Functional seaweed extract as well as preparation method and application thereof

Abstract

The invention relates to the technical field of soil improvement, in particular to a functional seaweed extract as well as a preparation method and application thereof. The preparation method comprises the following steps: (1) soaking seaweed with water, taking out, drying, mincing, adding an ethanol solution, stirring and extracting to obtain an extracted mixture; (2) centrifugally filtering the extracted mixture to obtain a seaweed solid substance and an extracting solution, and carrying out reduced pressure distillation on the extracting solution to obtain extracted seaweed; (3) grinding and crushing the extracted seaweed, and adding mixed enzyme for enzymolysis to obtain an enzymolysis product; (4) mixing the seaweed solid substance and the enzymolysis product, filtering, and centrifuging to obtain an extracting solution; and (5) adding a flocculating agent into the extracting solution for flocculation, carrying out solid-liquid separation, and carrying out vacuum concentration. Active components in seaweed can be fully extracted, the effectiveness of plant growth promoting components in the seaweed extract is improved, the physical and chemical indexes of sandy soil are improved, meanwhile, the water retention capacity of soil is improved, yield increase is promoted, and the improvement effect of the sandy soil is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of soil improvement, and in particular to a functional seaweed extract and a preparation method and application thereof. Background Art

[0002] Soil desertification causes loose soil texture, weakened water and fertilizer retention capacity, and a sharp decline in soil productivity, which seriously affects the normal growth and development of crops. In order to effectively improve degraded soil, prevent further desertification of soil, and promote the healthy growth of plants, adding sand conditioners to improve the physical and chemical properties of sand has become one of the important measures to improve desertified soil.

[0003] As an emerging type of fertilizer, seaweed fertilizer is increasingly used in the fertilizer market due to its excellent stress resistance and growth-promoting properties. In addition, compared with the secondary pollution that may be caused by chemical raw materials, seaweed fertilizer can avoid or reduce further damage to sandy soil.

[0004] Sandy soil improvement is a vital task that aims to improve the physical and chemical properties and nutritional content of desertified soil. However, in the field of sandy soil conditioners, the application of seaweed fertilizers is still in its infancy. By making full use of the functional active ingredients contained in seaweed, we can expect to significantly improve the texture of sandy soil and enhance the growth ability of crops. However, the existing seaweed extraction methods are difficult to effectively extract the active ingredients of seaweed, which in turn affects the growth ability of crops. At the same time, desertified soil has low water content and low water retention rate. Existing seaweed fertilizers are difficult to effectively play a water retention role when applied to sandy soil. Therefore, exploring how to effectively apply seaweed fertilizers to sandy soil improvement is an important technical issue that needs to be urgently solved in this field. Summary of the invention

[0005] In view of the technical problems that the active ingredients of existing seaweed fertilizers are difficult to effectively extract and have poor water retention performance, the purpose of the present invention is to provide a functional seaweed extract and a preparation method and application thereof, so as to fully extract the active ingredients in seaweed, improve the effectiveness of the components in the seaweed extract that promote plant growth, improve the physical and chemical indicators of sandy soil, and facilitate plant growth. At the same time, the water retention capacity of the soil is improved, production is increased, and the improvement effect of sandy soil is improved.

[0006] In a first aspect, the present invention provides a method for preparing a functional seaweed extract, comprising the following steps: (1) Soaking the seaweed in water, taking it out, drying it, and then grinding it, putting it into an ethanol solution and stirring and extracting it to obtain an extracted mixture; (2) centrifugally filtering the extracted mixture to obtain seaweed solid matter and an extract, and distilling the extract under reduced pressure to remove liquid to obtain extracted seaweed; (3) grinding and crushing the extracted seaweed, adding mixed enzymes for enzymolysis, and obtaining enzymolysis products; (4) The seaweed solid matter and the enzymatic hydrolysis product are mixed, filtered, and centrifuged to obtain an extract; (5) The extract is flocculated by adding a flocculant, the solid and the liquid are separated, and the separated liquid is concentrated under reduced pressure to obtain the seaweed extract.

