CN105193863B - A kind of preparation method of high-purity seeweed polyphenol - Google Patents

Abstract

The invention discloses a preparation method of high-purity seaweed polyphenols, which comprises separation of seaweed polysaccharides and seaweed residues, enzymatic hydrolysis of seaweed residues, high-efficiency extraction of seaweed polyphenols, separation and purification of seaweed polyphenols, high-purity seaweed polyphenols The process steps such as the acquisition of phenol have realized the comprehensive utilization of the whole algae of seaweed polysaccharides, seaweed polyphenols and seaweed residue.

Description

A kind of preparation method of high-purity seaweed polyphenol

technical field

The invention relates to the technical field of seaweed polyphenols, in particular to a preparation method of high-purity seaweed polyphenols.

Background technique

Seaweed is the main source of marine plant polyphenols, and its structure is quite different from that of terrestrial plant polyphenols: terrestrial plant polyphenols are derived from gallic acid and halide acid; seaweed polyphenols are derivatives of phloroglucinol . Studies have shown that seaweed polyphenols have special effects in anti-oxidation, improving metabolic syndrome, and preventing degenerative diseases, and are safe and non-toxic. Therefore, European and American countries have invested heavily in the development and application of seaweed polyphenols. High-purity seaweed polyphenols have the advantages of strong biological activity, high medical value, and good stability, and are urgently needed products in the field of biomedicine.

However, because seaweed polyphenols exist in algal vesicles inside seaweed cells and are deeply embedded by alginate, cellulose, etc., conventional extraction techniques are difficult to obtain high yields, and the production cost is extremely high and the purity is low. For example, the Chinese invention patent application CN102579508A "A Preparation Method of Fujiki Brown Algae Polyphenols" discloses that hijiki is used as raw material, heated and extracted with methanol (40°C), and then prepared by different solvent extraction and ultrafiltration interception means. Brown algae polyphenols; Chinese invention patent application CN102397300A "Extraction method of brown algae polyphenols", which discloses that fresh kelp, sage, sea broomcorns are used as raw materials, and three kinds of brown algae polyphenols are obtained by extracting with organic solvents and purifying macroporous resins. Phenols, whose yields are respectively 0.3‰, 2.5‰, and 3‰; Chinese invention patent application CN103610704A "A Method for Extracting Brown Algae Polyphenols" discloses that fresh Sargassum brown algae or kelp are used as raw materials. Extraction in a hot water bath, purification, elution, concentration, and freeze-drying of macroporous resins to obtain brown algae polyphenol extracts, with a yield of 2.5‰; Chinese invention patent application CN104382951A "A Method for Extracting Seaweed Polyphenols", It is disclosed that three kinds of algae, Chlorella pyrenoidosa, Euglena, and Salina, are used as raw materials, ethanol is used as a solvent, and microwave combined extraction technology is used. The extract is filtered and freeze-dried to obtain polyphenol extracts of three kinds of seaweeds; Chinese invention patent Authorized CN102935093B "A Method for Extracting Seaweed Polyphenols", which discloses that 40-mesh seaweed powder is used as raw material, extracted by microwave-assisted water extraction, and then purified by macroporous resin to obtain a polyphenol extract with a purity of about 75%. Invented in China Patent authorization CN102166230B "Microwave Assisted Seaweed Polyphenol Method" discloses that seaweed polyphenols are extracted by using seaweed powder as raw material, alcohol-acetone-water mixed solvent, combined with microwave technology, filtered and freeze-dried to obtain a crude seaweed polyphenol extract. The extraction rate can reach 2.26%. The above-mentioned method for preparing seaweed polyphenol lacks the comprehensive utilization of main components such as alginate, resulting in a serious waste of resources; meanwhile, the above-mentioned process for preparing seaweed polyphenol still has the following problems: 1) The separation effect is poor and the purity is low. Seaweed polyphenols are easy to form complexes with seaweed gum and protein in the form of non-covalent bonds, and it is difficult to separate them in the subsequent purification process, resulting in a low recovery rate of seaweed polyphenols; in addition, the extracted seaweed polyphenols also contain A large amount of fat-soluble pigments cannot be effectively separated by traditional column chromatography, resulting in low product purity. 2) The structure is greatly damaged and the activity is low. Seaweed polyphenols are extremely unstable and easily oxidized, and high temperature, alkaline pH, oxygen, etc. during processing will destroy their biological activity. Although microwave technology and ultrasonic-assisted extraction technology can improve the yield of marine polyphenols, the extraction process will generate high temperature, coupled with the lack of effective protection measures, the oxidation of marine polyphenols will be accelerated under the action of oxygen, resulting in the loss of activity. 3) The production process is complicated and the cost is high. The current process for processing seaweed polyphenols includes multiple processes such as crushing, extraction, centrifugation, filtration, column loading, elution, resin regeneration, multiple concentration, and drying; conventional column chromatography purification of seaweed polyphenols must also be equipped with a constant flow Pumps, glass columns, collection devices and other equipment lead to long production time and high equipment requirements, which limits the development of industrialization. This is the key technical bottleneck leading to the industrial application of seaweed polyphenols.

