Extraction method of antioxidant components of ginger

Abstract

The invention relates to a method for extracting antioxidant components from ginger, which comprises the following steps: preparing mixed powder from dried ginger and superfine silica powder, adding into an extraction solvent, and carrying out ultrasonic extraction to obtain an extracting solution; carrying out ultrafiltration treatment on the extracting solution, collecting ultrafiltrate, and carrying out rotary evaporation to obtain a concentrated solution; and mixing the concentrated solution with a mixed solvent, carrying out centrifugal purification, and drying under reduced pressure to obtain an oily liquid dried ginger antioxidant component. According to the method, superfine silica powder is added into the raw materials, an ethanol solution, glycerin, CTAB and vitamin C are adopted to prepare an extraction solvent, in the low-temperature ultrasonic extraction process, the problem that it is difficult to extract antioxidant components from the dried ginger is solved, the transfer rate and yield of 6-gingerol are effectively increased, the transfer rate of 6-gingerol in the dried ginger reaches 77.8%, and the yield of 6-gingerol in the dried ginger also reaches 43.6%. Afterwards, diethyl ether and n-hexane are compounded in the purification process to form a purification solvent, the purity of the product is effectively improved, and the purity of 6-gingerol reaches 98.6%.

Description

Technical Field

[0001] The invention relates to the technical field of plant component extraction, and in particular to a method for extracting antioxidant components from ginger. Background Art

[0002] Ginger is an important plant used for both medicine and food, with many effects such as antioxidant, antibacterial, and anticancer. Dried ginger made by sun drying or low temperature drying is spicy and hot in nature. It has the effects of warming the middle and dispelling cold, restoring yang and unblocking meridians, and warming the lungs and transforming phlegm. It is mainly used to treat cold pain in the abdomen, vomiting and diarrhea caused by spleen and stomach deficiency and cold, as well as symptoms such as yang deficiency syndrome and cough due to cold phlegm. It plays an important role in prescriptions such as Lizhong Pills for treating spleen and stomach deficiency and cold, Sini Decoction for treating yang deficiency syndrome, and Xiaoqinglong Decoction for treating cough and asthma due to cold phlegm.

[0003] Gingerol is an active ingredient in ginger. It has a powerful antioxidant effect, helps to remove free radicals in the body and slow down cell aging. Gingerol is a general term for ginger-related spicy substances such as gingerol, shogaol, gingerone, gingerol, gingerdione, and gingerdiol. Gingerol is a mixture, and the content of each component in gingerol from different sources is different. 6-gingerol in gingerol, also known as 6-gingerol, has a relatively high content in ginger and is one of the main spicy substances. It has biological activities such as anti-cancer, analgesic, anti-inflammatory and antioxidant effects. The molecular structure of 6-gingerol contains multiple active groups such as phenolic hydroxyl groups. These groups can react with free radicals in the body such as superoxide anion radicals (O 2 - ), hydroxyl radical (·OH), hydrogen peroxide (H 2 O 2 ) and other reactions, reducing the oxidative damage of free radicals to cells and biomacromolecules. In addition, 6-gingerol can 3+ ), copper ions (Cu 2+ ) and other metal ions that can act as catalysts to chelate, reduce the activity of metal ions, thereby inhibiting the oxidation reaction catalyzed by metal ions and reducing the generation of oxidation products. 6-gingerol can also activate the body's antioxidant enzyme system, such as superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), etc., to enhance the body's own antioxidant defense ability and maintain the body's redox balance. Therefore, as a natural antioxidant, 6-gingerol can be applied to food, medical care, cosmetics and other fields.

[0004] 6-gingerol in gingerol contains highly active phenolic hydroxyl groups. Due to the high water content in fresh ginger, the phenolic hydroxyl groups will dissociate into hydrogen ions under the action of water molecules, resulting in the oxidation and loss of 6-gingerol. In addition, the water content in fresh ginger is too high and it is not easy to crush. Moreover, a large amount of water content will dilute the extraction solvent, which is not conducive to extraction. Therefore, it is necessary to remove a large amount of water from the ginger. Since dried ginger has a lower water content than fresh ginger after drying, its antioxidant content is significantly higher than that of fresh ginger. The use of extraction solvent can be reduced during the extraction process, while reducing the oxidation loss of 6-gingerol. However, due to the dehydration and shrinkage of cells, the tissue structure becomes tight, and the cell walls and intracellular substances become more compact. This makes it more difficult for the solvent to encounter more obstacles during the penetration process when extracting antioxidant components, making it difficult to enter the cell to fully contact with gingerol and extract it, increasing the difficulty of extraction. Summary of the invention

[0005] Based on the above problems, the present invention aims to provide a method for extracting antioxidant components from ginger. The method effectively improves the transfer rate and yield of antioxidant components in dried ginger, improves the stability of the effective ingredient 6-gingerol during the extraction process, effectively inhibits the conversion or degradation of 6-gingerol, simplifies the purification steps, and reduces the loss during the purification process.

