335 results about "Alkaline proteinase" patented technology

The invention belongs to the field of bioactive peptides. The invention provides an angiotensin converting enzyme inhibitory peptide as well as a screening method and application thereof. The amino acid sequence of the inhibitory peptide is GKGLW and / or GDGLKW. According to the screening method of the ACE inhibitory peptide, the soybean protein is taken as a raw material, and the ACE inhibitory peptide is prepared and screened by adopting a targeted alkaline protease and chymotrypsin double-enzymolysis technology, so that rapid screening of the ACE inhibitory peptide is realized, and an experimental basis is provided for the structure-function relationship of the ACE inhibitory peptide. The inhibitory peptide provided by the invention has strong antihypertensive activity, high safety and no toxic or side effect. Digestive tract stability determination shows that the inhibitory peptide has good gastrointestinal tract stability in gastrointestinal tract digestion, and can still keep good activity after entering blood.

The invention discloses a preparation method and permeation promotion application of a high-purity sponge bone needle, and belongs to the technical field of sponge bone needles. Comprising the following steps: cutting a natural sponge into pieces, soaking in deionized water, carrying out ultrasonic oscillation, filtering, and cleaning to obtain a pretreated sponge; carrying out enzymolysis on the pretreated sponge with alkaline protease to obtain a primary zymolyte; and carrying out enzymolysis with ginger protease to obtain a secondary enzymolysis product, and carrying out vacuum freeze drying to obtain the high-purity sponge spicule. The natural sponge is subjected to enzymolysis treatment through alkaline protease and ginger protease, and the high-purity sponge spicule is obtained; wheat oligopeptide is grafted on the surface of a sponge spicule, and giant salamander skin collagen, a pomegranate seed extract, a lonicerae flos extract, a centella asiatica extract, an early celery extract, an iris tectorum extract, an oyster shell extract and calcium chloride mixed treatment materials are loaded, so that the repairing effect on skin inflammation acne is improved.

The invention discloses a preparation method and application of anti-photoaging collagen polypeptide. The preparation method comprises the following steps: unfreezing and cleaning silver carp skin, airing and cutting; naHCO3 is added, and soaking is carried out; adding Na2CO3 and carrying out ultrasonic impurity removal; performing ultrasonic-assisted treatment; adding protease for enzymolysis treatment; establishing an enzymolysis kinetic model under the alkaline protease condition; standing, cooling and centrifuging the enzymatic hydrolysate, collecting supernate, filtering, and performing vacuum freeze drying to obtain faint yellow SCSCP; the light aging resistant peptide SCSCP02 is separated, and the active peptide sequences of the light aging resistant peptide SCSCP02 are GPPGPPGTPGPQ, SGLPGPIGPPGPR and GLPGPIGPPGPR. The active substances which are extracted from the fish skin and have the anti-photoaging effect can reduce the risk of skin light damage caused by UVR by acting on various treatment targets, resource waste can be reduced, environmental pollution caused by biological resources can be relieved, and sustainable development of the industry can be promoted.

The invention relates to the technical field of biology, in particular to a DPP-IV inhibitory peptide extracted from buffalo cheese protein hydrolysate and application of the DPP-IV inhibitory peptide. An active component with the molecular weight smaller than 3 kDa is obtained through alkaline protease enzymolysis, ultrafiltration separation and LC-MS / MS identification, and the DPP-IV enzyme inhibitory activity IC50 value of the active component is 12.6 mg / mL. Four new DPP-IV inhibitory peptide fragments are found, are amino acid sequences in a sequence table SEQ ID NO: 1-4, have good DPP-IV inhibitory activity, and have good application prospects in being developed into functional foods or medicines for regulating blood sugar. In conclusion, the enzymolysis product and the peptide fragment can be prepared into antidiabetic drugs or functional foods, and have the advantages of being natural, safe and efficient. The invention provides a new strategy for high-valued utilization of buffalo milk resources and treatment of type 2 diabetes.

