64 results about "Salting out" patented technology

The invention relates to the technical field of isoflavone biotransformation, in particular to a soybean isoflavone aglycone preparation method based on enzymolysis. Comprising the following steps: inoculating Kluyveromyces marxianus into a basic culture medium for shake cultivation; after culturing, centrifuging, washing and resuspending to obtain a bacterial suspension as a leavening agent, and inoculating the bacterial suspension to a bean dreg composite culture medium for shaking table fermentation for 48-96 hours; centrifuging the fermentation liquor at 0-4 DEG C, and collecting supernate to obtain crude beta-glucosidase; the crude enzyme liquid is sequentially subjected to ammonium sulfate salting-out, ion exchange chromatography and twice sephadex chromatography, and purified beta-glucosidase liquid is obtained; and carrying out enzymatic reaction on soy isoflavone by using the purified beta-glucosidase liquid to obtain the soy isoflavone aglycone. The method has the advantages that the bean dreg culture medium is utilized for fermentation to produce beta-glucosidase, and the combined soy isoflavone is subjected to enzymolysis, so that the utilization of the byproduct bean dregs is improved, the biotransformation of isoflavone is realized, and the obtained product has better activity.

The invention discloses a preparation method of an ulinastatin crude product, which comprises the following steps: a, adsorbing urine of healthy adults by using macroporous adsorption resin, and then desorbing by using a salt solution to obtain an eluent; b, carrying out ultrafiltration concentration on the obtained eluent to obtain a first concentrated solution; c, purifying and eluting the concentrated solution obtained in the step b by using a lectin affinity chromatography column, and collecting a liquid phase; d, performing ultrafiltration concentration on the obtained liquid phase to obtain a second concentrated solution; and e, salting out the second concentrated solution, and filtering to obtain the ulinastatin crude product. The ulinastatin prepared by the preparation method disclosed by the invention is high in specific activity and long in shelf life.

The invention relates to the technical field of materials, in particular to a super-tough piezoelectric material and a preparation method thereof.The preparation method comprises the following steps that a preformed high polymer material is stretched while salting out in salting-out liquid, and the super-tough piezoelectric material is obtained after shaping. Through the synergistic effect of preforming and simultaneous stretching and salting-out, the secondary structure of protein in the fiber is changed, so that the toughness and piezoelectric property of the fiber material are improved, and the piezoelectric material with high piezoelectric property and high flexibility is prepared.

The invention discloses a high-strength microneedle with directional holes for biological analysis sampling and a preparation method of the high-strength microneedle, and belongs to the technical field of microneedles, the method comprises the following steps: filling a silk fibroin solution into a microneedle mold to form a microneedle preform, the microneedle preform comprising a needle body part and a backing part; performing directional freezing on the microneedle preform to enable ice crystals to directionally grow in the direction from the backing part to the needle body part, and demolding to obtain a frozen blank; the frozen blank is placed in an organic solution of a cross-linking agent, soaked at the low temperature lower than 0 DEG C for ice template low-temperature solvent exchange-cross-linking treatment, taken out and cleaned, then soaked in a salt solution for salting-out treatment strengthening, taken out and cleaned and freeze-dried, and the high-strength microneedle with the directional holes is obtained. The microneedle prepared through the method has high strength and excellent puncture performance, and the skin interstitial fluid collection speed and efficiency are greatly improved.

The invention discloses a preparation method and application of torreya grandis antioxidant emulsion, and relates to the field of food additives. The torreya grandis antioxidant emulsion is prepared by taking torreya grandis oil production waste as a raw material, performing selective degreasing, enzymolysis extraction, acid sedimentation and alkaline salting-out to obtain a torreya grandis antioxidant nutrient substance, and then performing self-assembly composite emulsification. According to the preparation method of the torreya grandis antioxidant emulsion, the used raw materials are purely natural and low in cost, beneficial substances with different polarities in torreya grandis are reserved to a great extent, and finally a natural food additive which is high in nutritional value, strong in antioxidant effect and relatively long in storage life is obtained.

