407 results about "Neutral protease" patented technology

The invention discloses preparation of a whey protein peptide mixture with immune and muscle-building effects, and relates to the technical field of food processing and bioengineering. The neutral protease is adopted and the pH is adjusted, so that the enzymolysis efficiency is effectively improved, and the enzymolysis time is greatly shortened; meanwhile, the whey protein peptide which is uniform in molecular weight distribution, free of peculiar smell and good in thermal stability is successfully prepared by accurately controlling enzymolysis conditions and combining microbial fermentation. The protein peptide can effectively improve thymus indexes and spleen indexes, enhance the proliferation capacity of splenic lymphocytes and the activity of NK cells, play an excellent immune regulation role and have a remarkable muscle building effect. The preparation process has the advantages of high efficiency, low cost, simplicity, convenience and the like, gives consideration to high quality and high functionality of the product, and has great application value.

The invention relates to a medicine for repairing skin wounds and a preparation method thereof, and belongs to the technical field of biological medicines.The medicine is prepared from, by mass, 25-30 parts of bee embryo peptide, 8-10 parts of alkannin derivative, 10-15 parts of armillaria mellea polysaccharide, 8-10 parts of inonotus obliquus polysaccharide, 6-8 parts of notoginsenoside and 5-7 parts of astragaloside. The bee fetus peptide is a product which is more than 500Da and is obtained by performing step-by-step enzymolysis on bee larva freeze-dried powder through trypsin and bacillus subtilis neutral protease to obtain enzymatic hydrolysate which is less than 3kDa, performing purification through a G-50 sephadex column, performing ultrafiltration and performing freeze-drying. The alkannin derivative is obtained by reacting alkannin with succinic anhydride and glucosamine-polyethylene glycol. A special method is adopted for preparing the bee embryo peptide and alkannin derivatives, the bee embryo peptide and alkannin derivatives are matched with other components to play a synergistic role, and the effects of high safety, high skin cell proliferation promoting capacity, excellent antibacterial performance and the like are achieved.

The invention provides an efficient enzymolysis fermentation method for hermetia illucens larvae. The efficient enzymolysis and fermentation method for the larvae of the hermetia illucens comprises the following steps: a, selecting fresh or chilled larvae of the hermetia illucens, firstly cleaning and removing impurities, then pulping by adopting hydraulic pressure, and controlling the particle size within the range of 1-5mm after pulping so as to ensure the subsequent enzymolysis and fermentation effects; b, according to the characteristics of hermetia illucens larvae, selecting compound protease and neutral protease as main enzymolysis agents, and mixing the raw materials, the enzymolysis agents and water according to the mass ratio of 10: 2: 5. According to the efficient enzymolysis and fermentation method for the hermetia illucens larvae, by optimizing the enzymolysis reaction and fermentation process, the antioxidant activity of polypeptide prepared from the hermetia illucens larvae can be effectively improved. By accurately selecting enzymolysis agents such as compound protease and neutral protease and reasonably combining fermentation strains, the method can significantly improve the antioxidant effect of the final product, so that the method has higher market competitiveness when being applied to the feed industry.

This invention relates to the technical field of deep processing of sturgeon by-products, and particularly to a sturgeon tendon peptide with antioxidant and pancreatic lipase inhibitory activities and its preparation method. The preparation method includes the following steps: mixing sturgeon with water and crushing it to form a first slurry; adding Bacillus licheniformis alkaline protease to the first slurry for a first hydrolysis; adding Bacillus subtilis neutral protease to the first hydrolysate for a second hydrolysis; adding a complex enzyme to the second hydrolysate for a third hydrolysis to obtain a sturgeon tendon hydrolysate; filtering the sturgeon tendon hydrolysate to remove impurities to obtain a filtrate, which is then filtered again to retain polypeptides, thus obtaining the sturgeon tendon peptide; wherein the complex enzyme includes pectinase and amylase. Using this method, a sturgeon tendon peptide with high glycosaminoglycan content can be obtained, which exhibits pancreatic lipase inhibitory activity, antioxidant activity, Staphylococcus aureus inhibitory activity, and prebiotic effects that promote the proliferation of Lactobacillus plantarum and Lactobacillus fermentum.

