Background
Fucoidan, also called fucoidan, is one of the fucoidan polysaccharides, which mainly includes three kinds: alginate, fucoidan sulfate and starch, wherein the content of alginate and fucoidan sulfate is relatively high, and the content of brown algae starch is low. Fucoidan is present on cell walls and in the intercellular substance, alginate is mainly present in cells, and starch is present in the intercellular substance.
In recent years, fucoidan sulfate has been receiving much attention because of its various excellent biological activities.
Fucoidan sulfate has effects of keeping moisture, repairing, reducing blood sugar, reducing blood lipid, resisting oxidation and blood coagulation, protecting liver, regulating immunity, and resisting tumor.
Common extraction methods of fucosan sulfate include water extraction, acid extraction, alkali extraction, enzyme method and ultrasonic extraction, which have the following advantages and disadvantages: the water extraction method can avoid the degradation of the fucoidan sulfate, is a common extraction method, and has two main defects, one of which is incapable of effectively extracting the fucoidan sulfate on the cell wall, so that the yield is low; secondly, the extraction temperature exceeds 60 ℃, the high temperature can lead the starch to be gelatinized, and the difficulty is brought to solid-liquid separation. The acid extraction method and the ultrasonic extraction can improve the yield of the fucoidan sulfate, but can degrade the fucoidan sulfate and influence the biological activity of the fucoidan sulfate; the enzyme method has mild conditions, has little influence on the structure of the fucoidan sulfate, and can also improve the yield, but the enzyme method destroys the cell wall of the brown algae, can introduce the sodium alginate and the starch in the cell, improves the difficulty for the purification of the fucose sulfate at the rear end, and has higher cost. When the extraction is carried out by the alkali extraction method, more sodium alginate, pigments, polyphenol and fat can be extracted, and the extract is dark in color and has more impurities, so that the obtained fucosan sulfate has low purity (less than 60%) and high conductivity.
Common purification methods of fucoidan sulfate include calcium chloride precipitation, membrane filtration and alcohol precipitation, and these methods have the following advantages and disadvantages: the calcium chloride precipitation method can effectively remove alginate, and has the defects that the addition amount is large and is generally 15-20% of the weight of brown algae, so that the conductivity of the product is high, and the desalting cost needs to be increased; the membrane filtration method can effectively separate the polysaccharide according to the molecular weight, and has two main defects, namely, the early investment is large, and the separation speed of the polysaccharide with high viscosity is low; the alcohol precipitation method can effectively remove impurities and decolor, and has the defects of two main aspects: the precipitation of polysaccharide is not selective, so that alginate and fucoidan sulfate can not be effectively separated; and the second requires an explosion-proof workshop.
In summary, the prior art routes mainly include the following three types:
(1) Water extraction: dried seaweed → mud and sand removal, drying → seaweed powder → hot water extraction → centrifugation → supernatant extraction → pH adjustment to neutrality → decompression concentration → ethanol precipitation → absolute ethyl ether and acetone washing twice → vacuum drying → crude seaweed polysaccharide.
(2) Acid extraction method: dried seaweed → water rinsing for removing impurities, air drying → crushing → leaching with 0.1mol/L HCl and formaldehyde solution → filtering to obtain filtrate → adding 0.5 mol/L NaOH to neutralize the filtrate → centrifuging to concentrate the supernatant → adding ethanol to 60% → standing → centrifugal precipitation → washing the precipitate with ethanol → drying under reduced pressure to obtain crude seaweed polysaccharide.
(3) Ultrasonic extraction method: dried seaweed powder → adding a proper amount of distilled water (treated by an ultrasonic wave device) → extracting solution filtration → concentration → ethanol precipitation → standing → centrifugal precipitation → washing the precipitate with ethanol → decompression drying to obtain a crude seaweed polysaccharide product.
The three methods have complicated operation steps and high cost, and are not beneficial to industrial large-scale production. Therefore, the development of a preparation method which is simple in operation, low in cost, high in extraction rate, suitable for large-scale production of fucosan sulfate, and capable of obtaining fucosan sulfate with low conductivity is urgently needed in the field.
