Method for preparing seaweed-based polysaccharide for feed based on composite low-value brown algae

Abstract

The invention belongs to the technical field of preparation of feed additives, and particularly relates to a method for preparing seaweed-based polysaccharide for feed based on composite low-value brown algae. According to the method, multiple kinds of composite low-value brown algae are adopted as raw materials for the first time, composite alkali liquor is creatively heated to assist ultrasonic extraction to prepare the seaweed-based polysaccharide for the feed, and in some embodiments of the method, compared with an ultrasonic extraction method without alkali heating, the polysaccharide extraction rate is increased by 1.2 times through composite alkali liquor heating to assist ultrasonic extraction. The used raw material is low-value brown algae which is wide in source and low in cost; the preparation process is simple to operate, clear in parameters of each step and easy to realize industrial production. The prepared seaweed-based polysaccharide for the feed is convenient to add in the feed, can remarkably improve the growth performance of animals, enhance the immunity and improve the intestinal health, has good economic benefits and social benefits, has wide application prospects in the feed industry, and is high in practicability.

Description

Technical Field

[0001] The invention belongs to the technical field of feed additive preparation, and particularly relates to a method for preparing feed seaweed-based polysaccharides based on composite low-value brown algae. Background Art

[0002] Fucoidan has attracted much attention in the feed field due to its multiple biological functions such as antioxidant, immunomodulatory, and improvement of intestinal flora. Fucoidan can be used to make feed in the form of gel, which can improve its sustained release and stability in the animal body, enhance its compatibility with feed, and also has a bonding effect to reduce feed powder and avoid the loss of nutrients. At present, the preparation of seaweed-based polysaccharide gel mostly uses high-value seaweed raw materials, which is relatively expensive. Low-value brown algae are abundant and inexpensive. Therefore, it is of great significance to develop a method for preparing low-cost, highly active seaweed-based polysaccharides for feed based on composite low-value brown algae. Summary of the Invention

[0003] The present invention aims to provide a method for preparing seaweed-based polysaccharides for feed based on composite low-value brown algae, which solves the problems of high raw material costs in the existing technology, and prepares seaweed-based polysaccharides for feed with good formability, high biological activity, strong functionality and sustained-release effect, meeting the feed industry's demand for high-quality functional additives.

[0004] The technical solution adopted by the present invention is as follows: a method for preparing seaweed-based polysaccharides for feed based on composite low-value brown algae, comprising the following steps: (1) Pretreatment of composite low-value brown algae: Select at least two low-value brown algae to form a composite low-value brown algae, repeatedly rinse with deionized water to remove surface sand and impurities, then place in a drying oven to dry until the moisture content is less than 10%, and then use a grinder to grind to 100 mesh to obtain a uniform composite low-value brown algae powder; (2) Synergistic extraction of polysaccharides: the composite low-value brown algae powder and the composite alkali solution are heated and mixed, and ultrasonic-assisted extraction is performed to obtain an extract; (3) Purification and concentration of polysaccharide solution: purifying and separating the extract from step (2) to obtain seaweed-based polysaccharides; In step (1), the low-value brown algae are kelp tails and Sargassum residues; In step (2), the composite alkali solution is an alkali solution prepared by combining potassium hydroxide, sodium bicarbonate and sodium carbonate.

[0005] Preferably, the composite low-value brown algae is kelp tail material and Sargassum residue, which are mixed in a mass ratio of 3:2.

[0006] Preferably, the mass ratio of potassium hydroxide, sodium bicarbonate and sodium carbonate is 4:3:2.

[0007] Preferably, the heating temperature of the composite low-value brown algae powder and the composite alkali solution is 60-100°C.

[0008] Preferably, the ultrasonic-assisted extraction parameters are set as follows: ultrasonic power of 50 W, frequency of 30 kHz, extraction time of 20 minutes, stopping for 1 minute every 5 minutes and then continuing until 20 minutes.

