White kidney bean extract composite microcapsule and application thereof

Abstract

The invention provides a white kidney bean extract composite microcapsule and application thereof. The white kidney bean extract composite microcapsule is prepared by the following specific steps: preparing dual-response white kidney bean extract composite microspheres, loading modified spirulina platensis, and preparing the white kidney bean extract composite microcapsule. Keratin modified spirulina platensis is used as a wall material, the white kidney bean extract composite microspheres are embedded in a spiral structure of spirulina platensis, quaternized chitosan on the outer layer of the microspheres and gastric acid resistant spirulina platensis generate electrostatic adsorption, and the stability of the white kidney bean extract composite microspheres is guaranteed; in addition, after the organism intakes food, glucose response and fat response are triggered at the same time, functional components in the microspheres are released, the activity of amylase in gastrointestinal tracts is inhibited, lipolysis is promoted, digestion and absorption of the organism on carbohydrates and fat are reduced, and therefore the purpose of reducing fat is achieved; the technical support can be provided for preparing functional products from the white kidney bean extract.

Description

Technical Field

[0001] The invention belongs to the technical field of functional food processing, and particularly relates to a white kidney bean extract composite microcapsule and application thereof. Background Art

[0002] White kidney bean extract is a highly effective amylase inhibitor derived from natural white kidney beans. Its core active ingredient is α-amylase inhibitory protein, which inhibits its activity by binding to α-amylase and changing its molecular conformation, effectively slowing down the digestion and absorption of starch in food, thereby reducing the release and absorption of glucose, reducing calorie intake, and assisting in weight loss. In addition, white kidney bean extract is rich in dietary fiber, which helps promote intestinal motility, improve digestive system function, and relieve constipation problems. Although white kidney bean extract has good hypoglycemic and lipid-lowering effects, its extract is mainly composed of protein, and the active ingredients are easily decomposed and inactivated in the stomach of the body. In addition, white kidney bean extract only has inhibitory activity on amylase, so white kidney bean extract has problems such as single action and stomach instability, which greatly affects the efficacy of white kidney bean extract. In the existing technical research, microencapsulation technology is used to embed white kidney bean extract to improve the stability of white kidney bean extract and ensure its biological activity. However, there will still be a large degree of loss when it is treated with simulated gastric juice for a long time, which affects the effect of white kidney bean extract. Therefore, based on the microencapsulation technology coupled with dual response, microcapsules loaded with multiple functional ingredients of white kidney bean extract were prepared. The synergistic effect of multiple functional ingredients of white kidney bean extract was used to reduce fat. Under the dual response, it can play a role efficiently, accurately and for a long time, providing research ideas for the preparation of functional products with white kidney bean extract. Summary of the invention

[0003] Technical problems to be solved: In view of the above technical problems, the purpose of the present invention is to provide a composite microcapsule of white kidney bean extract and its application. The specific steps include preparing dual-responsive composite microspheres of white kidney bean extract, loading modified Spirulina platensis, and preparing composite microcapsules of white kidney bean extract. The present invention uses keratin-modified Spirulina platensis as the wall material, embeds the composite microspheres of white kidney bean extract in the spiral structure of Spirulina platensis, and the quaternized chitosan on the outer layer of the microspheres and the gastric acid-resistant Spirulina platensis undergo electrostatic adsorption to ensure the stability of the composite microspheres of white kidney bean extract; in addition, after the body ingests food, the glucose response and fat response are triggered at the same time, releasing the effective ingredients in the microspheres, inhibiting the activity of amylase in the gastrointestinal tract and promoting fat decomposition, reducing the body's digestion and absorption of carbohydrates and fats, thereby achieving the purpose of fat reduction, and can provide technical support for the preparation of functional products of white kidney bean extract.