The invention provides a whey protein deep hydrolysate with low sensitization and an allergy relieving effect as well as a preparation method and application of the whey protein deep hydrolysate. According to the method, the alkaline protease, the neutral protease and the glutamyltransferase are sequentially used for carrying out first enzymolysis, second enzymolysis and third enzymolysis on the whey protein raw material, and the whey protein hydrolysate which is low in molecular weight, good in taste, good in digestion and absorption performance, low in sensitization and capable of effectively relieving allergic reaction of the organism is obtained.

The invention discloses a preparation method of antibacterial and hemostatic medical sponge, and relates to the technical field of preparation of medical sponge. The preparation method of the antibacterial hemostatic medical sponge comprises the following steps: cleaning silkworm cocoons after removing impurities, and immersing the cleaned silkworm cocoons in a neutral protease solution to complete degumming so as to obtain fibroin fibers; the preparation method comprises the following steps: dissolving chitosan in an acetic acid solution, dissolving polyvinyl alcohol in deionized water, adding sodium alginate, adding a silk fibroin solution to form a composite solution, dropwise adding an AgNO3 solution, introducing CO2, maintaining the pressure, quickly releasing the pressure, foaming, injecting into a mold, carrying out gradient freezing to form a multistage-aperture sponge matrix, immersing in a genipin ethanol solution, and transferring into a 5% CaC 12 solution for soaking. The silk fibroin provides a biocompatible substrate and promotes cell adhesion, the sponge is constructed into a hierarchical pore structure with a compact surface and a loose interior, and liquid absorption and blood coagulation factor enrichment are accelerated.

The invention discloses a preparation method for simultaneously and efficiently extracting crocodile polypeptide and crocodile oil, and relates to the technical field of biological extraction, crocodile meat is used as a raw material, and heating micro-pressure treatment is sequentially performed to promote component dissolution; a multi-stage enzymolysis process is adopted, alkaline protease, neutral protease and lipase are sequentially used, and a calcium phosphate system is used for assisting filtration and a natural antioxidant is added in a gradient manner in the enzymolysis process; performing plate frame filtration and standing layering subsequently to realize crude separation of the oil peptide; finally, the crocodile polypeptide liquid is subjected to multi-stage membrane filtration and spray drying, the crocodile crude oil is subjected to ultrasonic-assisted fishy smell removal, ceramic membrane fine filtration and gradient cooling phase change refining, and after enzymolysis treatment and before filtration, a composite additive is added into enzymatic hydrolysate and stirred. No organic solvent exists in the whole process, and the product yield, purity and oxidation stability are remarkably improved.

The invention relates to a preparation method of small-molecular-weight sea cucumber oligopeptide, the prepared sea cucumber oligopeptide and application, and belongs to the technical field of skin care products. The preparation method of the small-molecular-weight sea cucumber oligopeptide comprises the following steps: preparing sea cucumber fine powder; adding the sea cucumber fine powder into ultrapure water, adding papain and EDTA (Ethylene Diamine Tetraacetic Acid), and carrying out enzymolysis under the assistance of microwaves; adding trypsin and calcium ions, and carrying out enzymolysis under the assistance of microwaves; adding neutral protease and zinc ions, and performing enzymolysis under the assistance of microwaves to obtain final sea cucumber enzymatic hydrolysate; and decolorizing, separating and purifying, and freeze-drying to obtain the powdery small-molecular-weight sea cucumber oligopeptide. According to the preparation method of the small-molecular-weight sea cucumber oligopeptide, microwave heating and enzymolysis reaction are combined, the hydrolysis degree of a peptide chain is regulated and controlled by controlling an enzyme hydrolysis sequence and enzymolysis conditions, the small-molecular-weight sea cucumber oligopeptide with relatively concentrated and moderate molecular weight is prepared, and good biological activity of the sea cucumber oligopeptide is kept.

