Ginkgo biloba leaf extract based on functional food and preparation process thereof

Abstract

The invention relates to the technical field of functional food preparation, and discloses a ginkgo biloba extract based on functional food and a preparation process of the ginkgo biloba extract. The preparation process comprises the following steps: (1) treating ginkgo leaves; (2) carrying out solid-liquid separation, cooling the filtrate A, and crushing filter residues; (3) immersing the filter residue in water, carrying out solid-liquid separation to obtain a filtrate B, carrying out macroporous resin adsorption treatment on the filtrate B, and mixing the filtrate B with the filtrate A to obtain a ginkgo leaf extracting solution; (4) adding the filter residue, starch hydrolysate and glycosidase, and performing microwave extraction; (5) introducing supercritical CO2 for extraction; (6) removing CO2 from the extract, and concentrating to obtain the ginkgo leaf extract; and (7) obtaining the functional food. According to the method, the extraction rate of ginkgo flavone and ginkgolide is increased, no solvent such as ethyl alcohol participates in the whole preparation process, and the problem that the quality of the extract is reduced due to the fact that an alcohol solvent is prone to acid-base reaction is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of functional food preparation, in particular to ginkgo biloba leaf extract based on functional food, and also relates to the preparation process of the ginkgo biloba leaf extract. Background Art

[0002] Ginkgo biloba leaves contain relatively more lactones and flavonoids. These two substances can effectively enhance blood flow in the body and also have the effect of dilating blood vessels. Therefore, they have a certain effect in treating cardiovascular and cerebrovascular diseases. In addition to treating cardiovascular and cerebrovascular diseases, taking ginkgo biloba leaves also has the effects of delaying aging, preventing Alzheimer's disease, and maintaining good health. Based on the foregoing characteristics, ginkgo biloba leaf extract can be combined with green tea to make a functional food, namely, a ginkgo biloba leaf extract drink, to strengthen nutrition, relieve symptoms such as mental fatigue and slow reaction caused by brain decline, and improve blood circulation and memory.

[0003] For the preparation method of a ginkgo biloba leaf extract as disclosed in the invention patent with the reference number CN100446778C, it adopts the following steps: 1) Soaking ginkgo biloba leaves in ethanol and heating under reflux; 2) Adsorbing and purifying through a macroporous resin column; 3) Treating with high-concentration ethanol to obtain the ginkgo biloba leaf extract. For the preparation method of a ginkgo biloba leaf extract and its application in cigarettes as disclosed in the invention patent with the reference number CN107802025B, it adopts the following steps: (1) Cleaning, draining, and slicing fresh ginkgo biloba leaves for standby, extracting by microwave with an ethanol solution, filtering, and collecting the filtrate to obtain ginkgo biloba leaf extract A. (2) Collecting the ginkgo biloba leaf residue in step (1), adding water and a biological agent, hydrolyzing and fermenting, adding ethanol to the hydrolysis fermentation broth for constant-temperature reflux extraction, and filtering to obtain ginkgo biloba leaf extract B. (3) Combining ginkgo biloba leaf extract A and ginkgo biloba leaf extract B, and then performing vacuum concentration to obtain the ginkgo biloba leaf extract. The foregoing extraction modes all require the use of ethanol solvents. When alcohol solvents are involved in the extraction, there is a problem that acid-base reactions are likely to occur with alcohol solvents, resulting in a decline in the quality of the extract, leading to poor quality and stability of the ginkgo biloba leaf extract. Summary of the Invention

[0004] In view of the above-mentioned disadvantages of the prior art, the purpose of the present invention is to provide a ginkgo biloba leaf extract based on functional food and its preparation process to improve the extraction rate of ginkgo flavonoids and ginkgolides, while overcoming the problem that the quality of the extract decreases due to acid-base reactions easily occurring when alcohol solvents are involved in the extraction.