Disclosure of Invention
Aiming at the defects of the prior art, the invention aims to provide a method for preparing fucoidan sulfate and application thereof. The brown algae is cleaned and crushed, then is extracted by using a calcium hydroxide aqueous solution, the extracting solution is introduced with carbon dioxide to precipitate excessive calcium hydroxide, and finally, the cation exchange resin is used for removing impurities, so that the extraction and separation method is simple to operate, low in cost, high in extraction rate and suitable for large-scale production.
The invention washes brown algae with water to remove inorganic salt and impurities, air-dries and crushes to obtain brown algae powder. The calcium hydroxide aqueous solution is used as a solvent for low-temperature atomization extraction. Introducing carbon dioxide into the extract to remove excessive calcium hydroxide, and desalting with ion exchange resin to obtain fucosan sulfate.
The purpose of the invention is realized by the following technical scheme:
in a first aspect, the present invention provides a method for extracting fucoidan sulfate, comprising the steps of:
s1, cleaning brown algae, drying and then crushing the brown algae into brown algae powder;
s2, carrying out low-temperature atomization extraction on brown algae powder in a calcium hydroxide water solution, and filtering to obtain an extracting solution;
s3, introducing carbon dioxide into the extracting solution to precipitate excessive calcium hydroxide, and then filtering to obtain a filtrate;
and S4, adding cation exchange resin into the filtrate, stirring for 1-2 hours, filtering, and spray drying to obtain the fucosan sulfate.
Preferably, in the step S1, the drying temperature is 40-50 ℃, and the particle size of the brown algae powder is 10-40 meshes.
Preferably, in step S1, the brown algae includes at least one of black horny algae (Fucus vesiculosus), kelp (Sargassum pallidum), sargassum fusiforme (Hizikia fusiforme), undaria pinnatifida (Undaria pinnathida), and kelp (Laminaria japonica).
Preferably, in step S2, the temperature of the low-temperature atomization extraction is 40-50 ℃, and the extraction time is 0.5-1 hour.
Preferably, in step S2, the weight ratio of the brown algae powder to water is 1:8-1.
The calcium hydroxide used in the extraction process of the invention has good impurity removal effect (main effect) on one hand: can react with alginate to form water-insoluble calcium alginate, denature protein to separate out, complex starch, precipitate free sulfate radical; on the other hand, the cell wall can be softened, the fucoidan sulfate on the cell wall can be dissociated, and the yield of the fucoidan sulfate is improved. In previous experiments, the inventor finds that when other hydroxides are adopted, the effect of the invention can not be achieved, the purity and the yield of the fucoidan sulfate are reduced, and the conductivity is also increased.
Preferably, in step S3, when the carbon dioxide is introduced to precipitate the excessive calcium hydroxide, the pH of the extracting solution is controlled to be 7.5-8.0.
According to the invention, carbon dioxide is introduced into the extracting solution to precipitate redundant calcium hydroxide, the concentration of original calcium ions, magnesium ions and the like in the solution is reduced, and the influence of endogenous and exogenous cations on the conductivity is eliminated; ingredients with too high an electrical conductivity can reduce the viscosity of the thickener in the formulation, causing difficulties in formulation application.
Preferably, in step S4, the cation exchange resin is selected from one or both of a strong acid cation exchange resin and a weak acid cation exchange resin; the addition amount of cation exchange resin is 2-5% of the filtrate weight.
The invention uses cation exchange resin in the purification process, which can not only adsorb the residual cations in the solution, but also reduce the pH of the solution to 2-3, wherein the pH is the isoelectric point of the brown algae protein and the alginic acid, and can further remove the residual protein and the alginic acid.
Preferably, in step S4, the purity of the obtained fucoidan sulfate is 80-85%, and the conductivity of the prepared fucoidan sulfate as 1% by mass aqueous solution is 1.2-1.8mS/cm.
In a second aspect, the present invention provides a use of fucoidan sulfate extracted according to the aforementioned method in the preparation of cosmetics having moisturizing effect, wherein the fucoidan sulfate is added in an amount of 0.05-0.5wt%.