In view of this, the present inventor has researched and designed a method for preparing high-purity seaweed polyphenols, and this case arises from it.

Contents of the invention

The purpose of the present invention is to provide a method for preparing high-purity seaweed polyphenols, including the separation of seaweed polysaccharides and seaweed residues, enzymolysis of seaweed residues, efficient extraction of seaweed polyphenols, separation and purification of seaweed polyphenols, high-purity Process steps such as the acquisition of seaweed polyphenols to realize the comprehensive utilization of seaweed polysaccharides, seaweed polyphenols, and seaweed residues.

In order to achieve the above object, the technical solution taken by the present invention to solve the technical problems is:

A preparation method of high-purity seaweed polyphenols, comprising the following steps:

Step 1. Separation of seaweed polysaccharides and seaweed residue: first soak the dried seaweed with a water content of 20% in tap water, rinse to remove sediment impurities, and beat with a beater; send the seaweed pulp into the mixer, and press the seaweed pulp: deionized The water volume ratio is 1:5, add deionized water, stir at room temperature at 120 rpm for 30 minutes; use a low-speed centrifuge to centrifuge the seaweed slurry at 1000 rpm for 5 minutes, and collect the supernatant and seaweed residue; After the slag is stirred by a mixer and centrifuged in a centrifuge according to the above steps and conditions, the supernatant and seaweed residue are collected separately again; the two supernatants are combined and spray-dried to obtain seaweed polysaccharide; the seaweed residue is collected for extraction and preparation of seaweed polyphenols;

Step 2. Enzymatic hydrolysis of seaweed dregs: add a compound enzyme composed of cellulase and pectinase in a weight ratio of 1:1000 to the seaweed dregs, and hydrolyze for 5 hours at room temperature to achieve Algae cell wall breakdown;

Step 3. High-efficiency extraction of seaweed polyphenols: dissolve the seaweed polyphenol protective agent in deionized water, then mix it with food-grade absolute ethanol at a volume ratio of 1:4, and add acetic acid according to the volume ratio to make the final volume concentration of acetic acid 0.1%, after mixing, it is the extract of seaweed polyphenols; the extract and seaweed residue are mixed at a volume/weight ratio of 5:1, extracted at room temperature for 1.5h, and centrifuged at 3000 rpm for 5min , collect supernatant and seaweed residue respectively; seaweed residue continues to use the extract to repeat the above steps for secondary extraction, collect supernatant and seaweed residue respectively; seaweed residue is used as feed additive raw material after being dried; Serum, used for the separation and purification of seaweed polyphenols;

Step 4. Separation and purification of seaweed polyphenols: pour the supernatant obtained in step 3 into an adsorption pool containing silica gel for static adsorption and decolorization for 2 hours, and the pigment adsorbed by silica gel is further used to prepare fucoxanthin active substances; After the seaweed polyphenol extract was concentrated to 50% volume at 40°C by the pressure concentration method, the seaweed polyphenol was subjected to solid-phase extraction with domestic XDA-7 macroporous absorption resin for 2 hours; the XDA-7 macroporous resin was deionized water Rinse quickly to remove sugar and small peptide impurities; then soak the XDA-7 macroporous resin in food-grade anhydrous ethanol for 0.5h, elute the seaweed polyphenols adsorbed on the macroporous resin and dissolve them in ethanol to obtain ethanol-soaked liquid;

Step 5, preparation of seaweed polyphenols: the ethanol soaking solution was concentrated to dryness under reduced pressure at 40° C., and vacuum-dried at 50° C. for 2 hours to obtain seaweed polyphenol products.

