Spina date seed microcapsule and preparation method thereof

Abstract

The invention provides a spina date seed microcapsule and a preparation method thereof, and the preparation method comprises the following steps: (1) efficiently extracting saponin and flavonoid active ingredients in spina date seeds by adopting an ionic liquid and microwave-assisted synergistic extraction technology; (2) carrying out high-selectivity adsorption and enrichment on the extracting solution through macroporous adsorption resin, so as to improve the yield and purity of the target component; and (3) selecting maltodextrin and whey protein isolate to be compounded as a composite wall material, and carrying out microcapsule embedding on the enriched extract. The technical problems that the extraction efficiency of active ingredients of the spina date seeds is low, the microcapsule embedding effect is poor and the bioavailability is insufficient are solved through an extraction-enrichment-embedding integrated process, and an efficient and feasible new scheme is provided for deep processing of the spina date seeds with homology of medicine and food.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of food, medicine and health product processing, and particularly relates to a Zizyphus jujuba Mill. var. spinosus (Bunge) Hu ex H. F. Chou microcapsule and a preparation method thereof. BACKGROUND

[0002] Zizyphus jujuba Mill. var. spinosus (Bunge) Hu ex H. F. Chou is the dried mature seed of Ziziphus spina-christi (Mill.) Desv., which is a traditional medicine and food homologous material and has the effects of nourishing heart and liver, tranquilizing the mind and stopping sweating. Modern pharmacological studies have confirmed that saponins and flavonoids are the main material basis for the physiological activities of Zizyphus jujuba Mill. var. spinosus (Bunge) Hu ex H. F. Chou, such as sedation and sleep aid, and anti-anxiety. The stability of these active ingredients, the extraction purity, the bioavailability and the application performance of the final product directly determine the quality and market value of the Zizyphus jujuba Mill. var. spinosus (Bunge) Hu ex H. F. Chou processing product.

[0003] At present, the preparation of Zizyphus jujuba Mill. var. spinosus (Bunge) Hu ex H. F. Chou extract mainly relies on traditional methods such as decoction and alcohol extraction. These methods generally have the problems of long extraction time, low efficiency and high energy consumption, and high-temperature long-time treatment easily leads to the degradation or inactivation of heat-sensitive saponins and flavonoids. Although modern extraction technologies such as ultrasonic and microwave have been tried, there are still limitations in the aspects of wall breaking efficiency and selective dissolution of target components, and it is difficult to achieve high efficiency and high quality extraction at the same time. In the enrichment process, although the conventional alcohol precipitation and macroporous resin method has a certain effect, for the saponins and flavonoids with similar structures in Zizyphus jujuba Mill. var. spinosus (Bunge) Hu ex H. F. Chou, there is often a lack of high selectivity in adsorption and separation, which leads to the difficulty in simultaneous improvement of the yield and purity of the target product, and restricts the development of high-quality products.

[0004] In order to improve the application performance of Zizyphus jujuba Mill. var. spinosus (Bunge) Hu ex H. F. Chou extract, especially to solve the problems of easy moisture absorption, caking, strong medicinal smell and low bioavailability in the process of infusion and digestion, microcapsule technology has been widely used. However, the existing technology mainly uses single wall material for embedding: although malt dextrin has low cost and good solubility, its emulsification and film-forming compactness are insufficient, and the embedding rate and protection effect of hydrophobic active ingredients are not ideal; although protein wall materials such as whey protein have excellent emulsification performance, they are high in cost when used alone, and may affect the dissolution of the final product. The existing wall material system is difficult to balance the cost, embedding rate, stability and release characteristics.