[0006] The purpose of the present invention is achieved through the following technical solutions: A method for extracting antioxidant components from ginger, comprising the following steps: (1) Dry fresh ginger and mix it with micro-powdered silica gel and grind it into a mixed powder; (2) adding the mixed powder to an extraction solvent, placing the mixed powder in an ultrasonic extractor for ultrasonic extraction, collecting the filtrate 1 and the filter cake after filtering, performing a second ultrasonic extraction on the filter cake, collecting the filtrate 2 after filtering, and mixing the filtrate 1 and the filtrate 2 to obtain an extract; (3) subjecting the extract to ultrafiltration and collecting the ultrafiltrate; (4) rotary evaporating the ultrafiltrate into a concentrated solution; (5) mixing the concentrate with the mixed solvent for centrifugal purification, and collecting the centrifuge; (6) The centrifuged liquid is dried under reduced pressure to obtain an oily liquid, which is the antioxidant component 6-gingerol in dried ginger.

[0007] Furthermore, the step (1) is to remove impurities from the fresh ginger, clean it, and then cut it into 2-4 mm thick slices, and then dry it at a vacuum degree of -0.05 MPa to -0.08 MPa and a drying temperature of 35-40°C to obtain dried ginger with a moisture content of 1% to 4%, and then mix the dried ginger and micro-powdered silica gel in a mass ratio of 100:3-4, and grind it through a 60-80 mesh sieve to obtain a mixed powder.

[0008] Furthermore, the ultrasonic extraction in step (2) is specifically to mix the mixed powder with the extraction solvent in a mass ratio of 1:15~20, the ultrasonic vacuum degree is -0.05MPa~-0.08MPa, the ultrasonic temperature is 10~15°C, the ultrasonic frequency is 20~25kHz, the ultrasonic time is 45~60min, filtering is performed after ultrasonication, filtrate 1 and filter cake are collected, and the filter cake is subjected to secondary ultrasonic extraction, specifically, the filter cake and the extraction solvent are mixed in a ratio of 1:10~12, the ultrasonic vacuum degree is -0.05MPa~-0.08MPa, the ultrasonic temperature is 10~15°C, the ultrasonic frequency is 20~25kHz, the ultrasonic time is 30~40min, filtering is performed after ultrasonication, filtrate 2 is collected, and filtrate 1 and filtrate 2 are mixed to obtain an extract.

[0009] Furthermore, the extraction solvent in step (2) is an ethanol solution with a volume fraction of 30% to 40%. Glycerol is added at a stirring speed of 15 to 20 rpm, and stirring is continued for 1 to 2 minutes. Under continuous stirring conditions, hexadecyltrimethylammonium bromide (CTAB) is added, and stirring is continued for 3 to 5 minutes. Under continuous stirring conditions, vitamin C is added, and stirring is continued for 5 to 8 minutes to obtain an extraction solvent.

[0010] Furthermore, the usage ratio of the ethanol solution, glycerol, CTAB and vitamin C in the extraction solvent is 100:10~12:2~3:3~5.

[0011] Compared with fresh ginger, dried ginger has less water content due to drying, and its cells lose water and shrink, making its tissue structure tighter, and its cell walls and intracellular substances more compact. This makes it more difficult for the solvent to penetrate into the cells and fully contact and extract gingerols when extracting antioxidant ingredients, which increases the difficulty of extraction and reduces the transfer rate.

[0012] During the low-temperature ultrasonic process, it is ensured that the effective ingredients in the extraction process are not degraded by the influence of temperature.

[0013] In the present invention, an ethanol solution, glycerol, CTAB and vitamin C are used to prepare an extraction solvent, wherein the vitamin C improves the activity of CTAB and promotes the disruption of raw material cells by ultrasonic action, thereby improving the transfer rate of gingerol in the extraction process; and the addition of glycerol and ethanol promotes the penetration of ethanol into dry ginger and the attachment of CTAB and the like on the surface of the raw material, thereby improving the extraction efficiency of the solvent for gingerol; and simultaneously, during the extraction process, glycerol forms a continuous water film to protect the extracted effective components, thereby preventing the decomposition and loss of the extracted gingerol effective components caused by local overheating caused by ultrasound, and through the trade-off between the two, the extraction efficiency of gingerol is effectively improved.

[0014] High temperature will lead to the loss of gingerol components in dried ginger, and because dried ginger is difficult to extract, vacuum low-pressure ultrasonic cavitation extraction is used to improve the extraction efficiency of gingerol. However, the boiling point of the ethanol solution is lowered under vacuum, and local overheating will occur during the ultrasonic process, which makes the extraction process prone to boiling.

[0015] In the present invention, micro-powder silica gel is added to the raw material, and the micro-powder silica gel plays the role of a transfer medium in the raw material, thereby preventing the degradation and loss of the effective ingredients during the crushing process. In the extraction process, the micro-powder silica gel also plays the role of a transfer medium, and combined with the uniform transfer of the continuous water film formed by glycerol, the temperature uniformity in the extraction process is synergistically improved, and the stability of the extract is effectively protected. Secondly, in the extraction process, the introduction of micro-powder silica gel, in addition to improving the temperature uniformity, can also prevent the boiling caused by the reduction of the boiling point of the extraction solvent, thereby improving the extraction efficiency of gingerol.