Compared with the prior art, the invention has the following beneficial effects:
1) The invention adopts a low-temperature atomization extraction method in the extraction process, so that the water consumption is low and the period is short; the low-temperature extraction method avoids starch gelatinization, facilitates post-treatment, and improves the stability of the product in the solution; the calcium hydroxide aqueous solution is used as an extraction solvent, and the precipitation of impurities such as alginate and the extraction of fucoidan sulfate are synchronously carried out, so that the process flow is reduced, and the large-scale production is facilitated.
2) The method has the advantages of simple process, environmental protection and high extraction rate, and the prepared fucosan sulfate has excellent moisturizing effect.
3) The purity of the fucosan sulfate prepared by the method can reach more than 80%, and the conductivity of the water solution prepared by the method with the mass fraction of 1% is only 1.2-1.8mS/cm, so that compared with the existing method, the purity of the fucosan sulfate is obviously improved, and the conductivity of the fucosan sulfate is reduced.
Detailed Description
The present invention will be described in detail with reference to specific examples. The following examples will aid those skilled in the art in further understanding the present invention, but are not intended to limit the invention in any manner. It should be noted that variations and modifications can be made by persons skilled in the art without departing from the spirit of the invention. All falling within the scope of the present invention.
In the following examples, the purity of the fucose sulfate prepared was calculated as follows: an appropriate amount of solids (weight M) was taken and made up into a solution of approximately 5% strength with water. The barium chloride solution was slowly added dropwise to the solution until no precipitate was generated. Centrifuging, collecting precipitate, drying, and accurately weighing to obtain weight M1. The residue was measured for ignition by the method of general rules 0841 in the "Chinese pharmacopoeia" 2020 edition to obtain the weight M2 of the residue. The purity of fucoidan sulfate (%) =100 × (M1-M2)/M.
Example 1
The embodiment provides a method for extracting fucoidan sulfate, which comprises the following specific steps:
s1: washing Fucus vesiculosus 5kg with purified water to remove inorganic salt and other impurities on the surface, oven drying at 45 deg.C, and pulverizing into powder of Fucus vesiculosus 40 mesh;
s2: adding 0.2kg of calcium hydroxide into 50kg of water, stirring and mixing uniformly to form a calcium hydroxide aqueous solution, then carrying out atomization extraction on the fucus vesiculosus powder at 45 ℃ for 1h by using the calcium hydroxide aqueous solution as a solvent, and then filtering to obtain an extracting solution;
s3, introducing carbon dioxide into the extracting solution to adjust the pH value to 7.81, precipitating excessive calcium hydroxide, and filtering to obtain 37.2kg of filtrate;
s4, adding 1.86kg of cation exchange resin (D001 resin) into the filtrate obtained in the step S3 for desalting, stirring at room temperature for 1 hour, filtering, and spray-drying to obtain 0.085kg of solid matter, 83.5% of fucosan sulfate and 1.42% of yield. The fucosan sulfate prepared by the method is prepared into an aqueous solution with the mass fraction of 1%, the aqueous solution is placed for a week, the clarity and the transparency are realized, and the conductivity of the aqueous solution is measured to be 1.6mS/cm.
Example 2
The embodiment provides a method for extracting fucoidan sulfate, which comprises the following specific steps:
s1: washing Fucus vesiculosus 5kg with purified water to remove inorganic salt and other impurities on the surface, oven drying at 40 deg.C, and pulverizing into Fucus vesiculosus powder of 10 meshes;
s2: adding 0.125kg of calcium hydroxide into 40kg of water, stirring and mixing uniformly to form a calcium hydroxide aqueous solution, then carrying out atomization extraction on the fucus vesiculosus powder at 50 ℃ for 0.5h by using the calcium hydroxide aqueous solution as a solvent, and then filtering to obtain an extracting solution;
s3, introducing carbon dioxide into the extracting solution to adjust the pH value to 7.50, precipitating excessive calcium hydroxide, and filtering to obtain 25.5kg of filtrate;
s4, adding 0.51kg of cation exchange resin (D001 resin) into the filtrate obtained in the step S3 for desalting, stirring at room temperature for 1 hour, filtering, and performing spray drying to obtain 0.086kg of solid matter, 81.60% of fucosan sulfate and 1.40% of yield. The fucosan sulfate prepared by the method is prepared into an aqueous solution with the mass fraction of 1%, the aqueous solution is placed for a week, the clarity and the transparency are realized, and the conductivity of the aqueous solution is measured to be 1.78mS/cm.