[0005] In summary, the existing Zizyphus jujuba Mill. var. spinosus (Bunge) Hu ex H. F. Chou deep processing technology has obvious bottlenecks in each link of extraction, enrichment and embedding: the extraction efficiency and component protection are difficult to balance, the single function of wall material leads to low embedding effect and bioavailability, and the technologies at each link lack synergy, and cannot form an integrated and efficient preparation scheme. Therefore, it is of great industrial value and practical demand to develop a new method that can solve the above problems simultaneously and realize the efficient preparation of high-quality microcapsule powder from raw materials. SUMMARY

[0006] Technical problems to be solved: In view of the above technical problems, the present application provides a Zizyphus jujuba Mill. microcapsule and a preparation method thereof. By using ion liquid and microwave-assisted extraction technology, macroporous adsorption resin enrichment, and malt dextrin and whey protein complex as a composite wall material, the Zizyphus jujuba Mill. extract is microencapsulated to provide a Zizyphus jujuba Mill. microcapsule with high stability, good solubility and easy application, and solve the technical problems of low extraction efficiency of active ingredients of Zizyphus jujuba Mill., and poor microencapsulation effect and insufficient bioavailability.

[0007] Technical scheme: A preparation method of a Zizyphus jujuba Mill. microcapsule, comprising the following steps: S1. Raw material pretreatment: dry Zizyphus jujuba Mill. medicinal materials are weighed, crushed and sieved through a 40-60 mesh sieve to obtain Zizyphus jujuba Mill. powder; S2. Microwave-assisted ion liquid extraction: ion liquid and 60% ethanol aqueous solution are prepared into an extraction solution, the Zizyphus jujuba Mill. powder and the extraction solution are uniformly mixed, placed in a microwave synthesis instrument, the microwave parameters are set, and constant stirring is performed, after extraction is completed, cooling, centrifugation and reduced pressure concentration are performed until there is no alcohol taste, and a Zizyphus jujuba Mill. clear extract is prepared; S3. Enrichment: the Zizyphus jujuba Mill. clear extract is added with water to make the concentration of the Zizyphus jujuba Mill. raw medicinal material 500-1000 g / L, and the AB-8 macroporous adsorption resin column is enriched, and the eluent is concentrated under reduced pressure to prepare a Zizyphus jujuba Mill. extract; S4. Preparation of wall material solution: malt dextrin and whey protein isolate are dissolved in water, and stirred to prepare a wall material solution; S5. Preparation of core material dispersion liquid: the Zizyphus jujuba Mill. extract is mixed with a small amount of water and stirred uniformly to form a uniform core material dispersion liquid; S6. Emulsification and homogenization: the core material dispersion liquid is slowly added to the wall material solution, and homogenized at 30-50 MPa for 5 min, repeated for 3 times to form a stable emulsion; S7. Spray drying: the emulsion is spray dried to prepare a Zizyphus jujuba Mill. microcapsule.

[0008] Preferably, the ion liquid in step S2 is a choline, organic acid salt or amino acid ionic liquid.

[0009] Further, the choline ionic liquid is a eutectic solvent composed of choline and malate in a molar ratio of 1.5:1-1:1.5.

[0010] Preferably, the volume ratio of the ion liquid and the 60% ethanol aqueous solution in step S2 is 1:4-8.

[0011] Preferably, the solid-liquid ratio of the Zizyphus jujuba Mill. powder and the extraction solution in step S2 is 1:20-40.

[0012] Preferably, the power of the microwave in the step S2 is 300-600 W, the temperature of the microwave is 50-70℃, and the time of the microwave is 10-15 min.

[0013] Preferably, the relative density of the Suanzaoren clear extract in the step S2 is 1.10-1.20 g / cm 3 .

[0014] Preferably, the step of AB-8 macroporous adsorption resin column adsorption enrichment in the step S3 is as follows: after wet loading, 3-5 times column volume (BV) of pure water or 5% ethanol solution is used to flush at a flow rate of 2-4 BV / h; then 4-6 times column volume of 50%-70% ethanol solution is used to elute at a lower flow rate of 1-3 BV / h, and the eluate is collected; finally, 3-5 times column volume of 95% ethanol solution is used to flush at a flow rate of 2-4 BV / h, and the eluate is collected.

[0015] Preferably, the mass ratio of malt dextrin and whey protein isolate in the step S4 is 1-3:1.

[0016] Preferably, the mass concentration of the solid in the wall material solution in the step S4 is 20-30%.

[0017] Preferably, the mass ratio of the wall material and the core material in the emulsion in the step S6 is 2-4:1.