[0005] The preparation process of the ginkgo biloba leaf extract based on functional food includes the following steps: (1) Taking fresh ginkgo biloba leaves and performing alkali water cooking treatment; (2) Solid-liquid separation is carried out on the material after alkaline water cooking, and the obtained filtrate A is cooled for standby, and the filter residue is pulverized. (3) The filter residue is immersed in water, and then solid-liquid separation is carried out. The obtained filtrate B is subjected to macroporous resin adsorption treatment and then mixed with filtrate A to obtain ginkgo leaf extract; (4) Add the filter residue obtained in step (3) to the ginkgo leaf extract, stir and mix, then add starch hydrolyzate and glycosidase, and place it in a microwave extraction device for leaching treatment; (5) Transfer the material obtained after the leaching treatment in step (4) to an extraction tank, and introduce supercritical CO2 for extraction treatment; (6) After the extract obtained by supercritical CO2 extraction treatment is de-carbonated, filter to retain filtrate C, and concentrate filtrate C to obtain ginkgo leaf extract; (7) Take the ginkgo leaf extract and mix it with green tea solution to obtain a functional food, namely ginkgo leaf extract drink.

[0006] The above preparation process can improve the extraction rate of ginkgo flavonoids and ginkgolides, and at the same time overcome the problem that the quality of the extract decreases due to the easy occurrence of acid-base reactions when alcohol solvents are involved in the extraction.

[0007] As a further improvement of the above solution, in the alkaline water cooking process, the alkaline water used is an aqueous solution of sodium bicarbonate with a concentration of 5%, and the weight-to-volume ratio of ginkgo leaves to alkaline water is 1:3 - 6, the cooking temperature is 60 - 70 °C, and the cooking time is 20 - 30 min. In the present invention, the conditions of alkaline water cooking are optimized to inactivate enzymes without losing the active substances in ginkgo leaves, and ginkgolic acid is insoluble in alkaline water. Therefore, the harmful substance ginkgolic acid is not contained in filtrate A.

[0008] As a further improvement of the above solution, the filter residue is immersed in water and stirred at 40 °C for 20 - 40 min and then solid-liquid separation is carried out. In the present invention, by stirring, it is ensured that the filter residue is fully in contact with water, and combined with the characteristic that the solubility of ginkgolic acid is the largest at 40 °C, the dissolution of the harmful substance ginkgolic acid is promoted, and it is removed by macroporous resin adsorption.

[0009] As a further improvement of the above solution, the starch hydrolyzate is dextrin, maltose or glucose; the ratio of the starch hydrolyzate to glycosidase is 1 - 2.5:1, and the addition amount of glycosidase accounts for 1% - 3% of the total weight of fresh ginkgo leaves. In the present invention, by adding starch hydrolyzate and glycosidase, the flavonoid component combines with the starch hydrolyzate under the action of glycosidase to form glycosides, improving the hydrophilicity of flavonoid molecules, and thus promoting the dissolution of flavonoid components.

[0010] As a further improvement of the above solution, when performing the leaching treatment in a microwave extraction device, the microwave power is set to 550 W, the temperature is set to rise from room temperature to 45 - 55 °C within 10 - 30 min, and the leaching time is 80 - 100 min. In the present invention, microwave treatment is used during leaching to promote the release of ginkgo flavonoids and ginkgolides.

[0011] As a further improvement of the above solution, the extraction conditions include: the pressure in the extraction kettle is 7.15 - 8.5 MPa, the temperature in the extraction kettle is 32 - 36 °C, and the fluidization rate of CO2 in the extraction kettle is 3 - 15 mL / min.

[0012] As a further improvement of the above solution, the extract obtained by supercritical CO2 extraction treatment is subjected to decompression treatment, and the liquid CO2 is converted into gas for removal. In the present invention, based on supercritical CO2 extraction, the ginkgo flavonoids and ginkgolides in ginkgo leaves are extracted for the second time, thereby improving the extraction rate of the active ingredients in ginkgo leaves. Moreover, the active ingredients in ginkgo leaf cells are extracted by supercritical CO2, and carbon dioxide can be removed by reducing the pressure. The obtained ginkgo leaf extract has almost the same components as the ginkgo leaves themselves, making the quality of the ginkgo leaf extract good and stable.

