Microcapsule and preparation process thereof

Abstract

The preparation process comprises the following steps: S1, hydrogel preparation: stirring and dissolving modified sodium alginate, gelatin and purified water in a water bath at 60-65 DEG C for 1-3 hours, closing a water bath kettle for heating, and cooling to room temperature under the irradiation of an ultraviolet lamp to form hydrogel; s2, preparing a bacterial glue solution, namely adding bacterial powder and linseed oil into the hydrogel, homogenizing for 5-10 minutes by adopting a homogenizer under the condition of 4000-5000r / min, and uniformly stirring to obtain the bacterial glue solution; s3, microcapsule preparation: sterilizing an injector and a needle, irradiating the calcium acetate solution under an ultraviolet lamp for 15-20 minutes, then sucking the mycocolloid solution, extruding at the speed of 390-410 mL / h and the extrusion height of 8-12 cm, dripping into the calcium acetate solution for crosslinking, taking out the microcapsule after the mycocolloid solution is dripped, filtering, putting into the calcium acetate solution for continuous crosslinking for 25-35 minutes, taking out, and drying to obtain the microcapsule. The bacteria-containing microcapsule is obtained; and S4, freeze-drying and packaging: freeze-drying the obtained bacterium-containing microcapsules for 36-40 hours, taking out the freeze-dried microcapsules, and packaging the freeze-dried microcapsules.

Description

Technical Field

[0001] The present invention relates to the technical field of microcapsules, and in particular to a microcapsule and a preparation process thereof. Background Art

[0002] Current oral capsules are usually made by filling a specific form of intestinal flora mixture (fresh bacterial mud or freeze-dried powder) into acid-resistant enteric-coated capsules. The disintegration of enteric-coated capsules in the intestine helps the intestinal flora avoid the destruction of acidic gastric juice and various digestive enzymes in the stomach and reach the intestine for colonization. However, since the core of intestinal flora transplantation therapy is to transplant the intestinal flora ecosystem of a healthy donor, and successful colonization requires a certain number and abundance of effective flora and its matrix, in order to ensure the integrity of the intestinal flora ecosystem transplantation, the transplanted fresh bacterial mud or freeze-dried powder needs to have a certain amount. Therefore, the current enteric-coated capsules are generally large - the smallest enteric-coated capsule currently available on the market is a No. 3 capsule (size is 16mm long, 5.5mm wide, and the capacity is 0.12-0.2g). For young children or the elderly who have difficulty swallowing, it is impossible to perform flora transplantation by taking such a large enteric-coated capsule orally.

[0003] Probiotics are a type of active microorganisms that colonize in the human body and change the composition of the flora in a certain part. They have multiple functions such as maintaining the balance of intestinal flora, inhibiting the growth of pathogenic bacteria, enhancing the body's immunity, and preventing diseases. They are beneficial to human health and are widely used in food areas such as fermented products, dairy products, and milk beverages. Probiotics have harsh living conditions and are extremely sensitive to oxygen, gastric acid, enzymes, bile salts and other environmental factors. They are easily killed during processing, storage, digestion, etc., which leads to the inability of probiotic products to fully exert their efficacy in the human body. At present, probiotics are mainly microencapsulated through encapsulation technology to improve the stability of probiotics, reduce the death of probiotics, and increase their survival rate, so that they can smoothly reach the intestinal tract to exert their effects, which is beneficial to improving the bioavailability of probiotics.

[0004] A Chinese patent with application number 202010351092.3 discloses a probiotic microcapsule and its preparation method and application. The probiotics are encapsulated by three layers of materials. The first layer of encapsulation material includes whey protein and carrageenan, which can provide multiple protections for the sclerotia and are conducive to the growth of probiotics; the second layer of encapsulation material includes pectin and xanthan gum, which can reduce the impact of gastric juice on probiotics, thereby increasing the survival rate of probiotics when passing through gastric juice; the third layer of coating raw materials is enteric-soluble substances with the characteristics of sealing, resistance to gastric acid and resistance to digestive enzymes, which can make the outermost layer of the microcapsule degrade in the intestinal tract; although the use of multi-layer materials has achieved ideal encapsulation of probiotics, the preparation method involved is complicated and not conducive to industrial production. Summary of the invention

