Preparation method of freeze-dried powder with homology of medicine and food based on low-temperature extraction of natural plants

Abstract

The invention is applied to the technical field of food processing, and discloses a preparation method of low-temperature extraction medicinal and edible freeze-dried powder based on natural plants, and the preparation method comprises the following steps: S1, raw material pretreatment, S2, ultralow-temperature pre-cooling, S3, high-voltage pulsed electric field treatment, S4, low-temperature extraction, S5, multi-stage filtration, S6, vacuum concentration, and S7, freeze drying. According to the preparation method of the natural plant-based low-temperature extracted medicinal and edible homologous freeze-dried powder, an ultralow-temperature pre-cooling technology is adopted, an extremely low-temperature environment is created for the natural plants, possible damage to active components in the natural plants caused by high temperature is prevented from the source, a high-voltage pulsed electric field treatment means is introduced, the permeability of cell membranes can be ingeniously and remarkably improved, and the content of the active components in the natural plants is increased. And when the barrier action of the cell membrane is weakened, the extraction process becomes more efficient, so that more active ingredients can be smoothly dissolved out, damage to the active ingredients in the processing process is avoided to the greatest extent, and complete retention of the active ingredients is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of food processing, and in particular to a method for preparing a natural plant-based low-temperature extracted edible and medicinal freeze-dried powder. Background Art

[0002] In today's society, people are paying more and more attention to health, and their requirements for food are no longer limited to satisfying their appetite, but they pay more attention to its nutritional and health benefits. The concept of medicine and food having the same origin has gradually gained popularity in this context. Natural plants, as an important source of medicine and food having the same origin, are highly favored because they are rich in various ingredients that are beneficial to the human body.

[0003] Natural plants contain rich biologically active substances, such as polysaccharides, flavonoids, alkaloids, vitamins, etc. These ingredients have various health benefits such as antioxidant, anti-inflammatory, antibacterial, and immune regulation. For example, wolfberry polysaccharides in wolfberry have the effects of enhancing immunity, protecting the liver, and anti-aging; red date polysaccharides in red dates can regulate blood sugar, improve anemia, and enhance the body's antioxidant capacity; mucus protein, diosgenin and other ingredients in yam have a positive regulatory effect on the digestive system, cardiovascular system, etc.; lily polysaccharides and colchicine in lily have the effects of moistening the lungs and relieving cough, clearing the heart and calming the nerves; hawthorn acid, flavonoids and other ingredients in hawthorn help digestion, lower blood lipids, and protect the cardiovascular system.

[0004] However, traditional natural plant extraction methods often have some shortcomings. Traditional extraction methods usually use high-temperature treatment. Although it can improve the extraction efficiency to a certain extent, high temperature will destroy the active ingredients in the plant, reduce its nutritional value and health benefits. High temperature may cause changes in the structure of components such as polysaccharides and proteins, thereby reducing their biological activity; at the same time, high temperature may also cause the decomposition of heat-sensitive components such as vitamins, resulting in the loss of nutrients. In addition, traditional extraction methods may also introduce some harmful substances. For example, some harmful substances may be produced under high temperatures, posing a potential threat to human health. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a lyophilized powder of medicinal and edible properties based on low-temperature extraction of natural plants, so as to solve the problem that the traditional processing method proposed in the above background technology destroys the active ingredients in the plants and reduces their nutritional value and health care effects.

