Preparation process of freeze-drying protective agent concentrated solution

Abstract

The invention relates to the field of food science and technology, in particular to a preparation process of a freeze-drying protective agent concentrated solution, which improves the moisture control ability, activity retention rate and oxidation resistance of a freeze-dried product by optimizing the component proportion and introducing an advanced processing method. The preparation process comprises the following steps: dissolving the oligosaccharide, the natural polysaccharide, the glycerol, the polyhydric alcohols and other components under the temperature control condition of 40-50 DEG C; an antioxidant and a surfactant are added, and bubbles are removed through ultrasonic treatment; the protection effect is further improved by introducing the nano packaging material; and performing vacuum degassing, filtering treatment, multi-stage freezing and low-temperature vacuum drying to finally prepare a freeze-dried product of which the moisture content is lower than 1%. The product disclosed by the invention has excellent solubility and storage stability, the retention rate of the active ingredients can reach 85% or above after the active ingredients are stored for 6 months, and the product is suitable for the fields of biological medicines, food preservation and cosmetics.

Description

Technical Field

[0001] The invention relates to the field of food science and technology, and in particular to a preparation process of a freeze-dried protective agent concentrate. Background Art

[0002] With the development of industries such as biomedicine, food preservation and biological products, more and more bioactive substances need to maintain their activity and stability during long-term storage. Traditional protective agents are usually in liquid or powder form, but such protective agents are easily affected by the environment during storage, such as temperature, humidity, light, etc., which leads to decreased stability and reduced biological activity. Therefore, how to effectively protect these active substances, especially to prevent them from failing over a long period of time, has become an important issue in the current technical field.

[0003] Lyophilization is widely used in the preservation of biological products because it can extend the storage time of products by removing moisture and effectively reduce the degradation of active substances. However, the freeze-drying process itself cannot completely avoid the inactivation of active substances during drying or storage. Since large ice crystals may form or microstructural damage may occur during the freeze-drying process, many active substances may still lose their activity after freeze-drying. In addition, the moisture control of freeze-dried products is also very critical. If the moisture content is too high, the product is prone to moisture absorption during storage, resulting in degradation of active ingredients.

[0004] In the prior art, in order to improve the stability and activity retention rate of freeze-dried products, various protective agents are usually used to protect the active ingredients. However, the existing freeze-dried protective agent formulations often have the following problems:

[0005] Insufficient control of moisture content: The existing protective agent formula still has a high moisture content after freeze-drying, which causes the product to easily absorb moisture during long-term storage and the stability of the active ingredients cannot be guaranteed.

[0006] Low activity retention rate: Certain protective agents do not protect the active ingredients well during the freeze-drying process, resulting in a significant decrease in the biological activity of the product after freeze-drying and during storage.

[0007] Poor solubility: Some protective agents have poor solubility during the rehydration process and take a long time to dissolve, which affects the actual use efficiency.

[0008] Weak antioxidant properties: Some active substances are susceptible to oxidation during freeze-drying and storage, resulting in degradation of the active ingredients, so it is necessary to further improve the antioxidant capacity of the protective agent.

[0009] In order to overcome these problems, researchers have been committed to developing new freeze-drying protective agents in recent years, hoping to improve the moisture control, activity retention and antioxidant properties of freeze-dried products by optimizing the formula and improving the preparation process. In particular, through the introduction of nanotechnology, combined with a variety of bioactive materials and antioxidants, attempts are made to protect active ingredients through more efficient encapsulation methods, while reducing the damage to the structure caused by ice crystals during the freeze-drying process, thereby improving the stability and biological activity of the product.

[0010] In view of the above-mentioned deficiencies in the prior art, the present invention proposes a new preparation process for freeze-dried protective agent concentrate. Through scientific formula design and optimized freeze-drying process, the process significantly improves the moisture control and biological activity retention rate of freeze-dried products, improves solubility and antioxidant properties, and is suitable for the high-demand biomedicine and biological product fields. Summary of the invention

[0011] The purpose of the present invention is to provide a novel freeze-drying protective agent concentrate and a preparation process thereof, which can effectively prolong the storage time of biologically active substances and ensure their stability and activity retention rate during freeze-drying and storage, thereby being suitable for the fields of biomedicine, food preservation, etc.

[0012] Technical solution: The present invention optimizes the formula and improves the preparation process. The specific solution includes:

[0013] Formula design: A combination of oligosaccharides, natural polysaccharides, glycerol, polyols, antioxidants, surfactants, modified polysaccharides and nano-encapsulation materials is used with scientific and reasonable proportions to ensure moisture control of freeze-dried products and effective protection of active ingredients.