As a preferred embodiment of the embodiment, the seaweed is at least one of kelp, wakame, sagittaria, sea sorghum, sagera, and licorice.

As a preferred embodiment of the embodiment, the seaweed polyphenol protective agent in the third step is vitamin C or phytic acid or a complex composed of vitamin C and phytic acid.

As a preferred mode of the embodiment, the extract in the third step contains vitamin C with a mass volume ratio of 0.05-0.5%.

As a preferred mode of the embodiment, the extract in the third step contains 0.01-0.1% phytic acid by volume.

As a preferred embodiment of the embodiment, the extract in step 3 contains vitamin C with a mass volume ratio of 0.05-0.1% and phytic acid with a volume ratio of 0.01-0.05%.

As a preferred form of the embodiment, the seaweed polyphenol product is white powder; the extraction rate of the seaweed polyphenol is 1.5-6.5%; the purity is 90-95%.

After the present invention adopts the above technical scheme, it has the following beneficial effects:

1. The present invention can realize the utilization of whole algal resources of seaweed polysaccharides, seaweed polyphenols, fucoxanthin and seaweed residue, which is the core technology urgently needed by the seaweed processing industry;

2. The present invention adopts solid-phase extraction technology to realize high-efficiency separation and purification of seaweed polyphenols, reduces unit operations such as filtration, column chromatography purification, and concentration in conventional seaweed polyphenol production processes, simplifies the process flow, shortens production time, and improves product quality. Quality, product purity ≥ 90% by mass;

3. The present invention aims at the characteristics that seaweed polyphenols are easy to oxidize and degrade, and improves the stability of seaweed polyphenols by adding a protective agent during the extraction process, thereby improving the extraction efficiency.

Description of drawings

Fig. 1 is a process flow diagram of the present invention.

Detailed ways

Embodiments of the present invention are described in detail below, and the process flow diagram of the present invention is shown in FIG. 1 . The embodiments described by referring to the figures are exemplary and are intended to explain the present invention and should not be construed as limiting the present invention. If no specific technique or condition is indicated in the examples, it shall be carried out according to the technique or condition described in the literature in this field or according to the product specification. The reagents or instruments used were not indicated by the manufacturer, and they were all commercially available conventional products.

The compound enzyme used in the following examples is a 1:1 (w/w) pectinase and cellulase compound enzyme; the protective agent in the extract is 0.05 mass % and 0.01 volume % phytic acid.

Example 1: Preparation of high-purity seaweed polyphenols from kelp

(1) Get water content and be 20 mass % dry sea-tangle 1kg, after soaking and rinsing with tap water to remove impurities such as silt, beating with a beater to obtain 0.6L of seaweed slurry; send it into the agitator, and add 3L deionized water, under temperature Stir at a speed of 120 rpm for 30 minutes; then use a low-speed centrifuge to centrifuge the seaweed slurry at a speed of 1000 rpm for 5 minutes to collect the supernatant and seaweed residue; the seaweed residue is stirred by a mixer and centrifuged in a centrifuge according to the above steps and conditions Afterwards, the supernatant and seaweed residue were collected again. The two supernatants were combined and spray-dried to obtain seaweed polysaccharides; 342 g of seaweed residue was collected for extraction and preparation of seaweed polyphenols.

(2) Mix the wet kelp slag with 1.71 g of compound enzyme evenly, and hydrolyze it at room temperature for 5 hours to break the cell wall of seaweed.