The invention discloses a method for extracting and purifying natural active collagen, particularly relates to a method for purifying type I collagen, and belongs to the technical field of collagen production. By adopting a purification scheme of salting-out and ultrafiltration purification liquid change, high-purity and high-activity natural I-type collagen can be successfully obtained, and the problems of low biological activity and low protein purity caused by long collagen purification period and high non-target protein content in the traditional purification technology are solved. The method for purifying the I-type collagen mainly comprises the following steps: S1, carrying out pretreatment on raw materials, carrying out reaction by adopting an enzymolysis technology, and then obtaining I-type collagen enzymatic hydrolysate by adopting a centrifugation method; s2, preliminarily removing soluble impure protein, pepsin and other impurities by using a salting-out process; and S3, redissolving the crude extract, filtering through a polypropylene folded filter element to obtain a raw material solution, purifying the raw material solution through a tangential flow ultrafiltration method, and concentrating to obtain the I-type collagen purified solution.

The invention relates to the technical field of bioengineering, in particular to an SOD (superoxide dismutase) impurity removal and purification process which comprises the following steps: extracting SOD enzyme from fresh animal blood, separating high-purity red blood cells through gradient centrifugation, preparing a crude extract by combining hypotonic lysis and freeze thawing strengthening, then selectively precipitating hemoglobin and other heat-sensitive impurity proteins by adopting a gradient temperature rise thermal denaturation method, and purifying to obtain the SOD impurity removal and purification process. The method comprises the following steps: extracting SOD, removing pigments and lipid impurities by using a mixed adsorbent, further enriching SOD by using ammonium sulfate salting-out, and finally obtaining high-purity SOD powder through vacuum freeze drying by combining ion exchange chromatography and ultrafiltration concentration technologies. The method has the advantages of high efficiency, rapidness and low cost, impurities can be effectively removed through a combined process of hypotonic / freeze-thaw cracking, hemoglobin removal through thermal denaturation, ammonium sulfate salting-out, ion exchange chromatography and ultrafiltration concentration, the purity and the recovery rate of the SOD enzyme are remarkably improved, the whole purification process is carried out at 4 DEG C, and the method is suitable for industrial production. The influence of high temperature on the activity of the SOD enzyme is avoided.

The invention provides a preparation method of a terminal-peptide-free bovine type I collagen product. The preparation method comprises the following steps: obtaining a crushed bovine tissue raw material without impurities; the preparation method comprises the following steps: soaking a cattle tissue raw material in acid, and homogenizing to obtain cattle tissue homogenate; protease is added into the bovine tissue homogenate in batches for enzymolysis, the enzymolysis temperature is controlled to be 2-6 DEG C, after salting-out precipitation, pH value adjustment and redissolution are carried out on the bovine type I collagen extracting solution obtained in the middle batch, protease is added again for enzymolysis, salting-out precipitation, pH value adjustment and redissolution are carried out again, and the bovine type I collagen extracting solution is obtained. Repeating for multiple times to obtain a terminal-peptide-free bovine type I collagen solution; adjusting the pH value of the terminal-peptide-free bovine type I collagen solution, salting out, precipitating, centrifuging and washing to obtain terminal-peptide-free bovine type I collagen precipitate; and purifying the terminal-peptide-free bovine type I collagen precipitate to obtain the terminal-peptide-free bovine type I collagen product. According to the telopeptide-free bovine type I collagen product provided by the invention, no residual telopeptide is detected, and the purity is high.

The invention discloses a natural hirudin extraction method based on cell fermentation. The natural hirudin extraction method comprises the following steps: S1, providing leeches, and carrying out starvation treatment on the leeches; s2, taking out the leeches, cleaning the leeches with a metaldehyde solution, and then putting the leeches into purified water for cleaning; s3, inducing and stimulating the leeches, and collecting secretory fluid; s4, extracting hirudin in the secretion on the basis of cell fermentation to obtain fermentation liquor; s5, carrying out separation and purification treatment on the fermentation liquor based on ammonium sulfate fractional precipitation salting-out; and S6, further separating and purifying the fermentation liquor based on ion exchange chromatography. According to the method, the components of the leeches are utilized, the extraction rate of the hirudin is further improved through cell fermentation, a two-stage separation and purification system is established, the purification process is optimized, and the recovery rate and the purification effect of the hirudin are further improved.

The invention relates to low-fat collagen as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out acidolysis and enzymolysis on a pre-treated product; preheating, centrifuging and salting out the enzymolysis product; after salting out, carrying out secondary centrifugation, taking precipitate, re-dissolving the precipitate in an acetic acid solution, carrying out first pasteurization, and filtering; and carrying out ultrafiltration concentration on the filtered product, and carrying out secondary pasteurization on the concentrated solution to obtain the recombinant collagen. The collagen obtained by the extraction process disclosed by the invention is lower in grease content and lower in bacterial endotoxin content, and the purity, the safety, the thermal stability, the structural integrity, the applicability and the like of the collagen are guaranteed.