[0005] In order to solve the problems mentioned in the above background technology, the present invention provides a microcapsule and a preparation process thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A process for preparing microcapsules comprises the following steps: S1 hydrogel preparation: Dissolve the modified sodium alginate, gelatin and purified water in a water bath at 60-65°C for 1-3 hours with stirring, turn off the water bath for heating, and cool to room temperature under ultraviolet light to form a hydrogel; the modified sodium alginate and gelatin can be better dispersed in water at this temperature to form a uniform mixed system. At the same time, stirring can accelerate the dissolution process, allowing the raw materials to fully contact each other, which is conducive to forming a stable hydrogel structure; S2 Preparation of bacterial gel solution: Add bacterial powder and linseed oil to the hydrogel, use a homogenizer, homogenize for 5-10 minutes at 4000-5000r / min, stir evenly, and obtain a bacterial gel solution; ultraviolet light irradiation has the effect of sterilization and disinfection, reduces the contamination of microorganisms to the hydrogel system, thereby ensuring the purity and stability of the hydrogel, and the slow cooling process is conducive to forming a more uniform and regular gel network structure, avoiding gel structure defects caused by sudden temperature changes; S3 microcapsule preparation: sterilize the syringe and needle, place the calcium acetate solution under ultraviolet light for 15-20 minutes, then draw the bacterial gel solution, extrude it at a speed of 390-410mL / h, the extrusion height is 8-12cm, and drip it into the calcium acetate solution for cross-linking. After the bacterial gel solution dripping is completed, take out the microcapsules, filter them, place them in the calcium acetate solution for further cross-linking for 25-35 minutes, and then take them out to obtain bacteria-containing microcapsules; The homogenization process can make the bacterial powder and linseed oil evenly dispersed in the hydrogel to prevent agglomeration. The high-speed homogenization can effectively break large particles and form small and evenly distributed particles, ensuring that the bacterial powder and linseed oil can be evenly wrapped in the subsequent microcapsule production process, thereby improving the quality and performance of the microcapsules. When dropped into the calcium acetate solution, the carboxyl groups in the modified sodium alginate react with the calcium ions in the calcium acetate to form a stable microcapsule shell. The secondary cross-linking can further enhance the strength and stability of the microcapsule shell, so that the microcapsules can better protect the bacterial powder and linseed oil inside. S4 freeze-drying and packaging: freeze-dry the obtained bacteria-containing microcapsules for 36-40 hours, take them out and package them.

[0007] Preferably, the bacterial powder comprises Lactobacillus acidophilus, Lactobacillus paracasei, Clostridium butyricum and Bifidobacterium adolescentis powder, and the mass ratio of the Lactobacillus acidophilus, Lactobacillus paracasei, Clostridium butyricum and Bifidobacterium adolescentis powder is 1:(1-2):(1-2):3.

[0008] Preferably, the diameter of the bacterial powder particles is 35-45 microns; the activity of the bacterial powder is 250-300 billion / g.

[0009] Preferably, the mass ratio of the modified sodium alginate, gelatin and purified water is (8-10):(8-10):800.

[0010] Preferably, the ratio of bacterial powder to linseed oil is (12-15) g: (20-25) mL, wherein the mass ratio of bacterial powder to modified sodium alginate is (12-15): (8-10).

[0011] Preferably, the mass fraction of the calcium acetate solution is 2%.

[0012] Preferably, the modified sodium alginate is prepared by the following method: S1-1: Mix sodium alginate, triethylamine and deionized water, stir evenly at room temperature, and adjust the pH value to 8-9; S1-2: add a mixture of octenyl succinic anhydride and 1,2-propylene glycol dropwise, keep the temperature constant, continue stirring for 4-6 hours, and then adjust the pH value to 6.5-7; S1-3: Wash with deionized water until neutral, dry and then crush to obtain modified sodium alginate.

[0013] Preferably, the mass ratio of the sodium alginate, triethylamine and deionized water is (8-11):(0.5-1):50.

[0014] Preferably, the mass ratio of octenyl succinic anhydride to 1,2-propylene glycol is (1-3):65.

[0015] The invention discloses a microcapsule prepared by adopting a microcapsule preparation process.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. For the microcapsules containing bacterial powder, the stable shell of the present invention can better protect the activity of the bacterial powder. The modified sodium alginate can prevent the influence of external factors (such as oxygen, moisture, etc.) on the bacterial powder by enhancing the sealing and stability of the microcapsules, ensuring that the bacterial powder can maintain a high activity during storage and use, so as to better play its function. In the cross-linking step of microcapsule production, the active groups such as carboxyl in the modified sodium alginate can undergo ionic cross-linking reaction with calcium ions in calcium acetate. Since new functional groups have been connected to the molecular chain of the modified sodium alginate, the site and activity of its cross-linking reaction are changed, resulting in more sufficient and more uniform cross-linking, thereby making the shell of the microcapsule stronger and more stable, improving the quality and performance of the microcapsules, and extending the shelf life of the microcapsules.

