White kidney bean extract as well as preparation method and application thereof

Abstract

The invention relates to the technical field of plant active ingredient extraction, in particular to a white kidney bean extract, a preparation method and application thereof. The preparation method comprises the following steps: S1, pretreatment; s2, mineralization treatment: providing a mixed solution, adjusting the pH value of the mixed solution to 6-8, adding the pretreated white kidney beans into the mixed solution, and uniformly stirring; s3, mineralization reaction: putting the mixture obtained in S2 into a constant-temperature water bath, continuously stirring for 2-4 hours at 30-50 DEG C, and carrying out mineralization reaction; s4, extracting a white kidney bean extract: cooling a mineralized product obtained after the mineralization reaction to room temperature, adding a solvent into the mineralized product, and stirring at 30-50 DEG C for 1-3 hours; and S5, separation and purification. The invention provides a white kidney bean extract as well as a preparation method and application thereof, and aims to solve the problem of poor high temperature resistance of alpha-amylase inhibitory protein in the white kidney bean extract in related technologies.

Description

Technical Field

[0001] This application relates to the technical field of plant active ingredient extraction, and particularly relates to a white kidney bean extract, a preparation method thereof, and an application thereof. Background Art

[0002] For diabetic patients or people with high blood sugar, white kidney bean extract can help stabilize blood sugar levels. At the same time, the α-amylase inhibitory protein in white kidney bean extract can inhibit the activity of amylase, reduce the digestion and absorption of starchy foods by the body, thereby reducing calorie intake, and has a certain effect in weight management and weight loss.

[0003] The α-AI (α-amylase inhibitory protein) in white kidney bean extract can specifically inhibit the activities of salivary and intestinal α-amylases in humans and other animals, hinder the decomposition and digestion of carbohydrates such as starch, effectively slow down the digestion and absorption rate of carbohydrates, and avoid the rapid rise of blood sugar, thus having the effects of controlling weight gain, slowing down fat accumulation, and reducing blood sugar levels.

[0004] In the food industry, white kidney bean extract containing α-amylase inhibitory protein is usually applied to the production and processing of various foods, such as chewable candies, gummy candies, etc., and some high-temperature processing steps will be experienced, such as heating and dissolving, sterilization, etc. This requires that the α-amylase inhibitory protein has a certain high-temperature resistance to ensure that its activity can be retained as much as possible during the processing, so that the final product can exert the expected function of inhibiting starch digestion. Summary of the Invention

[0005] This application provides a white kidney bean extract, a preparation method thereof, and an application thereof to solve the problem of poor high-temperature resistance of the α-amylase inhibitory protein in the white kidney bean extract in the related art.

[0006] In the first aspect, a preparation method of a white kidney bean extract is provided, which includes the following steps: S1. Pretreatment: The washed white kidney beans are dried at 40-60°C, and the moisture content is controlled to be 10-15%. The dried white kidney beans are pulverized, and the particle size is controlled to be 80-200 mesh to obtain pretreated white kidney beans; S2. Mineralization treatment: A mixed solution is provided, and the pH of the mixed solution is adjusted to 6-8. The pretreated white kidney beans are added to the mixed solution and stirred evenly. The mixed solution includes a metal ion solution and a biomolecule solution; The mass-volume ratio of the pretreated white kidney beans to the metal ion solution is 1:10-1:20, and the metal ion solution is selected from at least one of 0.1-1 mol / L calcium chloride solution or 0.1-1 mol / L magnesium chloride solution; The mass-volume ratio of the pretreated white kidney beans to the biomolecular solution is 1:10 to 1:20, and the biomolecular solution is selected from one of a soybean protein solution at 1 to 5 g / mL and a chitosan acetate solution at 0.5 to 2 g / mL; S3. Mineralization reaction: Place the mixture obtained in S2 in a constant temperature water bath, and continuously stir at 30 to 50 °C for 2 to 4 h to carry out the mineralization reaction; S4. Extract white kidney bean extract: After cooling the mineralized product obtained from the mineralization reaction to room temperature, add a solvent to the mineralized product and stir at 30 to 50 °C for 1 to 3 h. The mass-volume ratio of the mineralized product to the solvent is 1:5 to 1:10, and the solvent includes deionized water and absolute ethanol mixed at 1:1; S5. Separation and purification: Filter the product obtained in S4 to obtain a preliminary filtrate. After centrifuging the preliminary filtrate for 10 to 30 min, concentrate and dry the filtrate after centrifugation to obtain a white kidney bean extract, where the centrifugation speed is 3000 to 5000 r / min.