The present application relates to the technical field of protein separation and purification, and specifically discloses a method for extracting bovine colostrum immunoglobulin. The method comprises the following steps: centrifugal degreasing: degreasing the bovine colostrum by centrifugation, followed by filtering the intermediate layer to obtain colostrum whey; ammonium sulfate salting out: diluting the colostrum whey, then adding a saturated ammonium sulfate solution, stirring, standing, centrifuging, removing the supernatant A, adding phosphate buffer to the precipitate A, stirring evenly, adding a saturated ammonium sulfate solution, standing, centrifuging, removing the precipitate B, adding a saturated ammonium sulfate solution to the supernatant B, centrifuging, removing the supernatant C, and obtaining the precipitate C; and purification: desalting the precipitate C using a gel column, concentrating it by ultrafiltration, and separating it by column chromatography to obtain the bovine colostrum immunoglobulin.

The invention relates to a composition of matter extracted from the plant Tribulus terrestris, having less than 400 µg per kilogram of dry matter pyrrolizidine alkaloids and at least 40% furostanol saponins and a Tribulus terrestris extract having at least 10% furostanol saponins and a concentration of pyrrolizidine alkaloids of less than 80 µg per liter extract. The invention is further directed to a method for the purification of pyrrolizidine alkaloids from Tribulus terrestris plant extract by salting out the saponins from the extract with a first salt solution until a precipitate forms, washing the precipitate with a second salt solution and then dissolving the precipitate in water, removing the remaining amount of salt from the obtained aqueous solution by extraction with alcohol, washing with water, and evaporating the residual alcohol to a final Tribulus terrestris extract, which can be dried.

The invention discloses a salt-tolerant clean fracturing fluid and a preparation method thereof, and the salt-tolerant clean fracturing fluid comprises the following components: an anionic-nonionic surfactant NPEC and a cationic surfactant CTAB, the preparation method comprises the following steps: step a, uniformly mixing an anionic-nonionic surfactant NPEC and a cationic surfactant CTAB according to a ratio; step b, adding water, stirring until the materials are completely dissolved, adjusting the pH value, and performing cooling and aging treatment; and c, adjusting the viscosity and rheological property of the fracturing fluid according to actual requirements by adding NaCl with different concentrations. The fracturing fluid prepared by the invention can effectively cope with the influence of hypersalinity formation water in shallow oil and gas reservoirs; the stability of the fracturing fluid is improved, and performance reduction caused by salting-out is reduced; the method has high salt tolerance, is suitable for development of shallow oil and gas reservoirs, does not need high-temperature crosslinking, and has good economical efficiency and practicability.

The invention relates to a method for purifying erythromycin thiocyanate, which comprises the following steps of: firstly, carrying out decoloration and impurity removal pretreatment on alkalized erythromycin fermentation liquor through combination of activated carbon adsorption and diatomite packed column filtration, then combining an acetone extract salifying primary crystallization method and a crystallization mother liquor salting-out secondary crystallization method, and finally drying to obtain the erythromycin thiocyanate. According to the method, the extraction process of erythromycin thiocyanate is optimized, the yield is increased while the purity of the erythromycin thiocyanate product is effectively improved, the content of erythromycin thiocyanate A reaches 90% or above, and the yield reaches 88% or above.

The utility model relates to the technical field of salting-out tanks, in particular to a salting-out tank for extracting nisin, which comprises a tank body, four supporting legs, a feeding structure, a stirring structure and a drawing structure, the bottom of the tank body is fixedly connected with the four supporting legs, the feeding structure and the stirring structure are mounted at the top of the tank body, and the drawing structure is mounted at the bottom of the tank body. A drawing structure is installed in the tank body and comprises a handle, a baffle, a fixing base, a fixing bolt, a drawer, a sliding rod and a filter plate. According to the device, the feeding structure is arranged, indirect adding of salt liquid can be achieved through the feeding structure, it is guaranteed that the solution can be evenly mixed, and then normal separation of nisin is guaranteed. The salting-out substance collecting box is provided with the drawing structure, the salting-out substance can be taken out by detaching the fixing bolt and pulling the handle to enable the handle to drive the drawer to be pulled outwards, the drawer can be opened through the drawing structure to collect the salting-out substance, the salting-out substance can be rapidly and conveniently collected, and the salting-out substance collecting box is convenient to use.