[0016] Furthermore, in the step (3), the ultrafiltration treatment is performed using an ultrafiltration membrane with a molecular cutoff of 3000Da, the ultrafiltration pressure is 0.1-0.3MPa, the ultrafiltration temperature is 30-35°C, and after the ultrafiltration is completed, the ultrafiltrate is collected.

[0017] Furthermore, in the step (4), the vacuum degree of the rotary evaporation is set to -0.03 to -0.05 MPa, the rotation speed is 150 to 180 rpm, the evaporation temperature is 35°C to 40°C, the ethanol is evaporated until the relative density of the liquid at 35°C is 1.05 to 1.08, and the pH of the solution is adjusted to 7.50 to 7.80 with a sodium bicarbonate solution having a mass fraction of 10%, to obtain a concentrated solution.

[0018] Furthermore, in the centrifugal purification in step (5), the concentrate and the purification solvent are placed in a centrifugal extractor at a temperature of 32-38° C., the flow ratio of the concentrate and the purification solvent is 1:3-5, the two-phase mixing flux is 10-12 L / h, and continuous centrifugal purification is performed, and the purification solvent item is collected after purification.

[0019] During the purification process, a specific ratio of ether and n-hexane was used to form a purification solvent, and the polarity of the purification solvent was adjusted. Under an alkaline environment, the flow rates of the concentrate and the purification solvent were controlled to effectively dissolve the 6-gingerol in the system and remove other impurities in the concentrate, so that high-purity 6-gingerol was obtained after final purification and concentration.

[0020] Furthermore, in the step (6), the reduced pressure drying is to place the purified solvent item under a vacuum degree of -0.05 MPa to -0.08 MPa and a drying temperature of 40 to 45° C. for 30 to 36 hours to obtain an oily liquid.

[0021] Most specifically, a method for extracting antioxidant components from ginger is characterized by comprising the following steps: (1) Remove impurities from fresh ginger, clean it, cut it into 2-4 mm thick slices, place it in a reduced pressure drying oven, dry it at a vacuum degree of -0.05 MPa to -0.08 MPa and a drying temperature of 35-40°C to obtain dried ginger with a moisture content of 1% to 4%, then mix the dried ginger and micro-powdered silica gel in a mass ratio of 100:3-4, grind them, pass them through a 60-80 mesh sieve, and collect the crushed mixed powder; (2) adding the mixed powder to an extraction solvent and placing the mixed powder in a low-temperature ultrasonic extractor for ultrasonic extraction. The ultrasonic extraction is performed twice. The first ultrasonic extraction is to mix the mixed powder with the extraction solvent in a mass ratio of 1:15-20, the ultrasonic vacuum degree is -0.05MPa--0.08MPa, the ultrasonic temperature is 10-15°C, the ultrasonic frequency is 20-25kHz, and the ultrasonic time is 45-60min. After ultrasonic extraction, filtering is performed to collect filtrate 1 and filter cake. The filter cake is subjected to secondary ultrasonic extraction. Specifically, the filter cake and the extraction solvent are mixed in a ratio of 1:10-12, the ultrasonic vacuum degree is -0.05MPa--0.08MPa, the ultrasonic temperature is 10-15°C, the ultrasonic frequency is 20-25kHz, and the ultrasonic time is 30-40min. After ultrasonic extraction, filtering is performed to collect filtrate 2. Filtrate 1 and filtrate 2 are mixed to obtain an extract. The extraction solvent is an ethanol solution with a volume fraction of 30% to 40%, glycerol is added under a stirring speed of 15 to 20 rpm, stirring is continued for 1 to 2 minutes, cetyltrimethylammonium bromide (CTAB) is added under continuous stirring, stirring is continued for 3 to 5 minutes, vitamin C is added under continuous stirring, and stirring is continued for 5 to 8 minutes to obtain the extraction solvent, wherein the usage ratio of the ethanol solution, glycerol, CTAB and vitamin C is 100:10:2:3; (3) placing the extract in an ultrafiltration membrane with a molecular cutoff of 3000Da for ultrafiltration treatment, the ultrafiltration pressure is 0.1~0.3MPa, the ultrafiltration temperature is 30~35℃, and the ultrafiltration is completed, collecting the ultrafiltrate; (4) Place the ultrafiltrate in a rotary evaporator, set the vacuum degree to -0.03~-0.05MPa, the rotation speed to 150~180rpm, and the evaporation temperature to 35℃~40℃, remove ethanol by rotary evaporation until the relative density of the liquid at 35℃ is 1.05~1.08, and adjust the pH of the solution to 7.50~7.80 with a 10% sodium bicarbonate solution to obtain a concentrated solution; (5) taking the concentrated solution and the purification solvent and placing them in a centrifugal extractor, controlling the temperature to 32-38° C., setting the two-phase mixing flux to 10-12 L / h, and the two-phase flow ratio of the concentrated solution to the purification solvent to 1:3-5, performing continuous centrifugal purification, and collecting the purified solution after purification, wherein the purification solvent is composed of ether and n-hexane in a volume ratio of 1:6-8; (6) The purified liquid is dried under reduced pressure to obtain an oily liquid, which is placed in a reduced pressure concentration drying oven with a vacuum degree set at -0.05 MPa to -0.08 MPa and a drying temperature set at 40 to 45°C for 30 to 36 hours to obtain an oily liquid, which is the antioxidant component 6-gingerol in dried ginger.