[0014] Solution preparation: Dissolve the components under temperature control conditions, use ultrasonic and high shear homogenization methods to ensure uniform solution, remove bubbles and improve product quality.

[0015] Freeze-drying process: Optimize freezing and freeze-drying parameters, use multi-stage freezing and low-temperature vacuum drying to reduce the damage of ice crystals to active ingredients and ensure that the moisture content is less than 1%.

[0016] Nano-encapsulation: Introducing nano-materials such as chitosan nanoparticles to further improve the stability and bioactivity retention rate of active ingredients through embedding and protection.

[0017] Beneficial effects of the present invention:

[0018] 1. The moisture content of the product after freeze-drying does not exceed 0.5%, and it still maintains good stability after storage for 6 months. During freeze-drying and storage, the biological activity retention rate reaches more than 85%, which is significantly better than existing products. The dissolution time in 200 mL of water at room temperature is controlled within 60 seconds, which improves the actual use efficiency, has excellent antioxidant performance, ensures the protection of the active ingredients of the product during storage, and extends the shelf life of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 Schematic diagram of the preparation process of an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments.

[0022] Embodiment 1:

[0023] Preparation process of standard lyophilized protective agent concentrate

[0024] 1. Raw material ratio:

[0025] Oligosaccharides (maltooligosaccharides): 15%

[0026] Natural polysaccharide (trehalose): 12%

[0027] Glycerin: 8%

[0028] Polyol (mannitol): 5%

[0029] Antioxidants (vitamin C, E): 0.5%

[0030] Surfactant (lecithin): 0.2%

[0031] Modified polysaccharide (chitosan): 10%

[0032] Water-based nano-encapsulation material (chitosan nanoparticles): 3%

[0033] Pure water: Remaining to 100%

[0034] 2. Solution preparation and homogenization:

[0035] Oligosaccharides and natural polysaccharides were dissolved in pure water at 40°C, followed by the addition of glycerol and polyols, and continued stirring to ensure uniformity. Antioxidants and surfactants were added, and bubbles were removed by ultrasonic treatment (40kHz, 10 minutes), followed by the addition of chitosan nanoparticles, and treatment with a high shear homogenizer (10000rpm, 20 minutes) to form a uniform solution.

[0036] 3. Vacuum degassing and filtration:

[0037] The solution was degassed at -0.08 MPa for 30 minutes and then filtered through a 0.22 μm filter membrane.

[0038] 4. Freezing and freeze-drying:

[0039] The solution was placed in a freezing tray and gradually cooled to -40°C. The freeze-drying process included: primary drying at -40°C and 50 Pa for 12 hours, and secondary drying at +20°C and 20 Pa for 6 hours. The moisture content of the final product was less than 1%.

[0040] 5. Post-processing:

[0041] After freeze-drying, nitrogen is used for replacement and double-layer vacuum-sealed packaging. The product has good stability and is suitable for long-term storage of biological products.

[0042] Example 2: Preparation process of plant extract freeze-dried protective agent

[0043] 1. Raw material ratio:

[0044] Oligosaccharides (isomalto-oligosaccharides): 10%

[0045] Plant polysaccharides (Ginkgo biloba extract): 5%

[0046] Glycerin: 6%

[0047] Polyol (sorbitol): 7%

[0048] Antioxidants (Tea Polyphenols): 1%

[0049] Surfactant (vegetable lecithin): 0.1%

[0050] Modified polysaccharide (sodium alginate): 8%

[0051] Nano-encapsulation material (sodium alginate nanoparticles): 4%

[0052] Pure water: Remaining to 100%

[0053] 2. Solution preparation:

[0054] Oligosaccharides and plant extract polysaccharides were dissolved in pure water at 30°C, glycerol and polyol were added, and magnetic stirring was used. Antioxidants and surfactants were added, and ultrasonic treatment (60kHz, 5 minutes) was used to ensure that the ingredients were evenly dispersed.

[0055] 3. Freezing and freeze-drying:

[0056] The solution was cooled to -30°C in a freezing tray and frozen for 12 hours. The freeze-drying stage was carried out at -30°C, 40 Pa for primary drying for 10 hours, and then at +15°C, 15 Pa for secondary drying for 5 hours. The moisture content of the final product was 0.5%.

[0057] 4. Post-processing:

[0058] After freeze-drying, it is packaged in an argon environment and double-wrapped with antioxidant materials. It is particularly suitable for preparations containing plant active ingredients, extending the shelf life and improving the stability of active substances.

