Grape seed anthocyanin and preparation method thereof

Abstract

The invention belongs to the technical field of anthocyanin extraction and purification, and particularly relates to grape seed anthocyanin and a preparation method thereof. According to the method, strong acid type cation exchange resin and saturated hydrochloric acid are combined, grape seed procyanidine is subjected to mild hydrolysis, obtained hydrolysate is subjected to macroporous resin chromatographic column adsorption and desorption, then concentration and vacuum freeze drying are conducted, and the anthocyanin extract is obtained. After cation exchange resin is adopted to adsorb generated anthocyanin cations, protons are dissociated, the concentration of acid is increased, meanwhile, solid-liquid separation of anthocyanin is promoted, finally, the use amount of part of saturated hydrochloric acid is reduced, the problem that anthocyanin is degraded due to too high acid concentration in the concentration process is effectively solved, and meanwhile, the concentration of anthocyanin is increased. According to the method, a macroporous resin adsorption method is adopted, and acid remaining in the prepared anthocyanin is effectively removed; meanwhile, through low-temperature control, the stability of the anthocyanin in an acid-free system is guaranteed, the anthocyanin extract with the purity higher than 30% is obtained, and the industrial value is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of anthocyanidin extraction, and specifically relates to a method for hydrolyzing grape seed extract with the assistance of a strong acid cationic resin and enriching it through a macroporous resin chromatography column to obtain high-content grape seed anthocyanidins, and grape seed anthocyanidins extracted by the method. Background Art

[0002] As a byproduct of the grape industry, grape seeds are known for being rich in proanthocyanidins. Proanthocyanidins, referred to as PC, are a mixture of bioflavonoids with a special molecular structure, among which oligomeric proanthocyanidins (OPC) are currently internationally recognized as natural antioxidants that are effective in removing free radicals in the human body. However, the antioxidant capacity of highly polymerized proanthocyanidins (PPC) is not strong, and its application is subject to a high degree of restriction. In order to improve the utilization value of grape seeds, it is a good idea to hydrolyze the proanthocyanidins in grape seed extract into anthocyanidins under acidic conditions.

[0003] Under normal circumstances, proanthocyanidins can usually be hydrolyzed into anthocyanidins by adding strong acid to an alcohol solution. For example, in "Study on the Preparation of Anthocyanidins and Antioxidant Capacity of Condensed Tannins from Bruguiera gymnorrhiza Calyx" (Zhang Liangliang, Lin Yiming, Forest Products Chemistry and Industry, December 2008, Vol. 28, No. 6), the authors used HCl-n-butanol method to hydrolyze the condensed tannins from Bruguiera gymnorrhiza Calyx to obtain anthocyanidin raw materials. "Study on the Polyphenol Components and Cellular Antioxidant Activity of Aralia nigra and the Process Research on the Conversion of Proanthocyanidins from Its Fruit Residues" and "Abstracts of the 17th Annual Conference of the Chinese Society of Video Science and Technology" (Gao Ningxuan et al.) reported that the Aralia nigra fruit residue was mixed with 95% ethanol, 4% hydrochloric acid, Fe 2+, and 1% ethanol at a solid-liquid ratio of 50:1. 3+ By mixing solutions with a concentration of 0.2 mg / mL and treating them at 80°C for 30 minutes, high-polymer proanthocyanidins can be effectively converted into anthocyanidins. However, in the above-mentioned technology, the amount of hydrochloric acid used is high, which will cause high pollution and bring a high burden to the equipment. In addition, during the concentration process of the hydrolyzate, the increase in acid content will in turn cause the degradation of the resulting compounds, which is not conducive to obtaining high-purity anthocyanidin products. Therefore, it is of great significance to develop a mild method for depolymerizing grape seed proanthocyanidins to generate anthocyanidins to solve the problem of high hydrochloric acid usage. Summary of the invention

[0004] One of the purposes of the present invention is to provide a method for preparing grape seed anthocyanidins, wherein the method uses a D001 or D002 type strong acid cation exchange resin in combination with saturated hydrochloric acid to mildly hydrolyze grape seed proanthocyanidins, and the resulting hydrolyzate is adsorbed by a macroporous resin chromatography column, concentrated after desorption, and vacuum freeze-dried to obtain anthocyanidin extract. The method can reduce the amount of acid used in the hydrolysis process, thereby achieving a mild depolymerization effect.