The invention relates to the technical field of deep processing of paeonia ostii, in particular to paeonia ostii peptide capable of whitening, moisturizing, tightening and promoting collagen synthesis as well as a preparation method and application of the paeonia ostii peptide. The paeonia ostii flower peptide capable of whitening, moisturizing, tightening and promoting collagen synthesis is prepared through water bath, homogenization, alkali extraction and acid precipitation pretreatment, three times of enzymolysis through compound enzyme of acid protease, cellulase and pectinase and alkaline protease and solid-liquid separation, operation is easy, the requirement for equipment is low, and the paeonia ostii flower peptide is suitable for industrial large-scale production. The prepared paeonia ostii flower peptide has good inhibition capability on tyrosinase, hyaluronidase and elastinase, and also has excellent anti-saccharification and anti-inflammatory effects. Besides, five paeonia ostii active peptide fragments are screened out, are high in activity and non-toxic, can be combined with tyrosinase, hyaluronidase, MMP-1, MMP-3 and COX-2 receptor protein, and have the effects of whitening, moisturizing, tightening and promoting collagen synthesis.

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 a crocodile hydrolyzed protein zinc skin care product, and relates to the technical field of skin care. The method comprises the following steps: step a, pretreating raw materials: taking fresh crocodile meat and bones, cleaning, mechanically crushing until the particle size is less than 5mm, and adding water according to the ratio of 1: (3-5) to prepare homogenate; step b, performing three-step enzymolysis, namely performing enzymolysis by adopting alkaline protease, flavourzyme and zinc chelating enzyme in sequence; according to the constructed technology of three-step enzymolysis and three-stage membrane separation, accurate preparation of crocodile protein zinc is achieved, and the zinc chelating rate is increased to 90% or above through the gradient effect of alkaline protease, flavourzyme and zinc chelating enzyme and directional release of zinc binding sites and is remarkably higher than that of a traditional single-enzyme hydrolysis technology; meanwhile, a combined purification technology of a ceramic membrane, an ultrafiltration membrane and a nanofiltration membrane is adopted to replace chemical precipitation and organic solvent extraction, so that the completeness of active ingredients is reserved, the risk of environmental pollution is reduced, and the method conforms to the green manufacturing trend of food industry.

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 discloses a corn peptide for dispelling effects of alcohol and protecting liver as well as a preparation method and application thereof, and belongs to the technical field of biological peptide extraction. The preparation method comprises the following steps: crushing and sieving corn, dissolving the corn in deionized water, adjusting the pH value to be alkaline, and performing ultrasonic-assisted extraction to obtain corn homogenate; centrifuging, taking supernate, adjusting the pH to be neutral, centrifuging, adding an ethanol solution with the mass fraction of 10%, standing, carrying out continuous flow centrifugation, suspending precipitates in distilled water, dialyzing in a dialysis bag, and freeze-drying to obtain crude corn protein; the preparation method comprises the following steps: preparing an aqueous solution, carrying out variable-temperature treatment, adjusting the pH value to be alkaline, adding trypsin and alkaline protease, carrying out enzymolysis, repeating the enzymolysis twice, and after the enzymolysis is finished, carrying out heating enzyme deactivation, centrifugation, sediment discarding, ultrafiltration, centrifugation, supernatant taking and spray drying to obtain the corn peptide. The corn peptide can remarkably shorten the drunkenness time and sobering time of mice and reduce the drunkenness duration, and has good effects of dispelling the effects of alcohol and protecting the liver.

The present invention discloses a black chicken liver hydrolyzed peptide that can be used to improve ulcerative colitis, and its preparation method and application, which belong to the field of biomedicine technology. The preparation method of the black chicken liver hydrolyzed peptide comprises the following steps: making black chicken liver into minced meat and mixing it with water, heating the obtained liquid material, adding alkaline protease for enzymatic hydrolysis, inactivating the enzyme and collecting the supernatant by centrifugation, and freeze-drying to obtain the black chicken liver hydrolyzed peptide. The present invention adopts formaldehyde titration to detect the degree of hydrolysis, adopts SDS-PAGE electrophoresis and Tricine-SDS-PAGE electrophoresis to detect the molecular weight, performs sequence analysis by LC-MS / MS, uses a database to predict the biological function of peptide segments, detects the antioxidant and blood pressure lowering ability of black chicken liver peptide by in vitro experiments, and detects the effect of black chicken liver peptide in improving colitis by mouse experiments. The results show that the black chicken liver peptide prepared by the present invention has the advantages of antioxidant, blood pressure lowering and improvement of ulcerative colitis.