[0004] Technical solution: A white kidney bean extract composite microcapsule, which uses white kidney bean extract as a main component and is prepared based on a dual response mechanism. A method for preparing white kidney bean extract composite microcapsules comprises the following steps: S1. Weigh white kidney bean extract, chickpea extract, cocoa bean extract, and L-carnitine, add water and dissolve evenly to obtain a mixed solution; S2. The quaternized chitosan was dissolved in water to prepare a quaternized chitosan solution having a mass concentration of 15-20%, and pancreatic lipase and concanavalin A were added and treated at 30-40 ° C for 2-4h to obtain a quaternized chitosan solution; S3. Using the mixed solution as the inner phase and the quaternized chitosan solution as the outer phase, a white kidney bean extract composite microsphere solution was prepared by microfluidic technology; S4. Spirulina platensis was pretreated and freeze-dried to obtain Spirulina platensis powder, which was dissolved in water to prepare a 20-30% solution of Spirulina platensis by mass concentration, and then mixed with keratin and genipin to obtain a modified Spirulina platensis solution; S5. Using the white kidney bean extract composite microsphere solution as the core material, uniformly drip it into the modified Spirulina platensis solution and stir it at 25-35°C and 200-300rpm for 2-3h, and vacuum dry it to prepare the white kidney bean extract composite microcapsules. Furthermore, in step S1, the ratio of white kidney bean extract, chickpea extract, cocoa bean extract and L-carnitine is (4-7):(1-1.5):(0.5-1.5):(1.5-2). Furthermore, the amount of concanavalin A added in step S2 is 10-15%. Furthermore, the concentration of pancreatic lipase in step S2 is 20-30 mg / mL. Furthermore, in step S3, the ratio of the mixed solution to the quaternized chitosan is (3-6):1; the microfluidic treatment conditions are that the flow rate of the mixed solution is 0.5-10 mL / h, and the flow rate of the quaternized chitosan solution is 20-40 mL / h. Furthermore, in step S4, the ratio of the Spirulina platensis solution, keratin and genipin is 2:(1-5):(0.5-1.5). The use of the above-mentioned white kidney bean extract composite microcapsule in the preparation of weight loss and fat reduction products. Beneficial effects: 1. The white kidney bean extract composite microcapsules prepared by the present invention use keratin-modified Spirulina platensis as the wall material. Under the cross-linking action of genipin, keratin is modified on the structure of Spirulina platensis through covalent bonds, which can prolong the retention time of the white kidney bean extract composite microcapsules, because keratin can interact with the mucin of the gastric mucosal layer in the body by hydrogen bonds, ionic bonds, hydrophobic bonds, etc., so that the white kidney bean extract composite microcapsules and the gastric mucosa adhere to each other, thereby making them stay in the stomach for a long time, laying a foundation for the effective ingredients in the white kidney bean extract composite microcapsules to play a role. 2. In the present invention, modified Spirulina platensis is used to load white kidney bean extract composite microspheres. The outer layer structure of the microspheres is quaternized chitosan modified with pancreatic lipase and concanavalin A. The positive charge of the chitosan can produce electrostatic adsorption with the negatively charged modified Spirulina platensis. The white kidney bean extract composite microspheres are embedded in the spiral structure of the modified Spirulina platensis to achieve the purpose of efficient loading. In addition, the modified Spirulina platensis has a good ability to resist the extreme pH of the stomach and can stably exist in the stomach of the body for a long time, thereby ensuring the stable survival of the effective components of the white kidney bean extract. 3. The microsphere structure of the white kidney bean extract composite microspheres of the present invention is quaternized chitosan of pancreatic lipase and concanavalin A, and its structure has dual responses, namely glucose response and fat response; when the food ingested by the body contains fat and sugar, the fat is decomposed to a lesser extent under the decomposition of the salivary enzyme system, while the sugar is decomposed into glucose. When entering the stomach of the body, pancreatic lipase responds to decompose fat, and concanavalin A specifically recognizes glucose and responds, causing the structure of the white kidney bean extract composite microspheres to decompose, releasing the white kidney bean extract and chickpea extract embedded in the microspheres. On the one hand, white bean extract, chickpea extract and cocoa bean extract can inhibit the activity of α-amylase in the gastrointestinal tract, reduce the body's absorption of carbohydrates, reduce the fat synthesis content, and promote the conversion of internal fat into carbohydrates to provide energy, thereby achieving the purpose of fat reduction; on the other hand, L-carnitine improves the body's utilization of fat, and quaternized chitosan and fatty acid carboxyl groups in fat substances undergo electrostatic bridging to form chitosan fatty acid salt complexes, thereby promoting the decomposition of fat, inhibiting its digestion and absorption, and achieving the purpose of fat reduction. 