[0022] The present invention has the following technical effects: In the present invention, micro-powdered silica gel is added to dried ginger, and an ethanol solution, glycerol, CTAB and vitamin C are used to prepare an extraction solvent. During the low-temperature ultrasonic extraction process, the problem that the dried ginger has a compact tissue structure, and the cell wall and the substances in the cell become more compact, which leads to the difficulty in extracting 6-gingerol, is solved, and the transfer rate and yield of 6-gingerol in the dried ginger are effectively improved. The transfer rate of 6-gingerol in the dried ginger reaches 77.8%, and the yield also reaches 43.6%. Afterwards, ether and n-hexane are compounded to form a purification solvent during the purification process, which effectively improves the purity of the product, and the purity of 6-gingerol reaches 98.6%. DETAILED DESCRIPTION

[0023] The present invention is described in detail below through examples. It is necessary to point out that the following examples are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above-mentioned contents of the present invention.

[0024] Example 1 A method for extracting antioxidant components from ginger, comprising the following steps: (1) Remove impurities from fresh ginger, clean it, cut it into 2-4 mm thick slices, place it in a vacuum drying oven, dry it at a vacuum degree of -0.06 MPa and a drying temperature of 38 °C to obtain dry ginger with a moisture content of 3%, then mix the dry ginger and micro-powdered silica gel in a mass ratio of 100:3.5, grind them, pass them through an 80-mesh sieve, and collect the mixed powder; (2) adding the mixed powder of step (1) to an extraction solvent, placing the mixture in a low-temperature ultrasonic extractor for ultrasonic extraction, wherein the ultrasonic extraction is performed twice. The first ultrasonic extraction is to mix the mixed powder with the extraction solvent in a mass ratio of 1:18, the ultrasonic vacuum degree is -0.06 MPa, the ultrasonic temperature is 12°C, the ultrasonic frequency is 22 kHz, and the ultrasonic time is 50 min. After ultrasonic extraction, the mixture is filtered to collect filtrate 1 and filter cake. The filter cake is subjected to secondary ultrasonic extraction, specifically, the filter cake and the extraction solvent are mixed in a mass ratio of 1:10, the ultrasonic vacuum degree is -0.06 MPa, the ultrasonic temperature is 12°C, the ultrasonic frequency is 22 kHz, and the ultrasonic time is 35 min. After ultrasonic extraction, the mixture is filtered to collect filtrate 2. Filtrate 1 and filtrate 2 are mixed to obtain an extract. The amount ratio of the ethanol solution, glycerol, CTAB and vitamin C is 100:10~12:2~3:3~5; The extraction solvent is a 35% ethanol solution, under the condition of a stirring speed of 18 rpm, glycerol is added, stirring is continued for 1 min, under the condition of continuous stirring, hexadecyltrimethylammonium bromide (CTAB) is added, stirring is continued for 4 min, under the condition of continuous stirring, vitamin C is added, and stirring is continued for 6 min to obtain the extraction solvent; (3) The extract was placed in an ultrafiltration membrane with a molecular cutoff of 3000Da for ultrafiltration treatment at an ultrafiltration pressure of 0.2MPa and an ultrafiltration temperature of 32°C. After the ultrafiltration was completed, the ultrafiltrate was collected; (4) The ultrafiltrate was placed in a rotary evaporator, and the vacuum degree was set to -0.04 MPa, the rotation speed was set to 160 rpm, and the evaporation temperature was set to 38°C. The ethanol was removed by rotary evaporation until the relative density of the liquid was 1.05-1.08 at 35°C. The pH of the solution was adjusted to 7.60 with a sodium bicarbonate solution having a mass fraction of 10%, and a concentrated solution was obtained; (5) placing the concentrated solution and the purification solvent in a centrifugal extractor, controlling the temperature to 35° C., setting the two-phase mixing flux to 10 L / h, and the two-phase flow ratio of the concentrated solution to the purification solvent to 1:4, performing continuous centrifugal purification, and collecting the purified solution after purification, wherein the purification solvent is composed of diethyl ether and n-hexane in a volume ratio of 1:7; (6) The purified liquid is dried under reduced pressure to obtain an oily liquid, which is placed in a reduced pressure concentration drying oven with a vacuum degree set at -0.6 MPa and a drying temperature set at 42°C for 32 hours to obtain an oily liquid, which is the antioxidant component 6-gingerol in dried ginger.

[0025] The transfer rate is calculated by the formula:

[0026] The calculation formula of yield is:

[0027] In the above formula, the dried raw material is the dried ginger in each embodiment. According to calculation, the transfer rate of 6-gingerol in Example 1 is 77.8%, the yield is 43.6%, and the purity of the final product is 98.6%.