The invention belongs to the technical field of dairy products and food biology, and particularly relates to a method for preparing hypoallergenic whey protein through combination of an enzyme method and glycosylation and application of the hypoallergenic whey protein. The method specifically comprises the following steps: carrying out enzymolysis on whey protein isolate by using alkaline protease to prepare a whey protein hydrolysate, adding allose, uniformly mixing, carrying out glycosylation reaction under a freeze-drying condition, and finally, carrying out ultrafiltration and dialysis to remove redundant sugar, so as to prepare a sample, namely the low-sensitization whey protein. According to the whey protein prepared by the method, the sensitization is effectively inhibited, the low sensitization after digestion is ensured, and the problem that the sensitization is increased in the digestion process is avoided.

The invention discloses a method for extracting antifreeze peptide from skin and bone byproducts of livestock and poultry animals and application of the antifreeze peptide, and relates to a method for extracting antifreeze peptide with high thermal hysteresis activity from skin and bone byproducts of a local variety sheepskin and bone of Xinjiang and application of the antifreeze peptide. Comprising an application of the sheep bone antifreeze peptide extracted by a method for extracting the antifreeze peptide from the sheepskin bone by-product to protect the cell integrity of fresh meat of livestock and poultry under low-temperature stress and an application of the sheep bone antifreeze peptide extracted by the method for extracting the antifreeze peptide from the sheepskin bone by-product to influence the survival rate of lactobacillus under low-temperature stress. Meanwhile, the heat stagnation activity of the extracted antifreeze peptide is gt; 5 DEG C; the sheep bone antifreeze peptide has the advantages that the sheep bone antifreeze peptide accounts for 24.8% when the molecular weight range is 1000 Daltons or above, the sheep bone antifreeze peptide accounts for 65.0% when the molecular weight range is 100-1000 Daltons, and the sheep bone antifreeze peptide accounts for 10.2% when the molecular weight range is lower than 180 Daltons; according to the method for hydrolyzing the sheepskin bone byproducts through the alkaline protease, the additional value and the utilization rate of the sheep bones and the sheepskin are improved to a great extent, and effective utilization of the sheep byproducts and maximization of the economic value are facilitated.

The invention relates to the technical field of preparation of small molecule peptides, and particularly discloses a preparation process of selenium-rich antioxidant pig lung polypeptide. The preparation process of the selenium-rich antioxidant pig lung polypeptide comprises the following steps: cleaning and decontaminating fresh pig lung, stripping trachea, removing grease, and mincing into meat paste to obtain a pig lung prefabricated material; mixing the pig lung prefabricated material with a vitamin C aqueous solution, adding nano silicon dioxide powder and eugenol into the mixture, performing ultrasonic treatment, cooling to-10 to-30 DEG C, preserving heat for 1-2 hours, heating to room temperature, performing homogenizing treatment, filtering, and collecting precipitates to obtain pretreated pig lungs; adding water into the pretreated pig lung, uniformly stirring, adjusting the pH value of the system, adding stability-enhancing alkaline protease for treatment, adjusting the system to be neutral, adding neutral protease for enzymolysis, and cooling to room temperature to obtain pig lung enzymatic hydrolysate; and carrying out centrifugation and ultrafiltration on the pig lung enzymatic hydrolysate, collecting permeate, carrying out nanofiltration, collecting concentrated solution, and drying.

The invention aims to provide a chlorella pyrenoidosa peptide with an effect of preventing alcoholic liver injury, which is prepared by the following steps: crushing chlorella pyrenoidosa, mixing with water, freezing and thawing, and performing ultrasonic treatment to prepare homogenate; alkaline protease is added for enzymolysis, and then flavourzyme is added for enzymolysis; and after the enzymolysis product is adsorbed by activated carbon, the supernate is adsorbed by using an SP Sephadex C25 cation exchange medium. The amino acid sequence of the chlorella pyrenoidosa peptide is PSEQ ID NO: 1-5. The chlorella pyrenoidosa peptide provided by the invention is obtained by enzymolysis, adsorption and cation exchange chromatography technologies, and is verified by a HepG2 cell model to obviously relieve alcoholic liver injury. The raw materials are natural and safe, the process is accurate and efficient, and industrialization potential is achieved. Meanwhile, the peptide is suitable for development of functional food, health care products and medicines, and a low-toxicity and sustainable liver protection solution is provided.