[0013] As a further improvement of the above solution, the concentration is carried out by distillation concentration, the temperature is 80 - 90 °C, and the concentration stops when the filtrate C is concentrated to 1 / 5 of the original volume. The obtained ginkgo leaf extract is a light yellow mucus.

[0014] As a further improvement of the above solution, the ratio of the ginkgo leaf extract to green tea is 0.5 - 1.5:3 - 6, and the green tea is any one of Longjing, Houkui, Maofeng, Guapian, and white tea. In the present invention, a ginkgo leaf extract drink is prepared using the ginkgo leaf extract and green tea solution. It is used as a functional food to strengthen nutrition, and is suitable for relieving symptoms such as mental fatigue and slow reaction caused by mental decline, and helps to improve blood circulation and memory.

[0015] A ginkgo leaf extract, calculated by the weight of the dried product, in the ginkgo leaf extract, the content of ginkgo flavonoids is 40 - 60%, and the content of ginkgolides is 12% - 22%.

[0016] As a further improvement of the above solution, the ginkgo leaf extract is prepared by using the preparation process of the ginkgo leaf extract based on functional food as described above.

[0017] Compared with the prior art, the beneficial effects of the present invention are: In the present invention, by adding starch hydrolyzate and glycosidase, flavonoid components combine with starch hydrolyzate under the action of glycosidase to form glycosides, enhancing the hydrophilicity of flavonoid molecules, thereby promoting the dissolution of flavonoid components. Moreover, since ginkgo leaves contain starch, ginkgolides, and polyphenolic substances, which all contain relatively many hydroxyl groups in their structures, they interact with each other through hydrogen bonds, electrostatic forces, and van der Waals forces and form complexes in ways such as adsorption and embedding, restricting the release and dissolution of ginkgolides. In the present invention, glycosidase is used to degrade starch, thereby reducing the binding between starch and ginkgolides and achieving the purpose of promoting ginkgolides.

[0018] In the present invention, enzymatic extraction and supercritical CO2 extraction are organically combined to achieve two extractions of active components from ginkgo leaves. While improving the extraction rates of ginkgo flavonoids and ginkgolides, the entire preparation process does not involve solvents such as ethanol, overcoming the problem that the quality of the extract decreases due to the easy occurrence of acid-base reactions with alcohol solvents. Brief Description of the Drawings

[0019] Figure 1 The following shows the process flow chart of the ginkgo leaf extract and its preparation process based on functional foods provided by the present invention. Detailed Description of the Embodiments

[0020] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following will further elaborate on the present invention in combination with embodiments. The additional aspects and advantages of the present invention will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present invention. It should be understood that the following description is only used to explain the present invention and is not used to limit the present invention.

[0021] As used herein, the terms "comprising", "including", "containing", or any other variation thereof are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or device containing the listed elements is not necessarily limited to those elements, but may include other elements not explicitly listed or elements inherent to such composition, step, method, article, or device.

[0022] When an equivalent, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, this should be understood to specifically disclose all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is separately disclosed. For example, when the range "1 to 5" is disclosed, the described range should be interpreted to include ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values and all integers and fractions within the range.

[0023] The following is a detailed description of the specific embodiments of the present invention.

[0024] Example 1 This example provides a preparation process of ginkgo biloba extract based on functional foods, which includes the following steps: (1) Take fresh ginkgo biloba leaves and conduct alkaline water cooking treatment. The purpose of alkaline water cooking is to inactivate the enzymes in ginkgo biloba leaves to prevent the degradation of active ingredients, and at the same time promote the dissociation of ginkgo flavonoids and ginkgolides. During the alkaline water cooking treatment, the alkaline water used is a 5% sodium bicarbonate aqueous solution, and the weight - volume ratio of ginkgo biloba leaves to alkaline water is 1:5. The cooking temperature is 65°C, and the cooking time is 25 min. In this example, the conditions of alkaline water cooking are optimized to achieve the purpose of inactivating enzymes without losing the active substances in ginkgo biloba leaves. And ginkgolic acid is insoluble in alkaline water, so the filtrate A does not contain this harmful substance, ginkgolic acid. (2) Perform solid - liquid separation on the material after alkaline water cooking. The obtained filtrate A is cooled for standby, and the filter residue is pulverized to facilitate the subsequent extraction of active substances.