[0005] To achieve the above object, the present invention adopts the following technical scheme: a method for preparing grape seed anthocyanidins, comprising the following steps:

[0006] S1, adding grape seed skin powder to an ethanol / saturated hydrochloric acid solution, wherein the mass fraction of saturated hydrochloric acid in the ethanol / saturated hydrochloric acid solution is 0.5% to 1.5%, and then adding an activated strong acid cation exchange resin for leaching, heating in a water bath at 60 to 80° C. for 30 to 100 minutes, and then filtering, washing the filter cake with a 0.5M to 1M potassium chloride solution until the washing liquid is colorless, and concentrating and dealcoholizing the washing liquid as the first solution for standby use;

[0007] S2. Take the activated HPD 300 or HPD 600 macroporous resin and load it into the chromatography column. The column temperature is controlled at -5°C to 20°C.

[0008] S3, taking the first solution of step S1 and loading it into a chromatography column filled with a macroporous resin, the volume mass ratio of the first solution to the macroporous resin is 1 ml: (2-10) g, adding water to wash after adsorption until the effluent is neutral, washing the chromatography column with an ethanol-water solution with a volume ratio of 4:6-6:4 until the washing liquid is colorless, concentrating the washing liquid to be alcohol-free, and vacuum freeze-drying to obtain anthocyanin extract;

[0009] Among them, steps S1 and S2 are performed in no particular order.

[0010] As a further improvement of the preparation method of grape seed anthocyanidins:

[0011] Preferably, the mass fraction of saturated hydrochloric acid in the ethanol / saturated hydrochloric acid solution in step S1 is 0.8% to 1.0%.

[0012] Preferably, in step S1, the ratio of the grape seed skin powder, ethanol / saturated hydrochloric acid solution and activated strong acid cation exchange resin used for extraction is 10 g: (20-50) ml: (1-3) g.

[0013] Preferably, in step S1, the ratio of the grape seed skin powder, ethanol / saturated hydrochloric acid solution and activated strong acid cation exchange resin used for extraction is 10 g:30 ml:1 g.

[0014] Preferably, the model of the strong acid cation exchange resin in step S1 is D001 or D002, and the manufacturer is Zhengzhou Hecheng New Material Technology Co., Ltd.

[0015] Preferably, the water bath heating temperature in step S1 is 65° C. to 75° C., and the heating time is 40 min to 60 min.

[0016] Preferably, the model of the chromatography column in step S2 is HPD 600.

[0017] Preferably, in step S2, the column temperature is controlled at 0°C to 5°C.

[0018] Preferably, in step S3, the volume mass ratio of the first solution to the macroporous resin is 1 ml: (3-5) g.

[0019] The second object of the present invention is to provide grape seed anthocyanidins prepared by any one of the above-mentioned methods for preparing grape seed anthocyanidins.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1) The present invention provides a method for preparing grape seed anthocyanidins, wherein the method uses a strong acidic cation exchange resin in combination with saturated hydrochloric acid to mildly hydrolyze grape seed proanthocyanidins, and the obtained hydrolyzate is adsorbed by a macroporous resin chromatography column, concentrated after desorption, and vacuum freeze-dried to obtain anthocyanidin extract. By using a cation exchange resin to adsorb anthocyanidins obtained from the hydrolysis of proanthocyanidins, solid-liquid separation of anthocyanidins is achieved, thereby promoting the complete hydrolysis reaction, thereby reducing the amount of hydrochloric acid used for hydrolysis, and effectively avoiding the problem of anthocyanidin degradation due to excessive acid concentration during the concentration process.

[0022] The method of the present invention adopts a macroporous resin adsorption method to effectively remove the salt and acid remaining in the prepared anthocyanidins; at the same time, through low temperature control, the stability of anthocyanidins in an acid-free system is guaranteed, and anthocyanidin extracts with a purity higher than 30% are obtained, which has industrial value.