The invention discloses a grape seed protein peptide with DPP-IV inhibitory activity and a preparation method thereof, and belongs to the field of comprehensive utilization of wine fermentation byproducts. The grape seed protein peptide disclosed by the invention is prepared from a zymolyte obtained by carrying out alkaline protease enzymolysis on grape seed protein prepared from grape seeds by an ultrasonic-assisted alkaline method. The grape seed protein peptide disclosed by the invention has a good DPP-IV inhibition effect, is a DPP-IV inhibitor from a natural plant source, and can be applied to functional foods and nutritional health-care products.

The invention discloses application of walnut peptide in preparation of a medicine for treating or preventing cognitive impairment of diabetes mellitus. The preparation process of the walnut peptide is as follows: after walnut protein is subjected to enzymolysis by alkaline protease, the molecular weight cut-off is 1t; and separating by using a 3kDa ultrafiltration tube to obtain the walnut peptide. The walnut peptide can effectively reduce the blood sugar level of a diabetic model mouse, regulate the disorder effect of blood fat, relieve brain tissue oxidative damage and hippocampal neuroinflammation damage of the diabetic model mouse, and improve learning and memory damage. The compound can be used for preparing medicines for treating or preventing cognitive impairment of diabetes mellitus.

The invention belongs to the technical field of gene engineering and enzyme engineering, and discloses an alkaline protease mutant and application thereof. Compared with parent alkaline protease with an amino acid sequence as shown in SEQ ID NO: 1, the alkaline protease mutant has disulfide key site pair mutation, and the disulfide key site pair has the following characteristics: i, the disulfide key site pair is not in the range of an active site # imgabs0 # of the alkaline protease mutant; ii, the difference value of amino acid site numbers is greater than or equal to 10; iii, the distance between two cysteine SG atoms forming a disulfide bond is within # imgabs 1 #; iv, the angle of Chi3 is 30 degrees lt; chi3lt; chi3lt; 140 DEG or-30 DEG gt; chi3gt; chi3gt; and-140 DEG C. Compared with the parent alkaline protease, the alkaline protease mutant has the advantages that the heat resistance and / or detergent tolerance are / is obviously improved, the decontamination effect on protein dirty cloth is better, and the requirements of the daily chemical washing industry can be better met.

The invention relates to aspergillus oryzae sourced protease and application thereof in traditional bean fermentation products, and belongs to the technical field of enzyme engineering and microbial engineering. The amino acid sequence provided by the invention comprises an acid protease, two neutral proteases and an alkaline protease, wherein the proteases have higher degradation degree on globulin and albumin; the enzyme activity is the highest at 45-50 DEG C, and the salt tolerance is good. When the soybean sauce is prepared, the physicochemical indexes, free amino acids, organic acids and flavor substances of the soybean sauce are remarkably improved; wherein the quantity and the content of flavor substances are remarkably increased, and the content of free amino acid is increased by 20-25%; and the flavor sensory evaluation is more pleasant. In the early stage to the middle stage of fermentation, the content of amino acid nitrogen in the soy sauce is remarkably increased, the production cycle of the soy sauce can be shortened, and the method has wide application prospects in the food industry.

The invention provides earthworm protein peptide as well as a preparation method and application thereof, and belongs to the technical field of medicines. The preparation method comprises the following steps: drying and crushing earthworms to obtain earthworm powder, adding the earthworm powder into water, adding immobilized compound enzyme for enzymolysis, carrying out magnet separation, adjusting the pH value of enzymatic hydrolysate for precipitation, collecting solids, adding the solids into water, adding a purifying agent for adsorption separation, adding the solids into a deep eutectic solvent, heating for desorption, carrying out magnet separation, carrying out ultrafiltration on residual liquid, and collecting protein peptide to obtain the earthworm protein peptide. The immobilized compound enzyme is prepared by immobilizing modified snail protease and alkaline protease on chitosan modified MOF / magnetic microspheres; the purifying agent is a passivated angiotensin converting enzyme immobilized magnetic agar ball. The high-activity earthworm protein peptide has the advantages of simple preparation method, high purity, good inhibition effect on angiotensin converting enzyme, safety, high efficiency, no side effect, good antihypertensive effect on hypertensive patients, good patient compliance, and wide application prospect.