[0006] To achieve the above object, the present invention provides the following technical solution: a method for preparing a lyophilized powder of medicinal and edible properties extracted at low temperature from natural plants, the preparation method comprising the following steps: S1. Raw material pretreatment: Select fresh, pest-free natural plants, process them appropriately according to different plants, and cut the processed raw materials into blocks or slices of appropriate size to increase the extraction area; S2, ultra-low temperature pre-cooling: put the cut raw materials into an ultra-low temperature refrigerator; S3, high-voltage pulse electric field treatment: the pre-cooled raw materials are placed in a high-voltage pulse electric field treatment device for treatment; S4, low temperature extraction: put the pre-cooled raw materials into the low temperature extraction equipment, add appropriate amount of distilled water and natural extractant, and use ultrasonic assisted extraction technology in the extraction process to accelerate the dissolution of active ingredients by using the cavitation effect and mechanical effect of ultrasound; S5, multi-stage filtration: the extract is first filtered through a coarse filter to remove larger impurities, then filtered through a microporous filter membrane to further remove tiny particles and impurities, and finally filtered through activated carbon to remove pigments and odors in the extract; S6. Vacuum concentration: placing the filtered extract into a vacuum concentration device and concentrating it at low temperature and low pressure until the extract is concentrated to 1 / 10 to 1 / 5 of its original volume; S7. Freeze drying: The concentrated extract is placed in a freeze dryer and freeze dried for a period of time to completely freeze it. The temperature is then gradually raised under negative pressure to sublime the frozen water to obtain a lyophilized powder of medicinal and edible properties.

[0007] Using the above technical solution, the temperature of the ultra-low temperature refrigerator in S2 is controlled at -80°C to -100°C, and the raw materials are pre-cooled in the ultra-low temperature refrigerator for 12 hours to 24 hours.

[0008] Using the above technical solution, the high voltage pulse electric field in S3 is set to have an electric field strength of 10 kV / cm to 30 kV / cm, a pulse frequency of 100 Hz to 500 Hz, and a raw material processing time of 5 min to 15 min.

[0009] Using the above technical solution, the natural extractant in S4 is one of lemon juice and apple cider vinegar, the extraction temperature is controlled at 30° C. to 45° C., and the extraction time is controlled at 2 h to 4 h.

[0010] Using the above technical solution, the ultrasonic power in S4 is set to 200W to 500W, and the extraction time is 30min to 60min.

[0011] By adopting the above technical solution, the pore size of the microporous filter membrane in S5 is 0.22 μm to 0.45 μm.

[0012] By adopting the above technical solution, the vacuum concentration temperature in S6 is 40°C to 50°C, and the vacuum degree is -0.08MPa to -0.1MPa.

[0013] By adopting the above technical solution, the freezing temperature of the extract in S7 is controlled at -40°C to -50°C, and the freezing time of the extract is controlled at 12h to 24h.

[0014] By adopting the above technical solution, the vacuum degree in S7 is controlled at -0.08MPa to -0.1MPa, and the temperature is controlled at 20°C to 30°C.

[0015] Compared with the prior art, the invention has the following beneficial effects: the method for preparing the lyophilized powder of medicine and food based on low-temperature extraction of natural plants: 1. In the preparation process, ultra-low temperature pre-cooling technology is first used to create an extremely low temperature environment for natural plants, preventing the damage of active ingredients in them caused by high temperature from the source. Then, high-voltage pulse electric field treatment is introduced. This innovative treatment method can cleverly increase the permeability of cell membranes. When the barrier effect of cell membranes is weakened, the extraction process becomes more efficient, so that more active ingredients can be dissolved smoothly. This perfect combination of ultra-low temperature pre-cooling, high-voltage pulse electric field treatment and low-temperature extraction avoids them from being damaged during the processing to the greatest extent, ensuring the complete retention of active ingredients. In addition, high-voltage pulsed electric fields can create instantaneous micropores or channels in the cell membrane of plant cells, increasing the permeability of the membrane. This increase in permeability is conducive to the infiltration of intracellular substances and the entry of external substances. When combined with ultra-low temperature treatment, the cell membrane will undergo certain changes under ultra-low temperature. The changes in the membrane structure formed before the high-voltage pulsed electric field treatment combined with the weakening of the barrier effect of the high-voltage pulsed electric field on the cell membrane will make the cells more susceptible to osmosis during the low-temperature extraction process, further enhancing the exchange of substances inside and outside the cells, which will help to extract the effective ingredients in the cells or perform other treatments.