[0023] 2) The purity of the grape seed anthocyanin prepared by the present invention reaches more than 30%, and it can be used as an antioxidant, and has certain application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a high performance liquid chromatography analysis chart of the grape seed anthocyanin extract obtained by the present invention;

[0025] Figure 2 is a high performance liquid chromatography analysis chart of the grape seed anthocyanin extract obtained by hydrolysis without resin in the comparative example of the present invention;

[0026] Figure 3 It is a high performance liquid chromatography analysis chart of the grape seed extract before hydrolysis in the comparative example of the present invention. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0028] Example 1

[0029] This embodiment provides a method for preparing grape seed anthocyanidins, which specifically comprises the following steps:

[0030] S1. Weigh 10 g of crushed grape seed skin powder, add 20 mL of ethanol / saturated hydrochloric acid solution (the mass fraction of saturated hydrochloric acid is 1.0%) and 1 g of activated strong acid cation exchange resin (model D001, manufacturer: Zhengzhou Hecheng New Material Technology Co., Ltd.) for extraction, heat in a water bath at 80° C. for 30 min, filter, wash the filter cake with 1 M potassium chloride solution until the washing liquid is colorless, and concentrate the washing liquid to dealcoholize to form the first solution for standby use;

[0031] S2. Take the activated HPD 300 macroporous resin and load it into a chromatography column (loading specification: column height 30 cm, inner diameter 25 mm), and control the column temperature at -5°C;

[0032] S3, take the first solution of step S1 and load it into the chromatography column filled with macroporous resin in step S2, the volume mass ratio of the first solution to the macroporous resin is 1ml:10g, after adsorption, add water to wash until the effluent is neutral, wash the chromatography column with ethanol aqueous solution with a volume ratio of 6:4 until the washing liquid is colorless, concentrate the washing liquid to be alcohol-free, and vacuum freeze-dry to obtain anthocyanin extract. After testing, the weight of the obtained anthocyanin extract is 13mg, and the anthocyanin content is 35%.

[0033] The test method for anthocyanin content is as follows: anthocyanin content is detected by high performance liquid chromatography; anthocyanin extract with a concentration of 0.5 mg / mL and a homemade anthocyanin standard are prepared using a 50% volume fraction methanol aqueous solution, filtered, and 10 μL is injected into a well-equilibrated reverse phase SPS100C18 column (column length: 250 mm, inner diameter: 4.6 mm, filler particle size: 10 μm). The mobile phase is a mixture of acetonitrile (phase A) and a 0.1% mass fraction formic acid aqueous solution (phase B), gradient elution, elution gradient: 0-40 min, phase A increases from 5% to 95% by volume, flow rate: 1.0 mL / min, detection wavelength 526 nm. The chromatogram of anthocyanin extract is shown in the following figure. Figure 1 As shown, the areas of chromatographic peak A, chromatographic peak B, and chromatographic peak C in the graph are integrated respectively, and the contents of A, B, and C are calculated respectively by comparing with the peak areas of the corresponding standard products, and the total content of the three anthocyanins is calculated.

[0034] Example 2

[0035] This embodiment provides a method for preparing grape seed anthocyanidins, which specifically comprises the following steps:

[0036] S1. Weigh 10 g of crushed grape seed skin powder, add 50 mL of ethanol / saturated hydrochloric acid solution (the mass fraction of saturated hydrochloric acid is 1.5%) and 3 g of activated strong acid cation exchange resin (model D001, manufacturer: Zhengzhou Hecheng New Material Technology Co., Ltd.) for extraction, heat in a water bath at 80° C. for 65 min, filter, wash the filter cake with 0.5 M potassium chloride solution until the washing liquid is colorless, and concentrate the washing liquid to dealcoholize to obtain the first solution for standby use;

[0037] S2. Take the activated HPD 300 macroporous resin and load it into a chromatography column (model filling specification: column height 30 cm, inner diameter 25 mm), and control the column temperature at 20°C;

[0038] S3, take the first solution of step S1 and load it into the chromatography column filled with macroporous resin in step S2, the volume mass ratio of the first solution and the macroporous resin is 1ml:2g, after adsorption, add water to wash until the effluent is neutral and no salt residue, wash the chromatography column with ethanol aqueous solution with a volume ratio of 5:5 until the washing liquid is colorless, concentrate the washing liquid to be alcohol-free, and vacuum freeze-dry to obtain anthocyanin extract. After testing, the weight of the obtained anthocyanin extract is 9.2mg, the anthocyanin content is 32%, and the anthocyanin content detection method is the same as Example 1.