[0007] Preferably, the metal ion solution includes a calcium chloride solution and a magnesium chloride solution with the same concentration, and the volume ratio of the magnesium chloride solution to the calcium chloride solution is 1:3 to 1:5; The preparation method of the mixed solution includes: Add a 0.1 to 1 mol / L magnesium chloride solution to a 0.1 to 1 mol / L calcium chloride solution. The volume ratio of the calcium chloride solution to the magnesium chloride solution is 1:3 to 1:5. After mixing evenly, add a soybean protein solution at 1 to 5 g / mL or a chitosan acetate solution at 0.5 to 2 g / mL, and stir evenly to obtain a mixed solution.

[0008] Preferably, S1 further includes enzymatic strengthening of the pretreated white kidney beans: Mix the crushed white kidney bean powder with a buffer solution at a mass-volume ratio of 1:5 to 1:10, and react at 30 to 40 °C for 2 to 3 h; The pH of the buffer solution is 4 to 5, and it includes cellulase, pectinase, and hemicellulase, and the ratio of cellulase, pectinase, and hemicellulase is 5:4:6.

[0009] Preferably, the preparation method of the buffer solution includes: Prepare a citric acid-sodium citrate solution with a pH of 5, add 1% cellulase, 0.8% pectinase, and 1.2% hemicellulase to it, and mix evenly to obtain a buffer solution.

[0010] Preferably, in the pH adjustment of S2, a hydrochloric acid solution or a sodium hydroxide solution is used for pH adjustment.

[0011] In a second aspect, a white kidney bean extract is provided, which is prepared by the preparation method of the white kidney bean extract guiding metal ions described in any one of the above.

[0012] In a third aspect, an application of the white kidney bean extract as described above in blood sugar control is provided, which includes a gel or chewable candy containing the white kidney bean extract.

[0013] The beneficial effects brought by the technical solution provided in this application include: This application provides a white kidney bean extract, a preparation method and its application. By mixing white kidney bean raw materials with non-toxic metal ions such as calcium / magnesium that have no impact on food safety, and then adding biomolecules for induced mineralization to guide the metal ions to form tiny mineral particles on the surface of white kidney bean cells. On the one hand, it helps to break the cell wall and cell membrane, making the effective component α-AI inside the cell more easily released; on the other hand, due to the differences in the interactions between the mineral particles and different components inside the cell, TI and PHA preferentially bind to the mineral particles, thereby reducing their activities, and at the same time causing changes in the structure, playing a certain stabilizing role in the molecular structure of α-AI, thus improving its high-temperature resistance. Therefore, it can solve the problem of poor high-temperature resistance of α-amylase inhibitor protein in white kidney bean extract in related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0015] Figure 1 It is a flowchart of the preparation method of the white kidney bean extract provided in this application; Figure 2 It is a schematic diagram of the α-AI activity of the white kidney bean extracts prepared in Examples 1 - 6 and Comparative Examples 1 - 3 provided in this application; Figure 3 It is a schematic diagram of the TI activity of the white kidney bean extracts prepared in Examples 1 - 6 and Comparative Examples 1 - 3 provided in this application; Figure 4 It is a schematic diagram of the PHA concentration of the white kidney bean extracts prepared in Examples 1 - 6 and Comparative Examples 1 - 3 provided in this application; Figure 5 It is a schematic diagram of the α-AI activity of the white kidney bean extracts prepared in Examples 3, 4 and Comparative Example 2 provided in this application at 80 °C and 100 °C. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some but not all of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts fall within the scope of protection of this application.