The invention discloses a preparation method of black garlic polysaccharide, which comprises the steps of extraction, enzymolysis deproteinization, ultrafiltration, concentration, drying, crushing and the like, and'enzymolysis deproteinization + ultrafiltration 'is the core step of the method. Wherein the enzymolysis deproteinization can be selected from papain, neutral protease, acid protease, alkaline protease and the like or a combination of the papain, the neutral protease, the acid protease and the alkaline protease. In the ultrafiltration step, an organic ultrafiltration membrane or an inorganic ceramic membrane or a combination of the organic ultrafiltration membrane and the inorganic ceramic membrane can be selected. The method has the remarkable advantages of simple process flow, low cost, safety, high efficiency, good finished product quality and the like. Pharmacological experiments prove that the black garlic polysaccharide prepared by the method disclosed by the invention has a remarkable anti-constipation effect, and can be used for preparing anti-constipation healthy products, including medicines, health-care foods and foods.

The invention discloses a composite double-protein hypoglycemic peptide as well as a preparation method and application thereof, and belongs to the technical field of animal and plant source double-protein active peptides. The method comprises the following steps: performing computer simulation enzyme digestion and virtual screening by utilizing bioinformatics to determine a protein raw material and protease, performing enzymolysis on animal and plant double proteins (soybean protein and casein) serving as raw materials by adopting neutral protease, and performing separation, purification and structural identification, thereby obtaining the protein. The protein peptide fragment with high alpha-glucosidase inhibitory activity is obtained by virtually screening molecular docking, and the amino acid sequences of the protein peptide fragment are shown as SEQ ID No: 6, SEQ ID No: 9 and SEQ ID No: 24. The compound double-protein peptide sequence provided by the invention has an inhibiting effect on the activity of alpha-glucosidase, can be used for preventing and treating diabetes mellitus, and can be used for long-term health care or treatment of people with impaired glucose tolerance or diabetics as a functional food ingredient.

The invention relates to the technical field of active peptides, in particular to a myocardial active peptide capable of relieving heart failure and protecting heart and a preparation method thereof. The method takes pig hearts as raw materials, and sequentially comprises the following steps: pretreating the pig hearts, adding water, and homogenizing; adding alkaline protease to carry out first constant-temperature enzymolysis; adding neutral protease and flavourzyme to carry out second constant-temperature enzymolysis; then lipase is added for third-time constant-temperature enzymolysis, and enzyme deactivation and cooling are carried out; and finally, adding activated carbon into the enzymatic hydrolysate, filtering with diatomite, and spray-drying to obtain the myocardial active peptide. According to the method, the yield and the purity of the active peptide are remarkably improved through a synergistic process of three-step enzymolysis and activated carbon purification, the obtained product is rich in small molecule peptide with a definite heart protection function, and a new way is provided for high-value utilization of pig heart resources and development of functional products for preventing and treating heart failure.

The invention discloses modified hydroxytyrosol as well as a preparation method and application thereof. The provided preparation method of the modified hydroxytyrosol comprises the following steps: in the presence of an acidic solvent, mixing hydroxytyrosol, protease and collagen for reaction, mixing a reaction product with an extraction agent, performing centrifugal layering, and collecting upper-layer components, thereby obtaining the modified hydroxytyrosol, the protease comprises one or two of neutral protease and trypsin. Under the enzymolysis action of protease, the collagen can be decomposed into amino acid monomers such as glycine, proline and hydroxyproline, and the amino acid monomers can be subjected to graft modification with hydroxytyrosol; meanwhile, collagen fragments which are not subjected to enzymolysis also exist, and are subjected to graft modification with hydroxytyrosol in the form of collagen characteristic fragments. The oxidation resistance and the stability of the obtained modified hydroxytyrosol are obviously improved compared with those of unmodified hydroxytyrosol.

The invention discloses a preparation method of micromolecular active collagen peptide, which comprises the following steps: (1) cutting fresh leather into fragments, pretreating the leather with a sodium bicarbonate solution, rinsing the leather with deionized water, and refrigerating and storing; (2) mixing papain, bromelain, pancreatin, pepsase, alkaline protease, neutral protease and flavourzyme to obtain a compound enzyme preparation; (3) performing high-pressure steam sterilization on the leather at 110-140 kPa and 120-122 DEG C to obtain leather with the hydrolysis degree of 75-85%, then adding distilled water into the leather to obtain mucilage, then adding a compound enzyme preparation into the mucilage, reacting for 5.5-6.5 hours at the pH of 6.8-7.2 and the temperature of 50-55 DEG C, and then performing enzyme inactivation at the temperature of 85-95 DEG C; and (4) after the reaction system is cooled to room temperature, purifying and centrifuging the reaction system, and taking clarified supernate, thereby obtaining the product. Different animal skins are treated, the proportion of peptide fragments with the molecular weight smaller than 1000 Da of the prepared small-molecule active collagen peptide is larger than or equal to 80%, and the hydroxyproline content is larger than 3%.