4. The method for preparing white kidney bean extract composite microcapsules of the present invention can provide a research basis for the compound use of white kidney bean extract and a variety of effective ingredients, and can also provide a theoretical basis for the efficient, accurate and long-lasting effect of white kidney bean extract in the gastrointestinal tract, broadening the research ideas of white kidney bean extract in functional products and having good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 The simulated gastric fluid stability of Example 8, Comparative Example 1 and Comparative Example 2; Figure 2is the food intake of Example 8, Comparative Example 1 and Comparative Example 2; Figure 3 The total food intake, body weight, liver weight and fat weight of Example 8, Comparative Example 1 and Comparative Example 2, wherein A represents the total food intake, B represents the body weight, C represents the liver weight and D represents the fat weight; Figure 4 The total cholesterol, triglycerides, low-density lipoprotein and high-density lipoprotein of Example 8, Comparative Example 1 and Comparative Example 2, wherein A represents total cholesterol, B represents triglycerides, C represents low-density lipoprotein and D represents high-density lipoprotein. DETAILED DESCRIPTION The present invention will be further described below in conjunction with embodiments, which are explanations of the present invention and are not limited to the following embodiments: Example 1 A method for preparing white kidney bean extract composite microspheres comprises the following steps: Step 1. Weigh 60g of white kidney bean extract, 10g of chickpea extract, 10g of cocoa bean extract, and 20g of L-carnitine, add water and dissolve evenly to prepare a mixed solution; Step 2. 15 g of quaternized chitosan was dissolved in 85 g of water to prepare a quaternized chitosan solution with a mass concentration of 15%, and 25 mg / mL of pancreatic lipase and 10 g of concanavalin A were added and treated at 35° C. for 3 h to prepare a quaternized chitosan solution; Step 3. Use 30 g of the mixed solution as the inner phase and 10 g of the quaternized chitosan solution as the outer phase, and use microfluidic technology, where the flow rate of the mixed solution is 0.5 mL / h and the flow rate of the quaternized chitosan solution is 25 mL / h, to prepare a white kidney bean extract composite microsphere solution. Example 2 A method for preparing white kidney bean extract composite microspheres comprises the following steps: Step 1. Weigh 60g of white kidney bean extract, 15g of chickpea extract, 10g of cocoa bean extract, and 15g of L-carnitine, add water and dissolve evenly to prepare a mixed solution A; Step 2. 15 g of quaternized chitosan was dissolved in 85 g of water to prepare a quaternized chitosan solution with a mass concentration of 15%, and 25 mg / mL of pancreatic lipase and 10 g of concanavalin A were added and treated at 35° C. for 3 h to prepare a quaternized chitosan solution; Step 3. Use 30 g of the mixed solution as the inner phase and 10 g of the quaternized chitosan solution as the outer phase, and use microfluidic technology, where the flow rate of the mixed solution is 0.5 mL / h and the flow rate of the quaternized chitosan solution is 25 mL / h, to prepare a white kidney bean extract composite microsphere solution. Example 3 A method for preparing white kidney bean extract composite microspheres comprises the following steps: Step 1. Weigh 60g of white kidney bean extract, 10g of chickpea extract, 5g of cocoa bean extract, and 20g of L-carnitine, add water and dissolve evenly to prepare a mixed solution A; Step 2. 15 g of quaternized chitosan was dissolved in 85 g of water to prepare a quaternized chitosan solution with a mass concentration of 15%, and 25 mg / mL of pancreatic lipase and 10 g of concanavalin A were added and fixed at 35° C. for 3 h to prepare a quaternized chitosan solution; Step 3. Use 30 g of the mixed solution as the inner phase and 10 g of the quaternized chitosan solution as the outer phase, and use microfluidic technology, where the flow rate of the mixed solution is 0.5 mL / h and the flow rate of the quaternized chitosan solution is 25 mL / h, to prepare a white kidney bean extract composite microsphere solution. Example 4 A method for preparing white kidney bean extract composite microspheres comprises the following steps: Step 1. Weigh 60g of white kidney bean extract, 10g of chickpea extract, 10g of cocoa bean extract, and 20g of L-carnitine, add water and dissolve evenly to prepare a mixed solution A; Step 2. 20 g of quaternized chitosan was dissolved in 80 g of water to prepare a quaternized chitosan solution with a mass concentration of 20%, and 25 mg / mL of pancreatic lipase and 10 g of concanavalin A were added and treated at 35° C. for 3 h to prepare a quaternized chitosan solution; Step 3. Use 30 g of the mixed solution as the inner phase and 10 g of the quaternized chitosan solution as the outer phase, and use microfluidic technology, where the flow rate of the mixed solution is 0.5 mL / h and the flow rate of the quaternized chitosan solution is 25 mL / h, to prepare a white kidney bean extract composite microsphere solution. Example 5 A method for preparing white kidney bean extract composite microspheres comprises the following steps: Step 1. Weigh 60g of white kidney bean extract, 10g of chickpea extract, 10g of cocoa bean extract, and 20g of L-carnitine, add water and dissolve evenly to prepare a mixed solution; Step 2. 