[0025] (3) Immerse the filter residue in water, stir at 40°C for 20 min and then perform solid - liquid separation. By stirring, it is ensured that the filter residue is fully in contact with water. Combining with the characteristic that the solubility of ginkgolic acid is the largest at 40°C, the dissolution of this harmful substance, ginkgolic acid, is promoted. The obtained filtrate B is subjected to macroporous resin adsorption treatment and then mixed with filtrate A to obtain ginkgo biloba extract. (4) Add the filter residue obtained in step (3) to the ginkgo biloba extract, stir and mix, then add starch hydrolyzate and glycosidase. By adding dextrin and glycosidase, the flavonoid components combine with the starch hydrolyzate under the action of glycosidase to form glycosides, improving the hydrophilicity of flavonoid molecules, and thus promoting the dissolution of flavonoid components. The ratio of dextrin to glycosidase is 1:1, and the addition amount of glycosidase accounts for 1% of the total weight of fresh ginkgo biloba leaves. Then put it into a microwave extraction device for extraction treatment. The microwave power is set to 550 W, the temperature is set to rise from room temperature to 45°C within 10 min, and the extraction time is 80 min. During extraction, microwave treatment is used to promote the release of ginkgo flavonoids and ginkgolides.

[0026] (5) Transfer the material obtained after the extraction treatment in step (4) to an extraction tank, and introduce supercritical CO2 for extraction treatment. The extraction conditions include: the pressure in the extraction kettle is 7.15 MPa, the temperature in the extraction kettle is 32°C, and the fluidization amount of CO2 in the extraction kettle is 3 mL / min.

[0027] (6)The extract obtained by supercritical CO2 extraction is subjected to decompression treatment, and the liquid CO2 is converted into gas for removal. After the CO2 is removed from the extract, the filtrate C is retained by filtration. The filtrate C is concentrated by distillation at a temperature of 80 °C until the volume of the filtrate C is concentrated to 1 / 5 of the original volume and then stopped, obtaining the 1# ginkgo leaf extract, which is a light yellow mucus.

[0028] In this example, based on supercritical CO2 extraction, the ginkgo flavonoids and ginkgolides in ginkgo leaves are extracted twice to improve the extraction rate of active ingredients in ginkgo leaves. Moreover, the active ingredients in ginkgo leaf cells are extracted by supercritical CO2, and carbon dioxide can be removed by reducing the pressure. The obtained ginkgo leaf extract has almost the same components as the ginkgo leaves themselves, making the quality of the ginkgo leaf extract good and stable. In this example, enzyme immersion extraction and supercritical CO2 extraction are organically combined to achieve two extractions of active ingredients in ginkgo leaves. While improving the extraction rates of ginkgo flavonoids and ginkgolides, the entire preparation process does not involve solvents such as ethanol, overcoming the problem of the quality decline of the extract caused by the easy occurrence of acid-base reactions with alcohol solvents.

[0029] (7)Take the ginkgo leaf extract and green tea solution and mix them. The ratio of the ginkgo leaf extract to green tea is 1.3:3, and the green tea used is Longjing tea, obtaining the ginkgo leaf extract drink, a functional food. In this example, the ginkgo leaf extract drink is prepared from the ginkgo leaf extract and green tea solution. As a functional food, it strengthens nutrition and is suitable for relieving symptoms such as mental fatigue and slow reaction caused by mental decline, and helps improve blood circulation and memory.