[0017] 2. Octenyl succinic anhydride contains carbon-carbon double bonds and anhydride functional groups in the present invention. The introduction of these functional groups changes the chemical structure of sodium alginate. The anhydride groups can react with the hydroxyl groups on the sodium alginate molecules, so that the sodium alginate molecular chains are connected with side chains with different chemical properties. This structural change makes the modified sodium alginate have better hydrophobicity, wherein the carbon-carbon double bonds can increase the flexibility of the molecular chains, and also provide reaction sites for further chemical modification. Due to the structural changes of the modified sodium alginate, it can interact better with gelatin, and its enhanced hydrophobicity and suitable dispersibility help to form a more stable gel network. This stable gel network can better wrap bacterial powder and linseed oil, and in the subsequent microcapsule preparation process, it can effectively prevent the leakage of internal substances. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Unless otherwise specified, the raw materials used in the present invention are all conventional products purchased from the market.

[0020] Sodium alginate was purchased from Aladdin, CAS number: 9005-38-3; Gelatin was purchased from Jiangsu Chengfeiyuan Biotechnology Co., Ltd., with the catalog number AL-645810294993; Flaxseed oil was purchased from Xi’an Tianhe Pharmaceutical Co., Ltd., with the product number TH-EEERW; Calcium acetate was purchased from Shandong Fushun New Material Technology Co., Ltd., CAS No.: 62-54-4; Lactobacillus acidophilus and Lactobacillus paracasei were purchased from Xi'an Tianhe Pharmaceutical Co., Ltd., with the product number TH-FDFGG; Clostridium butyricum was purchased from Henan Xinyangshao Bioenzyme Preparation Co., Ltd., model number is xyssw-1253; Bifidobacterium adolescentis powder was purchased from Xi'an Dongchi Biotechnology Co., Ltd., with the product number DC21080221; Octenyl succinic anhydride was purchased from Handan Huajun Chemical Co., Ltd., CAS No. 26680-54-6; 1,2-Propanediol was purchased from Aladdin, CAS No.: 57-55-6.

[0021] Preparation Example 1 The modified sodium alginate is prepared by the following method: S1-1: Mix 8 g of sodium alginate, 0.5 g of triethylamine and 50 g of deionized water, stir evenly at room temperature, and adjust the pH value to 8; S1-2: dropwise add a mixture of 1 g of octenylsuccinic anhydride and 65 g of 1,2-propylene glycol, keep the temperature constant, continue stirring for 4 h, and then adjust the pH value to 6.5; S1-3: Wash with deionized water until neutral, dry and then crush to obtain modified sodium alginate.

[0022] Preparation Example 2 The modified sodium alginate is prepared by the following method: S1-1: Mix 10 g of sodium alginate, 0.8 g of triethylamine and 50 g of deionized water, stir evenly at room temperature, and adjust the pH value to 8; S1-2: dropwise add a mixture of 2 g of octenylsuccinic anhydride and 65 g of 1,2-propylene glycol, keep the temperature constant, continue stirring for 4 h, and then adjust the pH value to 6.5; S1-3: Wash with deionized water until neutral, dry and then crush to obtain modified sodium alginate.

[0023] Preparation Example 3 The modified sodium alginate is prepared by the following method: S1-1: Mix 11 g of sodium alginate, 1 g of triethylamine and 50 g of deionized water, stir evenly at room temperature, and adjust the pH value to 8; S1-2: dropwise add a mixture of 3 g of octenylsuccinic anhydride and 65 g of 1,2-propylene glycol, keep the temperature constant, continue stirring for 4 h, and then adjust the pH value to 6.5; S1-3: Wash with deionized water until neutral, dry and then crush to obtain modified sodium alginate.