[0017] This application provides a preparation method of white kidney bean extract, which can solve the problem that the α-amylase inhibitory protein in the white kidney bean extract in the related art has poor high-temperature resistance. The method includes the following steps: S1. Pretreatment: The washed white kidney beans are dried at 40-60°C, and the moisture content is controlled to be 10-15% to facilitate subsequent crushing operations. The dried white kidney beans are crushed, and the particle size is controlled to be 80-200 mesh to obtain pretreated white kidney beans. The pretreated white kidney beans break the tissue structure of the white kidney beans through crushing, facilitating subsequent reactions.

[0018] S2. Mineralization treatment: Provide a mixed solution, and adjust the pH of the mixed solution to 6-8. Add the pretreated white kidney beans to the mixed solution and stir evenly. The mixed solution includes a metal ion solution and a biomolecule solution; The mass-volume ratio of the pretreated white kidney beans to the metal ion solution is 1:10-1:20, and the metal ion solution is selected from at least one of a 0.1-1 mol / L calcium chloride solution or a 0.1-1 mol / L magnesium chloride solution; The mass-volume ratio of the pretreated white kidney beans to the biomolecule solution is 1:10-1:20, and the biomolecule solution is selected from one of a 1-5 g / mL soybean protein solution and a 0.5-2 g / mL chitosan acetate solution.

[0019] Specifically, the metal ion solution provides metal ions, and biomolecules such as soybean protein and chitosan, which are rich in functional groups (such as amino groups, carboxyl groups, etc.). The metal ions and the functional groups on the biomolecules are combined through electrostatic attraction and coordination bonds to form a complex, which acts as a "nucleation site" to attract more metal ions in the solution to aggregate and form tiny mineral particles; when the pretreated white kidney beans are added thereto, on the one hand, during the continuous growth and aggregation of the mineral particles, a physical extrusion effect will be generated on the cell surface and its surroundings, just like tiny "wedges", gradually destroying the cell wall and cell membrane structures, making the substances inside the cells easier to release; on the other hand, due to the different affinities of different cell components (α-AI, TI, PHA) for the mineral particles, the mineral particles selectively interact with TI and PHA and then bind.

[0020] Furthermore, the mineral particles and the α-amylase inhibitor protein form a relatively stable complex structure, which protects it from the direct impact of high temperature to a certain extent, so that it can better maintain its spatial structure in a high temperature environment and reduce the loss of activity caused by thermal denaturation.

[0021] S3. Mineralization reaction: Place the mixture obtained in S2 in a constant temperature water bath and continuously stir at 30-50 °C for 2-4 h to carry out the mineralization reaction; S4. Extract white kidney bean extract: After cooling the mineralized product obtained after the mineralization reaction to room temperature, add a solvent to the mineralized product and stir at 30-50 °C for 1-3 h. The mass-volume ratio of the mineralized product to the solvent is 1:5-1:10, and the solvent includes deionized water and absolute ethanol mixed at a ratio of 1:1; S5. Separation and purification: Filter the product obtained in S4 to obtain a preliminary filtrate. After centrifuging the preliminary filtrate for 10-30 min, concentrate and dry the filtrate after centrifugation to obtain the white kidney bean extract, where the centrifugation speed is 3000-5000 r / min.

[0022] In some embodiments, the metal ion solution includes calcium chloride solution and magnesium chloride solution with the same concentration, and the volume ratio of the magnesium chloride solution to the calcium chloride solution is 1:3-1:5; The preparation method of the mixed solution includes: Add 0.1-1 mol / L magnesium chloride solution to 0.1-1 mol / L calcium chloride solution. The volume ratio of the magnesium chloride solution to the calcium chloride solution is 1:3-1:5. After mixing evenly, add 1-5 g / mL soy protein solution or 0.5-2 g / mL chitosan acetate solution, and stir evenly to obtain the mixed solution.

[0023] In some embodiments, S1 further includes enzymatic strengthening of the pretreated white kidney beans: Mix the crushed white kidney bean powder and the buffer solution at a mass-volume ratio of 1:5-1:10 and react at 30-40 °C for 2-3 h; The pH of the buffer solution is 4-5, and it includes cellulase, pectinase and hemicellulase, and the ratio of cellulase, pectinase and hemicellulase is 5:4:6.