[0018] Preferably, the inlet air temperature of the spray drying in the step S7 is 160-180℃, the outlet air temperature is 80-100℃, and the speed of the atomizer is 20,000-30,000 rpm.

[0019] The Suanzaoren microcapsule prepared by the preparation method. Beneficial effects

[0020] 1. The present application adopts the synergistic extraction technology of "ionic liquid" and "microwave assistance", and both of them play a significant synergistic effect. The ionic liquid greatly enhances the permeability of plant cell wall and the solubility of target components, and the microwave provides instantaneous and efficient penetration heating, which not only overcomes the bottleneck of long time consumption and high energy consumption of traditional extraction, but also avoids the degradation of heat-sensitive active ingredients such as Suanzaoren saponins and flavonoids, realizes the synchronous consideration of high-efficiency extraction and component integrity.

[0021] 2. For saponins and flavonoids in Suanzaoren, the present application optimizes the adsorption-desorption process parameters of weakly polar AB-8 macroporous adsorption resin, and clearly defines its specific adsorption characteristics for target components, effectively solving the problem of insufficient selectivity of conventional enrichment methods, and realizing the synchronous improvement of target product yield and purity.

[0022] 3. The present application selects malt dextrin and whey protein as a composite wall material, which complements the defects of single wall material. Malt dextrin is low in price but weak in emulsifying ability, while whey protein has good emulsifying property, film-forming property and core material binding ability. The two together form a dense and stable wall film structure, which not only solves the problems of insufficient embedding rate of single malt dextrin, high cost and poor solubility of single whey protein, but also achieves a balance between cost, embedding effect and stability, significantly improving the wrapping and protection efficiency of the core material.

[0023] 4. The prepared microcapsule particles are uniform and can be quickly dispersed and dissolved in water, with strong brewing applicability. The microcapsule structure can effectively protect the core material from being damaged too early during brewing, and at the same time, slowly release in the specific environment of the human digestive tract, avoid degradation of active ingredients in the stomach, greatly improve the absorption efficiency in the intestine, and significantly improve the bioavailability. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The preparation process flow chart of the Zizyphi Spinosi Semen microcapsule. DETAILED DESCRIPTION

[0025] The present application will be further described below in conjunction with examples, which are an explanation of the present application but the present application is not limited to the following examples: Example 1

[0026] This example is a preparation method of Zizyphi Spinosi Semen microcapsule, which comprises the following steps: S1. Raw material pretreatment: dry Zizyphi Spinosi Semen medicinal materials are weighed, crushed and passed through a 60-mesh sieve to prepare Zizyphi Spinosi Semen fine powder; S2. Microwave-assisted ionic liquid extraction: choline chloride and malate are prepared into choline-malate solvent according to a molar ratio of 1:1, choline chloride-malate solvent and 60% ethanol aqueous solution are prepared into extraction liquid according to a volume ratio of 1:4, Zizyphi Spinosi Semen fine powder and extraction liquid are mixed uniformly according to a ratio of 1:40 (g / mL), and then placed in a microwave synthesis instrument, with microwave power of 600 W, extraction temperature of 50℃ and extraction time of 10 min, and continuously stirred, after completion, cooled, centrifuged and concentrated under reduced pressure until no alcohol smell, to prepare Zizyphi Spinosi Semen clear extract with a relative density of 1.10 g / cm 3 Zizyphi Spinosi Semen clear extract; S3. Enrichment: Zizyphi Spinosi Semen clear extract is added with water to make the concentration of Zizyphi Spinosi Semen raw medicinal materials 800 g / L, and then enriched by AB-8 macroporous adsorption resin column, after wet sampling, 3 times column volume (BV) of pure water is used to flush at a flow rate of 3 BV / h; then 5 times column volume of 50% ethanol solution is used to elute at a lower flow rate of 1 BV / h, and the eluate is collected; finally, 5 times column volume of 95% ethanol solution is used to flush at a flow rate of 3 BV / h, and the eluate is collected, concentrated under reduced pressure to prepare Zizyphi Spinosi Semen extract; S4. Preparation of wall material solution: 60 g of malt dextrin and 30 g of whey protein isolate were dissolved in 210 mL of water, stirred thoroughly, and a wall material solution with a concentration of 30% was prepared; S5. Preparation of core material dispersion liquid: 25 g of Semen Ziziphi Spinosae extract was added to 15 mL of water and stirred uniformly to form a uniform core material dispersion liquid; S6. Emulsification and homogenization: the core material dispersion liquid was slowly added to the wall material solution, and homogenized at 30 MPa for 5 min, repeated 3 times, to form a stable emulsion; S7. Spray drying: the emulsion was spray dried, with an inlet air temperature of 180°C, an outlet air temperature of 88°C, and an atomizer speed of 25000 rpm, to prepare Semen Ziziphi Spinosae microcapsules. Example 2