[0024] Example 1 A process for preparing microcapsules comprises the following steps: S1 hydrogel preparation: 8 g of modified sodium alginate prepared in Preparation Example 1, 8 g of gelatin, and 800 g of purified water were dissolved in a water bath at 60°C for 1 h, the water bath was turned off for heating, and the mixture was cooled to room temperature under ultraviolet light to form a hydrogel; S2 Preparation of bacterial gelatin solution: 12 g bacterial powder and 20 mL linseed oil were added to the hydrogel, and homogenized at 4000 r / min for 5 min using a homogenizer, and stirred evenly to obtain a bacterial gelatin solution; wherein the bacterial powder particle diameter was 35 μm; and the bacterial powder activity was 250 billion / g; S3 microcapsule preparation: sterilize the syringe and needle, place 200mL of 2% calcium acetate solution under ultraviolet light for 15min, then draw the bacterial gel solution, extrude it at a speed of 390mL / h, the extrusion height is 8cm, and drip it into the calcium acetate solution for cross-linking. After the bacterial gel solution dripping is completed, take out the microcapsules, filter them, place them in the calcium acetate solution for further cross-linking for 25min, and then take them out to obtain bacteria-containing microcapsules; S4 freeze-drying and packaging: freeze-dry the obtained bacteria-containing microcapsules for 36 hours, take them out and package them.

[0025] The bacterial powder comprises lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder, and the mass ratio of the lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder is 1:1:1:3.

[0026] Example 2 A process for preparing microcapsules comprises the following steps: S1 hydrogel preparation: 9 g of modified sodium alginate prepared in Preparation Example 2, 9 g of gelatin, and 800 g of purified water were dissolved in a water bath at 65°C for 3 h, the water bath was turned off for heating, and the mixture was cooled to room temperature under ultraviolet light to form a hydrogel; S2 Preparation of bacterial gel solution: 13g bacterial powder and 22mL linseed oil were added to the hydrogel, and homogenized at 4200r / min for 5min using a homogenizer, and stirred evenly to obtain a bacterial gel solution; wherein the diameter of the bacterial powder particles was 40 microns; and the activity of the bacterial powder was 280 billion / g; S3 microcapsule preparation: sterilize the syringe and needle, place 200mL of 2% calcium acetate solution under ultraviolet light for 17min, then draw the bacterial gel solution, extrude it at a speed of 400mL / h, the extrusion height is 10cm, and drip it into the calcium acetate solution for cross-linking. After the bacterial gel solution dripping is completed, take out the microcapsules, filter them, place them in the calcium acetate solution for further cross-linking for 30min, and then take them out to obtain bacteria-containing microcapsules; S4 freeze-drying and packaging: freeze-dry the obtained bacteria-containing microcapsules for 38 hours, take them out and package them.

[0027] The bacterial powder comprises lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder, and the mass ratio of the lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder is 1:1.5:1.5:3.

[0028] Example 3 A process for preparing microcapsules comprises the following steps: S1 hydrogel preparation: 10 g of modified sodium alginate prepared in Preparation Example 3, 10 g of gelatin, and 800 g of purified water were dissolved in a water bath at 65°C for 3 h, the water bath was turned off for heating, and the mixture was cooled to room temperature under ultraviolet light to form a hydrogel; S2 Preparation of bacterial gelatin solution: 15 g bacterial powder and 25 mL linseed oil were added to the hydrogel, and homogenized at 4500 r / min for 10 min using a homogenizer, and stirred evenly to obtain a bacterial gelatin solution; wherein the bacterial powder particle diameter was 45 μm; and the bacterial powder activity was 280 billion / g; S3 microcapsule preparation: sterilize the syringe and needle, place 200mL of 2% calcium acetate solution under ultraviolet light for 20min, then draw the bacterial gel solution, extrude it at a speed of 410mL / h, the extrusion height is 12cm, and drip it into the calcium acetate solution for cross-linking. After the bacterial gel solution dripping is completed, take out the microcapsules, filter them, place them in the calcium acetate solution for further cross-linking for 35min, and then take them out to obtain bacteria-containing microcapsules; S4 freeze-drying and packaging: freeze-dry the obtained bacteria-containing microcapsules for 38 hours, take them out and package them.

[0029] The bacterial powder comprises lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder, and the mass ratio of the lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder is 1:2:2:3.