The invention provides collagen tripeptide liquid with moisturizing and anti-photoaging effects and a preparation method thereof, and relates to the technical field of bioactive peptides.The preparation method comprises the steps that pretreatment and first-time enzymolysis are conducted, specifically, pretreated fish skin and water are mixed, the pH value is adjusted, compound protease is added for enzymolysis, and first enzymatic hydrolysate is obtained; second-time enzymolysis: adjusting the pH value of the first enzymatic hydrolysate to 6.0-7.5, adding neutral protease for enzymolysis, and then adding aminopeptidase for enzymolysis for 20-40 minutes to obtain second enzymatic hydrolysate; and performing enzyme deactivation, decoloration, separation and purification to obtain collagen tripeptide liquid. Wherein the content of collagen tripeptide, the content of glycine-proline-hydroxyproline and the content of hydroxyproline are high, and good moisturizing and anti-photoaging effects are achieved.

The present invention relates to the field of traditional Chinese medicine, and relates to a dandelion compound peptide, a preparation method and uses thereof, comprising the following steps: (1) taking dry dandelion products, pulverizing, adding water, and performing steaming to obtain a liquid mixture; (2) then adding cellulase to the liquid mixture, maintaining the temperature, and stirring for enzymatic hydrolysis; then lowering the temperature, adding neutral protease, maintaining the temperature, and stirring for enzymatic hydrolysis; raising the temperature to inactivate the enzyme to obtain an enzymatic hydrolysate; (3) cooling the enzymatic hydrolysate, adding Bacillus licheniformis for fermentation, maintaining the temperature, and stirring for fermentation, and then raising the temperature for sterilization to obtain a fermentation broth; the present invention can extract active substances from metabolites of traditional Chinese medicine active substances, and the product is non-toxic.

The invention relates to the technical field of collagen extraction, and provides a collagen extraction process for increasing hydroxyproline content, which sequentially comprises the steps of raw material pretreatment, deliming and degreasing, directional enzymolysis, gradient pressure-temperature synergistic extraction, purification, concentration and drying, a composite pretreatment agent containing a proline hydroxylase activator, EDTA-2Na and neutral protease is adopted in the raw material pretreatment; deashing and degreasing are combined with a chelating agent solution and ultrasonic treatment; a compound enzyme solution composed of trypsin, papain and proline hydroxylase is used for directional enzymolysis; a two-stage gradient pressure-temperature cooperation mode is adopted for extraction; purification is realized through combination of gel filtration chromatography and ion exchange chromatography; and finally carrying out freeze concentration and vacuum freeze drying to obtain the product. According to the process, through a multi-step synergistic effect, the content of hydroxyproline in collagen is remarkably increased, the product purity is high, natural functional characteristics are reserved, and the process is suitable for the fields of food, cosmetics, biological medicine and the like.

The invention belongs to the technical field of biological fermentation, and particularly relates to ganoderma lucidum polypeptide and a preparation method and application thereof. The preparation method comprises the following steps: (1) taking ganoderma lucidum powder, adding water, and cooking to obtain a mixture 1; (2) adding bacillus subtilis liquid into the mixture 1, and fermenting to obtain ganoderma lucidum polypeptide fermentation liquid bacteria liquid; (3) adding neutral protease into the ganoderma lucidum polypeptide fermentation liquid for primary enzymolysis, and then adding aminopeptidase for secondary enzymolysis to obtain ganoderma lucidum polypeptide enzymatic hydrolysate; and (4) filtering, concentrating and spray-drying the lucid ganoderma polypeptide enzymatic hydrolysate to obtain the lucid ganoderma polypeptide. The molecular weight of the ganoderma lucidum polypeptide ranges from 200 Da to 5000 Da, molecular weight distribution is uniform, the polypeptide content can reach 31.11% at most, the ganoderma lucidum polypeptide can be applied to functional cosmetics, and the application range of the ganoderma lucidum polypeptide is widened.