Example 3
The embodiment provides a method for extracting fucoidan, which comprises the following specific steps:
s1: washing Fucus vesiculosus 5kg with purified water to remove inorganic salt and other impurities on the surface, oven drying at 50 deg.C, and pulverizing into 10 mesh Fucus vesiculosus powder;
s2: adding 0.225kg of calcium hydroxide into 75kg of water, stirring and mixing uniformly to form a calcium hydroxide aqueous solution, then carrying out atomization extraction on the fucus vesiculosus powder at 45 ℃ for 1h by using the calcium hydroxide aqueous solution as a solvent, and then filtering to obtain an extracting solution;
s3, introducing carbon dioxide into the extracting solution to adjust the pH value to 7.99, precipitating excessive calcium hydroxide, and filtering to obtain 58.5kg of filtrate;
s4, adding 2.925kg of cation exchange resin (D001 resin) into the filtrate obtained in the step S3 for desalination, stirring for 1 hour at room temperature, filtering, and spray drying to obtain 0.09kg of solid matter, wherein the purity of the fucosan sulfate is 84.7%, and the yield is 1.52%. The fucosan sulfate prepared by the method is prepared into an aqueous solution with the mass fraction of 1%, the aqueous solution is placed for a week, the clarity and the transparency are realized, and the conductivity of the aqueous solution is measured to be 1.30mS/cm.
Example 4
The embodiment provides a method for extracting fucoidan, which comprises the following specific steps:
s1: 5kg of kelp is washed by purified water to remove inorganic salt and other impurities on the surface, dried at 45 ℃ and crushed into kelp powder of 40 meshes;
s2: adding 0.15kg of calcium hydroxide into 50kg of water, stirring and mixing uniformly to form a calcium hydroxide aqueous solution, then carrying out atomization extraction for 1h at 45 ℃ by taking the calcium hydroxide aqueous solution as a solvent, and then filtering to obtain an extracting solution;
s3, introducing carbon dioxide into the extracting solution to adjust the pH value to 7.75, precipitating excessive calcium hydroxide, and filtering to obtain 35.2kg of filtrate;
s4, adding 1.0kg of cation exchange resin (D001 resin) into the filtrate obtained in the step S3 for desalting, stirring at room temperature for 1 hour, filtering, and performing spray drying to obtain 0.053kg of solid matter, wherein the purity of the fucoidan sulfate is 82.5%, and the yield is 0.87%. The fucosan sulfate prepared by the method is prepared into an aqueous solution with the mass fraction of 1%, the aqueous solution is placed for a week, the clarity and the transparency are realized, and the conductivity of the aqueous solution is measured to be 1.40mS/cm.
Comparative example 1
The comparative example provides a method for extracting fucoidan sulfate, which has the same specific steps as the example 1, except that: in step S2, instead of low temperature atomization, fucus vesiculosus powder is directly added into calcium hydroxide aqueous solution, stirred for 1 hour at 85-90 ℃ and filtered to obtain the extract.
Finally, 0.047kg of solid matter is obtained, the purity of the fucoidan sulfate is 72.5 percent, and the yield is 0.68 percent. The fucosan sulfate prepared by the method is a 1% aqueous solution with slight opalescence after being placed at room temperature for 1 week, and the conductivity of the aqueous solution is measured to be 1.65mS/cm.
Comparative example 2
The comparative example provides a method for extracting fucoidan sulfate, which has the same specific steps as the example 1, except that: step S3 is: adding 5% sodium carbonate aqueous solution to precipitate calcium hydroxide until no precipitate is generated in the solution, and filtering to obtain filtrate.
Finally, 0.089kg of solid matter is obtained, the purity of the fucoidan sulfate is 77.8 percent, and the yield is 1.38 percent. The fucosan sulfate prepared by the method is used for preparing an aqueous solution with the mass fraction of 1%, the aqueous solution is placed for a week, the clarity and the transparency are realized, and the conductivity of the aqueous solution is measured to be 13.7mS/cm.