The present application adopts an ultrasound-assisted combined salting-out method, and by screening a specific salting-out reagent, not only can the extraction efficiency be improved, but also the content of D-limonene can be greatly increased, and the subsequent purification operation can be reduced; the ultrasonic extraction of the present invention can be carried out at room temperature without heating, and the time required for the ultrasonic extraction step is short, which is more conducive to industrial production.

The present application provides a method for refining cefotaxime sodium, belonging to the technical field of pharmaceutical preparations. The crude cefotaxime hydrochloride is dissolved in a mixed solvent, the pH is adjusted to 2-4, a desalting agent is added for salting out, followed by decolorization, filtration, and the filtrate is retained. The mixed solvent is acetone + alcohol, acetone + alkane, or acetone + alcohol + alkane. The salifying agent is dissolved in the mixed solvent, and the resulting solution is dropped into the filtrate for salting, crystallization, filtration, washing, draining, and vacuum drying to obtain the finished product cefotaxime sodium. Applying the present application to the preparation of cefotaxime sodium not only reduces the impurity content of the product but also helps to reduce the acetone residue, with good product color and high yield.

This invention discloses a method for salting out salmon PDRN. The method includes: adding a soluble salt and an organic solvent to a salmon ooze enzymatic hydrolysate, mixing thoroughly, allowing the mixture to stand and separate into three phases, forming a three-phase salting-out extraction system consisting of an upper phase, an intermediate phase, and a lower phase; collecting the intermediate phase when the organic solvent is hydrophilic, and collecting the lower phase when the organic solvent is hydrophobic; purifying and drying the collected intermediate or lower phase to obtain PDRN powder. This invention uses salmon ooze enzymatic hydrolysate as raw material and extracts salmon PDRN product in one step through salting-out extraction. The PDRN product yield is greater than 5.0%, A260 / A280 is 1.8–2.0, A260 / A230 is ≥2.0, endotoxin content is <0.03 EU / mg, protein content is ≤0.5%, and molecular weight is 200–4000 bp. The method of this invention has the advantages of simple process, low cost, high yield, and high product purity, making it suitable for large-scale industrial production.

The invention relates to the field of bioengineering, in particular to a perch collagen peptide as well as a preparation method and application thereof. The invention provides a preparation method of perch collagen, which comprises the following steps: carrying out acid extraction on pretreated perch scales, hydrolyzing with a first enzyme, filtering, salting out filtrate, centrifuging, collecting precipitate, redissolving, purifying, hydrolyzing with a second enzyme, and heating to obtain the perch collagen, enzymes adopted by the first enzyme hydrolysis and the second enzyme hydrolysis can be the same or different; the enzyme comprises one or more of alkaline protease, papain, subtilisin and pepsin. The collagen peptide extracted from sea bass scales and processed into the sea bass scales is systematically researched and developed, and the collagen peptide has an excellent anti-photoaging effect and high replicability. The collagen peptide is low in molecular weight, high in oxidation resistance and wide in application range, and can be applied to the fields of cosmetics, oral collagen supplements and the like.

The invention relates to the field of traditional Chinese medicine extraction, and particularly discloses a comprehensive extraction process of berberine, which comprises the following steps: crushing fresh golden cypress to obtain golden cypress raw material powder, then taking a mixed solvent of a 10-20% methanol solution and citric acid as an entrainer, carrying out supercritical carbon dioxide extraction to obtain an extract, and concentrating the extract to obtain the berberine. Filtering to obtain cortex phellodendri filter residues and a polysaccharide extracting solution mainly containing cortex phellodendri polysaccharide; the cortex phellodendri filter residues in the step S1 are soaked with dilute sulphuric acid and extracted to obtain an extracting solution B containing berberine; adding hydrochloric acid into the extracting solution B for acidification, then adding sodium chloride for salting out, then filtering, and collecting precipitate to obtain berberine extract; the method has the characteristics that the berberine extraction period is shortened, the difficulty of viscous substances for subsequent treatment after acid extraction is solved, the extraction is more convenient and easy to operate, and meanwhile, the berberine extract with higher content is obtained through extraction.

The invention relates to the field of collagen preparation, in particular to a preparation method for improving the biological safety of collagen, a product and application. The preparation method comprises the following steps: pretreating raw materials; performing enzymolysis on the pre-treated product, and performing salting-out on the enzymolysis product; after redissolving the precipitate separated out by salting out, filtering by using a diatomite filter; and carrying out ultrafiltration and concentration on the filtered product to obtain the collagen. On the basis of ensuring the purity, the collagen obtained by the extraction process disclosed by the invention is higher in biological safety, sterile, lower in pathogen content and lower in bacterial endotoxin content, and can be ensured to be applied to the medical field.

