was purchased from Nanning Dongheng Huadao Biotechnology Co., Ltd., with the model number A-001 and the enzyme activity of 10,000-20,000 U / G; the dextrin used in Examples 5-7 of the present invention was purchased from Jiangxi Baiying Biotechnology Co., Ltd., with the product number 4523, specifically β-cyclodextrin; the yeast used in Examples 8-10 of the present invention was specifically Hanseniaspora uvarum cultured in YPD medium.

[0023] Example 1 This example provides a preparation method for grape raw materials for wine with high anthocyanin content, including the following steps: Use a grape peeling machine to separate the grape pulp and grape skins. The grape pulp is crushed to remove seeds, then kept warm at 60 °C for 3 h, filtered, and grape juice is obtained and the grape skins are collected.

[0024] Example 2 This example provides a preparation method for a hybrid adsorbent for wine with high anthocyanin content, including the following steps: B1. Add 2.7 g of ferric chloride hexahydrate and 30 mL of ethylene glycol solution to a 150 mL beaker, and stir magnetically at 100 r / min until the ferric chloride hexahydrate is completely dissolved in the ethylene glycol solution, and the solution becomes clear and transparent at this time. Then add 0.3 g of polyvinylpyrrolidone to the beaker, and then transfer the beaker to a water bath, heat and react at 55 °C for 1 h, then add 3 g of urea, and continue to stir for 30 min to obtain a mixture. Transfer the mixture to a stainless steel hydrothermal autoclave, and the hydrothermal autoclave reacts at 200 °C for 10 h, and collect the solid product. The solid product is washed with deionized water and collected by a magnet, and dried at 50 °C for 10 h to obtain black mesoporous iron oxide nanospheres.

[0025] B2. Add 1.8 g of ascorbic acid to 20 mL of deionized water, stir until the ascorbic acid is completely dissolved to obtain a dropping solution A; add 10 g of allyl alcohol polyoxyethylene ether to 200 mL of deionized water, then add 0.2 g of sodium persulfate, stir to dissolve and mix evenly to obtain a reaction solution. Dropwise add 20 mL of dropping solution A to 210 g of the reaction solution and add 3 g of mesoporous iron oxide nanospheres, where the dropping rate of dropping solution A is 1 mL / min to obtain a reaction system.

[0026] B3. The reaction system reacts at 70 °C for 1 h, then the temperature is raised to 85 °C and reacts for 2 h, then it is boiled at 95 °C for 4 h, and then filtered to obtain a composite solid. The composite solid is washed with deionized water, dried, ground and sieved through a 400-mesh sieve to prepare a copolymer, which is the synthesized hybrid adsorbent.

[0027] Example 3 This example provides a preparation method of a hybrid adsorbent for wine with high anthocyanin content, including the following steps: B1. Add 4 g of ferric chloride hexahydrate and 45 mL of ethylene glycol solution into a 150 mL beaker, and stir magnetically at 120 r / min until ferric chloride hexahydrate is completely dissolved in the ethylene glycol solution, and the solution becomes clear and transparent at this time. Then add 0.4 g of polyvinylpyrrolidone into the beaker, and then transfer the beaker to a water bath, heat and react at 60 °C for 1.5 h, then add 5 g of urea, and continue to stir for 45 min to obtain a mixture. Transfer the mixture to a stainless steel hydrothermal autoclave, and the hydrothermal autoclave reacts at 210 °C for 11 h, and collect the solid product. The solid product is washed with deionized water, collected by a magnet, and dried at 55 °C for 11 h to obtain black mesoporous iron oxide nanoparticles.

[0028] B2. Add 2.7 g of ascorbic acid into 26 mL of deionized water, and stir until ascorbic acid is completely dissolved to obtain a dropping solution A; add 12 g of allyl alcohol polyoxyethylene ether into 220 mL of deionized water, and then add 0.3 g of sodium persulfate, mix well to obtain a reaction solution. Dropwise add 25 mL of dropping solution A and add 6 g of mesoporous iron oxide nanoparticles into 260 g of the reaction solution, wherein the dropping rate of dropping solution A is 1 mL / min to synthesize a reaction system.