[0039] Example 3

[0040] This embodiment provides a method for preparing grape seed anthocyanidins, which specifically comprises the following steps:

[0041] S1. Weigh 10 g of crushed grape seed skin powder, add 35 mL of ethanol / saturated hydrochloric acid solution (the mass fraction of saturated hydrochloric acid is 0.5%) and 2 g of activated strong acid cation exchange resin (model D001, manufacturer: Zhengzhou Hecheng New Material Technology Co., Ltd.) for extraction, heat in a water bath at 80° C. for 100 min, filter, wash the filter cake with 0.75 M potassium chloride solution until the washing liquid is colorless, and concentrate the washing liquid to dealcoholize to obtain the first solution for standby use;

[0042] S2. Take the activated HPD 300 macroporous resin and load it into a chromatography column (model filling specification: column height 30 cm, inner diameter 25 mm), and control the column temperature at 20°C;

[0043] S3, take the first solution of step S1 and load it into the chromatography column filled with macroporous resin in step S2, the volume mass ratio of the first solution and the macroporous resin is 1ml:6g, after adsorption, add water to wash until the effluent is neutral and no salt residue, wash the chromatography column with ethanol aqueous solution with a volume ratio of 5:5 until the washing liquid is colorless, concentrate the washing liquid to be alcohol-free, and vacuum freeze-dry to obtain anthocyanin extract. After testing, the weight of the obtained anthocyanin extract is 10.2mg, the anthocyanin content is 30.8%, and the anthocyanin content detection method is the same as in Example 1.

[0044] Example 4

[0045] This embodiment provides a method for preparing grape seed anthocyanidins, which specifically comprises the following steps:

[0046] S1. Weigh 10 g of crushed grape seed skin powder, add 30 mL of ethanol / saturated hydrochloric acid solution (the mass fraction of saturated hydrochloric acid is 0.8%) and 2 g of activated strong acid cation exchange resin (model D001, manufacturer: Zhengzhou Hecheng New Material Technology Co., Ltd.) for extraction, heat in a water bath at 80° C. for 100 min, filter, wash the filter cake with 1 M potassium chloride solution until the washing liquid is colorless, and concentrate the washing liquid to dealcoholize to obtain the first solution for standby use;

[0047] S2. Take the activated HPD 600 macroporous resin and load it into a chromatography column (loading specification: column height 30 cm, inner diameter 25 mm), and control the column temperature at 12.5°C;

[0048] S3, take the first solution of step S1 and load it into the chromatography column filled with macroporous resin in step S2, the volume mass ratio of the first solution and the macroporous resin is 1ml:4g, after adsorption, add water to wash until the effluent is neutral and no salt residue, wash the chromatography column with ethanol aqueous solution with a volume ratio of 5:5 until the washing liquid is colorless, concentrate the washing liquid to be alcohol-free, and vacuum freeze-dry to obtain anthocyanin extract. After testing, the weight of the obtained anthocyanin extract is 11.5mg, the anthocyanin content is 33.4%, and the anthocyanin content detection method is the same as in Example 1.

[0049] Example 5

[0050] This embodiment provides a method for preparing grape seed anthocyanidins, which specifically comprises the following steps:

[0051] S1. Weigh 10 g of crushed grape seed skin powder, add 30 mL of ethanol / saturated hydrochloric acid solution (the mass fraction of saturated hydrochloric acid is 0.9%) and 1 g of activated strong acid cation exchange resin (model D001, manufacturer: Zhengzhou Hecheng New Material Technology Co., Ltd.) for extraction, heat in a 65° C. water bath for 60 min and filter, wash the filter cake with 1 M potassium chloride solution until the washing liquid is colorless, and concentrate the washing liquid to dealcoholize to obtain the first solution for standby use;

[0052] S2. Take the activated HPD 600 macroporous resin and load it into a chromatography column (loading specification: column height 30 cm, inner diameter 25 mm), and control the column temperature at 3°C;

[0053] S3, take the first solution of step S1 and load it into the chromatography column filled with macroporous resin in step S2, the volume mass ratio of the first solution and the macroporous resin is 1ml:3g, after adsorption, add water to wash until the effluent is neutral and no salt residue, wash the chromatography column with ethanol aqueous solution with a volume ratio of 6:4 until the washing liquid is colorless, concentrate the washing liquid to be alcohol-free, and vacuum freeze-dry to obtain anthocyanin extract. After testing, the weight of the obtained anthocyanin extract is 12.5mg, the anthocyanin content is 33.2%, and the anthocyanin content detection method is the same as in Example 1.