The invention discloses extraction of polydeoxyribonucleotide as well as preparation and application of a PDRN-Ce (Polydeoxyribonucleotide-Ce) microsphere cluster. The extraction and purification method comprises the following steps: mixing in-vitro fish testis tissues with water, carrying out crushing treatment and homogenization treatment on an obtained premix, carrying out proteolysis and solid-liquid separation, and collecting supernate to obtain enzymatic hydrolysate; wherein protease used for proteolysis comprises neutral protease; carrying out alcohol precipitation on the enzymatic hydrolysate by adopting an alcohol solvent, and collecting a precipitate; and dissolving the precipitate in water, desalting and drying. According to the extraction method, the purity and the yield of the poly-deoxyribonucleotide are remarkably improved, the preparation method is low in cost and convenient to operate, the prepared poly-deoxyribonucleotide is stable in property, small in molecular weight and easy to absorb by skin, in order to further improve the bioavailability of the extracted poly-deoxyribonucleotide, the PDRN-Ce microsphere cluster is prepared, and the PDRN-Ce microsphere cluster can be used for preparing the poly-deoxyribonucleotide. Good application prospects are realized.

The invention relates to a preparation method, a product and application of a whitening and antioxidant litchi peel extract. The preparation method comprises the following steps: (1) mixing litchi peel powder with water, and carrying out ultrasonic extraction to obtain a litchi peel crude extract; (2) mixing the litchi peel crude extract with a compound enzyme, carrying out an enzymatic hydrolysis reaction, and carrying out enzyme deactivation treatment after the reaction to obtain an enzymatic hydrolysate; (3) performing cation exchange resin purification on the enzymatic hydrolysate to obtain a litchi pericarp extract; the compound enzyme in the step (2) comprises papain, bromelain and neutral protease. The litchi pericarp extract prepared by the invention has excellent antioxidant capacity and whitening effect, is safe and non-irritant, and is more beneficial to absorption by the human skin surface.

The invention relates to a hemoglobin peptide capable of promoting iron absorption and a preparation method thereof, the mass content of polypeptide in the hemoglobin peptide is greater than 90%, and the hemoglobin peptide contains at least one of FERF and FDGL; the preparation method comprises the following steps: S1, adding trisodium citrate into fresh animal blood, centrifuging, adding a NaCl solution for washing, preparing the solution, and performing high-pressure homogenization wall breaking for 2-5 times to obtain a hemoglobin solution; s2, adding 10-200 U / mL of neutral protease, carrying out heat preservation treatment, then adding 5-50 U / mL of flavourzyme, carrying out enzymolysis, and carrying out enzyme deactivation to obtain an enzymatic hydrolysate; s3, filtering with an ultrafiltration membrane, and collecting permeate; s4, adjusting the pH value, adding into an anion exchange chromatographic column, eluting with a NaCl solution, and collecting the eluent; s5, desalting, concentrating and drying to obtain hemoglobin peptide; and S6, carrying out mass spectrometric detection, and screening bioactive peptides to obtain the oligopeptide with the activity of promoting iron absorption. The hemoglobin peptide obtained by the preparation method disclosed by the invention has relatively good iron chelation capability and iron absorption promoting capability, and the bioavailability of iron ions can be remarkably improved.

The present invention discloses a Dendrobium officinale protein hydrolysate composition, a preparation method thereof, and an application thereof in anti-aging cosmetics. The Dendrobium officinale protein hydrolysate composition consists of Dendrobium officinale protein hydrolysates TDM-1 and TDM-5, with a mass ratio of 1:(0.5-2); TDM-1 and TDM-5 are peptide components with a molecular weight ≤10 kDa and a peptide component with a molecular weight of 10 kDa < ≤50 kDa, which are obtained by enzymatic hydrolysis of Dendrobium officinale crude protein using a neutral protease and papain. TDM-1 and TDM-5 components have synergistic effects of antioxidant, anti-inflammatory, and barrier repair by inhibiting the activation of the MAPK / NF-κB signaling pathway and promoting ECM repair mediated by the TGF-β pathway, thereby achieving multi-target anti-aging and having low irritation. They can be used in dosage forms such as essences and creams, providing core raw materials for the development of natural anti-aging cosmetics.