[0059] Example 3: Preparation process of medical biologically active lyophilized protective agent

[0060] 1. Raw material ratio:

[0061] Oligosaccharides (glucose): 18%

[0062] Natural polysaccharide (sodium hyaluronate): 10%

[0063] Glycerin: 5%

[0064] Polyol (mannitol): 6%

[0065] Antioxidant (glutathione): 2%

[0066] Surfactant (PEG-400): 0.3%

[0067] Modified polysaccharide (chitosan): 12%

[0068] Nano-encapsulation material (hyaluronic acid nanoparticles): 5%

[0069] Pure water: Remaining to 100%

[0070] 2. Solution preparation and homogenization:

[0071] Oligosaccharides and natural polysaccharides were dissolved in pure water at 45°C, and glycerol and polyol were added in sequence, with the stirring speed maintained at 300 rpm. Antioxidants and surfactants were added, and ultrasonic treatment (50 kHz, 10 minutes) was performed, followed by the addition of chitosan and nanoparticles, and treatment was performed using a high shear homogenizer (12000 rpm, 15 minutes) to ensure a uniform solution.

[0072] 3. Vacuum degassing and filtration:

[0073] The degassing process was carried out at -0.09 MPa for 40 minutes, followed by filtration using a 0.22 μm filter membrane.

[0074] 4. Freezing and freeze-drying:

[0075] The solution was cooled to -50°C in a freezing tray and frozen for 24 hours. The freeze-drying stage was carried out at -50°C, 60Pa for 14 hours, and then at +20°C, 20Pa for 8 hours. The moisture content of the final product was controlled at 0.3%.

[0076] 5. Post-processing:

[0077] Protective packaging using a helium environment followed by sterile vacuum double packaging. This process is particularly suitable for freeze-dried protection of biologics and drugs, ensuring the stability and long-term storage of bioactive ingredients.

[0078] These three embodiments respectively demonstrate the preparation process of freeze-dried protective agent concentrate suitable for different application scenarios, with different formulas and optimization steps to ensure its performance and stability in different fields.

[0079] The following are various experimental data designed based on three embodiments by adopting China's national testing standards to verify the superior properties of the product and ultimately select the best solution and its advantages.

[0080] Experimental design

[0081] In order to evaluate the superior properties of the lyophilized protective agent concentrates of the three embodiments, the following key properties were tested:

[0082] 1. Moisture content: Tested according to the method specified in GB / T 6284-2006.

[0083] 2. Dissolution rate: Use the dissolution rate determination method specified in GB / T 6678-2003.

[0084] 3. Stability test: GB / T 6682-2008 is used to conduct room temperature, accelerated aging, and freeze-thaw cycle tests to test the stability of the product under different temperatures and humidity.

[0085] 4. Bioactivity retention: Use HPLC (high performance liquid chromatography) or specific bioactive ingredient content test to evaluate the retention of active substances during freeze-drying and storage.

[0086] 5. Antioxidant capacity: The antioxidant capacity determination method in GB / T 5009.5-2016 is adopted.

[0087] Experimental data

[0088] 1. Moisture content (%)

[0089]

[0090] 2. Dissolution rate (seconds)

[0091]

[0092] 3. Stability test

[0093] Normal temperature aging test (25°C, 60% humidity): measure the content of main components every 3 months Accelerated aging test (40°C, 75% humidity): measure the content of main components every 2 months

[0094] Freeze-thaw cycle test (-20℃ to 25℃, 12 hours per cycle): The changes in the content of the main components were measured in each cycle.

[0095]

[0096] 4. Bioactivity retention rate (%)

[0097]

[0098] 5. Antioxidant capacity (μmol TE / 100g)

[0099] Example Initial antioxidant capacity 3 months later (normal temperature) 6 months later (normal temperature) Example 1 50 45 40 Example 2 55 50 48 Example 3 60 58 55

[0100] This result analysis

[0101] Moisture content: Example 3 has the best moisture control, with a moisture content of 0.3% after freeze-drying and still maintained at 0.7% after 6 months, while the moisture content of Example 1 increases rapidly.

[0102] Dissolution rate: Example 3 has the fastest dissolution rate, and the dissolution time is shorter than that of other examples regardless of whether it is at room temperature or at low temperature.

[0103] Stability test: Example 3 performed best in room temperature and accelerated aging tests, with an activity retention rate of up to 85% after 6 months. It also showed good stability in the freeze-thaw cycle test, with an activity retention rate of more than 95%.

[0104] Biological activity retention rate: Example 3 has the best retention effect on biologically active ingredients after freeze-drying and during storage, showing obvious advantages.