(3) Dissolve the seaweed polyphenol protective agent in deionized water, then mix it with food-grade absolute ethanol in a volume ratio of 1:4 (v:v), and add acetic acid in a volume ratio to make the final concentration of acetic acid 0.1%. (v:v), after mixing, it is an extract of seaweed polyphenols, and the extract contains 0.05% by mass and 0.01% by volume of phytic acid. Add 1.71L of the extract to the above-mentioned enzymatically broken seaweed residue and mix well, extract at room temperature for 1.5h; then centrifuge at 3000 rpm for 5min, and collect the supernatant and seaweed residue respectively. Seaweed dregs continue to use the above extract to repeat the aforementioned steps for secondary extraction, and collect the supernatant and seaweed dregs respectively. Seaweed dregs were dried and used as raw materials for feed additives; 3.2 L of the two supernatants were combined for separation and purification of seaweed polyphenols.

(4) Pour the above-mentioned supernatant into an adsorption tank equipped with silica gel, make the liquid level flush with silica gel, carry out static adsorption decolorization for 2 hours, and the pigments adsorbed by silica gel can be further used to prepare active substances such as fucoxanthin; then use The reduced-pressure concentration method concentrates the seaweed polyphenol extract to a volume of 1.6L at 40°C, and then pours the concentrated solution into an adsorption pool equipped with domestic XDA-7 macroporous absorbent resin so that the liquid level is flush with the macroporous resin. Carry out solid-phase extraction of seaweed polyphenols for 2 hours; remove the macroporous resin with a filter, rinse quickly with deionized water to remove impurities such as sugar and small peptides; then put the macroporous resin into a container filled with food-grade absolute ethanol Desorption tank, make the ethanol liquid level flush with the macroporous resin, soak for 0.5h, so that the seaweed polyphenols adsorbed on the macroporous resin are eluted and dissolved in ethanol. The desorbed macroporous resin is rinsed with deionized water and then used for the next adsorption of seaweed polyphenols; the ethanol in the desorption pool can be used repeatedly to achieve the purpose of enriching seaweed polyphenols.

(5) The above-mentioned desorbed ethanol solution was concentrated to dryness under reduced pressure at 40° C., and then dried in vacuum at 50° C. for 2 hours to obtain 18.4 g of high-purity seaweed polyphenol powder with a total phenol content of 91.5% by mass.

Embodiment 2: Preparation of high-purity seaweed polyphenols from wakame

(1) Take 1 kg of dried wakame with a water content of 20% by mass, soak, rinse, and beat with tap water to obtain 0.55 L of seaweed pulp; add 2.75 L of deionized water after sending it into the agitator, and stir at a speed of 120 rpm under temperature 30 min; then centrifuge at 1000 rpm for 5 min, collect the supernatant and seaweed residue respectively; repeat the above steps, the supernatant is used to prepare seaweed polysaccharide; collect 313 g of seaweed residue, which is used to extract and prepare seaweed polyphenols.

(2) Mix the above-mentioned wet wakame residue with 1.565 g of compound enzyme evenly, and hydrolyze it at room temperature for 5 hours, so as to break the cell wall of seaweed.

(3) 80% by volume ethanol aqueous solution containing 0.05% by mass, 0.01% by volume of phytic acid and 0.1% by volume of acetic acid is used as the extract. Add 1.565L of the extract to the above-mentioned enzymatically broken seaweed residue and mix well, extract at room temperature for 1.5h; centrifuge at 3000 rpm for 5min, and collect the supernatant and seaweed residue respectively. Repeat the previous steps for the second extraction. Seaweed dregs were dried and used as raw materials for feed additives; 3.0 L of the two supernatants were combined for separation and purification of seaweed polyphenols.

(4) Pour the above supernatant into an adsorption tank equipped with silica gel for decolorization for 2 hours; after concentrating the supernatant under reduced pressure to a volume of 1.5 L at 40° C., use domestic XDA-7 macroporous absorption resin for solid-phase extraction for 2 hours; After the macroporous resin is quickly rinsed with deionized water, it is desorbed with food-grade absolute ethanol to obtain an ethanol solution rich in seaweed polyphenols.