15 g of quaternized chitosan was dissolved in 85 g of water to prepare a quaternized chitosan solution with a mass concentration of 15%, and 25 mg / mL of pancreatic lipase and 10 g of concanavalin A were added and treated at 35° C. for 3 h to prepare a quaternized chitosan solution; Step 3. Use 45 g of the mixed solution as the inner phase and 10 g of the quaternized chitosan solution as the outer phase, and use microfluidic technology, where the flow rate of the mixed solution is 0.5 mL / h and the flow rate of the quaternized chitosan solution is 25 mL / h, to prepare a white kidney bean extract composite microsphere solution. Example 6 A method for preparing white kidney bean extract composite microspheres comprises the following steps: Step 1. Weigh 60g of white kidney bean extract, 10g of chickpea extract, 10g of cocoa bean extract, and 20g of L-carnitine, add water and dissolve evenly to prepare a mixed solution A; Step 4. 15 g of quaternized chitosan was dissolved in 85 g of water to prepare a quaternized chitosan solution with a mass concentration of 15%, and 25 mg / mL of pancreatic lipase and 15 g of concanavalin A were added and treated at 35° C. for 3 h to prepare a quaternized chitosan solution; Step 5. Using the mixed solution as the inner phase and the quaternized chitosan solution as the outer phase, the white kidney bean extract composite microsphere solution was prepared by using microfluidic technology, wherein the flow rate of the mixed ball solution was 0.5 mL / h and the flow rate of the quaternized chitosan solution was 25 mL / h. Example 7 A method for preparing white kidney bean extract composite microspheres comprises the following steps: Step 1. Weigh 60g of white kidney bean extract, 10g of chickpea extract, 10g of cocoa bean extract, and 20g of L-carnitine, add water and dissolve evenly to prepare a mixed solution A; Step 2. 15 g of quaternized chitosan was dissolved in 85 g of water to prepare a quaternized chitosan solution with a mass concentration of 15%, and 30 mg / mL of pancreatic lipase and 10 g of concanavalin A were added and treated at 35° C. for 2 h to prepare a quaternized chitosan solution; Step 3. Use 30 g of the mixed solution as the inner phase and 10 g of the quaternized chitosan solution as the outer phase, and use microfluidic technology, where the flow rate of the mixed solution is 0.5 mL / h and the flow rate of the quaternized chitosan solution is 25 mL / h, to prepare a white kidney bean extract composite microsphere solution. Performance Testing (1) Average particle size Take an appropriate amount of white kidney bean extract composite microsphere solution, dilute it 100 times with water, put it in a 1 cm absorption dish, and then use a laser scattering particle size analyzer to measure the average particle size of the white kidney bean extract composite microsphere. (2) Encapsulation efficiency Accurately weigh 10.00 g of white kidney bean extract composite microspheres, add an appropriate amount of distilled water to make a microsphere suspension, centrifuge the solution at 15000 rpm / min and 4°C for 30 min, take the supernatant, and determine the content of L-carnitine by high performance liquid chromatography technology, and calculate the embedding efficiency of the white kidney bean extract composite microspheres. (3) α-amylase inhibition rate First, 10 μL of α-amylase solution (15 U / mL), 10 μL of α-amylase solution of different concentrations, and 20 μL of PBS buffer (0.1 M, pH 6.9) were added to the 96-well plate, and then placed in a multifunctional microplate reader and incubated at 37°C for 10 min (circular shaking for 30 s), and then taken out; then 20 μL of 1% soluble starch solution was added to each well, placed in a multifunctional microplate reader and reacted accurately at 37°C for 5 min (circular shaking for 30 s), and then taken out; 80 μL of DNS solution was shaken and heated in a boiling water bath for 15 min. After rapid cooling with ice water, 160 μL of deionized water was added to each well, and the mixture was allowed to stand for 10 min. The mixture was placed in a multifunctional microplate reader and the OD value was measured at a wavelength of 482 nm. A blank group (without adding white kidney bean extract composite microspheres), a blank control group (without adding α-amylase solution and white kidney bean extract composite microspheres) and an inhibition control group (without adding α-amylase solution) were set up, and the insufficient volume was supplemented with PBS; the calculation formula for the α-amylase inhibition rate was: α-amylase inhibition rate (%) = [1-(A3-A4) / (A1-A2)] × 100%, wherein: A1, A2, A3 and A4 were the OD values ​​of the blank group, blank control group, experimental group and inhibition control group at 482 nm, respectively. Table 1 Average particle size, embedding efficiency and α-amylase inhibition rate of Examples 1-7 Average particle size (μm) Embedding efficiency (%) α-Amylase inhibition rate (%) Example 1 47.55 89.26 78.34 Example 2 45.78 91.56 80.85 Example 3 46.31 90.84 79.92 Example 4 46.95 90.52 79.41 Example 5 48.23 88.36 77.53 Example 6 47.18 90.42 78.68 Example 7 47.79 89.63 77.80 As can be seen from