[0027] The present embodiment is a preparation method of Semen Ziziphi Spinosae microcapsules, comprising the following steps: S1. Raw material pretreatment: dry Semen Ziziphi Spinosae medicinal materials were crushed and passed through a 60-mesh sieve to prepare Semen Ziziphi Spinosae fine powder; S2. Microwave-assisted ionic liquid extraction: choline chloride and malate were prepared into choline chloride-malate solvent according to a molar ratio of 1:1, the choline chloride-malate solvent and 60% ethanol aqueous solution were prepared into extraction liquid according to a volume ratio of 1:8, the Semen Ziziphi Spinosae fine powder and the extraction liquid were mixed uniformly according to a ratio of 1:20 (g / mL), and were placed in a microwave synthesis instrument, with a microwave power of 600 W, an extraction temperature of 50°C, and an extraction time of 15 min, and were continuously stirred, after completion, were cooled, centrifuged, and concentrated under reduced pressure until no alcohol taste was left, to prepare Semen Ziziphi Spinosae clear extract with a relative density of 1.12 g / cm 3 Semen Ziziphi Spinosae clear extract; S3. Enrichment: the Semen Ziziphi Spinosae clear extract was added with water to make the concentration of Semen Ziziphi Spinosae raw medicinal materials 800 g / L, and was enriched by AB-8 macroporous adsorption resin column, after wet loading, 5 times column volume (BV) of pure water was used to flush at a flow rate of 4 BV / h; then 6 times column volume of 70% ethanol solution was used to elute at a lower flow rate of 1 BV / h, and the eluate was collected; finally, 3 times column volume of 95% ethanol solution was used to flush at a flow rate of 4 BV / h, and the eluate was collected, and was concentrated under reduced pressure, to prepare Semen Ziziphi Spinosae extract; S4. Preparation of wall material solution: 60 g of malt dextrin and 30 g of whey protein isolate were dissolved in 210 mL of water, stirred thoroughly, and a wall material solution with a concentration of 30% was prepared; S5. Preparation of core material dispersion liquid: 25 g of Semen Ziziphi Spinosae extract was added to 15 mL of water and stirred uniformly to form a uniform core material dispersion liquid; S6. Emulsification and homogenization: the core material dispersion liquid was slowly added to the wall material solution, and homogenized at 30 MPa for 5 min, repeated 3 times, to form a stable emulsion; S7. Spray drying: the emulsion is spray dried with an inlet temperature of 165℃, an outlet temperature of 85℃, and an atomizer speed of 25000 rpm to obtain the Zizyphi Spinosae Semen microcapsules. Example 3