[0007] Furthermore, in step (1), the seaweed includes one or both of Sargassum and Sargassum fusiformis.

[0008] Furthermore, in step (1), the mass concentration of the ethanol solution is 30%, the mass ratio of seaweed to the ethanol solution is 1:10-15, the extraction temperature is 45-55°C, and the extraction time is 1-3h.

[0009] Furthermore, in step (2), the centrifugal speed is 3500 r / min and the centrifugal time is 30 min.

[0010] Furthermore, in step (3), the enzyme mixture includes alginate lyase, cellulase, pectinase and protease, and the amount of each enzyme in the enzyme mixture is 1.5% to 2.0% of the mass of the extracted seaweed; the enzymatic hydrolysis temperature is 35 to 45°C, the enzymatic hydrolysis time is 4 to 8 hours, and the enzymatic hydrolysis pH value is 4.5 to 6.5.

[0011] Furthermore, in step (5), the flocculant is polyacrylamide, the amount of the flocculant in the extract is 3 mg / L, and the temperature of the reduced pressure concentration is ≤70°C.

[0012] In a second aspect, the present invention provides a functional seaweed extract prepared by the preparation method of the present invention.

[0013] In a third aspect, the present invention provides an application of a functional seaweed extract in the preparation of a desertified soil conditioner.

[0014] Furthermore, the desertified soil conditioner includes the following components in parts by weight: 60-75 parts of functional seaweed extract, 5-10 parts of organic material, and 20-35 parts of adhesive.

[0015] Furthermore, the organic material is humic acid and the binder is sodium carboxymethyl cellulose.

[0016] The beneficial effects of the present invention are: (1) The method for preparing the functional seaweed extract provided by the present invention adopts ethanol extraction + enzymatic hydrolysis technology. Ethanol as a solvent can dissolve a large amount of soluble components, and enzymatic hydrolysis helps to break the cell wall barrier, so that more active ingredients in the cells can be released. This method not only extracts the soluble components in the seaweed, but also further explores the active substances in the cells through enzymatic hydrolysis technology, thereby realizing the comprehensive utilization of seaweed resources, making full use of seaweed resources, improving the physical and chemical properties and nutritional components of desertified soil, and enhancing the growth ability of crops.

[0017] (2) The functional seaweed extract prepared by the present invention is used to prepare a desertified soil conditioner. The functional seaweed extract is a natural soil adhesive. Organic materials such as humic acid can increase the organic matter content. The adhesive can play a role of bonding when it comes into contact with water, thereby preventing sand loss and improving the water retention capacity of the soil. It can be used as a green sandy soil conditioner to effectively increase the field water holding capacity of desertified soil, reduce the bulk density of desertified soil, and help promote production increase. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a process flow chart of a specific implementation mode of the present invention. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only 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 should fall within the scope of protection of the present invention.

[0021] Example 1 A method for preparing a functional seaweed extract comprises the following steps: (1) Soak the Sargassum and Hijiki in water to remove impurities and surface salt, and then dry and mince; (2) mixing the minced seaweed with a 30% by weight ethanol solution at a weight ratio of 1:10 to form a mixture, stirring the mixture, and extracting at 45° C. for 1 hour; (3) The mixture obtained after the extraction in step (2) is cooled to room temperature, centrifuged at 3500 r / min for 30 min, filtered to obtain seaweed solid matter, and the filtrate is evaporated under reduced pressure to obtain the extracted seaweed for later use; (4) The extracted seaweed was ground into powder, and 1.5% alginate lyase, 1.5% cellulase, 1.5% pectinase and 1.5% protease were added based on the weight of the extracted seaweed, with a solid-liquid ratio of 1:20. The pH value was adjusted to 4.5 with lactic acid, and the mixture was enzymolyzed at 35°C for 4 h. The seaweed solid matter was then added and mixed evenly, filtered, and centrifuged at 8000 r / min for 5 min. Polyacrylamide flocculant (3 mg / L) was added to the separated liquid for solid-liquid separation. The separated liquid was concentrated under reduced pressure (temperature ≤70°C) to obtain a functional seaweed extract.