The invention discloses a natto active substance, natto-flavored konjac jelly and a preparation method thereof, and relates to the technical field of food processing. The preparation method of the natto active substance comprises the following steps: mixing mature natto and normal saline according to a volume ratio of (1-1.1): (2-2.2), extracting for 24-26 hours, centrifugally filtering the obtained extract liquid, and reserving supernate to obtain a crude extract liquid; and mixing the crude extract and an ammonium sulfate solution with the saturation degree of 30% according to the volume ratio of (28-32): (12-15), carrying out primary salting-out, then carrying out primary centrifugal filtration, adding an ammonium sulfate saturated solution into the supernatant obtained by the primary salting-out until the saturation degree is 70-72%, carrying out secondary salting-out, then carrying out secondary centrifugal filtration, and taking the precipitate, thereby obtaining the natto active substance. The preparation method is simple, the natto active substance is extracted from the mature natto through extraction and secondary salting-out, the extraction rate is high, the purity is high, the obtained natto active substance is applied to the jelly, the flavor of the jelly can be increased, and the digestibility of the jelly can be improved.

The invention provides a preparation method of a medical high-transparency collagen solution, which comprises the following steps: S1, taking fresh animal tissues, removing tissues such as hair, fascia, fat and blood meat, slicing, cleaning to remove blood water, washing with water, and freezing and crushing; s2, soaking the crushed materials in a mixed degreasing agent for degreasing; the mixed degreasing agent comprises a cationic surface active agent and lipase, and the cationic surface active agent comprises at least one of a bio-based surface active agent and a quaternary ammonium salt type surface active agent; the bio-based surfactant comprises at least one of rhamnolipid, sophorolipid and trehalose lipid; s3, freezing the degreased material, irradiating, soaking in purified water, filtering, and collecting a swelled material; s4, carrying out enzymolysis on the swelled substance; s5, collecting filtrate after enzymolysis, filtering after salting out, collecting filter residues, and cleaning in a salt solution to obtain a salting-out substance; s6, the salting-out substance is added into pure water to be dissolved, the mass fraction of collagen is controlled to range from 0.01% to 6.5%, then ultrafiltration is conducted, filtrate is collected, low-temperature storage is conducted, and a collagen solution is obtained. The collagen prepared by the preparation method has relatively high transparency, and meanwhile, the structure of the collagen is not damaged in the preparation process, that is, the finally obtained collagen solution still has a complete triple helix structure. And heavy metals or toxic and harmful reagents are not added in the whole extraction process, so that the problem of residues of the heavy metals or the toxic and harmful reagents does not exist, and the application range is widened.

The invention relates to the technical field of food contact grade plastic safety detection, and discloses a method for determining the content of limonene in a food contact grade plastic product, which comprises the following steps: S100, preparing a standard solution, S101, preparing an ethanol / water solvent (V: V = 1: 1), mixing 250mL of ethanol with 250mL of water, S102, preparing a mother solution (1000mu g / mL), accurately weighing 0.95-1.05 g (accurate to 0.001 g) of limonene in a 100mL volumetric flask containing 50mL of ethanol, and measuring the content of the limonene in the volumetric flask according to the standard solution. And fixing the volume to 100mL by using ethanol. According to the method for determining the content of limonene in the food contact grade plastic product, the ethanol / water mixed solvent is selected as the poising agent, so that plastic particles can be completely immersed in a liquid phase by the poising agent, and limonene can be transferred into the ethanol / water mixed solvent; the limonene emigrated from the plastic particles is more favorable for being distributed to a gas phase in a gas-liquid equilibrium state, so that the detection sensitivity is improved, and the distribution ratio of the limonene in the gas phase is further improved due to the addition of sodium chloride and a salting-out effect.

The present invention relates to a highly efficient method for purifying flue gas desulfurization amine liquid, comprising: adding a composite purifier to the regenerated lean agent to be purified, while simultaneously and continuously introducing nitrogen for stripping; after the composite purifier is added, continuing to introduce nitrogen for stripping for at least 3 minutes; after the stripping is completed, cooling the resulting mixed solution to 20-45°C, allowing it to stand for stratification and separation, resulting in a free amine liquid in the upper layer and a brine solution containing sulfate and degradation products in the lower layer. The purification method of the present invention utilizes stripping coupled with salting out to simultaneously and efficiently remove organic amine degradation products and sulfate, achieving a high single-stage purification removal rate. The device is also simple to operate, has low energy consumption, minimizes amine loss, and reduces the discharge of amine-containing wastewater, meeting the new requirements for clean production to achieve the dual carbon goals.