[0028] This example is a preparation method of Zizyphi Spinosae Semen microcapsules, comprising the following steps: S1. Raw material pretreatment: dry Zizyphi Spinosae Semen medicinal materials are weighed, crushed, and passed through a 60-mesh sieve to obtain Zizyphi Spinosae Semen powder; S2. Microwave-assisted ionic liquid extraction: choline chloride and malate are mixed in a molar ratio of 1:1 to prepare a choline chloride-malate solvent, the choline chloride-malate solvent and 60% ethanol aqueous solution are mixed in a volume ratio of 1:6 to prepare an extraction solution, the Zizyphi Spinosae Semen powder and the extraction solution are mixed uniformly at a ratio of 1:30 (g / mL), and then placed in a microwave synthesis instrument, with the microwave power set at 400 W, the extraction temperature set at 60℃, and the extraction time set at 10 min, while stirring continuously. After completion, the mixture is cooled, centrifuged, and concentrated under reduced pressure until no alcohol smell is detected, to obtain a Zizyphi Spinosae Semen clear extract with a relative density of 1.14 g / cm 3 Zizyphi Spinosae Semen clear extract; S3. Enrichment: the Zizyphi Spinosae Semen clear extract is added with water to make the concentration of the Zizyphi Spinosae Semen raw medicinal material 500 g / L, and then enriched by AB-8 macroporous adsorption resin column. After wet loading, 3 bed volumes (BV) of pure water are used to flush at a flow rate of 3 BV / h; then 5 BV of 50% ethanol solution is used to elute at a lower flow rate of 1 BV / h, and the eluate is collected; finally, 5 BV of 95% ethanol solution is used to flush at a flow rate of 3 BV / h, and the eluate is collected and concentrated under reduced pressure to obtain a Zizyphi Spinosae Semen extract; S4. Preparation of wall material solution: 60 g of malt dextrin and 30 g of whey protein isolate are dissolved in 210 mL of water, and stirred thoroughly to obtain a wall material solution with a concentration of 30%; S5. Preparation of core material dispersion: 45 g of Zizyphi Spinosae Semen extract is added to 25 mL of water and stirred uniformly to form a uniform core material dispersion; S6. Emulsification and homogenization: the core material dispersion is slowly added to the wall material solution, and homogenized at 30 MPa for 5 min, repeated for 3 times, to form a stable emulsion; S7. Spray drying: the emulsion is spray dried with an inlet temperature of 180℃, an outlet temperature of 95℃, and an atomizer speed of 20000 rpm to obtain the Zizyphi Spinosae Semen microcapsules. Example 4

[0029] This example is a preparation method of Zizyphi Spinosae Semen microcapsules, comprising the following steps: S1. Raw material pretreatment: dry Zizyphi Spinosae Semen medicinal materials are weighed, crushed, and passed through an 80-mesh sieve to obtain Zizyphi Spinosae Semen powder; S2. Microwave-assisted ionic liquid extraction: Choline chloride-malate solvent was prepared by mixing choline chloride and malate at a molar ratio of 1:1, and the choline chloride-malate solvent and 60% ethanol aqueous solution were mixed at a volume ratio of 1:5 to prepare an extraction solution. The fine powder of Semen Ziziphi Spinosae and the extraction solution were mixed uniformly at a ratio of 1:35 (g / mL), and then placed in a microwave synthesis instrument. The microwave power was set to 500 W, the extraction temperature was set to 55℃, and the extraction time was set to 15 min. The mixture was continuously stirred, and after completion, the mixture was cooled, centrifuged, and concentrated under reduced pressure until no alcohol smell was detected. Finally, Semen Ziziphi Spinosae microcapsules with a relative density of 1.18 g / cm 3 Semen Ziziphi Spinosae clear extract; S3. Enrichment: The Semen Ziziphi Spinosae clear extract was added with water to make the concentration of Semen Ziziphi Spinosae raw medicinal material 1000 g / L, and then subjected to enrichment by AB-8 macroporous adsorption resin column. After wet loading, 4 times the column volume (BV) of pure water was used to flush at a flow rate of 3 BV / h. Then, 5 times the column volume of 70% ethanol solution was used to elute at a lower flow rate of 3 BV / h, and the eluate was collected. Finally, 5 times the column volume of 95% ethanol solution was used to flush at a flow rate of 4 BV / h, and the eluate was collected. After concentration under reduced pressure, Semen Ziziphi Spinosae extract was obtained. S4. Preparation of wall material solution: 30 g of malt dextrin and 10 g of whey protein isolate were dissolved in 160 mL of water to prepare a wall material solution with a concentration of 20%; S5. Preparation of core material dispersion: 10 g of Semen Ziziphi Spinosae extract was added to 15 mL of water and stirred uniformly to form a uniform core material dispersion; S6. Emulsification and homogenization: The core material dispersion was slowly added to the wall material solution, and homogenized at 30 MPa for 5 min, repeated 3 times, to form a stable emulsion; S7. Spray drying: The emulsion was spray dried with an inlet air temperature of 165℃, an outlet air temperature of 85℃, and an atomizer speed of 25000 rpm to obtain Semen Ziziphi Spinosae microcapsules.