The present invention relates to a cartilage tissue single cell extraction kit and an extraction method thereof, the kit comprises: (1) a first enzyme for enzymatic hydrolysis, the first enzyme for enzymatic hydrolysis comprising one or more of trypsin, chondroitinase ABC and fucosidase; (2) a second enzyme for enzymolysis, wherein the second enzyme for enzymolysis comprises collagenase II, neutral protease II, hyaluronidase and Dnase I; and (3) a basic solution, wherein the basic solution comprises a basic culture medium and / or a buffer solution. The invention also provides a method for extracting single cells from cartilage tissues by using the kit. The cartilage tissue single-cell suspension prepared by the method has the advantages of high cell yield, high activity and the like, and has a wide application prospect.

The present invention discloses a preparation method of antioxidant sturgeon protein peptides, comprising the following steps: S1, extraction of crude sturgeon skin protein solution; S2, extraction of crude sturgeon swim bladder protein; S3, extraction of crude sturgeon meat protein solution; S4, mixed enzymatic hydrolysis; S5, subjecting the obtained enzymatic hydrolysis product to enzyme inactivation treatment first to obtain an enzymatic hydrolysis solution, and then sequentially ultrafiltering and vacuum drying the enzymatic hydrolysis solution to obtain antioxidant sturgeon protein peptides. The present invention mixes the proteins extracted from different parts of sturgeon in a specific ratio, and then performs enzymatic hydrolysis. The neutral protease and papain added can act synergistically to more comprehensively hydrolyze proteins, generating small peptides with specific functions. At the same time, glutathione added during enzymatic hydrolysis can protect the sulfhydryl groups of the enzyme and maintain the enzyme activity, so that the finally obtained sturgeon protein peptides have good antioxidant properties.

The invention relates to the technical field of microbial fermentation, and particularly discloses a microbial fermentation process for food processing. The composition used in the process comprises lactobacillus plantarum, aspergillus oryzae and a compound enzyme preparation containing neutral protease, cellulase and phytase. The preparation method comprises the following steps: firstly, pretreating the raw materials, then compounding lactobacillus plantarum and aspergillus oryzae into a fermentation starter according to a specific proportion, fermenting in a liquid environment, and implementing dynamic stepped oxygen control; adding a complex enzyme preparation in a hypha growth period; then transferring into solid matrix conversion to construct a porous structure; and finally, carrying out two-stage temperature-controlled vacuum drying to obtain the product. The composition disclosed by the invention can be used for fermenting plant-based raw materials such as beans and grains, and has the advantage that the availability of a substrate can be improved through the synergistic interaction of bacteria and enzymes; in addition, according to the process, through stepped oxygen control, the double-bacterium respiratory rhythm can be precisely adapted, and the problem of metabolism mutual exclusion in a constant oxygen mode is thoroughly solved.

The application provides a preparation method of seafood flavoring agent and shrimp paste, and relates to the technical field of food flavoring agents. The slurry of shrimp offal is subjected to enzymolysis by using a combination of neutral protease, flavor protease, nuclease and lipase, and then subjected to Maillard reaction, so that the seafood flavoring agent with high freshness, low bitterness and good flavor is obtained, and the seafood flavoring agent can be used for preparing shrimp paste.

The invention discloses an enzymolysis preparation process of wood frog skin micromolecule III type collagen peptide. The enzymolysis preparation process comprises the following steps: mixing defatted wood frog skin powder with water, and pretreating; adding a papain-neutral protease-glutamine protease hydrolysis system into the pretreated mixed solution, continuously hydrolyzing, performing centrifugal treatment after the hydrolysis is completed, heating supernate, adding alkaline protease into the supernate for hydrolysis and enzyme inactivation, and performing centrifugal treatment to obtain clear liquid rich in collagen peptide; carrying out multistage membrane separation coupling chromatography purification treatment and low-temperature vacuum concentration treatment on the clear liquid rich in collagen peptide to obtain a concentrated solution; and mixing the concentrated solution with a trehalose-hyaluronic acid composite wall material, and performing spray drying to obtain the collagen peptide nanocapsule. Efficient preparation and function enhancement of the wood frog skin type III collagen peptide can be achieved, and the prepared collagen peptide has the purity larger than or equal to 99.5% and the activity retention rate larger than 98% and is excellent in heat stability and moisturizing performance.