The invention discloses collagen sponge and a preparation method and application thereof. The preparation method comprises the steps of pretreatment, acidolysis, enzymolysis, salting-out, filtration, ultrafiltration and concentration, crosslinking, freeze-drying treatment and the like. The preparation process of the collagen sponge provided by the invention is simple to operate, the water absorption capacity of the prepared collagen sponge product can reach 40-60 times of the self weight, the hemostatic effect is good, the mechanical property is good, the requirements of industrial standards are met, and the application range is wide.

The present application discloses a recombinant sea cucumber peptide with soothing effect, a preparation method thereof and an application thereof, wherein the amino acid sequence with repairing effect is shown in SEQ ID NO. 1. The present application also provides a preparation method of a recombinant sea cucumber peptide, which mainly comprises: gene synthesis; constructing a vector plasmid: integrating the target gene sequence into the vector plasmid, and introducing the plasmid into a competent genetic engineering strain; fermenting and expressing the target product; obtaining a high-purity sea cucumber peptide by purification means (solid-liquid separation, salting out, isoelectric precipitation, chromatography technology, ultrafiltration), and the sea cucumber peptide has excellent water solubility and high purity, and can be widely used in cosmetics.

The invention discloses a holboellia latifolia seed protein extraction method in the technical field of protein extraction, and particularly comprises the following steps: crushing holboellia latifolia seeds, degreasing with n-hexane or petroleum ether, and drying; then, mixing the melon seed powder with a sodium hydroxide solution, and carrying out microwave treatment for 15-20 minutes; after cooling, carrying out pulsed electric field-assisted ultrasonic-assisted enzymolysis, and adding neutral protease; after the enzymolysis is finished, cooling and adding ammonium sulfate powder for salting out; centrifuging the salting-out mixed solution, collecting supernate, passing through an affinity chromatography column, flushing with a phosphate buffer solution with the pH value of 7.0, and eluting protein with an eluent containing sodium chloride with the concentration of 1-1.2 mol / L; and adjusting the pH value of the eluent to 10.5-11.5, centrifuging after extraction, adjusting the pH value of the supernatant to 5, centrifuging and collecting the precipitate. And dissolving the precipitate with a phosphate buffer solution, dialyzing and drying to obtain the holboellia latifolia seed protein. According to the extraction method, the extraction rate and the purity of the holboellia latifolia seed protein can be remarkably improved.

The present invention relates to a method for extracting isorhamnetin from seabuckthorn puree, so as to solve the problem that the traditional process only extracts the free isorhamnetin in the seabuckthorn puree, but cannot extract the isorhamnetin in the glycoside compound, resulting in the waste of isorhamnetin resources and the technical problem of reducing the yield of isorhamnetin. The method includes: 1) defatting the seabuckthorn puree; 2) spraying a weakly acidic buffer solution and a surfactant into the defatted raw material, and then adding naringinase and pectinase; 3) adding an ester solvent to the residue after double enzymolysis for extraction, concentrating the extract, adsorption filtering, and collecting the filtrate; 4) adding an electrolyte salting-out agent to the filtrate, extracting with alkaline water, collecting the upper liquid, washing with water to neutrality, concentrating the upper liquid and filtering; 5) recrystallization. The present invention can increase the yield by 30-40%, realize the purification of isorhamnetin, and the isorhamnetin content reaches more than 98%.

The invention provides sturgeon swimming bladder collagen as well as an acid leaching extraction method and application thereof, and relates to the technical field of protein extraction. The acid leaching extraction method provided by the invention comprises the following steps: performing alkali washing on sturgeon swimming bladders, degreasing, soaking in an acid solution, separating an extracting solution, and salting out to obtain collagen. The method provided by the invention can simply, conveniently and quickly obtain the sturgeon swimming bladder acid-soluble collagen with strong antioxidant activity, not only can effectively reduce the waste of sturgeon swimming bladders and sustainably utilize sturgeon resources, but also has higher extraction rate of the sturgeon swimming bladder collagen, and is beneficial to industrial production; meanwhile, the prepared acid-soluble collagen of the sturgeon swimming bladder can effectively inhibit and improve premature ovarian failure.