[0028] Comparative Example 1 Compared with Example 1, the difference is that in step (1) the following is performed: Fresh ginger was cleaned and then cut into 2-4 mm thick slices, placed in a vacuum drying oven, dried to 3% moisture at a vacuum degree of -0.06 MPa and a drying temperature of 38°C, then crushed through an 80-mesh sieve, and the crushed powder was collected; the remaining steps were the same as in Example 1. That is, in Comparative Example 1, micro-powder silica gel was not used to mix with dried ginger to prepare powder.

[0029] In the extraction step (2), due to the lack of micro-powdered silica gel and glycerol water film to form a good transfer medium, obvious boiling occurred during the ultrasonic process.

[0030] According to calculation, the transfer rate of 6-gingerol in Comparative Example 1 was 62.3%, the yield was 30.3%, and the purity of the final product was 96.2%.

[0031] Comparative Example 2 Different from Example 1, the steps for preparing the solvent for extraction in step (2) are as follows: Take a 35% ethanol solution by volume, add CTAB under the condition of stirring speed of 18 rpm, continue stirring for 4 minutes, add vitamin C under the condition of continuing stirring, and continue stirring for 6 minutes to obtain the extraction solvent; the remaining steps are the same as in Example 1.

[0032] No glycerol was added to the extraction solvent, and slight boiling occurred during the extraction process in step (2).

[0033] Because there is no glycerol component in the extraction solvent, there is no glycerol to form a continuous water film in the extraction process to form a good transfer medium with micro-powder silica gel, local overheating occurs in the ultrasonic cavitation process, resulting in slight boiling, and there is no protection of the water film, under the promotion of the surface activity, the ultrasound damages the structure of the effective ingredient 6-gingerol, causing it to further decompose and form losses, and after calculation, the transfer rate of 6-gingerol in Comparative Example 2 is 57.2%, the yield is 24.5%, and the purity of the final product is 93.7%. It can be seen that although the transfer rate of 6-gingerol is high in the extraction process of Comparative Example 2, due to the large-scale loss of 6-gingerol in the extraction process, the yield is significantly decreased, and the purity of the final product is also significantly decreased.

[0034] Comparative Example 3 Different from Example 1, the steps for preparing the solvent for extraction in step (2) are as follows: Take a 35% ethanol solution by volume, add glycerol under the condition of stirring at a speed of 18 rpm, continue stirring for 1 minute, add benzyltriethylammonium chloride (BTEAC) under continuous stirring, continue stirring for 4 minutes, add vitamin C under continuous stirring, continue stirring for 6 minutes, and obtain an extraction solvent; the remaining steps are the same as those in Example 1. That is, CTAB in Example 1 is replaced with BTEAC.

[0035] According to calculation, the transfer rate of 6-gingerol in Comparative Example 3 was 71.3%, the yield was 31.7%, and the purity of the final product was 92.4%.

[0036] In Comparative Example 3, due to the replacement of CTAB with BTEAC, the influence of the surface activity on the polarity of the solvent is different, and the influence on ultrasonic cavitation is more obvious than CTAB, not only the transfer rate of 6-gingerol slightly decreases, but also 6-gingerol is damaged to a certain extent in the process, so the yield and purity all show obvious decreases. With no addition of any surfactant as the blank group, after calculation, the transfer rate of 6-gingerol in the blank group is 50.9%, the yield is 33.4%, and the finished product purity is 90.2%. Due to the absence of CTAB in the blank group, the ultrasonic cavitation effect is not only not improved, and the water film formed by glycerol hinders the rupture effect of ultrasonic cavitation on the raw material cells, thereby reducing the release of 6-gingerol, thereby causing the transfer rate to decline, and the final extraction efficiency is not high.

[0037] Stability test: The other steps were the same as those in Example 1. During the centrifugal purification process in step (5), the total amount of the purification solvent remained unchanged. The ratio of the purification solvent was adjusted to observe the change in the purity of the final extract with respect to the purification solvent. The prepared liquid product was placed at 25° C., a relative humidity of 70%, and natural light to observe its stability change. The results are shown in Table 1.

[0038] Table 1:

[0039] It can be seen that the finished products obtained by using ether, n-hexane and methanol as purification solvents alone all have impurities and low purity. When ether, methanol and n-hexane are used as purification solvents in combination, although the purity of the finished products is improved, the yield of the methanol and n-hexane composite purification solvent group is significantly lower than that of the single n-hexane group, and is equivalent to that of the single methanol group. That is, improper selection of composite purification solvents may have a negative impact on the yield and purity of 6-gingerol.

[0040] In addition, during the purification process, if the two-phase flow ratio of the concentrate and the purification solvent is not well controlled, not only the yield of the final product obtained by purification will be affected, but the purity will also decrease significantly. In the present invention, the purity of the product purified at a two-phase flow ratio of the concentrate and the purification solvent of 1:3 to 5 is relatively high, all above 98%, and the yield is also above 40%.