[0030] Example 2 This example provides a preparation process of ginkgo leaf extract based on functional food, which includes the following steps: (1)Take fresh ginkgo leaves and conduct alkaline water cooking treatment. The purpose of alkaline water cooking is to inactivate the enzymes in ginkgo leaves to prevent the degradation of active ingredients, and at the same time promote the dissociation of ginkgo flavonoids and ginkgolides. During the alkaline water cooking treatment, the alkaline water used is a 5% sodium bicarbonate aqueous solution, and the weight-volume ratio of ginkgo leaves to alkaline water is 1:5. The cooking temperature is 65 °C, and the cooking time is 25 min. (2)Perform solid-liquid separation on the material after alkaline water cooking. The obtained filtrate A is cooled for standby, and the filter residue is pulverized to facilitate the subsequent extraction of active substances.

[0031] (3) The filter residue is immersed in water and stirred at 40 °C for 25 min, followed by solid-liquid separation. Stirring is carried out to ensure sufficient contact between the filter residue and water. Combining with the property that the solubility of ginkgolic acid is the largest at 40 °C, the dissolution of this harmful substance, ginkgolic acid, is promoted. The obtained filtrate B is subjected to macroporous resin adsorption treatment and then mixed with filtrate A to obtain the ginkgo leaf extract. (4) The filter residue obtained in step (3) is added to the ginkgo leaf extract. After stirring and mixing, starch hydrolyzate and glycosidase are added. By adding maltose and glycosidase, the flavonoid component combines with the starch hydrolyzate under the action of glycosidase to form glycosides, improving the hydrophilicity of the flavonoid molecule, and thus promoting the dissolution of the flavonoid component. The ratio of maltose to glycosidase is 1.5:1, and the addition amount of glycosidase accounts for 1.5% of the total weight of fresh ginkgo leaves. Then it is put into a microwave extraction device for extraction treatment. The microwave power is set at 550 W, and the temperature is set to rise from room temperature to 50 °C within 25 min. The extraction time is 90 min. During extraction, microwave treatment is used to promote the release of ginkgo flavonoids and ginkgolides.

[0032] (5) The material obtained after the extraction treatment in step (4) is transferred to an extraction tank, and supercritical CO2 is introduced for extraction treatment. The extraction conditions include: the pressure in the extraction kettle is 7.8 MPa, the temperature in the extraction kettle is 33 °C, and the fluidization rate of CO2 in the extraction kettle is 10 mL / min.

[0033] (6) The extract obtained by supercritical CO2 extraction treatment is subjected to decompression treatment, and the liquid CO2 is converted into gas, thus being removed. After the extract is de-carbonated, the filtrate C is filtered and retained. The filtrate C is concentrated by distillation concentration at a temperature of 85 °C. The concentration stops when the filtrate C is concentrated to 1 / 5 of the original volume, and 2# ginkgo leaf extract is obtained, which is a pale yellow mucus.

[0034] (7) The ginkgo leaf extract and green tea solution are mixed. The ratio of the ginkgo leaf extract to green tea is 1:5, and the green tea used is Houkui, to obtain the functional food of ginkgo leaf extract drink.

[0035] Example 3 This example provides a preparation process of ginkgo leaf extract based on functional food, which includes the following steps: (1) Fresh ginkgo leaves are taken and subjected to alkaline water cooking treatment. The purpose of alkaline water cooking is to inactivate the enzymes in ginkgo leaves to prevent the degradation of active ingredients, and at the same time promote the dissociation of ginkgo flavonoids and ginkgolides. During the alkaline water cooking treatment, the alkaline water used is a 5% sodium bicarbonate aqueous solution, and the weight-to-volume ratio of ginkgo leaves to alkaline water is 1:6. The cooking temperature is 70 °C, and the cooking time is 30 min. (2)Perform solid-liquid separation on the material after alkaline water cooking. The obtained filtrate A is cooled for standby, and the filter residue is pulverized to facilitate the subsequent extraction of active substances.