Table 1, among Examples 1-7, the average particle size of the white kidney bean extract composite microspheres prepared in Example 2 is the smallest, but the encapsulation efficiency and α-amylase inhibition rate are the highest, indicating that the ratio of white kidney bean extract, chickpea extract, cocoa bean extract and L-carnitine, and the addition amounts of pancreatic lipase and concanavalin A will affect the average particle size, encapsulation efficiency and α-amylase inhibition rate of the white kidney bean extract composite microspheres. Example 8 A method for preparing white kidney bean extract composite microcapsules comprises the following steps: S1. Spirulina platensis was pretreated and freeze-dried to obtain Spirulina platensis powder, which was dissolved in water to prepare a 25% solution of Spirulina platensis by mass concentration, and then mixed with 30g of keratin and 10g of genipin to obtain a modified Spirulina platensis solution; S2. Using the white kidney bean extract composite microsphere solution as the core material, it was uniformly dripped into the modified Spirulina platensis solution and stirred at 30°C and 300 rpm for 2 h, and then vacuum dried to prepare the white kidney bean extract composite microcapsules. Example 9 A method for preparing white kidney bean extract composite microcapsules comprises the following steps: S1. Spirulina platensis was pretreated and freeze-dried to obtain Spirulina platensis powder, which was dissolved in water to prepare a 20% solution of Spirulina platensis by mass concentration, and then mixed with 30g of keratin and 10g of genipin to obtain a modified Spirulina platensis solution; S2. Using the white kidney bean extract composite microsphere solution as the core material, it was uniformly dripped into the modified Spirulina platensis solution and stirred at 30°C and 200 rpm for 2.5 h, and then vacuum dried to prepare the white kidney bean extract composite microcapsules. Example 10 A method for preparing white kidney bean extract composite microcapsules comprises the following steps: S1. Spirulina platensis was pretreated and freeze-dried to obtain Spirulina platensis powder, which was dissolved in water to prepare a 25% solution of Spirulina platensis, and then mixed with 40g of keratin and 10g of genipin to obtain a modified Spirulina platensis solution; S2. Using the white kidney bean extract composite microsphere solution as the core material, it was uniformly dripped into the modified Spirulina platensis solution and stirred at 30°C and 200 rpm for 3 hours, and then vacuum dried to prepare the white kidney bean extract composite microcapsules. Comparative Example 1 This comparative example differs from Example 8 in that keratin and genipin are not added. A method for preparing white kidney bean extract composite microcapsules comprises the following steps: S1. The platensis Spirulina powder is prepared by pretreatment and freeze-drying, and the platensis Spirulina powder is dissolved in water to prepare a 25% platensis Spirulina solution to prepare a platensis Spirulina solution; S2. Using the white kidney bean extract composite microsphere solution as the core material, it was uniformly dripped into the Spirulina platensis solution and stirred at 30°C and 300 rpm for 2 h, and then vacuum dried to prepare the white kidney bean extract composite microcapsules. Comparative Example 2 The difference between this comparative example and Example 8 is that Spirulina platensis is replaced by β-cyclodextrin. A method for preparing white kidney bean extract composite microcapsules comprises the following steps: S1. β-cyclodextrin is dissolved in water to prepare a 25% mass concentration of Spirulina platensis solution, and then mixed with 30g keratin and 10g genipin to prepare a modified β-cyclodextrin solution; S2. Using the white kidney bean extract composite microsphere solution as the core material, it was uniformly dripped into the modified β-cyclodextrin solution and stirred at 30°C and 300 rpm for 2 h, and then vacuum dried to prepare the white kidney bean extract composite microcapsules. Performance Testing (1) Average particle size, encapsulation efficiency, and α-amylase inhibition rate Table 2 Average particle size, embedding efficiency, and α-amylase inhibition rate of Examples 8-10 and Comparative Examples 1-2 Average particle size (μm) Embedding efficiency (%) α-Amylase inhibition rate (%) Example 8 225.41 90.32 79.89 Example 9 247.66 89.77 78.24 Example 10 234.72 89.34 78.65 Comparative Example 1 284.69 80.42 70.11 Comparative Example 2 280.21 82.35 74.06 As can be seen from Table 2, the average particle sizes of Examples 8, 9 and 10 are all smaller than those of Comparative Examples 1 and 2, indicating that the negatively charged Spirulina platensis can electrostatically attract the quaternary ammonium chitosan (positively charged) of the outer layer structure of the composite microspheres loaded with white kidney bean extract, thereby enhancing the close connection between the composite microspheres of white kidney bean extract and the Spirulina platensis structure, reducing the average particle size of the composite microcapsules of white kidney bean extract, thereby improving the encapsulation efficiency of the composite microcapsules of white kidney bean extract, encapsulating more effective ingredients, and thus being able to better