[0009] Preferably, in step (3), the small molecule impurities are removed by dialyzing for 72 hours using a dialysis bag (molecular weight cut-off 10,000 Da) or by ultrafiltration to obtain a purified polysaccharide solution. Finally, the polysaccharide solution is concentrated under reduced pressure to a polysaccharide volume of 1 / 3 of the original solution, and 3 times the volume of anhydrous ethanol is added to the supernatant for alcohol precipitation to obtain seaweed-based polysaccharides.

[0010] The beneficial effects of the present invention are as follows: For the first time, the present invention uses a variety of composite low-value brown algae as raw materials, and innovatively uses composite alkali solution heating to assist ultrasonic extraction to prepare feed seaweed-based polysaccharides. In some embodiments of the present invention, the polysaccharide extraction is improved by 1.2 times by composite alkali solution heating assisted ultrasonic extraction compared to the ultrasonic extraction method without alkali heating. The raw material used in the present invention is low-value brown algae, which is widely available and low in cost; the preparation process is simple to operate, the parameters of each step are clear, and it is easy to achieve industrial production. The prepared feed seaweed-based polysaccharides are easy to add to feed, can significantly improve the growth performance of animals, enhance immunity, and improve intestinal health, have good economic and social benefits, have broad application prospects in the feed industry, and are highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, without paying any creative work, other drawings obtained based on these drawings still fall within the scope of the present invention.

[0012] Figure 1 Schematic diagram of the preparation method of the present invention; Figure 2 This is a photo of the seaweed-based polysaccharide obtained by alcohol precipitation using the preparation method of the present invention. DETAILED DESCRIPTION

[0013] Example 1: (1) Pretreatment of composite low-value brown algae: Low-value brown algae kelp tails and Sargassum residues were mixed in a mass ratio of 3:2, with a total weight of 60 g. The mixture was rinsed three times with deionized water to remove surface sediment and impurities. The mixture was then dried in a 50°C constant temperature drying oven until the moisture content was less than 10%. The mixture was then crushed to 100 mesh using a grinder to obtain a uniform composite low-value brown algae powder. By combining multiple low-value brown algae, the structural differences of different brown algae polysaccharides were fully utilized, laying the foundation for subsequent gel performance improvement. (2) Synergistic extraction of polysaccharides: Compound low-value brown algae powder: alkali solution = 1:25 ( m / v ) were heated to 80°C and mixed for 1 hour. The total alkali concentration was 3%. When mixed in a 4:3:2 mass ratio, the concentrations of potassium hydroxide, sodium bicarbonate, and sodium carbonate were 1.33%, 1.00%, and 0.67%, respectively. Afterward, ultrasonic-assisted extraction was performed at a power of 50 W and a frequency of 30 kHz for 20 minutes, with a 1-minute pause every 5 minutes before continuing for 20 minutes. The combined alkali extraction and ultrasound synergistically disrupted the brown algae cell wall structure, promoting polysaccharide release and improving extraction efficiency. (3) Use a dialysis bag (molecular weight cutoff 10,000 Da) for 72 hours or ultrafiltration (molecular weight cutoff 10,000 Da) to remove small molecular impurities and obtain a purified polysaccharide solution. Finally, the polysaccharide solution is concentrated at 55°C under reduced pressure until the polysaccharide volume is 1 / 3 of the original solution. Add 3 times the volume of anhydrous ethanol to the supernatant and let it stand at 4°C for 12 hours for alcohol precipitation to obtain seaweed-based polysaccharide. Oven dry, the dry weight is 11.5 g.

[0014] Comparative Example 1: (1) Pretreatment of composite low-value brown algae: Mix low-value brown algae kelp tails and Sargassum residues in a mass ratio of 3:2, with a total weight of 60g. Rinse repeatedly with deionized water three times to remove surface sediment and impurities, then dry in a constant temperature drying oven at 50°C until the moisture content is less than 10%. Then use a grinder to crush to 100 mesh to obtain a uniform composite low-value brown algae powder. By combining multiple low-value brown algae, the structural differences of different brown algae polysaccharides are fully utilized, laying the foundation for subsequent gel performance improvement.