[0054] Example 6

[0055] This embodiment provides a method for preparing grape seed anthocyanidins, which specifically comprises the following steps:

[0056] S1. Weigh 10 g of crushed grape seed skin powder, add 30 mL of ethanol / saturated hydrochloric acid solution (the mass fraction of saturated hydrochloric acid is 0.9%) and 2 g of activated strong acid cation exchange resin (model D001, manufacturer: Zhengzhou Hecheng New Material Technology Co., Ltd.) for extraction, heat in a 65° C. water bath for 40 min and filter, wash the filter cake with 1 M potassium chloride solution until the washing liquid is colorless, and concentrate and dealcoholize the washing liquid to obtain the first solution for standby use;

[0057] S2. Take the activated HPD 600 macroporous resin and load it into a chromatography column (loading specification: column height 30 cm, inner diameter 25 mm), and control the column temperature at 0°C;

[0058] S3, take the first solution of step S1 and load it into the chromatography column filled with macroporous resin in step S2, the volume mass ratio of the first solution and the macroporous resin is 1ml:5g, after adsorption, add water to wash until the effluent is neutral and no salt residue, wash the chromatography column with ethanol aqueous solution with a volume ratio of 6:4 until the washing liquid is colorless, concentrate the washing liquid to be alcohol-free, and vacuum freeze-dry to obtain anthocyanin extract. After testing, the weight of the obtained anthocyanin extract is 13.5mg, the anthocyanin content is 34.2%, and the anthocyanin content detection method is the same as in Example 1.

[0059] Example 7

[0060] This embodiment provides a method for preparing grape seed anthocyanidins, which specifically comprises the following steps:

[0061] S1. Weigh 10 g of crushed grape seed skin powder, add 30 mL of ethanol / saturated hydrochloric acid solution (the mass fraction of saturated hydrochloric acid is 0.9%) and 3 g of activated strong acid cation exchange resin (model D002, manufactured by Zhengzhou Hecheng New Material Technology Co., Ltd.) for extraction, heat in a 65° C. water bath for 50 min and filter, wash the filter cake with 1 M potassium chloride solution until the washing liquid is colorless, and concentrate the washing liquid to dealcoholize to obtain the first solution for standby use;

[0062] S2. Take the activated HPD 600 macroporous resin and load it into a chromatography column (loading specification: column height 30 cm, inner diameter 25 mm), and control the column temperature at 5°C;

[0063] S3, take the first solution of step S1 and load it into the chromatography column filled with macroporous resin in step S2, the volume mass ratio of the first solution and the macroporous resin is 1ml:5g, after adsorption, add water to wash until the effluent is neutral and no salt residue, wash the chromatography column with ethanol aqueous solution with a volume ratio of 4:6 until the washing liquid is colorless, concentrate the washing liquid to be alcohol-free, and vacuum freeze-dry to obtain anthocyanin extract. After testing, the weight of the obtained anthocyanin extract is 13.7mg, the anthocyanin content is 34.0%, and the anthocyanin content detection method is the same as in Example 1.

[0064] Example 8

[0065] This embodiment provides a method for preparing grape seed anthocyanidins, which specifically comprises the following steps:

[0066] S1. Weigh 10 g of crushed grape seed skin powder, add 50 mL of ethanol / saturated hydrochloric acid solution (the mass fraction of saturated hydrochloric acid is 1.5%) and 3 g of activated strong acid cation exchange resin (model D002, manufacturer: Zhengzhou Hecheng New Material Technology Co., Ltd.) for extraction, heat in a 75° C. water bath for 50 min and filter, wash the filter cake with 0.5 M potassium chloride solution until the washing liquid is colorless, and concentrate the washing liquid to dealcoholize to obtain the first solution for standby use;

[0067] S2. Take the activated HPD 300 macroporous resin and load it into a chromatography column (model filling specification: column height 30 cm, inner diameter 25 mm), and control the column temperature at 20°C;

[0068] S3, take the first solution of step S1 and load it into the chromatography column filled with macroporous resin in step S2, the volume mass ratio of the first solution and the macroporous resin is 1ml:2g, after adsorption, add water to wash until the effluent is neutral and no salt residue, wash the chromatography column with ethanol aqueous solution with a volume ratio of 5:5 until the washing liquid is colorless, concentrate the washing liquid to be alcohol-free, and vacuum freeze-dry to obtain anthocyanin extract. After testing, the weight of the obtained anthocyanin extract is 8.8mg, the anthocyanin content is 30.1%, and the anthocyanin content detection method is the same as in Example 1.