[0036] (3)Immerse the filter residue in water, stir for 35 min at 40 °C, and then perform solid-liquid separation. By stirring, ensure that the filter residue is fully in contact with water. Combining with the characteristic that the solubility of ginkgolic acid is the largest at 40 °C, promote the dissolution of this harmful substance, ginkgolic acid. The obtained filtrate B is subjected to macroporous resin adsorption treatment and then mixed with filtrate A to obtain ginkgo leaf extract. (4)Add the filter residue obtained in step (3) to the ginkgo leaf extract. After stirring and mixing, add starch hydrolyzate and glycosidase. By adding glucose and glycosidase, the flavonoid component combines with the starch hydrolyzate under the action of glycosidase to form glycosides, improving the hydrophilicity of flavonoid molecules, and then promoting the dissolution of flavonoid components. The ratio of glucose to glycosidase is 2:1, and the addition amount of glycosidase accounts for 2.5% of the total weight of fresh ginkgo leaves. Then put it into a microwave extraction device for extraction treatment. The microwave power is set to 550 W, and the temperature is set to rise from room temperature to 45 °C within 20 min. The extraction time is 90 min. During extraction, use microwave treatment to promote the release of ginkgo flavonoids and ginkgolides.

[0037] (5)Transfer the material obtained after the extraction treatment in step (4) to an extraction tank, and introduce supercritical CO2 for extraction treatment. The extraction conditions include: the pressure in the extraction kettle is 8.0 MPa, the temperature in the extraction kettle is 35 °C, and the fluidization rate of CO2 in the extraction kettle is 8 mL / min.

[0038] (6)The extract obtained by supercritical CO2 extraction treatment is subjected to decompression treatment, and the liquid CO2 is converted into gas for removal. After the extract is de-carbonated, filter to retain filtrate C, and concentrate filtrate C. The concentration is carried out by distillation concentration at a temperature of 85 °C. Stop when filtrate C is concentrated to 1 / 5 of the original volume to obtain 3# ginkgo leaf extract, which is a light yellow mucus.

[0039] (7)Take the ginkgo leaf extract and mix it with green tea solution. The ratio of ginkgo leaf extract to green tea is 1:4, and the green tea used is Maofeng to obtain the functional food of ginkgo leaf extract drink.

[0040] Example 4 This example provides a preparation process of ginkgo leaf extract based on functional food, which includes the following steps: (1) Take fresh ginkgo leaves and subject them to alkaline water cooking. The purpose of alkaline water cooking is to inactivate the enzymes in ginkgo leaves to prevent the degradation of active ingredients and at the same time promote the dissociation of ginkgo flavonoids and ginkgolides. During the alkaline water cooking process, the alkaline water used is a 5% sodium bicarbonate aqueous solution, and the weight - volume ratio of ginkgo leaves to alkaline water is 1:6. The cooking temperature is 70 °C and the cooking time is 30 min. (2) Perform solid - liquid separation on the material after alkaline water cooking. The obtained filtrate A is cooled for standby, and the filter residue is pulverized to facilitate the subsequent extraction of active substances.

[0041] (3) Immerse the filter residue in water, stir at 40 °C for 40 min and then perform solid - liquid separation. By stirring, ensure that the filter residue is fully in contact with water. Combining with the characteristic that the solubility of ginkgolic acid is the largest at 40 °C, promote the dissolution of this harmful substance, ginkgolic acid. The obtained filtrate B is subjected to macroporous resin adsorption treatment and then mixed with filtrate A to obtain the ginkgo leaf extract. (4) Add the filter residue obtained in step (3) to the ginkgo leaf extract, stir and mix, then add starch hydrolyzate and glycosidase. By adding dextrin and glycosidase, the flavonoid component combines with the starch hydrolyzate under the action of glycosidase to form glycosides, improving the hydrophilicity of flavonoid molecules and thus promoting the dissolution of flavonoid components. The ratio of dextrin to glycosidase is 2.5:1, and the addition amount of glycosidase accounts for 3% of the total weight of fresh ginkgo leaves. Then put it into a microwave extraction device for extraction treatment. The microwave power is set to 550 W, the temperature is set to rise from room temperature to 55 °C within 30 min, and the extraction time is 100 min. During extraction, use microwave treatment to promote the release of ginkgo flavonoids and ginkgolides.