[0030] To further illustrate the technical effects of the present application, the present application also provides comparative examples, as follows: Comparative Example 1

[0031] The difference between the present comparative example and Example 1 is that the wall material of the Semen Ziziphi Spinosae microcapsules in the present comparative example is malt dextrin, and the preparation method comprises the following steps: S1~3. Same as S1~3 of Example 1; S4. Preparation of wall material solution: 30 g of malt dextrin and 10 g of whey protein isolate were dissolved in 160 mL of water to prepare a wall material solution with a concentration of 20%; S5. Preparation of core material dispersion: 10 g of Semen Ziziphi Spinosae extract was added to 15 mL of water and stirred uniformly to form a uniform core material dispersion; S6. Emulsification and homogenization: The core material dispersion was slowly added into the wall material solution, and homogenized at 30 MPa for 5 min, repeated for 3 times, to form a stable emulsion; S7. Spray drying: The emulsion was spray dried with an inlet temperature of 180 °C, an outlet temperature of 89 °C, and an atomizer speed of 25000 rpm, to obtain the Zizyphi Spinosae Semen microcapsules. Comparative Example 2

[0032] The difference between this comparative example and Example 1 is that in this comparative example, the whey protein isolate is replaced by soybean protein isolate, and the other steps are the same as in Example 1. Comparative Example 3

[0033] The difference between this comparative example and Example 1 is that in this comparative example, the microwave-assisted extraction is replaced by ultrasonic-assisted extraction, and the preparation method comprises the following steps: S1. Same as S1 of Example 1; S2. The Zizyphi Spinosae Semen fine powder was mixed with 50% ethanol at a ratio of 1:10 (g / mL) and ultrasonically extracted at a frequency of 60 kHz and a power of 300 W, with an extraction temperature of 50 °C and a single extraction time of 80 min, repeated for 3 times. The extraction liquid was combined and filtered, and then concentrated under reduced pressure until there was no alcohol smell, to obtain the Zizyphi Spinosae Semen extract; S3. Same as S3 of Example 1; S4-7. Same as S4-7 of Example 1. Comparative Example 4

[0034] The difference between this comparative example and Example 1 is that in this comparative example, the AB-8 macroporous adsorption resin column is replaced by activated carbon, and the preparation method comprises the following steps: S1-2. Same as S1-2 of Example 1; S3. The Zizyphi Spinosae Semen extract was added with water to make the concentration of the Zizyphi Spinosae Semen raw medicinal material 800 g / L, and 1% (w / v) of powdered medicinal-grade activated carbon was added. The mixture was heated to 60 °C and continuously stirred for 30 min to allow the activated carbon to fully contact and adsorb the pigments. After decolorization, the mixture was hot-filtered to obtain a clear medicinal liquid with significantly lighter color, and then concentrated under reduced pressure to obtain the Zizyphi Spinosae Semen extract; S4-7. Same as S4-7 of Example 1. Index Test

[0035] 1. Determination of moisture content: A certain amount of microcapsule powder was placed in an oven and dried at 105 °C until the weight was constant. The moisture content was calculated according to the mass difference before and after drying the sample.

[0036] 2. Solubility determination: 1 g of microcapsule powder was added to 10 mL of distilled water, stirred with a magnetic stirrer for 30 min, centrifuged at 4000 rpm for 10 min, and the supernatant was collected in an evaporating dish and dried at 105°C for 24 h. The solubility was calculated according to the formula; Solubility calculation formula: solubility / % = (m2-m1) / [(1-B)m] x 100, where m: sample mass (g); m1: mass of evaporating dish (g); m2: mass of evaporating dish and insoluble (g); B: moisture content of the sample (%).