[0024] Optionally, the preparation method of the buffer solution includes: Prepare a citric acid-sodium citrate solution with a pH of 5, add 1% cellulase, 0.8% pectinase, and 1.2% hemicellulase thereto, and mix evenly to obtain the buffer solution.

[0025] It should be noted that the percentages in 1% cellulase, 0.8% pectinase, and 1.2% hemicellulase are mass-volume ratios, that is, the mass grams of the corresponding enzymes contained in every 100 mL of citric acid-sodium citrate solution.

[0026] Specifically, cellulase, pectinase, and hemicellulase can specifically decompose the cellulose, pectin, and hemicellulose components in the white kidney bean cell wall, more fully destroy the cell wall structure in advance, and make the α-AI inside the cell easier to release before bioinduced mineralization treatment. On the one hand, during the subsequent entire extraction process, α-AI can be more fully extracted and shows higher activity. On the other hand, enzymatic hydrolysis not only destroys the cell wall but also affects the distribution and structure of TI and PHA inside the cell, making TI and PHA more likely to interact with mineral particles, etc. during the subsequent bioinduced mineralization treatment process, thereby further changing their structure and reducing their activity.

[0027] In some embodiments, in the S2 of adjusting pH, a hydrochloric acid solution or a sodium hydroxide solution is used for pH adjustment. Example 1

[0028] The preparation method of the white kidney bean extract provided in this example includes the following steps: S1. Pretreatment: The washed white kidney beans are dried at 60 °C, and their moisture content is controlled to be 10%. The dried white kidney beans are pulverized, and their particle size is controlled to be 80 mesh to obtain pretreated white kidney beans; S2. Mineralization treatment: Take 100 mL each of 0.1 mol / L calcium chloride solution and 1 g / mL soy protein solution, mix the two, adjust the pH to 6 to obtain a mixed solution, and add 10 g of pretreated white kidney beans to the mixed solution and stir evenly; S3. Mineralization reaction: The mixture obtained in S2 is placed in a constant temperature water bath and continuously stirred at 50 °C for 2 h for mineralization reaction; S4. Extracting the white kidney bean extract: After the mineralized product obtained from the mineralization reaction is cooled to room temperature, take 4 g of the mineralized product, add 20 mL of deionized water and 20 mL of absolute ethanol to the mineralized product, and stir at 50 °C for 1 h; S5. Separation and purification: Filter the product obtained in S4 to obtain a preliminary filtrate. After centrifuging the preliminary filtrate for 10 min, concentrate and dry the filtrate after centrifugation to obtain the white kidney bean extract, where the centrifugation speed is 5000 r / min. Example 2

[0029] The preparation method of the white kidney bean extract provided in this example includes the following steps: S1. Pretreatment: The cleaned white kidney beans are dried at 40°C, and their moisture content is controlled at 15%. The dried white kidney beans are pulverized, and their particle size is controlled at 200 mesh to obtain pretreated white kidney beans; S2. Mineralization treatment: Take 200 mL of 1 mol / L calcium chloride solution and 150 mL of 1 g / mL soy protein solution. After mixing the two, adjust the pH to 8 to obtain a mixed solution. Add 10 g of pretreated white kidney beans to the mixed solution and stir evenly; S3. Mineralization reaction: The mixture obtained in S2 is placed in a constant temperature water bath and continuously stirred at 30°C for 4 h to carry out the mineralization reaction; S4. Extract white kidney bean extract: After cooling the mineralized product obtained from the mineralization reaction to room temperature, take 4 g of the mineralized product, add 10 mL of deionized water and 10 mL of absolute ethanol to the mineralized product, and stir at 30°C for 3 h; S5. Separation and purification: Filter the product obtained in S4 to obtain a preliminary filtrate. After centrifuging the preliminary filtrate for 30 min, concentrate and dry the filtrate after centrifugation to obtain white kidney bean extract, where the centrifugation speed is 3000 r / min. Example 3