[0029] B3. The reaction system reacts at 77 °C for 1.5 h, then the temperature is raised to 90 °C and reacts for 2.2 h, then it is boiled at 98 °C for 5 h, and then filtered to obtain a composite solid. The composite solid is washed with deionized water, dried, ground and sieved through a 400-mesh sieve to prepare copolymer beads, which are the synthesized hybrid adsorbent.

[0030] Example 4 This example provides a preparation method of a hybrid adsorbent for wine with high anthocyanin content, including the following steps: B1. Add 5.4 g of ferric chloride hexahydrate and 50 mL of ethylene glycol solution to a 150 mL beaker. With magnetic stirring at 200 r / min until the ferric chloride hexahydrate is completely dissolved in the ethylene glycol solution, and the solution becomes clear and transparent at this time. Then add 0.5 g of polyvinylpyrrolidone to the beaker, and then transfer the beaker to a water bath. Heat and react at 65 °C for 2 h, then add 6 g of urea, and continue stirring for 50 min to obtain a mixture. Transfer the mixture to a stainless steel hydrothermal reactor, and react the hydrothermal reactor at 220 °C for 12 h, and collect the solid product. The solid product is washed with deionized water and collected by a magnet, and dried at 60 °C for 12 h to obtain black mesoporous iron oxide nanoparticles.

[0031] B2. Add 3.6 g of ascorbic acid to 30 mL of deionized water, and stir until the ascorbic acid is completely dissolved to obtain a dropping solution A; add 15 g of allyl alcohol polyoxyethylene ether to 300 mL of deionized water, and then add 0.4 g of sodium persulfate, mix well to obtain a reaction solution. Gradually drop 30 mL of dropping solution A into 310 g of the reaction solution and add 10 g of mesoporous iron oxide nanoparticles, wherein the dropping rate of the dropping solution A is 1 mL / min to synthesize a reaction system.

[0032] B3. React the reaction system at 80 °C for 2 h, then raise the temperature to 95 °C and react for 3 h, then boil at 100 °C for 6 h, and then filter to obtain a composite solid. The composite solid is washed with deionized water, dried, ground and passed through a 500-mesh sieve to prepare a copolymer bead, which is the synthesized hybrid adsorbent.

[0033] Example 5 This example provides a preparation method of grape skin composite microcapsules for wine with high anthocyanin content, including the following steps: A1. Freeze-dry the grape skins in Example 1 with liquid nitrogen, the freeze-drying temperature is -40 °C, and the freeze-drying time is 5 h; then crush and pass through a 50-mesh sieve to obtain grape skin powder. Add citric acid to a 55%wt ethanol solution to adjust the pH of the ethanol solution to 6 to obtain an acidified ethanol solution; add 1 g of cellulase and 20 g of grape skin powder to 200 mL of the acidified ethanol solution, mix well, and treat at 45 °C with 200 W for 40 min to obtain an anthocyanin extract. Mix the anthocyanin extract and the hybrid adsorbent prepared in Example 2 in a mass ratio of 100:1, then let it stand and adsorb at 25 °C for 20 h, and then filter to obtain the adsorbed anthocyanin extract. The adsorbed anthocyanin extract is centrifuged at 3000 r / min for 5 min at room temperature, and then rotary evaporated and concentrated to 1 / 2 of the original volume to obtain an anthocyanin concentrate.

[0034] A2. Add 5 g of dextrin to 200 mL of 40% wt ethanol aqueous solution, heat to 45 °C, and stir until the dextrin is completely dissolved to obtain a dextrin solution. Add 3 g of dodecyl trimethyl ammonium bromide to 200 mL of the dextrin solution, stir for 20 min, and then concentrate at 80 °C until crystals precipitate to obtain a supersaturated modified dextrin solution. Then add 5 mL of anthocyanin concentrate and 1 g of emulsifier polyvinyl alcohol to 20 mL of the modified dextrin solution, stir and homogenize. The temperature of homogenization is 40 °C and the pressure of homogenization is 20 MPa. Then emulsify at an emulsification speed of 2000 r / min for 3 min to obtain an emulsion.

[0035] A3. Add the emulsion to a peristaltic pump and extrude it into isopropanol through a nozzle. The mass ratio of the emulsion to isopropanol is 1:10. At this time, the dextrin dehydrates and hardens and wraps on the surface of the anthocyanin solid to obtain a crude product. Then separate the crude product from the dehydration solvent isopropanol, dry and crush it to 600 mesh to synthesize grape skin composite microcapsules.