[0041] Example 2 A method for extracting antioxidant components from ginger, comprising the following steps: (1) Remove impurities from fresh ginger, clean it, cut it into 2-4 mm thick slices, place it in a vacuum drying oven, dry it at a vacuum degree of -0.05 MPa and a drying temperature of 35°C to make dried ginger with a moisture content of 4%, then mix the dried ginger and micro-powdered silica gel in a mass ratio of 100:3, grind them, pass them through a 60-mesh sieve, and collect the mixed powder after grinding; (2) adding the mixed powder of step (1) to an extraction solvent, placing the mixture in a low-temperature ultrasonic extractor for ultrasonic extraction, wherein the ultrasonic extraction is performed twice, wherein the first ultrasonic extraction is to mix the mixed powder with the extraction solvent in a mass ratio of 1:15, the ultrasonic vacuum degree is -0.05 MPa, the ultrasonic temperature is 15°C, the ultrasonic frequency is 25 kHz, the ultrasonic time is 45 min, filtering is performed after ultrasonication, collecting filtrate 1 and filter cake, and performing secondary ultrasonic extraction on the filter cake, specifically, mixing the filter cake with the extraction solvent in a mass ratio of 1:10, the ultrasonic vacuum degree is -0.05 MPa, the ultrasonic temperature is 15°C, the ultrasonic frequency is 25 kHz, the ultrasonic time is 40 min, filtering is performed after ultrasonication, collecting filtrate 2, and mixing filtrate 1 and filtrate 2 to obtain an extract, wherein the amount ratio of the ethanol solution, glycerol, CTAB and vitamin C is 100:12:3:5; The extraction solvent is a 30% ethanol solution by volume, glycerol is added under a stirring speed of 20 rpm, stirring is continued for 2 minutes, hexadecyltrimethylammonium bromide (CTAB) is added under continuous stirring, stirring is continued for 5 minutes, vitamin C is added under continuous stirring, stirring is continued for 8 minutes, and the extraction solvent is obtained; (3) The extract was placed in an ultrafiltration membrane with a molecular cutoff of 3000Da for ultrafiltration treatment at an ultrafiltration pressure of 0.1MPa and an ultrafiltration temperature of 35°C. After the ultrafiltration was completed, the ultrafiltrate was collected; (4) The ultrafiltrate was placed in a rotary evaporator, and the vacuum degree was set to -0.03 MPa, the rotation speed was set to 180 rpm, and the evaporation temperature was set to 35°C. The ethanol was removed by rotary evaporation until the relative density of the liquid at 35°C was 1.05-1.08. The pH value of the solution was adjusted to 7.80 with a sodium bicarbonate solution having a mass fraction of 10%, and a concentrated solution was obtained; (5) placing the concentrated solution and the purification solvent in a centrifugal extractor, controlling the temperature to 32° C., setting the two-phase mixing flux to 10 L / h, and the two-phase flow ratio of the concentrated solution to the purification solvent to 1:3, performing continuous centrifugal purification, and collecting the purified solution after purification, wherein the purification solvent is composed of diethyl ether and n-hexane in a volume ratio of 1:6; (6) The purified liquid is dried under reduced pressure to obtain an oily liquid, which is placed in a reduced pressure concentration drying oven with a vacuum degree set at -0.05 MPa and a drying temperature set at 40°C for 30 hours to obtain an oily liquid, which is the antioxidant component 6-gingerol in dried ginger.

[0042] The transfer rate of 6-gingerol in Example 2 was calculated to be 76.9%, the yield was 42.4%, and the purity of the final product was 98.1%.