[0030] The preparation method of the white kidney bean extract provided in this example includes the following steps: S1. Pretreatment: The cleaned white kidney beans are dried at 50°C, and their moisture content is controlled at 12%. The dried white kidney beans are pulverized, and their particle size is controlled at 120 mesh to obtain pretreated white kidney beans; S2. Mineralization treatment: Add 30 mL of 0.5 mol / mL magnesium chloride solution to 120 mL of 0.5 mol / L calcium chloride solution. After mixing evenly, add 100 mL of 3 g / mL soy protein solution, stir evenly, and obtain a mixed solution. Add 10 g of pretreated white kidney beans to the mixed solution and stir evenly; S3. Mineralization reaction: The mixture obtained in S2 is placed in a constant temperature water bath and continuously stirred at 40°C for 3 h to carry out the mineralization reaction; S4. Extract white kidney bean extract: After cooling the mineralized product obtained from the mineralization reaction to room temperature, take 4 g of the mineralized product, add 16 mL of deionized water and 16 mL of absolute ethanol to the mineralized product, and stir at 40°C for 2 h; S5. Separation and purification: Filter the product obtained in S4 to obtain a preliminary filtrate. After centrifuging the preliminary filtrate for 20 min, concentrate and dry the filtrate after centrifugation to obtain white kidney bean extract, where the centrifugation speed is 4000 r / min. Example 4

[0031] The preparation method of the white kidney bean extract provided by this embodiment includes the following steps: S1. Pretreatment: The washed white kidney beans are dried at 50°C, and their moisture content is controlled to be 10%. The dried white kidney beans are pulverized, and their particle size is controlled to be 150 mesh to obtain pretreated white kidney beans; Perform enzymatic strengthening on the pretreated white kidney beans: Provide a buffer solution: Prepare 500 mL of a citric acid-sodium citrate solution with a pH of 5, add 5 g of cellulase, 4 g of pectinase, and 6 g of hemicellulase to it, and mix evenly to obtain a buffer solution.

[0032] Mix 10 g of the pretreated white kidney bean powder with 50 mL of the buffer solution, react at 30°C for 3 h, and complete the enzymatic strengthening.

[0033] S2. Mineralization treatment: Add 40 mL of 0.2 mol / mL magnesium chloride solution to 120 mL of 0.5 mol / L calcium chloride solution, mix evenly, then add 200 mL of 0.5 g / mL chitosan acetate solution to it, stir evenly to obtain a mixed solution, add 10 g of the pretreated white kidney beans together with 50 mL of the buffer solution to the mixed solution, and stir evenly; S3. Mineralization reaction: Place the mixture obtained in S2 in a constant temperature water bath, continuously stir at 40°C for 3 h to carry out the mineralization reaction; S4. Extract the white kidney bean extract: After cooling the mineralized product obtained after the mineralization reaction to room temperature, take 4 g of the mineralized product, add 16 mL of deionized water and 16 mL of absolute ethanol to the mineralized product, and stir at 40°C for 2 h; S5. Separation and purification: Filter the product obtained in S4 to obtain a preliminary filtrate, centrifuge the preliminary filtrate for 20 min, and then concentrate and dry the filtrate after centrifugation to obtain the white kidney bean extract, where the centrifugation speed is 4000 r / min.

[0034] Example 5 The preparation method of the white kidney bean extract provided by this embodiment includes the following steps: S1. Pretreatment: The washed white kidney beans are dried at 50°C, and their moisture content is controlled to be 10%. The dried white kidney beans are pulverized, and their particle size is controlled to be 100 mesh to obtain pretreated white kidney beans; Perform enzymatic strengthening on the pretreated white kidney beans: Provide a buffer solution: Prepare 500 mL of a citric acid-sodium citrate solution with a pH of 4, add 5 g of cellulase, 4 g of pectinase, and 6 g of hemicellulase to it, and mix evenly to obtain a buffer solution.

[0035] Mix 10 g of pretreated white kidney bean powder with 100 mL of buffer solution, and after reacting at 40 °C for 2 h, the enzymatic hydrolysis enhancement is completed.