[0036] Example 6 This example provides a preparation method of grape skin composite microcapsules for wine with high anthocyanin content, including the following steps: A1. Freeze-dry the grape skins in Example 1 with liquid nitrogen. The temperature of freeze-drying is -43 °C and the time of freeze-drying is 5.2 h. Then crush and pass through a 100-mesh sieve to obtain grape skin powder. Add citric acid to a 55% wt ethanol solution to adjust the pH of the ethanol solution to 5 to obtain an acidified ethanol solution. Add 2 g of cellulase and 25 g of grape skin powder to 200 mL of the acidified ethanol solution, mix well, and treat at 50 °C with 300 W for 45 min to obtain an anthocyanin extract. Mix the anthocyanin extract and the hybrid adsorbent prepared in Example 3 according to a mass ratio of 100:2, then let it stand and adsorb at 25 °C for 22 h, and then filter to obtain the adsorbed anthocyanin extract. The adsorbed anthocyanin extract is centrifuged at 4000 r / min for 8 min at room temperature, and then rotary evaporated and concentrated to 1 / 2 of the original volume to obtain an anthocyanin concentrate.

[0037] A2. Add 8 g of dextrin to 200 mL of 45% wt ethanol aqueous solution, heat to 50 °C, and stir until the dextrin is completely dissolved to obtain a dextrin solution. Add 4 g of dodecyl trimethyl ammonium bromide to 200 mL of the dextrin solution, mix well, react at 95 °C for 2.5 h, and then concentrate until crystals precipitate to obtain a modified dextrin solution in a supersaturated state. Then add 6 mL of anthocyanin concentrate and 1 g of emulsifier polyvinyl alcohol to 25 mL of the modified dextrin solution, stir and homogenize. The temperature of homogenization is 50 °C and the pressure of homogenization is 30 MPa. Then emulsify at an emulsification speed of 2600 r / min for 4 min to obtain an emulsion.

[0038] A3. The emulsion is added into a peristaltic pump and extruded into isopropanol through a nozzle. The mass ratio of the emulsion to isopropanol is 1:10. At this time, the dextrin dehydrates and hardens and wraps on the surface of the anthocyanin solid to obtain a crude product. Then, the crude product is separated from the dehydration solvent isopropanol, dried and crushed to 600 meshes to synthesize grape skin composite microcapsules.

[0039] Example 7 This example provides a preparation method of grape skin composite microcapsules for wine with high anthocyanin content, including the following steps: A1. The grape skins in Example 1 are freeze-dried with liquid nitrogen. The freeze-drying temperature is -50°C and the freeze-drying time is 6 h. Then, they are crushed and sieved through a 50-mesh sieve to obtain grape skin powder. Citric acid is added to a 65%wt ethanol solution to adjust the pH of the ethanol solution to 4 to obtain an acidified ethanol solution. 3 g of cellulase and 30 g of grape skin powder are added to 200 mL of the acidified ethanol solution. After mixing, it is treated at 55°C with 500 W for 50 min to obtain an anthocyanin extract. The anthocyanin extract and the hybrid adsorbent prepared in Example 4 are mixed in a mass ratio of 100:2, and then left to adsorb at 25°C for 24 h, and then filtered to obtain the adsorbed anthocyanin extract. The adsorbed anthocyanin extract is centrifuged at 5000 r / min for 10 min at room temperature, and then rotary evaporated and concentrated to 1 / 3 of the original volume to obtain an anthocyanin concentrate.

[0040] A2. 10 g of dextrin is added to 200 mL of a 50%wt ethanol aqueous solution and heated to 55°C, and stirred until the dextrin is completely dissolved to obtain a dextrin solution. 5 g of dodecyl trimethyl ammonium bromide is added to 200 mL of the dextrin solution and mixed well. It reacts at 100°C for 3 h, and then is concentrated until crystals precipitate to obtain a supersaturated modified dextrin solution. Then, 10 mL of the anthocyanin concentrate and 3 g of the emulsifier polyvinyl alcohol are added to 30 mL of the modified dextrin solution, stirred and homogenized. The homogenization temperature is 60°C and the homogenization pressure is 40 MPa. Then, it is emulsified. The emulsification speed is 3000 r / min and the emulsification duration is 5 min to obtain an emulsion.