(5) The above-mentioned desorbed ethanol solution was concentrated to dryness under reduced pressure at 40° C., and then dried in vacuum at 50° C. for 2 hours to obtain 27.6 g of high-purity seaweed polyphenol powder with a total phenol content of 93.2% by mass.

Embodiment 3: Sea millet prepares high-purity seaweed polyphenols

(1) Take 1 kg of dry sea millet with a water content of 20% by mass, soak, rinse, and beat with tap water to obtain 0.5 L of seaweed slurry; add 2.5 L of deionized water after sending it into the agitator, and use 120 rpm under temperature. Stir for 30 minutes; then centrifuge at 1000 rpm for 5 minutes to collect the supernatant and seaweed residue; repeat the above steps, the supernatant is used to prepare seaweed polysaccharides; collect 410 g of seaweed residue, which is used to extract and prepare seaweed polyphenols.

(2) Mix the above-mentioned wet wakame residue with 2.05 g of compound enzyme evenly, and hydrolyze it at room temperature for 5 hours, so as to break the cell wall of seaweed.

(3) 80% by volume ethanol aqueous solution containing 0.05% by mass, 0.01% by volume of phytic acid and 0.1% by volume of acetic acid is used as the extract. Add 2.05L of the extract to the enzymatically broken seaweed residue and mix well, extract at room temperature for 1.5h; centrifuge at 3000rpm for 5min, and collect the supernatant and seaweed residue respectively. Repeat the previous steps for the second extraction. Seaweed dregs were dried and used as raw materials for feed additives; 3.8 L of the two supernatants were combined for separation and purification of seaweed polyphenols.

(4) Pour the above supernatant into an adsorption tank equipped with silica gel for decolorization for 2 hours; after concentrating the supernatant under reduced pressure to a volume of 1.9L at 40°C, use domestic XDA-7 macroporous absorption resin for solid-phase extraction for 2 hours; After the macroporous resin is quickly rinsed with deionized water, it is desorbed with food-grade absolute ethanol to obtain an ethanol solution rich in seaweed polyphenols.

(5) The above-mentioned desorbed ethanol solution was concentrated to dryness under reduced pressure at 40° C., and then dried in vacuum at 50° C. for 2 hours to obtain 38.5 g of high-purity seaweed polyphenol powder with a total phenol content of 90% by mass.

Example 4: Preparation of high-purity seaweed polyphenols from Hijiki

(1) Take 1 kg of dry hijiki with a water content of 20% by mass, soak, rinse, and beat with tap water to obtain 0.65 L of seaweed slurry; add 3.25 L of deionized water after sending it into the mixer, and use 120 rpm under temperature. Stir for 30 minutes; then centrifuge at 1000 rpm for 5 minutes to collect the supernatant and seaweed residue; repeat the above steps, the supernatant is used to prepare seaweed polysaccharide; collect 350 g of seaweed residue, which is used to extract and prepare seaweed polyphenols.

(2) Mix the above-mentioned wet wakame residue with 1.75 g of compound enzyme, and hydrolyze it at room temperature for 5 hours to break the cell wall of seaweed.

(3) 80% by volume ethanol aqueous solution containing 0.05% by mass, 0.01% by volume of phytic acid and 0.1% by volume of acetic acid is used as the extract. Add 1.75L of the extract to the enzymatically broken seaweed residue and mix well, extract at room temperature for 1.5h; centrifuge at 3000 rpm for 5min, and collect the supernatant and seaweed residue respectively. Repeat the previous steps for the second extraction. Seaweed slag was dried and used as raw material for feed additives; 3.4 L of supernatants from two times were combined for separation and purification of seaweed polyphenols.

(4) Pour the above supernatant into an adsorption tank equipped with silica gel for decolorization for 2 hours; after concentrating the supernatant under reduced pressure to a volume of 1.7L at 40°C, use domestic XDA-7 macroporous absorption resin for solid-phase extraction for 2 hours; After the macroporous resin is quickly rinsed with deionized water, it is desorbed with food-grade absolute ethanol to obtain an ethanol solution rich in seaweed polyphenols.