[0022] 60 parts of the functional seaweed extract prepared in Example 1, 10 parts of humic acid and 32 parts of sodium carboxymethyl cellulose were uniformly mixed, and the water content was adjusted to 15% to 25% to prepare a desertified soil conditioner.

[0023] Example 2 A method for preparing a functional seaweed extract comprises the following steps: (1) Soak the Sargassum and Hijiki in water to remove impurities and surface salt, and then dry and mince; (2) mixing the minced seaweed with a 30% by weight ethanol solution at a weight ratio of 1:15 to form a mixture, stirring the mixture, and extracting at 50° C. for 3 hours; (3) The mixture obtained after the extraction in step (2) is cooled to room temperature, centrifuged at 3500 r / min for 30 min, filtered to obtain seaweed solid matter, and the filtrate is evaporated under reduced pressure to obtain the extracted seaweed for later use; (4) The extracted seaweed was ground into powder. Based on the weight of the extracted seaweed, 1.5% alginate lyase, 1.5% cellulase, 2% pectinase and 2% protease were added at a solid-liquid ratio of 1:20. The pH value was adjusted to 5.5 with lactic acid. The mixture was enzymolyzed at 40°C for 5 h. The seaweed solid matter was then added and mixed evenly. The mixture was filtered and centrifuged at 8000 r / min for 5 min. Polyacrylamide flocculant (3 mg / L) was added to the separated liquid for solid-liquid separation. The separated liquid was concentrated under reduced pressure (temperature ≤70°C) to obtain a functional seaweed extract.

[0024] 70 parts of the functional seaweed extract prepared in Example 2, 8 parts of humic acid and 20 parts of sodium carboxymethyl cellulose were uniformly mixed, and the water content was adjusted to 15% to 25% to prepare a desertified soil conditioner.

[0025] Example 3 A method for preparing a functional seaweed extract comprises the following steps: (1) Soak the Sargassum and Hijiki in water to remove impurities and surface salt, and then dry and mince; (2) mixing the minced seaweed with a 30% by weight ethanol solution in a weight ratio of 1:15 to form a mixture, stirring the mixture, and extracting at 55° C. for 2 hours; (3) The mixture obtained after the extraction in step (2) is cooled to room temperature, centrifuged at 3500 r / min for 30 min, filtered to obtain seaweed solid matter, and the filtrate is evaporated under reduced pressure to obtain the extracted seaweed for later use; (4) The extracted seaweed was ground into powder, and 1.5% alginate lyase, 1.5% cellulase, 2% pectinase and 2% protease were added based on the weight of the extracted seaweed, with a solid-liquid ratio of 1:20. The pH value was adjusted to 6.5 with lactic acid, and the mixture was enzymolyzed at 45°C for 6 h. The seaweed solid matter was then added and mixed evenly, filtered, and centrifuged at 8000 r / min for 5 min. Polyacrylamide flocculant (3 mg / L) was added to the separated liquid for solid-liquid separation. The separated liquid was concentrated under reduced pressure (temperature ≤70°C) to obtain a functional seaweed extract. 75 parts of the functional seaweed extract prepared in Example 3, 8 parts of humic acid and 35 parts of sodium carboxymethyl cellulose were uniformly mixed, and the water content was adjusted to 15% to 25% to prepare a desertified soil conditioner.

[0026] Example 4 A method for preparing a functional seaweed extract comprises the following steps: (1) Soak the Sargassum and Hijiki in water to remove impurities and surface salt, and then dry and mince; (2) mixing the minced seaweed with a 30% by weight ethanol solution at a weight ratio of 1:10 to form a mixture, stirring the mixture, and extracting at 55° C. for 3 hours; (3) The mixture obtained after the extraction in step (2) is cooled to room temperature, centrifuged at 3500 r / min for 30 min, filtered to obtain seaweed solid matter, and the filtrate is evaporated under reduced pressure to obtain the extracted seaweed for later use; (4) Grind the extracted seaweed into powder, add 2% alginate lyase, 2% cellulase, 2% pectinase and 2% protease based on the weight of the extracted seaweed, with a solid-liquid ratio of 1:20, adjust the pH value to 6.5 with lactic acid, perform low-temperature enzymolysis at 40°C for 6 hours, then add the seaweed solid matter and mix evenly, filter, centrifuge at 8000 r / min for 5 minutes, add polyacrylamide flocculant (dosage 3 mg / L) to the separated liquid for solid-liquid separation, and concentrate the separated liquid under reduced pressure (temperature ≤70°C) to obtain a functional seaweed extract; 60 parts of the functional seaweed extract prepared in Example 4, 5 parts of humic acid and 32 parts of sodium carboxymethyl cellulose were uniformly mixed, and the water content was adjusted to 15% to 25% to prepare a desertified soil conditioner.