[0015] (2) Synergistic extraction of polysaccharides: Compound low-value brown algae powder: water = 1:25 ( m / v ) were heated at 80°C and mixed for 1 hour. Subsequently, ultrasonic-assisted extraction was performed at a power of 50 W and a frequency of 30 kHz for 20 minutes, with a 1-minute pause every 5 minutes before continuing for 20 minutes. (3) Purification and concentration of polysaccharide solution: Use dialysis bag (molecular weight cutoff 10,000 Da) for 72 hours or ultrafiltration (molecular weight cutoff 10,000 Da) to remove small molecular impurities and obtain a purified polysaccharide solution. Finally, the polysaccharide solution is concentrated at 55°C under reduced pressure until the polysaccharide volume is 1 / 3 of the original solution. Add 3 times the volume of anhydrous ethanol to the supernatant and let it stand at 4°C for 12 hours for alcohol precipitation to obtain seaweed-based polysaccharide, which is then dried to a dry weight of 5.5 g.

[0016] Comparative Example 2: (1) Pretreatment of composite low-value brown algae: Mix low-value brown algae kelp tails and Sargassum residues in a mass ratio of 3:2, with a total weight of 60 g. Rinse repeatedly with deionized water three times to remove surface sediment and impurities, then dry in a constant temperature drying oven at 50°C until the moisture content is less than 10%. Then use a grinder to crush to 100 mesh to obtain a uniform composite low-value brown algae powder. By combining multiple low-value brown algae, the structural differences of different brown algae polysaccharides are fully utilized, laying the foundation for subsequent gel performance improvement.

[0017] (2) Synergistic extraction of polysaccharides: Compound low-value brown algae powder: alkali solution = 1:25 ( m / v ) were heated to 80°C and mixed for 1 hour. The mass concentration of potassium hydroxide was 3%. Ultrasonic-assisted extraction was then performed at a power of 50 W and a frequency of 30 kHz for 20 minutes, with a 1-minute pause every 5 minutes before continuing for 20 minutes. (3) Purification and concentration of polysaccharide solution: Use dialysis bag (molecular weight cutoff 10,000 Da) for 72 hours or ultrafiltration (molecular weight cutoff 10,000 Da) to remove small molecular impurities and obtain a purified polysaccharide solution. Finally, the polysaccharide solution is concentrated at 55°C under reduced pressure until the polysaccharide volume is 1 / 3 of the original solution. Add 3 times the volume of anhydrous ethanol to the supernatant and let it stand at 4°C for 12 hours for alcohol precipitation to obtain seaweed-based polysaccharide, which is then dried to a dry weight of 9 g.

[0018] Comparative Example 3: (1) Pretreatment of composite low-value brown algae: Mix low-value brown algae kelp tails and Sargassum residues in a mass ratio of 3:2, with a total weight of 60 g. Rinse repeatedly with deionized water three times to remove surface sediment and impurities, then dry in a constant temperature drying oven at 50°C until the moisture content is less than 10%. Then use a grinder to crush to 100 mesh to obtain a uniform composite low-value brown algae powder. By combining multiple low-value brown algae, the structural differences of different brown algae polysaccharides are fully utilized, laying the foundation for subsequent gel performance improvement.

[0019] (2) Synergistic extraction of polysaccharides: Compound low-value brown algae powder: alkali solution = 1:25 ( m / v ) were heated to 80°C and mixed for 1 hour. The mass concentration of sodium bicarbonate was 3%. Ultrasonic-assisted extraction was then performed at a power of 50 W and a frequency of 30 kHz for 20 minutes, with a 1-minute pause every 5 minutes before continuing for 20 minutes. (3) Purification and concentration of polysaccharide solution: Use dialysis bag (molecular weight cutoff 10,000 Da) for 72 hours or ultrafiltration (molecular weight cutoff 10,000 Da) to remove small molecular impurities and obtain a purified polysaccharide solution. Finally, the polysaccharide solution is concentrated at 55°C under reduced pressure until the polysaccharide volume is 1 / 3 of the original solution. Add 3 times the volume of anhydrous ethanol to the supernatant and let it stand at 4°C for 12 hours for alcohol precipitation to obtain seaweed-based polysaccharide, which is then dried to a dry weight of 6.5 g.