(5) The above-mentioned desorbed ethanol solution was concentrated to dryness under reduced pressure at 40° C., and then dried in vacuum at 50° C. for 2 hours to obtain 15.3 g of high-purity seaweed polyphenol powder with a total phenol content of 94.1% by mass.

Example 5: Preparation of high-purity seaweed polyphenols from Radix Glycyrrhizae

(1) Take 1 kg of dry licorice with a water content of 20% by mass, soak, rinse, and beat with tap water to obtain 0.8 L of seaweed slurry; add 4.0 L of deionized water after sending it into the mixer, and stir at 120 rpm under temperature 30 min; then centrifuge at 1000 rpm for 5 min, collect the supernatant and seaweed residue respectively; repeat the above steps, the supernatant is used to prepare seaweed polysaccharide; collect 280 g of seaweed residue, which is used to extract and prepare seaweed polyphenols.

(2) Mix the above-mentioned wet wakame residue with 1.4 g of compound enzyme, and hydrolyze it at room temperature for 5 hours to break the cell wall of seaweed.

(3) 80% by volume ethanol aqueous solution containing 0.05% by mass, 0.01% by volume of phytic acid and 0.1% by volume of acetic acid is used as the extract. Add 1.4L of the extract to the above-mentioned enzymatically broken seaweed residue and mix well, extract at room temperature for 1.5h; centrifuge at 3000 rpm for 5min, and collect the supernatant and seaweed residue respectively. Repeat the previous steps for the second extraction. Seaweed dregs were dried and used as raw materials for feed additives; 2.5 L of supernatants from two times were combined for separation and purification of seaweed polyphenols.

(4) Pour the above supernatant into an adsorption tank equipped with silica gel for decolorization for 2 hours; after concentrating the supernatant under reduced pressure to a volume of 1.25L at 40°C, use domestic XDA-7 macroporous absorption resin for solid-phase extraction for 2 hours; After the macroporous resin is quickly rinsed with deionized water, it is desorbed with food-grade absolute ethanol to obtain an ethanol solution rich in seaweed polyphenols.

(5) The above-mentioned desorbed ethanol solution was concentrated to dryness under reduced pressure at 40° C., and then dried in vacuum at 50° C. for 2 hours to obtain 65.2 g of high-purity seaweed polyphenol powder with a total phenol content of 95% by mass.

The invention aims at the characteristic that seaweed polyphenols are easy to be oxidized and degraded, and improves the stability of seaweed polyphenols by adding a protective agent during the extraction process, thereby improving the extraction efficiency. In the experiment, the protective effects of vitamin C, phytic acid and their compound preparations were comparatively studied by using the kelp slag after enzymatic hydrolysis and breaking the wall as raw materials. The fixed ratio of kelp slag and extract (80% ethanol aqueous solution containing 0.1% acetic acid) is 1:5 (w:v), extract at room temperature for 1.5h, extract twice, and judge the effect of protective agent by the extraction rate of seaweed polyphenols , and the results are shown in Table 1. The experimental results found that under the action of the protective agent, the extraction rate of seaweed polyphenols was significantly improved. Among them, the protective effect of phytic acid is better than that of vitamin C, and the compound agent composed of the two has the best effect. By comparing the protective effect of different concentration combinations of vitamin C and phytic acid on seaweed polyphenols, it was found that the protective effect of 0.05% by mass and 0.01% by volume of phytic acid was not significantly different from other combinations.

Table 1 The influence of protective agent on the extraction rate of seaweed polyphenols

In a word, the present invention is based on the utilization of the whole algae resources of seaweed, reduces the damage to seaweed polyphenols in the production process by adding protective agents, and adopts the combination technology of biological enzyme wall breaking and solid phase extraction to achieve high efficiency and high purity of seaweed polyphenols The goal is to reduce unit operations such as column chromatography in traditional processes, and has technical advantages such as green environmental protection, low energy and high efficiency.

Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limitations to the present invention. Variations, modifications, substitutions, and modifications to the above-described embodiments are possible within the scope of the present invention.