[0069] Example 9

[0070] This embodiment provides a method for preparing grape seed anthocyanidins, which specifically comprises the following steps:

[0071] S1. Weigh 10 g of crushed grape seed skin powder, add 50 mL of ethanol / saturated hydrochloric acid solution (the mass fraction of saturated hydrochloric acid is 1.5%) and 3 g of activated strong acid cation exchange resin (model D001, manufacturer: Zhengzhou Hecheng New Material Technology Co., Ltd.) for extraction, heat in a 60° C. water bath for 50 min and filter, wash the filter cake with 1 M potassium chloride solution until the washing liquid is colorless, and concentrate the washing liquid to dealcoholize to form the first solution for standby use;

[0072] S2. Take the activated HPD 300 macroporous resin and load it into a chromatography column (model filling specification: column height 30 cm, inner diameter 25 mm), and control the column temperature at 20°C;

[0073] S3, take the first solution of step S1 and load it into the chromatography column filled with macroporous resin in step S2, the volume mass ratio of the first solution and the macroporous resin is 1ml:2g, after adsorption, add water to wash until the effluent is neutral and no salt residue, wash the chromatography column with ethanol aqueous solution with a volume ratio of 5:5 until the washing liquid is colorless, concentrate the washing liquid to be alcohol-free, and vacuum freeze-dry to obtain anthocyanin extract. After testing, the weight of the obtained anthocyanin extract is 9.8mg, the anthocyanin content is 30.31%, and the anthocyanin content detection method is the same as in Example 1.

[0074] Example 10

[0075] This embodiment provides a method for preparing grape seed anthocyanidins, which specifically comprises the following steps:

[0076] S1. Weigh 10 g of crushed grape seed skin powder, add 20 mL of ethanol / saturated hydrochloric acid solution (the mass fraction of saturated hydrochloric acid is 1.0%) and 1 g of activated strong acid cation exchange resin (model D001, manufacturer: Zhengzhou Hecheng New Material Technology Co., Ltd.) for extraction, heat in a 70° C. water bath for 30 min and filter, wash the filter cake with 1 M potassium chloride solution until the washing liquid is colorless, and concentrate and dealcoholize the washing liquid to obtain the first solution for standby use;

[0077] S2. Take the activated HPD 300 macroporous resin and load it into a chromatography column (loading specification: column height 30 cm, inner diameter 25 mm), and control the column temperature at 5°C;

[0078] S3, take the first solution of step S1 and load it into the chromatography column filled with macroporous resin in step S2, the volume mass ratio of the first solution to the macroporous resin is 1ml:10g, after adsorption, add water to wash until the effluent is neutral, wash the chromatography column with ethanol aqueous solution with a volume ratio of 6:4 until the washing liquid is colorless, concentrate the washing liquid to be alcohol-free, and vacuum freeze-dry to obtain anthocyanin extract. After testing, the weight of the obtained anthocyanin extract is 12.8mg, and the anthocyanin content is 36.1%.

[0079] Comparative Example

[0080] This comparative example provides a method for preparing grape seed anthocyanidins, which specifically comprises the following steps:

[0081] S1. Weigh 10 g of crushed grape seed skin powder, add 30 mL of ethanol / saturated hydrochloric acid solution (the mass fraction of saturated hydrochloric acid is 0.5%) for extraction, heat in a water bath at 65° C. for 50 min, filter, and concentrate the filtrate to dealcoholize to obtain the first solution for standby use;

[0082] S2. Take the activated HPD 600 macroporous resin and load it into a chromatography column (loading specification: column height 30 cm, inner diameter 25 mm), and control the column temperature at 3°C;