[0020] Comparative Example 4: (1) Pretreatment of composite low-value brown algae: Low-value brown algae kelp tails and Sargassum residues were mixed in a mass ratio of 3:2, with a total weight of 60 g. The mixture was rinsed three times with deionized water to remove surface sediment and impurities. The mixture was then dried in a 50°C constant temperature drying oven until the moisture content was less than 10%. The mixture was then crushed to 100 mesh using a grinder to obtain a uniform composite low-value brown algae powder. By combining multiple low-value brown algae, the structural differences of different brown algae polysaccharides were fully utilized, laying the foundation for subsequent gel performance improvement.

[0021] (2) Synergistic extraction of polysaccharides: Compound low-value brown algae powder: alkali solution = 1:25 ( m / v ) were heated to 80°C and mixed for 1 hour. The mass concentration of sodium carbonate was 3%. Ultrasonic-assisted extraction was then performed at a power of 50 W and a frequency of 30 kHz for 20 minutes, with a 1-minute pause every 5 minutes before continuing for 20 minutes. (3) Purification and concentration of polysaccharide solution: Use dialysis bag (molecular weight cut-off 10,000 Da) for 72 hours or ultrafiltration (molecular weight cut-off 10,000 Da) to remove small molecular impurities and obtain a purified polysaccharide solution. Finally, the polysaccharide solution is concentrated at 55°C under reduced pressure until the polysaccharide volume is 1 / 3 of the original solution. Add 3 times the volume of anhydrous ethanol to the supernatant and let it stand at 4°C for 12 hours for alcohol precipitation to obtain seaweed-based polysaccharide, which is then dried to a dry weight of 8 g.

[0022] The above disclosure is merely a preferred embodiment of the present invention and certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for preparing seaweed-based polysaccharides for feed based on composite low-value brown algae, characterized in that The following steps are involved: (1) Pretreatment of composite low-value brown algae: Select at least two low-value brown algae to form a composite low-value brown algae, repeatedly rinse with deionized water to remove surface sand and impurities, then place in a drying oven to dry until the moisture content is less than 10%, and then use a grinder to grind to 100 mesh to obtain a uniform composite low-value brown algae powder; (2) Synergistic extraction of polysaccharides: the composite low-value brown algae powder and the composite alkali solution are heated and mixed, and ultrasonic-assisted extraction is performed to obtain an extract; (3) Purification and concentration of polysaccharide solution: purifying and separating the extract from step (2) to obtain seaweed-based polysaccharides; In step (1), the low-value brown algae are kelp tails and Sargassum residues; In step (2), the composite alkali solution is an alkali solution prepared by combining potassium hydroxide, sodium bicarbonate and sodium carbonate.

2. The method for preparing seaweed-based polysaccharides for feed based on composite low-value brown algae according to claim 1, characterized in that: The composite low-value brown algae is kelp tail material and Sargassum residue, which are mixed in a mass ratio of 3:

2.

3. The method for preparing seaweed-based polysaccharides for feed based on composite low-value brown algae according to claim 1, characterized in that: The mass ratio of potassium hydroxide, sodium bicarbonate and sodium carbonate is 4:3:

2.

4. The method for preparing seaweed-based polysaccharides for feed based on composite low-value brown algae according to claim 1, characterized in that: The heating temperature of the composite low-value brown algae powder and the composite alkali solution is 60-100°C.

5. The method for preparing seaweed-based polysaccharides for feed based on composite low-value brown algae according to claim 1, characterized in that: The parameters of ultrasonic-assisted extraction were set as follows: ultrasonic power of 50 W, frequency of 30 kHz, extraction time of 20 min, and stopping for 1 min every 5 min before continuing until 20 min.

6. The method for preparing seaweed-based polysaccharides for feed based on composite low-value brown algae according to claim 1, characterized in that: In step (3), the small molecule impurities are removed by dialyzing for 72 hours using a dialysis bag (molecular weight cut-off 10,000 Da) or by ultrafiltration to obtain a purified polysaccharide solution. Finally, the polysaccharide solution is concentrated under reduced pressure to a polysaccharide volume of 1 / 3 of the original solution. Three times the volume of anhydrous ethanol is added to the supernatant for alcohol precipitation to obtain seaweed-based polysaccharides.

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