[0036] S2. Mineralization treatment: Add 30 mL of 0.5 mol / mL magnesium chloride solution to 150 mL of 1 mol / L calcium chloride solution. After mixing evenly, add 150 mL of 1 g / mL chitosan acetate solution thereto. After stirring evenly, a mixed solution is obtained. Add 10 g of pretreated white kidney beans together with 100 mL of buffer solution to the mixed solution and stir evenly; S3. Mineralization reaction: Place the mixture obtained in S2 in a constant temperature water bath and continuously stir at 40 °C for 3 h to carry out the mineralization reaction; S4. Extract white kidney bean extract: After cooling the mineralized product obtained after the mineralization reaction to room temperature, take 4 g of the mineralized product, and add 16 mL of deionized water and 16 mL of absolute ethanol thereto, and stir at 40 °C for 2 h; S5. Separation and purification: Filter the product obtained in S4 to obtain a preliminary filtrate. After centrifuging the preliminary filtrate for 20 min, concentrate and dry the filtrate after centrifugation to obtain white kidney bean extract, wherein the centrifugation speed is 4000 r / min. Example 6

[0037] The preparation method of the white kidney bean extract provided in this example includes the following steps: S1. Pretreatment: Dry the washed white kidney beans at 50 °C and control their moisture content to be 15%. Crush the dried white kidney beans and control their particle size to be 100 mesh to obtain pretreated white kidney beans; Perform enzymatic hydrolysis enhancement on the pretreated white kidney beans: Provide buffer solution: Prepare 500 mL of citric acid - sodium citrate solution with a pH of 5, add 5 g of cellulase, 4 g of pectinase, and 6 g of hemicellulase thereto, and after mixing evenly, obtain a buffer solution.

[0038] Mix 10 g of pretreated white kidney bean powder with 60 mL of buffer solution, and after reacting at 35 °C for 2 h, the enzymatic hydrolysis enhancement is completed.

[0039] S2. Mineralization treatment: Add 40 mL of 0.1 mol / mL magnesium chloride solution to 120 mL of 0.1 mol / L calcium chloride solution. After mixing evenly, add 100 mL of 2 g / mL chitosan acetate solution thereto. After stirring evenly, a mixed solution is obtained. Add 10 g of pretreated white kidney beans together with 60 mL of buffer solution to the mixed solution and stir evenly; S3. Mineralization reaction: Place the mixture obtained in S2 in a constant temperature water bath and continuously stir at 40 °C for 3 h to carry out the mineralization reaction; S4. Extract white kidney bean extract: After cooling the mineralized product obtained from the mineralization reaction to room temperature, take 4 g of the mineralized product, add 16 mL of deionized water and 16 mL of absolute ethanol thereto, and stir at 40 °C for 2 h; S5. Separation and purification: Filter the product obtained in S4 to obtain a preliminary filtrate. After centrifuging the preliminary filtrate for 20 min, concentrate and dry the filtrate after centrifugation to obtain white kidney bean extract, wherein the centrifugation speed is 4000 r / min.

[0040] Comparative Example 1 Except for not performing steps S2 and S3, other treatment steps are the same as those in Example 3.

[0041] Comparative Example 2 Except for not adding a metal ion solution in step S2, other treatment steps are the same as those in Example 4.

[0042] Comparative Example 3 Except for not adding a biomolecule solution in step S2, other treatment steps are the same as those in Example 4.

[0043] For the white kidney bean extracts prepared in Examples 1-6 and Comparative Examples 1-3, the activities of α-AI (α-amylase inhibitor protein), TI (trypsin inhibitor), and PHA (phytohemagglutinin) were tested. The test results are shown in Figures 2 to 5 as follows.

[0044] It can be known that the white kidney bean extract prepared in Example 4 has a high α-AI activity and a high inhibition rate on TI. Figure 4 For the PHA activity test results, it can be seen that the concentration of PHA in Examples 1-6 decreased compared with Comparative Examples 1-3, and all were lower than 80%, that is, the preparation methods used in Examples 1-6 had a certain inhibitory effect on the content of PHA in the white kidney bean extract.

[0045] Furthermore, as shown in Figure 5 as follows, Examples 3 and 4 were selected from the examples as representative products and subjected to a high-temperature test. The white kidney bean extracts prepared in Examples 3 and 4 had a high inhibition rate on α-AI at high temperature, that is, they were less affected by high temperature, which was beneficial for the further development of high-temperature resistant products.