[0083] S3, take the first solution of step S1 and load it into the chromatography column filled with macroporous resin in step S2, the volume mass ratio of the first solution and the macroporous resin is 1ml:5g, after adsorption, add water to wash until the effluent is neutral and no salt residue, wash the chromatography column with ethanol water solution with a volume ratio of 6:4 until the washing liquid is colorless, concentrate the washing liquid to be alcohol-free, and vacuum freeze-dry to obtain anthocyanin extract. After testing, the weight of the obtained anthocyanin extract is 20.1mg, the anthocyanin content is 2.0%, and the anthocyanin content detection method is the same as in Example 1, and its chromatogram is as follows Figure 2 As shown by Figure 2 It can be seen that the content of anthocyanins in the product obtained by hydrolyzing grape seed extract without adding strong cation exchange resin is much lower than that of grape seed extract assisted by strong cation exchange resin, which fully demonstrates the reliability of the scheme of hydrolyzing grape seed extract assisted by strong cation exchange resin to produce anthocyanins. Figure 3 ,Depend on Figure 3 It can be seen that unhydrolyzed grape seed extract does not contain anthocyanins.

[0084] Those skilled in the art should understand that the above are only some specific embodiments of the present invention, rather than all embodiments. It should be noted that for those of ordinary skill in the art, many modifications and improvements can be made, and all modifications or improvements that do not exceed the scope of protection of the present invention should be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing grape seed anthocyanidins, characterized in that: The steps include: S1, adding grape seed skin powder to an ethanol / saturated hydrochloric acid solution, wherein the mass fraction of saturated hydrochloric acid in the ethanol / saturated hydrochloric acid solution is 0.5% to 1.5%, and then adding an activated strong acid cation exchange resin for leaching, heating in a water bath at 60° C. to 80° C. for 30 min to 100 min, and filtering, washing the filter cake with a 0.5M to 1M potassium chloride solution until the washing liquid is colorless, and concentrating and dealcoholizing the washing liquid as the first solution for standby use; S2. Take the activated HPD 300 or HPD 600 macroporous resin and load it into the chromatography column. The column temperature is controlled at -5°C to 20°C. S3, taking the first solution of step S1 and loading it into a chromatography column filled with a macroporous resin, the volume mass ratio of the first solution to the macroporous resin is 1 ml: (2-10) g, adding water to wash after adsorption until the effluent is neutral, washing the chromatography column with an ethanol-water solution with a volume ratio of 4:6-6:4 until the washing liquid is colorless, concentrating the washing liquid to be alcohol-free, and vacuum freeze-drying to obtain anthocyanin extract; Among them, steps S1 and S2 are performed in no particular order.

2. The method for preparing grape seed anthocyanidins according to claim 1, characterized in that: The mass fraction of saturated hydrochloric acid in the ethanol / saturated hydrochloric acid solution in step S1 is 0.8% to 1.0%.

3. The method for preparing grape seed anthocyanidins according to claim 1, characterized in that: In step S1, the ratio of the grape seed skin powder, ethanol / saturated hydrochloric acid solution and activated strong acid cation exchange resin used for extraction is 10 g: (20-50) ml: (1-3) g.

4. The method for preparing grape seed anthocyanidins according to claim 3, characterized in that: In step S1, the amount ratio of grape seed skin powder, ethanol / saturated hydrochloric acid solution and activated strong acid cation exchange resin used for extraction is 10g:30ml:1g.

5. The method for preparing grape seed anthocyanidins according to claim 1, 2 or 3, characterized in that: The model of the strong acid cation exchange resin in step S1 is D001 or D002, and the manufacturer is Zhengzhou Hecheng New Material Technology Co., Ltd.

6. The method for preparing grape seed anthocyanidins according to claim 1, characterized in that: In step S1, the water bath heating temperature is 65° C. to 75° C., and the heating time is 40 min to 60 min.

7. The method for preparing grape seed anthocyanidins according to claim 1, characterized in that: The model of the chromatography column in step S2 is HPD 600.

8. The method for preparing grape seed anthocyanidins according to claim 1, characterized in that: In step S2, the column temperature is controlled at 0°C to 5°C.

9. The method for preparing grape seed anthocyanidins according to claim 1, characterized in that: In step S3, the volume mass ratio of the first solution to the macroporous resin is 1 ml: (3-5) g.

10. Grape seed anthocyanin prepared by the method for preparing grape seed anthocyanin according to any one of claims 1 to 9.

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