[0041] A3. The emulsion is added into a peristaltic pump and extruded into isopropanol through a nozzle. The mass ratio of the emulsion to isopropanol is 2:10. At this time, the dextrin dehydrates and hardens and wraps on the surface of the anthocyanin solid to obtain a crude product. Then, the crude product is separated from the dehydration solvent isopropanol, dried and crushed to 500 meshes to synthesize grape skin composite microcapsules.

[0042] Example 8 This example provides a preparation method of wine with high anthocyanin content, including the following steps: S1. Select a 1000 mL fermenter, and then sequentially add 500 mL of the grape juice prepared in Example 1, 20 g of the grape skin composite microcapsules prepared in Example 5, 25 mL of SO2, 0.025 mg of pectinase, and 15 mL of yeast.

[0043] S2. The temperature for cultivation and fermentation is 18 °C, and the duration of cultivation and fermentation is 25 days; during the fermentation process, open the lid of the fermenter twice a day, morning and evening, to fully stir the fermenter to make the fermented matter evenly mixed up and down. After fermentation is completed, filter through a filter membrane with a pore size of 1.5 μm, sterilize and package, and finally obtain wine with a high anthocyanin content.

[0044] Example 9 This example provides a method for preparing wine with a high anthocyanin content, including the following steps: S1. Select a 1000 mL fermenter, and then sequentially add 500 mL of the grape juice prepared in Example 1, 20 g of the grape skin composite microcapsules prepared in Example 6, 28 mL of SO2, 0.035 mg of pectinase, and 20 mL of yeast.

[0045] S2. The temperature for cultivation and fermentation is 20 °C, and the duration of cultivation and fermentation is 28 days; during the fermentation process, open the lid of the fermenter twice a day, morning and evening, to fully stir the fermenter to make the fermented matter evenly mixed up and down. After fermentation is completed, filter through a filter membrane with a pore size of 1.2 μm, sterilize and package, and finally obtain wine with a high anthocyanin content.

[0046] Example 10 This example provides a method for preparing wine with a high anthocyanin content, including the following steps: S1. Select a 1000 mL fermenter, and then sequentially add 500 mL of the grape juice prepared in Example 1, 20 g of the grape skin composite microcapsules prepared in Example 7, 30 mL of SO2, 0.05 mg of pectinase, and 25 mL of yeast.

[0047] S2. The temperature for cultivation and fermentation is 18 °C, and the duration of cultivation and fermentation is 30 days; during the fermentation process, open the lid of the fermenter twice a day, morning and evening, to fully stir the fermenter to make the fermented matter evenly mixed up and down. After fermentation is completed, filter through a filter membrane with a pore size of 1 μm, sterilize and package, and finally obtain wine with a high anthocyanin content.

[0048] Comparative Example 1 The difference between this comparative example and Example 10 is that when preparing the grape skin composite microcapsules, in step A2, ammonium dodecyl trimethyl bromide was not added to the dextrin solution, and it was directly stirred and concentrated, and then an emulsion was further prepared.

[0049] Comparative Example 2 The difference between this comparative example and Example 10 is that when preparing the hybrid adsorbent, urea was not added in step B1.

[0050] Comparative Example 3 The difference between this comparative example and Example 10 is that when preparing the hybrid adsorbent, steps B2 and B3 were cancelled, and mesoporous Fe₃O₄ nanospheres of equal mass were used to replace the hybrid adsorbent.

[0051] Performance test: 1. Measure 100 mL of wine, then add sodium chloride to the wine to adjust the chloride ion strength to 0.2 mol / L; then add copper sulfate pentahydrate to the wine to adjust the concentration of copper ions to 20 mg / L, and then adjust the pH value of the wine to 3.6 by dropping hydrochloric acid and sodium hydroxide. Then, 0.2 g of the hybrid adsorbents prepared in Examples 2-4 and Comparative Examples 2-3 were respectively added to the wine, and left to adsorb for 12 h. Then, the concentration of copper ions in the wine was measured by flame atomic absorption spectrometry, and its adsorption rate was calculated.