[0030] Example 4 A process for preparing microcapsules comprises the following steps: S1 hydrogel preparation: 8 g of modified sodium alginate prepared in Preparation Example 2, 8 g of gelatin, and 800 g of purified water were dissolved in a water bath at 60°C for 1 h, the water bath was turned off for heating, and the mixture was cooled to room temperature under ultraviolet light to form a hydrogel; S2 Preparation of bacterial gelatin solution: 12 g bacterial powder and 20 mL linseed oil were added to the hydrogel, and homogenized at 4000 r / min for 5 min using a homogenizer, and stirred evenly to obtain a bacterial gelatin solution; wherein the bacterial powder particle diameter was 35 μm; and the bacterial powder activity was 250 billion / g; S3 microcapsule preparation: sterilize the syringe and needle, place 200mL of 2% calcium acetate solution under ultraviolet light for 15min, then draw the bacterial gel solution, extrude it at a speed of 390mL / h, the extrusion height is 8cm, and drip it into the calcium acetate solution for cross-linking. After the bacterial gel solution dripping is completed, take out the microcapsules, filter them, place them in the calcium acetate solution for further cross-linking for 25min, and then take them out to obtain bacteria-containing microcapsules; S4 freeze-drying and packaging: freeze-dry the obtained bacteria-containing microcapsules for 36 hours, take them out and package them.

[0031] The bacterial powder comprises lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder, and the mass ratio of the lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder is 1:1:1:3.

[0032] Example 5 A process for preparing microcapsules comprises the following steps: S1 hydrogel preparation: 8 g of modified sodium alginate prepared in Preparation Example 3, 8 g of gelatin, and 800 g of purified water were dissolved in a water bath at 60°C for 1 h, the water bath was turned off for heating, and the mixture was cooled to room temperature under ultraviolet light to form a hydrogel; S2 Preparation of bacterial gelatin solution: 12 g bacterial powder and 20 mL linseed oil were added to the hydrogel, and homogenized at 4000 r / min for 5 min using a homogenizer, and stirred evenly to obtain a bacterial gelatin solution; wherein the bacterial powder particle diameter was 35 μm; and the bacterial powder activity was 250 billion / g; S3 microcapsule preparation: sterilize the syringe and needle, place 200mL of 2% calcium acetate solution under ultraviolet light for 15min, then draw the bacterial gel solution, extrude it at a speed of 390mL / h, the extrusion height is 8cm, and drip it into the calcium acetate solution for cross-linking. After the bacterial gel solution dripping is completed, take out the microcapsules, filter them, place them in the calcium acetate solution for further cross-linking for 25min, and then take them out to obtain bacteria-containing microcapsules; S4 freeze-drying and packaging: freeze-dry the obtained bacteria-containing microcapsules for 36 hours, take them out and package them.

[0033] The bacterial powder comprises lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder, and the mass ratio of the lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder is 1:1.5:1:3.

[0034] Example 6 A process for preparing microcapsules comprises the following steps: S1 hydrogel preparation: 9 g of modified sodium alginate prepared in Preparation Example 1, 9 g of gelatin, and 800 g of purified water were dissolved in a water bath at 65°C for 3 h, the water bath was turned off for heating, and the mixture was cooled to room temperature under ultraviolet light to form a hydrogel; S2 Preparation of bacterial gel solution: 13g bacterial powder and 22mL linseed oil were added to the hydrogel, and homogenized at 4200r / min for 5min using a homogenizer, and stirred evenly to obtain a bacterial gel solution; wherein the diameter of the bacterial powder particles was 40 microns; and the activity of the bacterial powder was 280 billion / g; S3 microcapsule preparation: sterilize the syringe and needle, place 200mL of 2% calcium acetate solution under ultraviolet light for 17min, then draw the bacterial gel solution, extrude it at a speed of 400mL / h, the extrusion height is 10cm, and drip it into the calcium acetate solution for cross-linking. After the bacterial gel solution dripping is completed, take out the microcapsules, filter them, place them in the calcium acetate solution for further cross-linking for 30min, and then take them out to obtain bacteria-containing microcapsules; S4 freeze-drying and packaging: freeze-dry the obtained bacteria-containing microcapsules for 38 hours, take them out and package them.

[0035] The bacterial powder comprises lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder, and the mass ratio of the lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder is 1:1.5:1.5:3.