[0105] Antioxidant capacity: Example 3 has the highest initial antioxidant capacity and still maintains a high antioxidant capacity after storage for 6 months, which is better than the other two examples.

[0106] in conclusion

[0107] According to the experimental data analysis, Example 3 exhibits the best overall performance and has the following advantages:

[0108] Excellent moisture control: The moisture content after freeze-drying is extremely low, which facilitates long-term storage and maintains good stability.

[0109] Fast dissolving: It dissolves quickly at room temperature and low temperature, making it easy to use.

[0110] Excellent biological activity retention: Even after long-term storage and freeze-thaw cycles, the biological activity can still be well maintained.

[0111] Strong antioxidant ability: The addition of antioxidants combined with nano-encapsulation technology effectively improves the antioxidant properties of the product.

[0112] Therefore, Example 3 is the best solution and is suitable for the high-demand biomedical field, especially for scenarios with strict requirements on product stability and biological activity.

[0113] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A process for preparing a freeze-dried protective agent concentrate, characterized in that: The following steps are involved: Prepare the protective agent solution according to the following weight percentage ratio: Oligosaccharides: 10% to 20%; Natural polysaccharides: 5% to 15%; Glycerin: 5% to 10%; Polyols: 5% to 10%; Antioxidants: 0.1% to 2%; Surfactant: 0.1% to 0.5%; Modified polysaccharides: 5% to 15%; Nano-encapsulation materials: 1% to 5%; Pure water: remaining to 100%; Dissolve oligosaccharides and natural polysaccharides in pure water at 40°C to 50°C, add glycerol and polyols in sequence, and stir evenly; adding an antioxidant and a surfactant, and performing ultrasonic treatment at a frequency of 40 kHz to 60 kHz for 5 to 10 minutes to promote uniform dispersion of the solution and remove bubbles; Add the nano-encapsulation material to the solution and process it using a high shear homogenizer at 10,000 to 12,000 rpm for 10 to 20 minutes to ensure that the nanoparticles are evenly dispersed; Degassing by vacuum (pressure of -0.08 MPa to -0.09 MPa) for 30 to 40 minutes, followed by filtration using a 0.22 μm filter membrane; Distribute the solution evenly in a freezing tray to a thickness of 5 to 7 mm and freeze as follows: First, cool down from room temperature to 0℃ and keep it for 30 minutes; Then reduce to -20°C and keep for 1 hour; Finally, it was lowered to -40°C and maintained for 2 hours; The frozen solution is freeze-dried, with the primary drying temperature at -40°C and the vacuum degree below 50Pa for 12 to 14 hours, and the secondary drying temperature at +20°C and the vacuum degree below 20Pa for 6 to 8 hours to ensure that the moisture content of the product is less than 1%.

2. A process for preparing a freeze-dried protective agent concentrate according to claim 1, characterized in that: The nano packaging material is chitosan nanoparticles or hyaluronic acid nanoparticles.

3. A process for preparing a freeze-dried protective agent concentrate according to claim 1, characterized in that: The antioxidant is at least one of vitamin C, vitamin E, tea polyphenols or glutathione.

4. The process for preparing a freeze-dried protective agent concentrate according to claim 1, characterized in that: Phase change material (ethylene glycol) is used to assist freezing during the freezing process to reduce the damage of ice crystals to the active ingredients.

5. A process for preparing a freeze-dried protective agent concentrate according to any one of claims 1 to 4, characterized in that: During the vacuum degassing process, the pressure was maintained between -0.08 MPa and -0.09 MPa, and ultrasonic treatment was used to remove bubbles in the solution to ensure the uniformity of the solution.

6. A freeze-dried protective agent concentrate according to any one of claims 1 to 5, characterized in that: The moisture content after freeze-drying does not exceed 0.5%, and after being stored at room temperature for 6 months, the active ingredient retention rate reaches more than 85%.

7. A freeze-dried protective agent concentrate according to claim 6, characterized in that: The protective agent has good solubility, and the dissolution time in 200 mL of water is within 60 seconds at room temperature.

8. A freeze-dried protective agent concentrate according to claim 6, characterized in that: The protective agent has strong antioxidant capacity, with an initial antioxidant capacity of 50 to 60 μmol TE / 100 g, and the antioxidant capacity remains not less than 55 μmol TE / 100 g after storage for 6 months.

9. A freeze-dried protective agent concentrate according to claim 6, characterized in that: The product is double-packaged, with the inner layer being a vacuum-sealed bag and the outer layer being sealed with moisture-proof material, and is stored in a nitrogen or argon environment to ensure its long-term stability.

Images