[0052] Adsorption rate (%) = [(copper ion concentration before adsorption - copper ion concentration after adsorption) / copper ion concentration before adsorption] × 100% Table 1. Test data of sample performance

[0053] Data analysis: The data in Table 1 were detected and analyzed. After the hybrid adsorbents prepared in Examples 2-4 were successively added to the wine for adsorption, they all had a high adsorption rate for metal copper ions, showing that the adsorption rate reached over 99%; however, in Comparative Example 2, when preparing the hybrid adsorbent, urea was not added; the addition of urea helps to expand the pore structure in the synthesized Fe₃O₄ microspheres, thereby increasing the self-adsorption capacity. Therefore, the adsorption rate of the hybrid adsorbent synthesized in Comparative Example 2 was relatively low.

[0054] In Comparative Example 3, after synthesizing mesoporous Fe₃O₄ nanospheres by hydrothermal method, organic monomers were not used for addition polymerization and coating of the mesoporous Fe₃O₄ nanospheres; the adsorption rate of mesoporous Fe₃O₄ nanospheres modified by coating with a kind of organic resin for metal ion impurities is higher. Therefore, the adsorption rate of the hybrid adsorbent prepared in Comparative Example 3 for metal ion impurities decreased.

[0055] 2. Sequentially, the wines prepared in Examples 8-10 and Comparative Examples 1-3 were mixed with equal volumes of 0.2 mmol / L DPPH solution, placed in a constant temperature incubator to react in the dark for 30 minutes, and after the reaction, the absorbance of the solution was detected at 517 nm using an ELISA reader and recorded as A1. The DPPH solution was replaced with anhydrous ethanol as a control group, and the absorbance was recorded as A2. The wine was replaced with anhydrous ethanol, and the absorbance was recorded as A3, thereby calculating the DPPH removal rate R of the wines prepared in Examples 7-9 and Comparative Examples 1-3.

[0056] R=

(A1-A2) / A3

[0057] Data analysis: A comparative analysis of the data in Table 2 revealed that the wines prepared in Examples 8-10 of the present invention had a relatively high anthocyanin content, as shown by a relatively high DPPH free radical scavenging rate; however, in Comparative Example 1, when synthesizing the emulsion, the dextrin solution was not modified by adding dodecyltrimethylammonium bromide; the emulsion modified with a surfactant can further improve its encapsulation efficiency and encapsulation stability, and the prepared grape skin composite microcapsules have a high anthocyanin content, and the active anthocyanin components can be fully released during the fermentation process, thereby obtaining a wine with a high anthocyanin content after fermentation.

[0058] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

[0059] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0060] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to only the specific embodiments. Obviously, many modifications and variations can be made according to the content of this specification. These embodiments are selected and specifically described in this specification in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention. The present invention is only limited by the claims and their full scope and equivalents.

Claims

1. A method for preparing a wine with a high anthocyanin content, characterized in that, It includes the following steps: S1. Add grape juice, grape skin composite microcapsules, pectinase and yeast into a fermenter, and then introduce sulfur dioxide gas. S2. The fermenter is cultured and fermented at a temperature of 18 - 20 °C for a duration of 25 - 30 d to obtain wine with a high anthocyanin content.

2. The preparation method of a wine with a high anthocyanin content according to claim 1, characterized in that, In step S1, the preparation method of the grape skin composite microcapsules includes the following steps: A1. Add cellulase and grape skin powder into an acidified ethanol solution, mix well, and stir at 45 - 55 °C with a power of 200 - 500 W for 40 - 50 min to obtain an anthocyanin extract; mix the anthocyanin extract with a hybrid adsorbent, stand for adsorption, filter, and obtain the adsorbed anthocyanin extract; centrifuge the adsorbed anthocyanin extract and rotary evaporate and concentrate it to 1 / 3 - 1 / 2 of the original volume to obtain an anthocyanin concentrate. A2. Add dextrin into an ethanol aqueous solution, heat to 45 - 55 °C and stir until the dextrin is completely dissolved to obtain a dextrin solution; add dodecyltrimethylammonium bromide to the dextrin solution, stir, and then concentrate at 80 - 85 °C until crystals precipitate to obtain a supersaturated modified dextrin solution; add the anthocyanin concentrate and an emulsifier to the modified dextrin solution, stir, homogenize, and emulsify to obtain an emulsion. A3. Extrude the emulsion into isopropanol to obtain a crude product; then separate, dry, and pulverize the crude product to synthesize grape skin composite microcapsules.