[0046] The present application also provides an application of the above-mentioned white kidney bean extract in blood sugar control, which includes a gel or chewable candy containing the white kidney bean extract.

[0047] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A preparation method of white kidney bean extract, characterized in that, It includes the following steps: S1. Pretreatment: The cleaned white kidney beans are dried at 40 - 60 °C, and the moisture content is controlled to be 10 - 15%. The dried white kidney beans are pulverized, and the particle size is controlled to be 80 - 200 mesh to obtain pretreated white kidney beans; S2. Mineralization treatment: Provide a mixed solution, and adjust the pH of the mixed solution to 6 - 8. Add the pretreated white kidney beans into the mixed solution and stir evenly. The mixed solution includes a metal ion solution and a biomolecule solution; The mass - to - volume ratio of the pretreated white kidney beans to the metal ion solution is 1:10 - 1:

20. The metal ion solution is selected from at least one of 0.1 - 1 mol / L calcium chloride solution or 0.1 - 1 mol / L magnesium chloride solution; The mass - to - volume ratio of the pretreated white kidney beans to the biomolecule solution is 1:10 - 1:

20. The biomolecule solution is selected from one of 1 - 5 g / mL soy protein solution and 0.5 - 2 g / mL chitosan acetate solution; S3. Mineralization reaction: Place the mixture obtained in S2 in a constant - temperature water bath, and continuously stir at 30 - 50 °C for 2 - 4 h to carry out the mineralization reaction; S4. Extract white kidney bean extract: After cooling the mineralized product obtained from the mineralization reaction to room temperature, add a solvent to the mineralized product and stir at 30 - 50 °C for 1 - 3 h. The mass - to - volume ratio of the mineralized product to the solvent is 1:5 - 1:

10. The solvent includes deionized water and absolute ethanol mixed at a ratio of 1:1; S5. Separation and purification: Filter the product obtained in S4 to obtain a preliminary filtrate. After centrifuging the preliminary filtrate for 10 - 30 min, concentrate and dry the filtrate after centrifugation to obtain white kidney bean extract, where the centrifugation speed is 3000 - 5000 r / min.

2. The method for preparing white kidney bean extract according to claim 1, wherein: The metal ion solution includes calcium chloride solution and magnesium chloride solution with the same concentration, and the volume ratio of the magnesium chloride solution to the calcium chloride solution is 1:3 - 1:5; The preparation method of the mixed solution includes: Add 0.1 - 1 mol / L magnesium chloride solution to 0.1 - 1 mol / L calcium chloride solution. The volume ratio of the calcium chloride solution to the magnesium chloride solution is 1:3 - 1:

5. After mixing evenly, add 1 - 5 g / mL soy protein solution or 0.5 - 2 g / mL chitosan acetate solution, and stir evenly to obtain a mixed solution.

3. The preparation method of the white kidney bean extract according to claim 1, wherein, S1 further includes an enzymatic hydrolysis treatment of the pretreated white kidney beans: Mix the pretreated white kidney beans and a buffer solution at a mass - to - volume ratio of 1:5 - 1:10, and react at 30 - 40 °C for 2 - 3 h; The pH of the buffer solution is 4 - 5, and it includes cellulase, pectinase, and hemicellulase, and the ratio of cellulase, pectinase, and hemicellulase is 5:4:

6.

4. The preparation method of the white kidney bean extract according to claim 3, wherein, The preparation method of the buffer solution includes: Prepare a citric acid - sodium citrate solution with a pH of 5, add 1% cellulase, 0.8% pectinase, and 1.2% hemicellulase thereto, and mix evenly to obtain a buffer solution.

5. The preparation method of the white kidney bean extract according to claim 1, characterized in that: In the step S2 of adjusting the pH, a hydrochloric acid solution or a sodium hydroxide solution is used for pH adjustment.

6. A white kidney bean extract, which is prepared by the preparation method of the white kidney bean extract according to any one of claims 1 to 5.

Images