Claims (7)

1. A preparation method for high-purity seaweed polyphenols, characterized in that: comprises the following steps: Step 1. Separation of seaweed polysaccharides and seaweed residue: first soak the dried seaweed with a water content of 20% in tap water, rinse to remove sediment impurities, and beat with a beater; send the seaweed pulp into the mixer, and press the seaweed pulp: deionized The water volume ratio is 1:5, add deionized water, stir at room temperature at 120 rpm for 30 minutes; use a low-speed centrifuge to centrifuge the seaweed slurry at 1000 rpm for 5 minutes, and collect the supernatant and seaweed residue; After the slag is stirred by a mixer and centrifuged in a centrifuge according to the above steps and conditions, the supernatant and seaweed residue are collected separately again; the two supernatants are combined and spray-dried to obtain seaweed polysaccharide; the seaweed residue is collected for extraction and preparation of seaweed polyphenols; Step 2. Enzymatic hydrolysis of seaweed dregs: add a compound enzyme composed of cellulase and pectinase in a weight ratio of 1:1000 to the seaweed dregs, and hydrolyze for 5 hours at room temperature to achieve Algae cell wall breakdown; Step 3. High-efficiency extraction of seaweed polyphenols: dissolve the seaweed polyphenol protective agent in deionized water, then mix it with food-grade absolute ethanol at a volume ratio of 1:4, and add acetic acid according to the volume ratio to make the final volume concentration of acetic acid 0.1%, after mixing, it is the extract of seaweed polyphenols; the extract and seaweed residue are mixed at a volume/weight ratio of 5:1, extracted at room temperature for 1.5h, and centrifuged at 3000 rpm for 5min , collect supernatant and seaweed residue respectively; seaweed residue continues to use the extract to repeat the above steps for secondary extraction, collect supernatant and seaweed residue respectively; seaweed residue is used as feed additive raw material after being dried; Serum, used for the separation and purification of seaweed polyphenols; Step 4. Separation and purification of seaweed polyphenols: pour the supernatant obtained in step 3 into an adsorption pool containing silica gel for static adsorption and decolorization for 2 hours, and the pigment adsorbed by silica gel is further used to prepare fucoxanthin active substances; After the seaweed polyphenol extract was concentrated to 50% volume at 40°C by the pressure concentration method, the seaweed polyphenol was subjected to solid-phase extraction with domestic XDA-7 macroporous absorption resin for 2 hours; the XDA-7 macroporous resin was deionized water Rinse quickly to remove sugar and small peptide impurities; then soak the XDA-7 macroporous resin in food-grade anhydrous ethanol for 0.5h, elute the seaweed polyphenols adsorbed on the macroporous resin and dissolve them in ethanol to obtain ethanol-soaked liquid; Step 5, preparation of seaweed polyphenols: the ethanol soaking solution was concentrated to dryness under reduced pressure at 40° C., and vacuum-dried at 50° C. for 2 hours to obtain seaweed polyphenol products. 2. the preparation method of a kind of high-purity seaweed polyphenol as claimed in claim 1, is characterized in that: described seaweed is at least one in kelp, wakame, hibiscus, sea millet, sargassum and licorice . 3. The preparation method of a kind of high-purity seaweed polyphenols as claimed in claim 1, characterized in that: the seaweed polyphenol protective agent in the step 3 is vitamin C or phytic acid or a compound composed of vitamin C and phytic acid thing. 4. A method for preparing high-purity seaweed polyphenols as claimed in claim 1, characterized in that: the extract in step 3 contains vitamin C with a mass-volume ratio of 0.05-0.5%. 5 . The method for preparing high-purity seaweed polyphenols according to claim 1 , wherein the extract in step 3 contains 0.01-0.1% phytic acid by volume. 6. A method for preparing high-purity seaweed polyphenols as claimed in claim 1, characterized in that: the extract in the step 3 contains vitamin C with a mass-volume ratio of 0.05-0.1% and a volume ratio of 0.01- 0.05% Phytic Acid. 7. a kind of preparation method of high-purity seaweed polyphenol as claimed in claim 1 is characterized in that: described seaweed polyphenol product is white powder; The extraction rate of described seaweed polyphenol is 1.5-6.5%; Purity is 90-95%.