inhibit α-amylase. (2) Stability in simulated gastric juice digestion The simulated gastric juice digestion stability of Example 2, Example 8, Comparative Example 1 and Comparative Example 2 was determined as follows: the white kidney bean extract composite microcapsules were added to simulated gastric juice (pH 1.5), and incubated on a constant temperature shaking shaker (37° C., 100 rpm) for 0 h, 2 h, 4 h, 6 h, 8 h, and 10 h, respectively. An appropriate amount of supernatant was taken by centrifugation, and the α-amylase inhibition rate was determined. The ratio of the α-amylase inhibition rate to the initial α-amylase inhibition rate represented the release rate of the effective ingredients in the white kidney bean extract composite microcapsules, which reflected the simulated gastric juice digestion stability of the white kidney bean extract composite microcapsules. Depend on Figure 1 It can be seen that the white bean extract composite microspheres prepared in Example 2 were loaded with Spirulina platensis without keratin modification. After 4 hours of simulated gastric juice digestion, the release rate of the white bean extract composite microspheres was very close to 100%, indicating that the effective ingredients had been completely released; after 10 hours of simulated gastric juice digestion, the release rates of Comparative Examples 1 and 2 were both above 70%. The results showed that the white bean extract composite microcapsules prepared with Spirulina platensis without modification or with modified β-cyclodextrin would also cause the loss of effective ingredients after gastric juice digestion, and could not achieve the purpose of long-term release in the stomach of the body. Figure 1 In Example 8, white kidney bean extract composite microspheres are used as core materials, and keratin cross-linked with genipin and Spirulina platensis are used as wall materials to prepare white kidney bean extract composite microcapsules, and their release rates are significantly lower than those of Comparative Examples 1 and 2, indicating that on the one hand, the negative charge of Spirulina platensis interacts electrostatically with the quaternary ammonium chitosan (positive charge) on the outer layer of the white kidney bean extract composite microspheres to tightly embed them, and at the same time, Spirulina platensis has good resistance to gastric acid; on the other hand, genipin covalently binds to the amino acids in keratin and modifies the structure of Spirulina platensis, thereby enhancing the tight connection between the microspheres and the wall materials in the white kidney bean extract composite microcapsules. The presence of genipin and Spirulina platensis can improve the stability of the white kidney bean extract composite microcapsules in gastric acid, thereby allowing the white kidney bean extract composite microcapsules to exert their long-lasting effect. (3) Animal testing The rat obesity model was used to evaluate the anti-obesity effect of the white kidney bean extract composite microcapsules prepared in Example 8, Comparative Example 1 and Comparative Example 2, and the specific method was as follows: ① Model construction: 60 SPF SD male rats were selected and divided into a modeling group (50 rats) and a blank group (10 rats). The modeling group was fed with a high-calorie diet for 2 weeks, and the blank group was fed with a normal diet for 2 weeks. The initial body weight, body weight after 2 weeks, and weight gain of the rats were recorded. ② Group feeding: After the model was successfully established, the 50 rats in the modeling group were ranked according to their weight gain, and the rats with slow weight gain were eliminated, and 40 rats were screened out for subsequent experiments; the 40 rats were divided into 4 groups, namely, the model group (10 rats), the embodiment 8 group (10 rats), the comparative example 1 group (10 rats), and the comparative example 2 group (10 rats), and a 6-week feeding experiment was carried out. The feeding methods of each test group are shown in Table 3; Table 3 Feeding methods of the model group, Example 8 group, Comparative Example 1 group, Comparative Example 2 group and blank group Group Feeding method Model Group High-calorie diet was fed, and an equal volume of sterile water was gavage Example 8 Group The patients were fed with high-calorie feed and gavaged with 10 mL / kg of the white kidney bean extract composite microcapsule solution prepared in Example 8. Comparative Example 1 The patients were fed with high-calorie feed and gavaged with 10 mL / kg of the white kidney bean extract composite microcapsule solution prepared in Example 1. Comparative Example 2 The patients were fed with high-calorie feed and gavaged with 10 mL / kg of the white kidney bean extract composite microcapsule solution prepared in Example 2. Blank Group Normal feed was fed, and an equal volume of sterile water was gavage ③ Index determination: The body weight, food intake and weight gain of the rats were recorded weekly. After 6 weeks of feeding, all mice in the blank group, model group, Example 8 group, Comparative Example 1 group and Comparative Example 2 group were anesthetized with 1% sodium pentobarbital (0.5 mL / 100 g), and blood samples were taken for determination. At the same time, the liver, subcutaneous fat, perirenal fat and testicular fat were collected by dissection