[0016] 2. The preparation method can effectively retain various precious nutrients in natural plants during the whole process, such as vitamin C with antioxidant effects, carotene that is beneficial to eyesight, and iron, a trace element essential to the human body. At the same time, the clever use of natural extractants not only greatly improves the extraction efficiency, but also adds rich nutrients to the freeze-dried powder.

[0017] 3. After multiple stages of filtration, the impurities in the extract are removed layer by layer and become purer. The reduction of impurities greatly reduces the adverse effects on the solubility and stability of the freeze-dried powder. The subsequent vacuum concentration further improves the purity and concentration of the extract. The pure extract brings good solubility to the freeze-dried powder, allowing it to dissolve quickly in various solvents, making it convenient for people to use. At the same time, the improvement in stability also ensures that the freeze-dried powder can maintain its excellent quality during storage and transportation, and is not prone to deterioration or performance degradation. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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] The present invention provides a technical solution: a method for preparing lyophilized powder of medicinal and edible homology extracted at low temperature based on natural plants. Example 1

[0020] Preparation of Lycium barbarum freeze-dried powder Raw material pretreatment: Select fresh, pest-free wolfberries, wash and dry them, then cut them into small pieces.

[0021] Ultra-low temperature precooling: Put the cut wolfberries into an ultra-low temperature refrigerator and precool them at -90℃ for 18 hours.

[0022] High-voltage pulse electric field treatment: The pre-cooled wolfberry was placed in a high-voltage pulse electric field treatment device, and the electric field strength was set to 20 kV / cm, the pulse frequency to 300 Hz, and the treatment time to 10 minutes.

[0023] Low-temperature extraction: Place the processed wolfberry into a low-temperature extraction device, add appropriate amounts of distilled water and lemon juice, and extract at 35°C for 3 hours. Ultrasonic-assisted extraction is used during the extraction process, with an ultrasonic power of 300W and an extraction time of 45 minutes.

[0024] Multi-stage filtration: First, filter the extract through a coarse filter, then filter through a microporous filter membrane with a pore size of 0.3μm, and finally filter through activated carbon.

[0025] Vacuum concentration: Place the filtered extract into a vacuum concentration device and concentrate it to 1 / 8 of the volume of the extract at 45°C and a vacuum degree of -0.09MPa.

[0026] Freeze drying: Freeze the concentrated extract at -45°C for 18 hours, then gradually heat it to 25°C under a vacuum degree of -0.09MPa to sublimate the frozen water to obtain wolfberry freeze-dried powder.

[0027] Experimental data: The test showed that the content of wolfberry polysaccharide in the wolfberry freeze-dried powder was 4.1%, the content of carotene was 0.38mg / 100g, and the content of vitamin C was 55mg / 100g. Compared with the traditional high-temperature extraction method, the content of wolfberry polysaccharide increased by 25%, and the retention rate of nutrients was significantly improved. The wolfberry freeze-dried powder is rich in betaine, with a content of 0.5%; in addition, the content of flavonoids is 0.25mg / 100g; Antioxidant performance test: Through the DPPH free radical scavenging experiment, the free radical scavenging rate of the wolfberry freeze-dried powder reached 75%, which is significantly higher than the wolfberry products prepared by traditional extraction methods; Solubility test: At room temperature of 25°C, add 10g of Lycium barbarum freeze-dried powder into 100ml of distilled water, stir evenly, and it will completely dissolve within 5 minutes to form a uniform red solution without obvious precipitation and impurities; Stability test: After the wolfberry freeze-dried powder was placed at room temperature for 12 months, its main component content was tested again. The wolfberry polysaccharide content only decreased by 2%, the carotene content decreased by 1.5%, and the vitamin C content decreased by 5%, indicating that it has good stability. Example 2

[0028] Preparation of freeze-dried red date powder Raw material pretreatment: Select fresh, pest-free red dates, wash them, remove the core, and cut them into slices.