The invention discloses phospholipid-rich egg yolk polypeptide powder as well as a preparation method and application thereof, and belongs to the technical field of food processing and medical health care. The preparation method of the phospholipid-rich egg yolk polypeptide powder specifically comprises the following steps: beating a fresh egg to separate egg yolk, adding water to dilute, adjusting the pH value to 5.0-6.0, centrifuging, and taking a precipitated phase; adding water to dilute the precipitate, adjusting the pH value to 7.0-9.0, and centrifuging to obtain a slurry phase supernatant; adding neutral protease into the pulp phase supernatant, and carrying out an enzymolysis reaction; after the reaction, concentrating, drying, freezing and crushing; placing the crushed material in a supercritical carbon dioxide extraction device for deoiling, and after deoiling, mechanically crushing and screening to obtain phospholipid-rich egg yolk polypeptide powder; the phospholipid-rich egg yolk polypeptide powder has relatively high dispersibility and stability, also has relatively high activity, has a very good promotion effect in improvement of a cognitive function, shows huge application potential in the technical fields of functional foods, health care products and medicines, and has extremely wide market prospects.

The invention relates to the technical field of collagen peptide preparation, and discloses a collagen peptide as well as a preparation method and application thereof. The preparation method of the collagen peptide comprises the following steps: adding water into Hefang crucian carp skin, regulating the Hefang crucian carp skin into feed liquid with the optimal pH value of protease, then adding the protease into the feed liquid for enzymolysis, inactivating after enzymolysis, and centrifuging to take supernate, so as to obtain the collagen peptide. The protease comprises one or more than two of alkaline protease, animal protease and neutral protease. According to the present invention, the He-prescription crucian carp skin is adopted as the preparation raw material, the protease most suitable for the raw material is adopted to perform enzymolysis to prepare the collagen peptide, the optimal enzymolysis process parameters are determined, and compared with the conventional tilapia skin collagen peptide, Hunan crucian carp skin collagen peptide and collagen tripeptide in the antioxidant function, the antioxidant activity is significantly improved, and the antioxidant activity is significantly improved; therefore, the method for preparing the crucian carp skin collagen peptide with remarkable antioxidant activity is established, and the application range of crucian carp processing byproducts is further expanded.

The invention provides a preparation method of a single-cell sequencing suspension fixedly preserved in situ. The invention provides digestive juice for preparing a single-cell suspension. The digestive juice is a solution composed of collagenase II and neutral protease. The invention also provides a kit containing the digestive juice. The invention provides application of the digestive juice to preparation of a kit and application of the kit to in-situ fixed preservation of cells and preparation of a single-cell suspension. The invention also provides a preparation method of the in-situ immobilized preserved cell and the single-cell suspension, and the single-cell suspension prepared by the preparation method.

The invention relates to the field of biological product preparation, in particular to a preparation method of high-activity oyster-derived small molecule peptide. The method comprises the following steps: selecting fresh meat of pacific oysters or ostrea rivularis as a raw material, degreasing, adding water, crushing, filtering, sequentially carrying out compound protease and neutral protease hydrolysis, implanting a sensor and a probe in hydrolysis, monitoring in real time, and dynamically adjusting reaction conditions; adding a targeting microcapsule wrapping an ascorbic acid glutathione composite protective agent, and releasing the protective agent when a target peptide signal is detected; separating and concentrating through a gradient membrane, and purifying the target peptide by using a molecular imprinting chromatographic column; carrying out alkaline hydrolysis on enzymatic hydrolysis residues to prepare chitosan for cyclic utilization, carrying out enzymatic hydrolysis on residual residues to generate collagen peptide, treating and recycling wastewater, and recovering protease. According to the method, the technical effects that the high-activity and high-purity target peptide is prepared, the resource utilization rate is increased, the production cost is reduced, the target peptide has good oxidation resistance and biological activity, the intestinal enzyme degradation rate is reduced after glycosylation modification, and the blood half-life period is prolonged are achieved.