and separation, and the weight was recorded. Table 4 Initial body weight, body weight and weight gain after 2 weeks in the modeling group and blank group Group Initial body mass (g) Body weight after 2 weeks (g) Weight gain (g) Modeling Group 205.10±6.21 347.20±5.28** 142.10±3.45** Blank Group 203.30±4.02 304.50±3.14 101.20±2.11 Note: ** indicates p < 0.01, compared with the blank group. As shown in Table 4, after the rats were fed with high-calorie diet for 2 weeks, the body weight and weight gain of the rats in the modeling group were significantly higher than those in the blank group (p<0.01), indicating that the obesity model of rats was successfully established. Depend on Figure 2It can be seen that within 6 weeks of feeding, the food intake of the model group, the blank group, the Example 8 group, the comparative example 1 group and the comparative example 2 group all showed an increasing trend, among which the food intake of the model group was the largest, while the food intake of the Example 8 group was the smallest, which was lower than that of the blank group. This indicates that when the white kidney bean extract composite microcapsules prepared in Example 8 were gavaged into rats, keratin could interact with the mucin in the gastric mucosal layer of the rat stomach, so that the white kidney bean extract composite microcapsules adhered to the gastric mucosa and prolonged the retention time in the stomach; the fat in the high-calorie feed was decomposed by the lipase response inside the white kidney bean extract composite microcapsules, and the sugars were converted into glucose after digestion. It is specifically recognized by concanavalin A and releases a variety of effective ingredients in the white kidney bean extract composite microcapsules; on the other hand, the white kidney bean extract, chickpea extract and cocoa bean extract in the white kidney bean extract composite microcapsules contain α-amylase inhibitors, dietary fiber and other substances, which can effectively reduce the absorption rate of carbohydrates in the body and increase the volume of the stomach, thereby slowing down the gastric emptying rate and increasing the sense of fullness; on the other hand, L-carnitine can promote the fatty acids in high-calorie feed to enter the mitochondria for oxidative decomposition to produce energy, which can reduce the desire for food and intake, thereby reducing the feed intake of rats during the feeding test. Depend on Figure 3 It can be seen that the body weight, liver weight and fat weight of Example 8 are all lower than those of the model group, and the liver weight and fat weight are not significantly different from those of the blank group (normal feed), indicating that the use of white kidney bean extract composite microcapsules to gavage rats can improve the fat situation of obese rats and achieve the purpose of fat reduction. The body weight, liver weight and fat weight of the comparative example 1 group and the comparative example 2 group are all higher than those of the comparative example 8 group, indicating that the comparative example 1 does not use the modified platen Spirulina to load the white kidney bean extract composite microcapsules to gavage rats, and the retention time in the stomach is shorter than that of the comparative example 8, which makes the effective components easy to be excreted from the body, so the fat reduction effect of obese rats is not ideal; while the comparative example 4 uses the white kidney bean extract composite microcapsules prepared by cross-linking keratin modified β-cyclodextrin with genipin, and its survival in gastric juice is unstable, resulting in a large loss of effective components, so the fat reduction effect of obese rats is not significant. Depend on Figure 4It can be seen that the serum total cholesterol level of the obese rats in the model group fed with high-calorie feed was higher than that in the blank group, and the triglyceride content was increased, indicating that the experimental rats had abnormal lipid metabolism. After 6 weeks of intervention by gavage of white kidney bean extract composite microcapsules in Example 8, the total cholesterol and triglyceride contents were lower than those in the blank group, and both low-density lipoprotein and high-density lipoprotein returned to normal levels, indicating that the glucose and fat produced by digestion of high-calorie feed can respond to lipase and concanavalin A in the white kidney bean extract composite microcapsules, release white kidney bean extract, chickpea extract, cocoa bean extract and L-carnitine, inhibit the activity of α-amylase in the body, reduce the body's digestion and absorption of glucose, and promote the decomposition and metabolism of fat. At the same time, quaternized chitosan and fatty acid carboxyl groups undergo electrostatic bridging to form a stable complex that is excreted from the body, thereby reducing fat accumulation in the body, reducing the content of total cholesterol and triglycerides, avoiding fat accumulation, and achieving the purpose of fat reduction. The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A composite microcapsule of white kidney bean extract, characterized in that: The white kidney bean extract composite microcapsule takes the white kidney bean extract as a main component and is prepared based on a dual response mechanism.