[0042] (5) Transfer the material obtained after the extraction treatment in step (4) to an extraction tank, and introduce supercritical CO₂ for extraction treatment. The extraction conditions include: the pressure in the extraction kettle is 8.5 MPa, the temperature in the extraction kettle is 36 °C, and the fluidization rate of CO₂ in the extraction kettle is 15 mL / min.

[0043] (6) The extraction liquid obtained after supercritical CO₂ extraction treatment is subjected to decompression treatment, and the liquid CO₂ is converted into gas and thus removed. After the extraction liquid is de - CO₂, filter to retain filtrate C, and concentrate filtrate C. The concentration is carried out by distillation concentration at 90 °C. Stop when filtrate C is concentrated to 1 / 5 of the original volume to obtain the 4# ginkgo leaf extract, which is a light yellow mucus.

[0044] (7) Mix the ginkgo leaf extract and green tea solution. The ratio of ginkgo leaf extract to green tea is 1.5:6, and the green tea used is white tea to obtain the functional food, the ginkgo leaf extract drink.

[0045] Comparative Example 1 The difference between this comparative example and Example 3 is as follows: Step (4) is not carried out, and the ginkgo leaf extract is directly subjected to supercritical CO2 extraction. The rest is the same as in Example 3, and Ginkgo biloba extract No. 5 is obtained.

[0046] Comparative Example 2 The difference between this comparative example and Example 3 is as follows: Step (5) is not carried out, and the leaching solution is directly concentrated. The rest is the same as in Example 3, and Ginkgo biloba extract No. 6 is obtained.

[0047] Comparative Example 3 The difference between this comparative example and Example 3 is as follows: 60% ethanol solution is used for extraction to replace Steps (4) to (5). The rest is the same as in Example 3, and Ginkgo biloba extract No. 7 is obtained.

[0048] Next, the ginkgo flavonoids and ginkgolides in Ginkgo biloba extracts No. 1 to No. 7 are measured. The measurement results are shown in Table 1. In Table 1, the contents of ginkgo flavonoids and ginkgolides are replaced by mass percentages.

[0049] The measurement of ginkgo flavonoids is as follows: The Ginkgo biloba extract is dried to a constant weight. 2.0 g of the sample is taken, 10 ml of 30% ethanol solution is added, and after extraction for a certain time with a condenser reflux device, it is filtered, diluted, shaken well, left standing for 5 min, then 1 ml of 5% aluminum nitrate solution is added, 6 min later 3 ml of 4% NaOH solution is added, diluted with 30% ethanol, shaken well, and after standing, the content of ginkgo flavonoids is measured at 510 nm with a UV-visible spectrophotometer model UV2550.

[0050] The measurement of ginkgolides is as follows: The Ginkgo biloba extract is dried to a constant weight. 2.0 g of the sample is taken, dissolved in methanol, purified by an acidic alumina column, and the content of ginkgolides is determined by reverse HPLC.

[0051] Table 1 Contents of ginkgo flavonoids and ginkgolides in Ginkgo biloba extracts No. 1 to No. 7

[0052] The reason for the difference is that when the enzyme concentration increases to a certain extent, the enzyme molecules are too saturated, and a part of them has no chance to bind to the substrate, resulting in a decrease in the enzymatic hydrolysis efficiency, and further a decrease in the contents of ginkgo flavonoids and ginkgolides in the obtained Ginkgo biloba extract. In Ginkgo biloba extracts No. 5 to No. 7, the contents of ginkgo flavonoids and ginkgolides are significantly reduced. This indicates that in the present invention, enzymatic extraction and supercritical CO2 extraction have a synergistic effect, and compared with the traditional extraction method using alcohol solvents, the extraction rates of ginkgo flavonoids and ginkgolides in the preparation process of the present invention are significantly improved.