[0029] Ultra-low temperature precooling: Place the red date slices in an ultra-low temperature refrigerator and precool at -85°C for 20 hours.

[0030] High-voltage pulse electric field treatment: Place the pre-cooled red dates into a high-voltage pulse electric field treatment device, set the electric field strength to 25 kV / cm, the pulse frequency to 400 Hz, and the treatment time to 8 minutes.

[0031] Low-temperature extraction: Place the processed red dates into a low-temperature extraction device, add appropriate amounts of distilled water and apple cider vinegar, extract at 40°C for 2.5 hours, and perform ultrasonic-assisted extraction at the same time, with an ultrasonic power of 400W and an extraction time of 50 minutes.

[0032] Multi-stage filtration: The extract is filtered through a coarse filter, a microporous filter membrane (pore size 0.25 μm) and activated carbon in sequence.

[0033] Vacuum concentration: In a vacuum concentration device, concentrate the extract to 1 / 7 of the volume at 42°C and a vacuum degree of -0.085 MPa.

[0034] Freeze drying: first freeze the concentrated extract at -42°C for 20 hours, then heat it to 28°C under a vacuum degree of -0.09 MPa to sublime the water to obtain freeze-dried red date powder.

[0035] Experimental data: The red date freeze-dried powder has a red date polysaccharide content of 4.7%, a vitamin C content of 480 mg / 100 g, and an iron content of 6 mg / 100 g. Compared with the traditional method, the red date polysaccharide content is increased by 28%, and the nutritional components are richer. The content of cyclic adenosine monophosphate in the freeze-dried red date powder is 0.03 mg / 100 g, and the content of triterpenoids is 0.15%; Antioxidant performance test: Under the same experimental conditions, the scavenging rate of freeze-dried red dates powder on DPPH free radicals was 70%, and the scavenging rate on superoxide anion free radicals was 65%; Solubility test: 15g of freeze-dried red date powder was added to 150ml of warm water. It was completely dissolved within 3 minutes. The solution was dark red and had no granular feel. Stability test: After 12 months of storage at room temperature, the polysaccharide content of red dates decreased by 3%, the vitamin C content decreased by 8%, and the iron content remained basically unchanged, proving its good stability.

[0036] Example 3: Preparation of Chinese Yam Freeze-dried Powder Raw material pretreatment: Select fresh, pest-free yam, wash and peel it, and cut it into strips.

[0037] Ultra-low temperature precooling: Place the yam strips in an ultra-low temperature refrigerator and precool at -95°C for 16 hours.

[0038] High-voltage pulse electric field treatment: Place the pre-cooled yam into a high-voltage pulse electric field treatment device, set the electric field strength to 15 kV / cm, the pulse frequency to 250 Hz, and the treatment time to 12 minutes.

[0039] Low temperature extraction: put the processed yam into the low temperature extraction equipment, add an appropriate amount of distilled water, extract at 42℃ for 3.5 hours, during which ultrasonic assisted extraction is used, the ultrasonic power is 250W, and the extraction time is 55 minutes.

[0040] Multi-stage filtration: The extract is filtered through a coarse filter, a microporous filter membrane (pore size 0.4 μm) and activated carbon.

[0041] Vacuum concentration: In a vacuum concentration device, concentrate the extract to 1 / 6 of the volume at 48°C and a vacuum degree of -0.095 MPa.

[0042] Freeze drying: Freeze the concentrated extract at -48°C for 16 hours, then heat it to 22°C under a vacuum degree of -0.095 MPa to sublime the water to obtain yam freeze-dried powder.