2. A method for preparing white kidney bean extract composite microcapsules, characterized in that: The following steps are involved: S1. Weigh white kidney bean extract, chickpea extract, cocoa bean extract, and L-carnitine, add water and dissolve evenly to obtain a mixed solution; S2. The quaternized chitosan was dissolved in water to prepare a quaternized chitosan solution having a mass concentration of 15-20%, and pancreatic lipase and concanavalin A were added and treated at 30-40 ° C for 2-4h to obtain a quaternized chitosan solution; S3. Using the mixed solution as the inner phase and the quaternized chitosan solution as the outer phase, a white kidney bean extract composite microsphere solution was prepared by microfluidic technology; S4. Spirulina platensis was pretreated and freeze-dried to obtain Spirulina platensis powder, which was dissolved in water to prepare a 20-30% solution of Spirulina platensis by mass concentration, and then mixed with keratin and genipin to obtain a modified Spirulina platensis solution; S5. Using the white kidney bean extract composite microsphere solution as the core material, uniformly drip it into the modified Spirulina platensis solution and stir it at 25-35°C and 200-300rpm for 2-3h, and vacuum dry it to prepare the white kidney bean extract composite microcapsules.

3. The method for preparing a composite microcapsule of white kidney bean extract according to claim 2, characterized in that: In step S1, the ratio of white kidney bean extract, chickpea extract, cocoa bean extract and L-carnitine is (4-7):(1-1.5):(0.5-1.5):(1.5-2).

4. The method for preparing a composite microcapsule of white kidney bean extract according to claim 2, characterized in that: The amount of concanavalin A added in step S2 is 10-15%.

5. The method for preparing a composite microcapsule of white kidney bean extract according to claim 2, characterized in that: The concentration of pancreatic lipase in step S2 is 20-30 mg / mL.

6. The method for preparing a composite microcapsule of white kidney bean extract according to claim 2, characterized in that: The ratio of the mixed solution to the quaternized chitosan in step S3 is (3-6):1; the microfluidic treatment conditions are that the flow rate of the mixed solution is 0.5-10 mL / h, and the flow rate of the quaternized chitosan solution is 20-40 mL / h.

7. The method for preparing a composite microcapsule of white kidney bean extract according to claim 2, characterized in that: In the step S4, the ratio of the Spirulina platensis solution, keratin and genipin is 2:(1-5):(0.5-1.5).

8. Use of the white kidney bean extract composite microcapsule according to claim 1 in the preparation of weight loss and fat reduction products.

Images