[0037] 3. Determination of embedding rate: (1) 0.5 g of microcapsule powder was placed in a centrifuge tube, 20 mL of anhydrous ethanol was added, and shaken for 5 min, centrifuged at 5000 rpm for 10 min, the supernatant was taken, and the washing was repeated twice, and all the supernatant was combined and diluted to a certain volume with anhydrous ethanol. This solution is the surface saponin solution (A solution); (2) 0.5 g of microcapsule powder was added to an appropriate amount of 50% ethanol, and ultrasonic crushing was performed for 30 min to assist extraction. After cooling to room temperature, the supernatant was taken by centrifugation, and the extraction was repeated twice. The supernatant was combined and diluted to a certain volume with the corresponding solvent. This solution is the total saponin solution (B solution); (3) The absorbance of A solution and B solution was determined at 455 nm by vanillin-perchloric acid method. The embedding rate was calculated according to the formula; Embedding rate calculation formula: embedding rate / % = (M B -M A ) / M B x 100; where M A : mass of surface saponin in microcapsule sample (mg); M B : mass of total saponin in microcapsule sample (mg).

[0038] 4. Release rate determination: (1) Preparation of simulated gastric juice: 2 g of NaCl and 3.2 g of pepsin were weighed and added to 200 mL of distilled water, stirred and dissolved, and the pH was adjusted to 1.2 with 1 mol / L HCl solution. Pour into a 500 mL volumetric flask and dilute to volume; (2) Preparation of simulated intestinal juice: 3.4 g of KH2PO4 and 5 g of trypsin were weighed and added to 200 mL of distilled water, stirred and dissolved, and the pH was adjusted to 7.0 with 0.5 mol / L NaOH solution. Pour into a 500 mL volumetric flask and dilute to volume; (3) In vitro simulated digestion experiment: 5.0 g of microcapsule powder was weighed and placed in 50 mL of simulated gastric juice, and a water tank was used for continuous oscillation at 37°C for 2 h. After filtration, it was added to 50 mL of simulated intestinal juice, and the same conditions were used for oscillation for 2 h. The supernatant was obtained by centrifugation, and the total saponin content was measured by the vanillin-perchloric acid method, and the total flavonoid content was measured by the sodium nitrite-aluminum nitrate-sodium hydroxide colorimetric method.

[0039] Table 1 Index test results of Zizyphus jujuba Mill. microcapsules

[0040] As shown in Table 1, the contents of saponins and flavonoids in the Zizyphus jujuba Mill. microcapsules obtained by microwave-assisted ionic liquid extraction and macroporous adsorption resin enrichment in Examples 1-4 were higher, the total saponin content was (39.82±3.75)~(44.34±5.85) mg / g, and the total flavonoid content was (30.46±4.29)~(36.26±4.89) mg / g. The solubility of the Zizyphus jujuba Mill. microcapsules in Examples 1-4 was (91.29±5.79)~(95.29±7.51)%, the embedding rate was (89.18±5.73)~(92.17±5.13)%, and the release rate was (78.22±4.18)~(82.12±3.87)%, which were significantly higher than those of Comparative Examples 1-4. It is shown that the Zizyphus jujuba Mill. microcapsules prepared by the method of the application have high effective components, high embedding rate, good stability, good solubility and can achieve controlled release. Compared with Comparative Examples 1-2, the Zizyphus jujuba Mill. microcapsule wall material is a combination of malt dextrin and whey protein isolate, not a simple physical mixture, but a synergistic effect at the molecular level and in the processing process, which ultimately optimizes both the solubility (product applicability) and the embedding rate (product stability and effectiveness) of the two key indicators. Compared with Comparative Example 3, the core material of the Zizyphus jujuba Mill. microcapsule uses microwave-assisted ionic liquid extraction technology, which has high contents of total saponins and total flavonoids, reduces the extraction time and improves the extraction efficiency, thereby greatly improving the intrinsic quality and market value of the product. Compared with Comparative Example 4, the enrichment of the core material of the Zizyphus jujuba Mill. microcapsule uses weakly polar macroporous resin adsorption, which has high contents of total saponins and total flavonoids, directly indicating that the potential efficacy of the final product is stronger. At the same time, the reduction of impurities improves the stability and processing performance of the product.