[0043] Example 3 A method for extracting antioxidant components from ginger, comprising the following steps: (1) Remove impurities from fresh ginger, clean it, cut it into 2-4 mm thick slices, place it in a vacuum drying oven, dry it at a vacuum degree of -0.08 MPa and a drying temperature of 40°C to obtain dried ginger with a moisture content of 1%, then mix the dried ginger and micro-powdered silica gel in a mass ratio of 100:4, grind them, pass them through an 80-mesh sieve, and collect the mixed powder after grinding; (2) adding the mixed powder of step (1) to an extraction solvent, placing the mixture in a low-temperature ultrasonic extractor for ultrasonic extraction, wherein the ultrasonic extraction is performed twice. The first ultrasonic extraction is to mix the mixed powder with the extraction solvent in a mass ratio of 1:20, the ultrasonic vacuum degree is -0.08 MPa, the ultrasonic temperature is 10°C, the ultrasonic frequency is 20 kHz, and the ultrasonic time is 60 min. After ultrasonic extraction, the mixture is filtered to collect filtrate 1 and filter cake. The filter cake is subjected to secondary ultrasonic extraction, specifically, the filter cake and the extraction solvent are mixed in a ratio of 1:12, the ultrasonic vacuum degree is -0.08 MPa, the ultrasonic temperature is 10°C, the ultrasonic frequency is 20 kHz, and the ultrasonic time is 30 min. After ultrasonic extraction, the mixture is filtered to collect filtrate 2. Filtrate 1 and filtrate 2 are mixed to obtain an extract. The ratio of the ethanol solution, glycerol, CTAB and vitamin C is 100:11:2.5:4. The extraction solvent is a 40% ethanol solution, under the condition of a stirring speed of 15 rpm, glycerol is added, and stirring is continued for 1 minute. Under the condition of continuous stirring, hexadecyltrimethylammonium bromide (CTAB) is added, and stirring is continued for 3 minutes. Under the condition of continuous stirring, vitamin C is added, and stirring is continued for 5 minutes to obtain the extraction solvent; (3) The extract was placed in an ultrafiltration membrane with a molecular cutoff of 3000Da for ultrafiltration treatment at an ultrafiltration pressure of 0.3MPa and an ultrafiltration temperature of 30°C. After the ultrafiltration was completed, the ultrafiltrate was collected; (4) The ultrafiltrate was placed in a rotary evaporator, and the vacuum degree was set to -0.05 MPa, the rotation speed was set to 150 rpm, and the evaporation temperature was set to 40°C. The ethanol was removed by rotary evaporation until the relative density of the liquid at 35°C was 1.05-1.08. The pH value of the solution was adjusted to 7.50 with a sodium bicarbonate solution having a mass fraction of 10%, and a concentrated solution was obtained; (5) taking the concentrated solution and the purification solvent and placing them in a centrifugal extractor, controlling the temperature to 38° C., setting the two-phase mixing flux to 12 L / h, and the two-phase flow ratio of the concentrated solution to the purification solvent to 1:5, performing continuous centrifugal purification, and collecting the purified solution after purification, wherein the purification solvent is composed of diethyl ether and n-hexane in a volume ratio of 1:8; (6) The purified liquid is dried under reduced pressure to obtain an oily liquid, which is placed in a reduced pressure concentration drying oven with a vacuum degree set at -0.08 MPa and a drying temperature set at 45°C for 36 hours to obtain an oily liquid, which is the antioxidant component 6-gingerol in dried ginger.

[0044] The transfer rate of 6-gingerol in Example 1 was calculated to be 77.1%, the yield was 41.5%, and the purity of the final product was 98.2%.

Claims

1. A method for extracting antioxidant components from ginger, characterized in that: The steps include: (1) Dry fresh ginger and mix it with micro-powdered silica gel and grind it into a mixed powder; (2) adding the mixed powder to an extraction solvent, placing the mixed powder in an ultrasonic extractor for ultrasonic extraction, collecting the filtrate 1 and the filter cake after filtering, performing a second ultrasonic extraction on the filter cake, collecting the filtrate 2 after filtering, and mixing the filtrate 1 and the filtrate 2 to obtain an extract; (3) subjecting the extract to ultrafiltration treatment and collecting the ultrafiltrate; (4) rotary evaporating the ultrafiltrate into a concentrated solution; (5) mixing the concentrate with the mixed solvent for centrifugal purification, and collecting the centrifuge; (6) The centrifuged liquid is dried under reduced pressure to obtain an oily liquid, which is the antioxidant component 6-gingerol in dried ginger.

2. A method for extracting antioxidant components from ginger as claimed in claim 1, characterized in that: The step (1) comprises removing impurities from fresh ginger, cleaning it, and then cutting it into 2-4 mm thick slices, and then drying it at a vacuum degree of -0.05 MPa to -0.08 MPa and a drying temperature of 35-40° C. to obtain dried ginger with a moisture content of 1% to 4%, and then mixing the dried ginger and micro-powdered silica gel in a mass ratio of 100:3-4, and crushing it through a 60-80 mesh sieve to obtain a mixed powder.

3. A method for extracting antioxidant components from ginger as claimed in claim 1 or 2, characterized in that: The ultrasonic extraction in step (2) specifically comprises mixing the mixed powder with the extraction solvent in a mass ratio of 1:15-20, the ultrasonic vacuum degree is -0.05MPa--0.08MPa, the ultrasonic temperature is 10-15°C, the ultrasonic frequency is 20-25kHz, the ultrasonic time is 45-60min, filtering is performed after ultrasonication, collecting filtrate 1 and filter cake, and performing secondary ultrasonic extraction on the filter cake, specifically mixing the filter cake with the extraction solvent in a mass ratio of 1:10-12, the ultrasonic vacuum degree is -0.05MPa--0.08MPa, the ultrasonic temperature is 10-15°C, the ultrasonic frequency is 20-25kHz, the ultrasonic time is 30-40min, filtering is performed after ultrasonication, collecting filtrate 2, and mixing filtrate 1 and filtrate 2 to obtain an extract.

4. The method for extracting antioxidant components from ginger according to claim 3, characterized in that: The extraction solvent in step (2) is an ethanol solution with a volume fraction of 30% to 40%. Glycerol is added at a stirring speed of 15 to 20 rpm, and stirring is continued for 1 to 2 minutes. Under continuous stirring conditions, hexadecyltrimethylammonium bromide (CTAB) is added, and stirring is continued for 3 to 5 minutes. Under continuous stirring conditions, vitamin C is added, and stirring is continued for 5 to 8 minutes to obtain the extraction solvent.