Comparative example 3
The comparative example provides a method for extracting fucoidan sulfate, which has the same specific steps as example 3, except that: in step S2 of this comparative example, the amount of calcium hydroxide added was 0.3kg.
Finally, the solid 0.0865kg is obtained, and the fucosan sulfate has the purity: 81.4%, yield 1.41%. The fucosan sulfate prepared by the method is used for preparing an aqueous solution with the mass fraction of 1%, the aqueous solution is placed for a week, the clarity and the transparency are realized, and the conductivity of the aqueous solution is measured to be 3.70mS/cm.
Comparative example 4
The comparative example provides a method for extracting fucoidan sulfate, which has the same specific steps as the example 2, except that: in step S2 of this comparative example, the amount of calcium hydroxide added was 0.1kg.
The final solid content is 0.892kg, the fucosan sulfate purity is 73.5%, and the yield is 1.31%. The fucosan sulfate prepared by the method is prepared into an aqueous solution with the mass fraction of 1%, the aqueous solution is placed for a week, the aqueous solution is clear and transparent, and the conductivity of the aqueous solution is measured to be 2.5mS/cm.
Comparative example 5
The comparative example provides a method for extracting fucoidan sulfate, which has the same specific steps as the example 1, except that: in step S2 of this comparative example, sodium hydroxide was used instead of calcium hydroxide.
The final solid content is 0.13kg, the fucoidan sulfate purity is 53.2%, and the yield is 1.38%. The fucosan sulfate prepared by the method is prepared into an aqueous solution with the mass fraction of 1%, and the conductivity of the aqueous solution is measured to be 15.7mS/cm.
Verification of moisturizing efficacy of fucoidan sulfate prepared in example 1
The experimental method comprises the following steps:
1. subject selection: healthy subjects of 20-50 years old are 11-14 people, male and female are not limited.
2. Sample preparation: 0.2% hyaluronic acid HA and 0.05%, 0.25%, 0.5% fucoidan sulfate (hereinafter referred to as Sea-Gel) aqueous solution (prepared from the solid prepared in example 1 and water in percentage by mass).
3. The immediate test method comprises the following steps: inner side of forearm of left and right hand is marked with 3X 3cm 2 Test area, same arm mark 3 areas simultaneously, the interval of area is 1cm. Both test samples and blank were randomly distributed on the left and right arms. Measuring blank value 30min after cleaning each test area, detecting each test part with instrument, repeating for 3 times, and obtaining average value as basic value. Then 2.0 +/-0.1 mg of sample/cm 2 The test sample is uniformly coated in the test area. Dividing after smearingThe skin moisture content, TEWL, was measured for 1.5h, 3h, 6h, 24h test area and blank control area, respectively, and the test area and control area were examined 3 times each to obtain the average.
The moisture content of the skin and the transepidermal water loss rate (TEWL) are two major indexes for evaluating whether a sample has the moisturizing effect through a human body clinical experiment. Meanwhile, TEWL is also a common index for reflecting the barrier function of the stratum corneum, and the TEWL detection value is increased for the crowd with damaged skin barrier function.
4. The long-acting test method comprises the following steps: the basic value detection steps are the same as the real-time test method. Different samples are smeared 2 times in the morning and at night every day, the skin moisture content and TEWL in the tested area and the blank control area are respectively measured 7 days, 14 days after smearing and 3 days after no smearing, the test area and the control area are respectively detected 3 times, and the average value is obtained.
5. The main instruments/reagents are shown in table 1 below.
TABLE 1
Instrument/reagent name
|
Brand
|
Model/goods number
|
Remarks for note
|
Multifunctional skin tester
|
CK
|
MPA6
|
Self-calibration
|
CM825 probe
|
CK
|
-
|
Self-calibration
|
TM300 probe
|
CK
|
-
|
Self-calibration |
6. The analysis method comprises the following steps:
all the test data were divided by the baseline and then by the blank to make the blank 100%, and the effect of each sample on skin moisture and TEWL was calculated and the rate of change was recorded as MMV% and TEWL%, respectively. Significant differences between the samples and the blank were calculated by the method of TTest, P <0.05, P <0.01, P <0.001. The calculation formula is as follows:
detection change value% = detection after use/detection before use × 100%
Rate of change% = detection change value Sample set Detecting the variation value Blank group ×100%
7. And (3) immediate test results:
the effect of applying Sea-Gel at concentrations of 0.05%, 0.25% and 0.5% for 1.5h on skin moisture was first tested and the results are shown in fig. 1. As can be seen from FIG. 1, the increase rates of Sea-Gel of 0.05%, 0.25% and 0.5% in the skin moisture content after 1.5 hours were 5.2%, 12.2% and 14.4%, respectively, as compared with the control group (Water).