[0043] Experimental data: The mucin content of the yam freeze-dried powder is 1.75%, and the vitamin C content is 26mg / 100g. Compared with the traditional method, the nutrient retention rate is increased by 30%, and the active ingredients are better retained; The allantoin content in the freeze-dried yam powder is 0.2%, and the diosgenin content is 0.3%; Antioxidant performance test: The scavenging rate of yam freeze-dried powder on hydroxyl free radicals is 60%, and the inhibition rate on lipid peroxidation is 55%; Solubility test: 12g of yam freeze-dried powder was added to 120ml of distilled water and dissolved completely within 4 minutes. The solution was milky white and uniform without precipitation. Stability test: After 12 months of storage, the mucin content decreased by 1.5% and the vitamin C content decreased by 4%, indicating that it has good stability.

[0044] The above specific embodiments further illustrate the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and do not limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention are included in the protection scope of the present invention.

Claims

1. A method for preparing a lyophilized powder of medicinal and edible properties extracted at low temperature from natural plants, characterized in that: The preparation method comprises the following steps: S1. Raw material pretreatment: Select fresh, pest-free natural plants, process them appropriately according to different plants, and cut the processed raw materials into blocks or slices of appropriate size to increase the extraction area; S2, ultra-low temperature precooling: the cut raw materials are placed in an ultra-low temperature refrigerator, the temperature of the ultra-low temperature refrigerator is controlled at -80°C to -100°C, and the raw materials are precooled in the ultra-low temperature refrigerator for 12 hours to 24 hours; S3, high-voltage pulse electric field treatment: the pre-cooled raw material is placed in a high-voltage pulse electric field treatment device for treatment; the high-voltage pulse electric field is set to have an electric field strength of 10 kV / cm to 30 kV / cm, a pulse frequency of 100 Hz to 500 Hz, and a raw material treatment time of 5 min to 15 min; S4, low temperature extraction: the pre-cooled raw materials are placed in a low temperature extraction device, and an appropriate amount of distilled water and a natural extractant are added. Ultrasonic assisted extraction technology is used in the extraction process to accelerate the dissolution of active ingredients by utilizing the cavitation effect and mechanical effect of ultrasound. The low temperature extraction device is one of an ultrasonic extraction tank and a low temperature ultrasonic extractor; S5, multi-stage filtration: the extract is first filtered through a coarse filter to remove larger impurities, then filtered through a microporous filter membrane to further remove tiny particles and impurities, and finally filtered through activated carbon to remove pigments and odors in the extract; S6. Vacuum concentration: placing the filtered extract into a vacuum concentration device and concentrating it at low temperature and low pressure until the extract is concentrated to 1 / 10 to 1 / 5 of the original volume; the vacuum concentration temperature is 40° C. to 50° C., and the vacuum degree is -0.08 MPa to -0.1 MPa; S7. Freeze drying: The concentrated extract is placed in a freeze dryer and freeze dried for a period of time to completely freeze it. The temperature is then gradually raised under negative pressure to sublime the frozen water to obtain a lyophilized powder of medicinal and edible properties.

2. The method for preparing a lyophilized powder of medicinal and edible nature extracted from natural plants at low temperature according to claim 1, characterized in that: The natural extractant in S4 is one of lemon juice and apple cider vinegar, the extraction temperature is controlled at 30°C to 45°C, and the extraction time is controlled at 2h to 4h. The ultrasonic power in S4 is set to 200W to 500W, and the extraction time is 30min to 60min.

3. The method for preparing a lyophilized powder of medicinal and edible nature extracted at low temperature from natural plants according to claim 1, characterized in that: The pore size of the microporous filter membrane in S5 is 0.22 μm to 0.45 μm.

4. A method for preparing a lyophilized powder of medicinal and edible nature extracted at low temperature from natural plants according to any one of claims 1 to 3, characterized in that: In the step S7, the freezing temperature of the extract is controlled at -40°C to -50°C, and the freezing time of the extract is controlled at 12h to 24h.

5. The method for preparing a natural plant-based low-temperature extracted lyophilized powder of medicinal and edible properties according to claim 5, characterized in that: The vacuum degree of the negative pressure condition in S7 is controlled at -0.08 MPa to -0.1 MPa, and the temperature is controlled at 20°C to 30°C.