[0036] Example 7 A process for preparing microcapsules comprises the following steps: S1 hydrogel preparation: 9 g of modified sodium alginate prepared in Preparation Example 3, 9 g of gelatin, and 800 g of purified water were dissolved in a water bath at 65°C for 3 h, the water bath was turned off for heating, and the mixture was cooled to room temperature under ultraviolet light to form a hydrogel; S2 Preparation of bacterial gel solution: 13g bacterial powder and 22mL linseed oil were added to the hydrogel, and homogenized at 4200r / min for 5min using a homogenizer, and stirred evenly to obtain a bacterial gel solution; wherein the diameter of the bacterial powder particles was 40 microns; and the activity of the bacterial powder was 280 billion / g; S3 microcapsule preparation: sterilize the syringe and needle, place 200mL of 2% calcium acetate solution under ultraviolet light for 17min, then draw the bacterial gel solution, extrude it at a speed of 400mL / h, the extrusion height is 10cm, and drip it into the calcium acetate solution for cross-linking. After the bacterial gel solution dripping is completed, take out the microcapsules, filter them, place them in the calcium acetate solution for further cross-linking for 30min, and then take them out to obtain bacteria-containing microcapsules; S4 freeze-drying and packaging: freeze-dry the obtained bacteria-containing microcapsules for 38 hours, take them out and package them.

[0037] The bacterial powder comprises lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder, and the mass ratio of the lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder is 1:1:1.5:3.

[0038] Example 8 A process for preparing microcapsules comprises the following steps: S1 hydrogel preparation: 10 g of modified sodium alginate prepared in Preparation Example 1, 10 g of gelatin, and 800 g of purified water were dissolved in a water bath at 65°C for 3 h, the water bath was turned off for heating, and the mixture was cooled to room temperature under ultraviolet light to form a hydrogel; S2 Preparation of bacterial gelatin solution: 15 g bacterial powder and 25 mL linseed oil were added to the hydrogel, and homogenized at 4500 r / min for 10 min using a homogenizer, and stirred evenly to obtain a bacterial gelatin solution; wherein the bacterial powder particle diameter was 45 μm; and the bacterial powder activity was 280 billion / g; S3 microcapsule preparation: sterilize the syringe and needle, place 200mL of 2% calcium acetate solution under ultraviolet light for 20min, then draw the bacterial gel solution, extrude it at a speed of 410mL / h, the extrusion height is 12cm, and drip it into the calcium acetate solution for cross-linking. After the bacterial gel solution dripping is completed, take out the microcapsules, filter them, place them in the calcium acetate solution for further cross-linking for 35min, and then take them out to obtain bacteria-containing microcapsules; S4 freeze-drying and packaging: freeze-dry the obtained bacteria-containing microcapsules for 38 hours, take them out and package them.

[0039] The bacterial powder comprises lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder, and the mass ratio of the lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder is 1:2:1.5:3.

[0040] Example 9 A process for preparing microcapsules comprises the following steps: S1 hydrogel preparation: 10 g of modified sodium alginate prepared in Preparation Example 2, 10 g of gelatin, and 800 g of purified water were dissolved in a water bath at 60°C for 2 h, the water bath was turned off for heating, and the mixture was cooled to room temperature under ultraviolet light to form a hydrogel; S2 Preparation of bacterial gelatin solution: 15 g bacterial powder and 25 mL linseed oil were added to the hydrogel, and homogenized at 4200 r / min for 8 min using a homogenizer, and stirred evenly to obtain a bacterial gelatin solution; wherein the bacterial powder particle diameter was 45 μm; and the bacterial powder activity was 280 billion / g; S3 microcapsule preparation: sterilize the syringe and needle, place 200mL of 2% calcium acetate solution under ultraviolet light for 20min, then draw the bacterial gel solution, extrude it at a speed of 410mL / h, the extrusion height is 12cm, and drip it into the calcium acetate solution for cross-linking. After the bacterial gel solution dripping is completed, take out the microcapsules, filter them, place them in the calcium acetate solution for further cross-linking for 35min, and then take them out to obtain bacteria-containing microcapsules; S4 freeze-drying and packaging: freeze-dry the obtained bacteria-containing microcapsules for 36 hours, take them out and package them.

[0041] The bacterial powder comprises lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder, and the mass ratio of the lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder is 1:1.5:2:3.

[0042] Comparative Example 1 The difference between this comparative example and Example 1 is that the modified sodium alginate in Preparation Example 1 is replaced by common commercially available sodium alginate purchased from Aladdin, CAS No.: 9005-38-3.

[0043] Comparative Example 2 The difference between this comparative example and Example 1 is that in the preparation process of the modified sodium alginate in Preparation Example 1, octenyl succinic anhydride is not added.

[0044] Comparative Example 3 The difference between this comparative example and Example 1 is that the bacterial powder is Lactobacillus acidophilus.