[0027] Example 5 A method for preparing a functional seaweed extract comprises the following steps: (1) Soak the Sargassum and Hijiki in water to remove impurities and surface salt, and then dry and mince; (2) mixing the minced seaweed with a 30% by weight ethanol solution at a weight ratio of 1:10 to form a mixture, stirring the mixture, and extracting at 55° C. for 3 hours; (3) The mixture obtained after the extraction in step (2) is cooled to room temperature, centrifuged at 3500 r / min for 30 min, filtered to obtain seaweed solid matter, and the filtrate is evaporated under reduced pressure to obtain the extracted seaweed for later use; (4) Grind the extracted seaweed into powder, add 2% alginate lyase, 2% cellulase, 2% pectinase and 2% protease based on the weight of the extracted seaweed, with a solid-liquid ratio of 1:20, adjust the pH value to 4.5 with lactic acid, perform low-temperature enzymolysis at 45°C for 5 hours, then add the seaweed solid matter and mix evenly, filter, centrifuge at 8000 r / min for 5 minutes, add polyacrylamide flocculant (dosage 3 mg / L) to the separated liquid for solid-liquid separation, and concentrate the separated liquid under reduced pressure (temperature ≤70°C) to obtain a functional seaweed extract; 60 parts of the functional seaweed extract obtained in Example 5, 8 parts of humic acid, and 32 parts of sodium carboxymethyl cellulose were uniformly mixed, and the water content was adjusted to 15% to 25% to prepare a desertified soil conditioner.

[0028] Comparative Example 1 A method for preparing a functional seaweed extract comprises the following steps: (1) Soaking Sargassum and Sargassum fusiformis in water to remove impurities and surface salt, and then grinding into powder after drying; (2) Based on the weight of seaweed powder, 1.5% alginate lyase, 1.5% cellulase, 1.5% pectinase and 1.5% protease were added at a solid-liquid ratio of 1:20. The pH value was adjusted to 4.5 with lactic acid. The mixture was enzymolyzed at 35°C for 4 h. The mixture was filtered and centrifuged at 8000 r / min for 5 min. Polyacrylamide flocculant (3 mg / L) was added to the separated liquid for solid-liquid separation. The separated liquid was concentrated under reduced pressure (temperature ≤70°C) to obtain the functional seaweed extract.

[0029] Comparative Example 1 The preparation method of the desertified soil conditioner is the same as that of Example 1.

[0030] Comparative Example 2 A method for preparing a functional seaweed extract comprises the following steps: (1) Soak the Sargassum and Hijiki in water to remove impurities and surface salt, and then dry and mince; (2) mixing the minced seaweed with a 30% by weight ethanol solution at a weight ratio of 1:10 to form a mixture, stirring the mixture, and extracting at 45° C. for 2 hours; (3) The mixture obtained after extraction in step (2) is cooled to room temperature, and a polyacrylamide flocculant (dosage 3 mg / L) is added for solid-liquid separation. The separated liquid is concentrated under reduced pressure (temperature ≤ 70°C) to obtain a functional seaweed extract.

[0031] Comparative Example 2 The preparation method of the desertified soil conditioner is the same as that of Example 1.