The effect on skin moisture content, TEWL, after various time periods following 0.5% sea-Gel application was tested continuously and the results are shown in FIGS. 2 and 3. As can be seen from FIG. 2, the HA samples treated with Sea-Gel 0.5% significantly increased the skin water content compared to the blank control group (NT group) by 19%, 11%, 12% at 1.5h, 3h, 6h, respectively, and still increased 10% at 24h, which is stronger than 0.2%. As can be seen from FIG. 3, the decrease of 2.1% and 5.3% in Sea-Gel was observed after 3h and 24h compared with NT group, while the increase of about 4% in HA-treated group after 3h compared with NT group.
8. Long-term test results:
finally, the change in skin moisture content, TEWL, after continuous daily use of 0.5% Sea-Gel was tested and the results are shown in FIGS. 4 and 5. As can be seen from fig. 4 and 5, sea-Gel showed significant improvement in skin moisture content and TEWL after 7 days of continuous use, compared to the blank control group (NT group), with 24% and 34% increase in skin moisture content and 14% decrease in TEWL, respectively, after 7 days and 14 days of continuous use. Compared with the HA group, sea-Gel HAs stronger effect of improving the water content (P is less than 0.01). At 48h after the last use (results of +48h in fig. 4), sea-Gel still raised skin hydration to 132% compared to the NT group, whereas HA group was only 108%.
In conclusion, 0.05% -0.5% of Sea-Gel can improve the water content of the skin after 1.5 hours of one-time use, and the maximum improvement rate reaches 19%.
The Sea-Gel with the concentration of 0.5 percent can obviously improve the water content of the skin after being used for 1.5 to 24 hours for 2 times a day and 7 to 14 days, and the maximum improvement rate reaches 34 percent. The TEWL can be obviously reduced after the continuous use for 7 to 14 days, and the maximum reduction rate reaches 19 percent.
Therefore, the fucoidan sulfate prepared by the embodiment of the invention can increase the moisture content of the skin, reduce the water loss of the skin, maintain the normal function of the skin and have the effects of moisturizing and repairing.
Verification of moisturizing efficacy of fucoidan sulfate prepared in example 2, comparative example 1, and comparative example 2
The fucosan sulfate obtained in comparative example 1 and comparative example 2 was evaluated for moisturizing efficacy in the same manner as in verification example 1.
The fucoidan sulfate (solid) obtained in comparative example 1 and comparative example 2 were prepared into 0.5% aqueous solutions (corresponding to the treatment group of comparative example 1 and the treatment group of comparative example 2, respectively), and the change in the moisture content of the skin 24 hours after one-time use was examined. The results are as follows:
as can be seen from fig. 6, compared to the blank control group (NT group), HA treatment group, and 0.5% Sea-Gel treatment group treated under the same conditions in verification example 2, the skin moisture content was significantly increased by the 0.5% Sea-Gel treatment group 24 hours after use, and the increase rate reached 10%. While the comparative example 1 treatment group was not effective, the comparative example 2 treatment group even decreased by 13%. As can be seen from FIG. 7, the amount of TEWL was reduced by 5.3% in the Sea-Gel treatment group at 0.5% for 24 hours compared to the NT group, while the amount of increase was about 1% and 5% in the comparative example 1 treatment group and the comparative example 2 treatment group, respectively.
The fucoidan sulfates obtained by the methods of examples 2 to 5 of the present invention also had moisturizing effects comparable to those of the fucoidan sulfates obtained by the method of example 1.
The invention has many applications and the above description is only a preferred embodiment of the invention. It should be noted that the above examples are only for illustrating the present invention, and are not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications can be made without departing from the spirit of the invention, and these modifications should be construed as within the scope of the invention.