[0045] Comparative Example 4 The difference between this comparative example and Example 1 is that the bacterial powder is Lactobacillus paracasei.

[0046] Comparative Example 5 The difference between this comparative example and Example 1 is that the bacterial powder is Clostridium butyricum.

[0047] Comparative Example 6 The difference between this comparative example and Example 1 is that the bacterial powder is Bifidobacterium adolescentis bacterial powder.

[0048] The performance tests of Examples 1-9 and Comparative Examples 1-6 were performed, and the results are shown in Table 1: Microcapsule mechanical property test: Place the microcapsule on an analytical balance and gradually pressurize its front side with appropriate weights until it breaks. The pressure displayed on the balance changes from small to large and then suddenly decreases. Record the maximum front pressure at this time, which is the mechanical strength of the microcapsule. Randomly test 20 microcapsules and take the average value. The samples were stored at room temperature for 6 months, and the live bacteria test was carried out according to the standard of GB4789.35 National Food Safety Standard Food Microbiology Test Lactic Acid Bacteria Test, and the value obtained was the live bacteria count. Survival rate: Survival rate (%) = 100% × live bacteria count (cfu / g) / actual bacterial load (cfu / g).

[0049] Table 1 The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A process for preparing microcapsules, characterized in that: The following steps are involved: S1 hydrogel preparation: Dissolve the modified sodium alginate, gelatin and purified water in a water bath at 60-65°C for 1-3 hours with stirring, turn off the water bath heating, and cool to room temperature under ultraviolet light to form a hydrogel; S2 Preparation of bacterial gelatin solution: Add bacterial powder and linseed oil to the hydrogel, use a homogenizer, homogenize at 4000-5000r / min for 5-10min, stir evenly, and obtain a bacterial gelatin solution; S3 microcapsule preparation: sterilize the syringe and needle, place the calcium acetate solution under ultraviolet light for 15-20 minutes, then draw the bacterial gel solution, extrude it at a speed of 390-410mL / h, the extrusion height is 8-12cm, and drip it into the calcium acetate solution for cross-linking. After the bacterial gel solution dripping is completed, take out the microcapsules, filter them, place them in the calcium acetate solution for further cross-linking for 25-35 minutes, and then take them out to obtain bacteria-containing microcapsules; S4 freeze-drying and packaging: freeze-dry the obtained bacteria-containing microcapsules for 36-40 hours, take them out and package them.

2. A process for preparing microcapsules according to claim 1, characterized in that: The bacterial powder comprises lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder, and the mass ratio of the lactobacillus acidophilus, lactobacillus paracasei, clostridium butyricum and bifidobacterium adolescentis bacterial powder is 1:(1-2):(1-2):

3.

3. A process for preparing microcapsules according to claim 2, characterized in that: The diameter of the bacterial powder particles is 35-45 microns; the activity of the bacterial powder is 250-300 billion / g.

4. The process for preparing microcapsules according to claim 1, characterized in that: The mass ratio of the modified sodium alginate, gelatin and purified water is (8-10):(8-10):

800.

5. The process for preparing microcapsules according to claim 1, characterized in that: The ratio of the bacterial powder to the linseed oil is (12-15) g: (20-25) mL, wherein the mass ratio of the bacterial powder to the modified sodium alginate is (12-15): (8-10).

6. The process for preparing microcapsules according to claim 1, characterized in that: The mass fraction of the calcium acetate solution is 2%.

7. The process for preparing microcapsules according to claim 1, characterized in that: The modified sodium alginate is prepared by the following method: S1-1: Mix sodium alginate, triethylamine and deionized water, stir evenly at room temperature, and adjust the pH value to 8-9; S1-2: add a mixture of octenyl succinic anhydride and 1,2-propylene glycol dropwise, keep the temperature constant, continue stirring for 4-6 hours, and then adjust the pH value to 6.5-7; S1-3: Wash with deionized water until neutral, dry and then crush to obtain modified sodium alginate.

8. A process for preparing microcapsules according to claim 7, characterized in that: The mass ratio of the sodium alginate, triethylamine and deionized water is (8-11):(0.5-1):

50.

9. The process for preparing microcapsules according to claim 7, characterized in that: The mass ratio of the octenyl succinic anhydride to 1,2-propylene glycol is (1-3):

65.

10. A microcapsule prepared by the process for preparing microcapsules according to any one of claims 1 to 9.

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