[0041] The above merely describes preferred embodiments of the present application, and is not intended to limit the present application in any form. Any person skilled in the art, without departing from the spirit and technical solutions of the present application, can make many possible changes and modifications to the technical solutions of the present application, or modify equivalent embodiments with 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 application, without departing from the technical solutions of the present application, still belongs to the protection scope of the technical solutions of the present application.

Claims

1. A method for preparing jujube seed microcapsules, characterized in that, Includes the following steps: S1. Raw material pretreatment: Weigh the dried jujube seed medicinal material, crush it and pass it through a 40-60 mesh sieve to obtain jujube seed fine powder; S2. Microwave-assisted ionic liquid extraction: The ionic liquid and 60% ethanol aqueous solution are used to prepare the extraction solution. The jujube seed powder and the extraction solution are mixed evenly and placed in a microwave synthesizer. The microwave parameters are set and the mixture is stirred continuously. After extraction, the mixture is cooled, centrifuged, and concentrated under reduced pressure until there is no alcohol taste, thus obtaining jujube seed extract. S3. Enrichment: Water is added to the jujube seed extract to make the concentration of the original jujube seed medicinal material 500~1000 g / L. The extract is then enriched by adsorption on an AB-8 macroporous adsorption resin column. The eluent is concentrated under reduced pressure to obtain the jujube seed extract. S4. Preparation of wall material solution: Dissolve maltodextrin and whey protein isolate in water and stir thoroughly to obtain the wall material solution; S5. Preparation of core material dispersion: Mix jujube seed extract with a small amount of water and stir evenly to form a uniform core material dispersion; S6. Emulsification and homogenization: Slowly add the core material dispersion to the wall material solution, homogenize at 30~50 MPa for 5 min, repeat 3 times to form a stable emulsion; S7. Spray drying: After spray drying the emulsion, jujube seed microcapsules are obtained.

2. The method for preparing jujube seed microcapsules according to claim 1, characterized in that: The ionic liquid in step S2 is a choline-based, organic acid salt, or amino acid-based ionic liquid.

3. The method for preparing jujube seed microcapsules according to claim 2, characterized in that: The choline-based ionic liquid is a eutectic solvent composed of choline and malate in a molar ratio of 1.5:1 to 1:1.

5.

4. The method for preparing jujube seed microcapsules according to claim 1, characterized in that: In step S2, the volume ratio of the ionic liquid to the 60% ethanol aqueous solution is 1:4~8; the solid-liquid ratio of the jujube seed powder to the extract is 1:20~40; the microwave power is 300~600 W, the microwave temperature is 50~70℃, and the microwave time is 10~15 min; the relative density of the jujube seed extract is 1.10~1.20 g / cm³. 3 .

5. The method for preparing jujube seed microcapsules according to claim 1, characterized in that, The steps for adsorption and enrichment of the AB-8 macroporous adsorption resin column in step S3 are as follows: After wet loading, wash with 3-5 column volumes (BV) of pure water or 5% ethanol solution at a flow rate of 2-4 BV / h; then elute with 4-6 column volumes of 50%-70% ethanol solution at a lower flow rate of 1-3 BV / h, and collect the eluent; finally, wash with 3-5 column volumes of 95% ethanol solution at a flow rate of 2-4 BV / h, and collect the eluent.

6. The method for preparing jujube seed microcapsules according to claim 1, characterized in that: In step S4, the mass ratio of maltodextrin to whey protein isolate is 1-3:1; the mass concentration of solids in the wall material solution is 20-30%.

7. The method for preparing jujube seed microcapsules according to claim 1, characterized in that: In step S6, the mass ratio of wall material to core material in the emulsion is 2~4:

1.

8. The method for preparing jujube seed microcapsules according to claim 1, characterized in that: In step S7, the inlet air temperature of the spray dryer is 160~180℃, the outlet air temperature is 80~100℃, and the atomizer speed is 20000~30000 rpm.

9. The jujube seed microcapsules prepared by the preparation method according to any one of claims 1-8.

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