3. The preparation method of a wine with high anthocyanin content according to claim 2, characterized in that, In step A1, the preparation method of the acidified ethanol solution is: add citric acid to an ethanol solution with a concentration of 55 - 65% wt to adjust the pH of the ethanol solution to 4 - 6 to prepare the acidified ethanol solution; the preparation method of the grape skin powder is: freeze-dry the grape skin, pulverize and sieve it to prepare the grape skin powder; the dosage ratio of the acidified ethanol solution, cellulase, and grape skin powder is 200 mL: 1 - 3 g: 20 - 30 g; the centrifugation speed is 3000 - 5000 r / min and the centrifugation duration is 5 - 10 min.

4. The preparation method of a wine with high anthocyanin content according to claim 2, characterized in that, In step A2, the concentration of the ethanol aqueous solution is 40 - 50% wt, and the dosage ratio of dextrin to ethanol is 5 - 10 g: 200 mL; the dosage ratio of the dextrin solution to dodecyltrimethylammonium bromide is 200 mL: 3 - 5 g; the dosage ratio of the modified dextrin solution, anthocyanin concentrate, and emulsifier is 20 - 30 mL: 5 - 10 mL: 1 - 3 g; the homogenization temperature is 40 - 60 °C and the homogenization pressure is 20 - 40 MPa; the emulsification speed is 2000 - 3000 r / min and the emulsification duration is 3 - 5 min.

5. The preparation method of a wine with high anthocyanin content according to claim 2, characterized in that, In step A3, the mass ratio of the emulsion to isopropanol is 1 - 2:

10.

6. The preparation method of a wine with high anthocyanin content according to claim 2, characterized in that, In step A1, the preparation method of the hybrid adsorbent includes the following steps: B1. Dissolve ferric chloride hexahydrate in ethylene glycol, then add polyvinylpyrrolidone, heat and react at 55 - 65 °C for 1 - 2 h, then add urea and continue to stir for 30 - 50 min to obtain a mixture; react the mixture at 200 - 220 °C for 10 - 12 h, collect the solid product; the solid product is subjected to post-treatment to synthesize mesoporous iron oxide nanoparticles. B2. Add ascorbic acid to deionized water and stir until the ascorbic acid is completely dissolved to obtain A dropping solution; add allyl alcohol polyoxyethylene ether to deionized water, and then add sodium persulfate and mix well to obtain a reaction solution; dropwise add the A dropping solution to the reaction solution and add mesoporous iron oxide nanoparticles to obtain a reaction system. B3. React the reaction system at 70 - 80 °C for 1 - 2 h, then raise the temperature to 85 - 95 °C and react for 2 - 3 h, then boil the spheres at 95 - 100 °C for 4 - 6 h, and then filter to obtain a composite solid; the composite solid is subjected to post-process treatment to synthesize a copolymer hybrid adsorbent.

7. A method for preparing a wine with a high anthocyanin content according to claim 1, characterized in that, In step B1, the dosage ratio of ferric chloride hexahydrate, ethylene glycol and polyvinylpyrrolidone is 2.7 - 5.4 g: 30 - 50 mL: 0.3 - 0.5 g.

8. The preparation method of a wine with high anthocyanin content according to claim 1, characterized in that, In step B2, the dosage ratio of ascorbic acid, deionized water and sodium persulfate is 1.8 - 3.6 g: 20 - 30 mL; the dosage ratio of allyl alcohol polyoxyethylene ether, deionized water and sodium persulfate is 10 - 15 g: 200 - 300 mL: 0.2 - 0.4 g; the dosage ratio of the reaction solution, the A dropping solution and the mesoporous iron oxide nanoparticles is 210 - 310 g: 20 - 30 mL: 3 - 10 g.

9. The preparation method of a wine with high anthocyanin content according to claim 1, characterized in that, In step S1, the dosage ratio of grape juice, grape skin composite microcapsules, pectinase, yeast and the introduced SO2 is 500 mL: 20 - 40 g: 0.025 - 0.05 mg: 15 - 25 mL: 25 - 30 mL.

Images