[0053] The above embodiments are only preferred embodiments of the present invention. Any simple modification, amendment, and alternative change made to the above embodiments based on the technical essence of the present invention shall fall within the scope of the technical solution of the present invention.

Claims

1. Preparation process of ginkgo biloba extract based on functional food, characterized in that, It includes the following steps: (1) Take fresh ginkgo leaves and cook them with alkaline water; (2) Perform solid-liquid separation on the material after alkaline water cooking. The obtained filtrate A is cooled for standby, and the filter residue is pulverized; (3) Immerse the filter residue in water, then perform solid-liquid separation. The obtained filtrate B is subjected to macroporous resin adsorption treatment and then mixed with filtrate A to obtain ginkgo leaf extract; (4) Add the filter residue obtained in step (3) to the ginkgo leaf extract, stir and mix, then add starch hydrolyzate and glycosidase, and put it into a microwave extraction device for leaching treatment; (5) Transfer the material obtained after the leaching treatment in step (4) to an extraction tank, and introduce supercritical CO2 for extraction treatment; (6) After the extract obtained by supercritical CO2 extraction treatment is de-carbonated, filter and retain filtrate C, and concentrate filtrate C to obtain ginkgo leaf extract; (7) Take the ginkgo leaf extract and mix it with green tea solution to obtain a functional food, namely ginkgo leaf extract drink.

2. The preparation process of ginkgo biloba extract based on functional foods according to claim 1, characterized in that, During the alkaline water cooking treatment process, the alkaline water used is a 5% sodium bicarbonate aqueous solution, and the weight-volume ratio of ginkgo leaves to alkaline water is 1:3 - 6. The cooking temperature is 60 - 70°C, and the cooking time is 20 - 30 min.

3. The preparation process of ginkgo biloba extract based on functional food according to claim 1, characterized in that, Immerse the filter residue in water, stir at 40°C for 20 - 40 min, and then perform solid-liquid separation.

4. The preparation process of ginkgo biloba extract based on functional food according to claim 1, characterized in that, The starch hydrolyzate is dextrin, maltose or glucose; the ratio of the starch hydrolyzate to glycosidase is 1 - 2.5:1, and the addition amount of glycosidase accounts for 1% - 3% of the total weight of fresh ginkgo leaves.

5. The preparation process of ginkgo biloba extract based on functional food according to claim 4, characterized in that, When putting it into a microwave extraction device for leaching treatment, the microwave power is set to 550 W, and the temperature is set to rise from room temperature to 45 - 55°C within 10 - 30 min, and the leaching time is 80 - 100 min.

6. The preparation process of ginkgo biloba extract based on functional food according to claim 1, characterized in that, The extraction conditions include: the pressure in the extraction kettle is 7.15 - 8.5 MPa, the temperature in the extraction kettle is 32 - 36°C, and the fluidization amount of CO2 in the extraction kettle is 3 - 15 mL / min; The extract obtained by supercritical CO2 extraction treatment is subjected to depressurization treatment, and the liquid CO2 is converted into gas, so as to be removed.

7. The preparation process of ginkgo biloba extract based on functional food according to claim 1, characterized in that, The concentration is carried out by distillation concentration, the temperature is 80 - 90°C, and the concentration stops when filtrate C is concentrated to 1 / 5 of the original volume. The obtained ginkgo leaf extract is a light yellow mucus.

8. The preparation process of ginkgo biloba extract based on functional food according to claim 1, characterized in that, The ratio of the ginkgo leaf extract to green tea is 0.5 - 1.5:3 - 6, and the green tea is any one of Longjing, Houkui, Maofeng, Guapian and white tea.

9. A ginkgo biloba leaf extract, characterized in that, Calculated by the weight of the dried product, in the ginkgo leaf extract, the content of ginkgo flavonoids is 40 - 60%, and the content of ginkgolides is 12% - 22%.

10. The ginkgo biloba leaf extract according to claim 9, characterized in that, The ginkgo leaf extract is prepared by using the preparation process of ginkgo leaf extract based on functional food as described in any one of claims 1 to 8.

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