[0032] Table 1 shows the desertified soil conditioner prepared by Examples 1-5 of the present invention and the desertified soil conditioner prepared by Comparative Examples 1-2 for comparison. Wheat seeds were soaked in 40°C warm water for 6 hours, the water was drained, and Examples 1-5 and Comparative Examples 1-2 were added in sequence according to the designed treatment and mixed. After the seeds germinated, they were cultured in a planting basket. The effectiveness of the plant growth promoting component of the seaweed extract was judged by the wheat seed development rate.

[0033] Table 1 Effect of seaweed extract on wheat germination rate

[0034] Table 2 shows the sandy soil conditioner provided by Examples 1-5 of the present invention, and the control group does not add any soil conditioner. A sandy soil culture test was conducted, with 3 replicates for each treatment. After 15 days, various physical indicators were measured, among which soil bulk density, field water holding capacity and saturated water content were measured by the ring knife method. The sandy soil is sandy soil along the Yellow River, which was sieved to remove impurities and dried. The test results are shown in the following table: Table 2 Effects of sandy soil conditioners on the physical properties of sandy soil

[0035] It can be seen that compared with the control group, the saturated water content and field water holding capacity of the sandy soil in the embodiment are significantly improved, and the soil bulk density is significantly reduced, indicating that the seaweed-derived soil conditioner of the present invention can effectively improve the soil structure, increase water retention, and improve the quality of cultivated land.

[0036] Although the present invention has been described in detail with reference to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily think of changes or substitutions within the technical scope disclosed by the present invention, and these shall be within the scope of protection of the present invention.

Claims

1. A method for preparing a functional seaweed extract, characterized in that: The steps include: (1) Soaking the seaweed in water, taking it out, drying it, and then grinding it, putting it into an ethanol solution and stirring and extracting it to obtain an extracted mixture; (2) centrifugally filtering the extracted mixture to obtain seaweed solid matter and an extract, and distilling the extract under reduced pressure to remove liquid to obtain extracted seaweed; (3) grinding and crushing the extracted seaweed, adding mixed enzymes for enzymolysis, and obtaining enzymolysis products; (4) The seaweed solid matter and the enzymatic hydrolysis product are mixed, filtered, and centrifuged to obtain an extract; (5) The extract is flocculated by adding a flocculant, the solid and the liquid are separated, and the separated liquid is concentrated under reduced pressure to obtain the seaweed extract.

2. The method for preparing a functional seaweed extract according to claim 1, characterized in that: In step (1), the seaweed includes one or both of Sargassum and Sargassum fusiformis.

3. The method for preparing a functional seaweed extract according to claim 1, characterized in that: In step (1), the mass concentration of the ethanol solution is 30%, the mass ratio of seaweed to the ethanol solution is 1:10-15, the extraction temperature is 45-55°C, and the extraction time is 1-3h.

4. The method for preparing a functional seaweed extract according to claim 1, characterized in that: In step (2), the centrifugal speed is 3500 r / min and the centrifugal time is 30 min.

5. The method for preparing a functional seaweed extract according to claim 1, characterized in that: In step (3), the enzyme mixture includes alginate lyase, cellulase, pectinase and protease, and the amount of each enzyme in the enzyme mixture is 1.5% to 2.0% of the mass of the extracted seaweed; the enzymatic hydrolysis temperature is 35 to 45°C, the enzymatic hydrolysis time is 4 to 8 hours, and the enzymatic hydrolysis pH value is 4.5 to 6.

5.

6. The method for preparing a functional seaweed extract according to claim 1, characterized in that: In step (5), the flocculant is polyacrylamide, the amount of the flocculant in the extract is 3 mg / L, and the temperature of the reduced pressure concentration is ≤70°C.

7. A functional seaweed extract obtained by the preparation method according to any one of claims 1 to 6.

8. Use of the functional seaweed extract according to claim 7 in preparing a desertified soil conditioner.

9. The use according to claim 8, characterized in that The desertified soil conditioner comprises the following components in parts by weight: 60-75 parts of functional seaweed extract, 5-10 parts of organic materials and 20-35 parts of adhesive.

10. The use according to claim 9, characterized in that The organic material is humic acid and the binder is sodium carboxymethyl cellulose.

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