5. A method for extracting antioxidant components from ginger as described in any one of claims 1 to 4, characterized in that: The ultrafiltration treatment in step (3) is performed using an ultrafiltration membrane with a molecular cutoff of 3000Da, an ultrafiltration pressure of 0.1-0.3MPa, and an ultrafiltration temperature of 30-35°C. After the ultrafiltration is completed, the ultrafiltrate is collected.

6. A method for extracting antioxidant components from ginger as claimed in claim 5, characterized in that: In the step (4), the rotary evaporation is performed by setting the vacuum degree to -0.03 to -0.05 MPa, the rotation speed to 150 to 180 rpm, the evaporation temperature to 35°C to 40°C, and ethanol is evaporated until the relative density of the liquid at 35°C is 1.05 to 1.08, and the pH value of the solution is adjusted to 7.50 to 7.80 with a sodium bicarbonate solution having a mass fraction of 10%, thereby obtaining a concentrated solution.

7. A method for extracting antioxidant components from ginger as claimed in claim 6, characterized in that: The reduced pressure drying in step (6) is to place the purified solvent item under a vacuum degree of -0.05 MPa to -0.08 MPa and a drying temperature of 40 to 45° C. for 30 to 36 hours to obtain an oily liquid.

8. A method for extracting antioxidant components from ginger, characterized in that: The steps include: (1) Remove impurities from fresh ginger, clean it, cut it into 2-4 mm thick slices, place it in a reduced pressure drying oven, dry it at a vacuum degree of -0.05 MPa to -0.08 MPa and a drying temperature of 35-40°C to obtain dried ginger with a moisture content of 1% to 4%, then mix the dried ginger and micro-powdered silica gel in a mass ratio of 100:3-4, grind them, pass them through a 60-80 mesh sieve, and collect the mixed powder after grinding; (2) adding the mixed powder to an extraction solvent and placing the mixed powder in a low-temperature ultrasonic extractor for ultrasonic extraction. The ultrasonic extraction is performed twice. The first ultrasonic extraction is to mix the mixed powder with the extraction solvent in a mass ratio of 1:15-20, the ultrasonic vacuum degree is -0.05MPa--0.08MPa, the ultrasonic temperature is 10-15°C, the ultrasonic frequency is 20-25kHz, and the ultrasonic time is 45-60min. After ultrasonic extraction, filtering is performed to collect filtrate 1 and filter cake. The filter cake is subjected to secondary ultrasonic extraction. Specifically, the filter cake and the extraction solvent are mixed in a ratio of 1:10-12, the ultrasonic vacuum degree is -0.05MPa--0.08MPa, the ultrasonic temperature is 10-15°C, the ultrasonic frequency is 20-25kHz, and the ultrasonic time is 30-40min. After ultrasonic extraction, filtering is performed to collect filtrate 2. Filtrate 1 and filtrate 2 are mixed to obtain an extract. The extraction solvent is prepared by taking an ethanol solution with a volume fraction of 30% to 40%, adding glycerol under a stirring speed of 15 to 20 rpm, and continuing to stir for 1 to 2 minutes. Under continuous stirring, cetyltrimethylammonium bromide (CTAB) is added, and stirring is continued for 3 to 5 minutes. Under continuous stirring, vitamin C is added, and stirring is continued for 5 to 8 minutes to obtain the extraction solvent. The usage ratio of the ethanol solution, glycerol, CTAB and vitamin C is 100:10 to 12:2 to 3:3 to 5. (3) placing the extract in an ultrafiltration membrane with a molecular cutoff of 3000Da for ultrafiltration treatment, the ultrafiltration pressure is 0.1~0.3MPa, the ultrafiltration temperature is 30~35℃, and the ultrafiltration is completed, collecting the ultrafiltrate; (4) Place the ultrafiltrate in a rotary evaporator, set the vacuum degree to -0.03~-0.05MPa, the rotation speed to 150~180rpm, and the evaporation temperature to 35℃~40℃, remove ethanol by rotary evaporation until the relative density of the liquid at 35℃ is 1.05~1.08, and adjust the pH of the solution to 7.50~7.80 with a 10% sodium bicarbonate solution to obtain a concentrated solution; (5) taking the concentrated solution and the purification solvent and placing them in a centrifugal extractor, controlling the temperature to 32-38° C., setting the two-phase mixing flux to 10-12 L / h, and the two-phase flow ratio of the concentrated solution to the purification solvent to 1:3-5, performing continuous centrifugal purification, and collecting the purified solution after purification, wherein the purification solvent is composed of ether and n-hexane in a volume ratio of 1:6-8; (6) The purified liquid is dried under reduced pressure to obtain an oily liquid, which is placed in a reduced pressure concentration drying oven with a vacuum degree set at -0.05 MPa to -0.08 MPa and a drying temperature set at 40 to 45 °C for 30 to 36 h to obtain an oily liquid, which is the antioxidant component 6-gingerol in dried ginger.

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