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 provides a nutrition enhancer beneficial to bone health of middle-aged and elderly people, a preparation method of the nutrition enhancer and application of the nutrition enhancer in preparation of medial care food, and belongs to the field of nutritious food. The nutrient supplement comprises a plant fermentation product, osteopontin peptide, collagen peptide, N-acetylglucosamine and calcium, vitamins and mineral substances can be added, and the plant fermentation product is obtained by performing anaerobic fermentation on rhizoma drynariae and chestnuts through a complex microbial inoculant composed of lactobacillus reuteri and bifidobacterium longum subsp. Longum; the collagen peptide is prepared by performing enzymolysis on bovine bones through alkaline protease and flavourzyme; the hydrogel is prepared by adopting a sodium alginate-calcium chloride-carboxymethyl chitosan micro-capsule embedding process. An in-vitro experiment shows that the nutrition enhancer can remarkably promote osteoblast proliferation, differentiation and mineralization; animal experiments show that the bone mineral density of osteoporosis model mice can be effectively improved. The nutrition enhancer disclosed by the invention is suitable for preparing care food and bone health products, and has a remarkable effect of improving bone health of middle-aged and elderly people.

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 relates to a preparation method and application of a sea cucumber egg-derived peptide compound. The preparation method of the sea cucumber egg source peptide compound comprises the following steps: performing synchronous enzymolysis on sea cucumber egg powder by using alkaline protease-trypsin; the sea cucumber ovum source active peptide is obtained by further carrying out ultrafiltration, sephadex chromatography and high performance liquid chromatography separation and adopting liquid chromatography-mass spectrometry technology analysis, a computer-aided screening technology and in-vitro verification, and the amino acid sequence of the sea cucumber ovum source active peptide comprises one or more of WGN, WI GG and GFPVG (Fibroblast Growth Factor Peptide Growth Growth Growth Growth Growth Growth Growth Growth Growth Growth Growth Growth Growth Growth Growth Growth Growth Growth). The sea cucumber ovum-derived peptide compound and the sea cucumber ovum-derived active peptide provided by the invention have double activities of resisting oxidation and inhibiting tyrosinase, can reduce the melanin content, and have the advantages of good water solubility, good safety and the like.

The invention discloses a method for preparing high-F-value oligopeptide from whey protein, and belongs to the technical field of food biology. According to the method, whey protein is taken as a raw material, step-by-step synergistic enzymolysis of alkaline protease-chymotrypsin-flavourzyme is performed, and an activated carbon selective adsorption dearomatization process is combined, so that the F value and the hydrolysis degree of oligopeptide are remarkably improved. The enzymolysis efficiency is high, and the final hydrolysis degree is gt; 30%; the dearomatization effect is excellent, and the product F value is gt; 26; the method is simple in process and low in cost, high-value conversion of whey protein can be achieved, and the prepared high-F-value oligopeptide can be applied to the fields of sports nourishment, food for special medical purposes and the like and has remarkable industrial value.

The invention discloses an egg yolk polypeptide capable of improving learning cognitive ability and a preparation method and application thereof, and the egg yolk polypeptide capable of improving learning cognitive ability is obtained by combining ultrasonic alkali treatment with alkaline protease enzymolysis and desalting by using an integrated membrane separation technology. According to the preparation method, the compact structure of the yolk can be destroyed through the ultrasonic alkali treatment and the enzymolysis process, the enzymolysis efficiency of the yolk can be improved, a large number of bioactive peptides are released, the bioactive peptide yield of a final product is stabilized to be 60% or above, the molecular weight of the bioactive peptides is intensively distributed to be 180-2000 Da, and the nutrition utilization rate is improved. The egg yolk polypeptide prepared by the method can significantly increase the value-added rate of nerve cells and improve the spatial memory ability and cognitive flexibility of mice, ultrasonic alkali treatment is combined with biological enzymolysis, no organic solvent or strong acid and strong alkali is added, and the production process of natural protein hydrolysate is natural and safe and meets the food-grade safety production standard.

The invention discloses black-bone chicken liver hydrolyzed peptide capable of improving ulcerative colitis as well as a preparation method and application of the black-bone chicken liver hydrolyzed peptide, and belongs to the technical field of biological medicines. The preparation method of the black-bone chicken liver hydrolyzed peptide comprises the following steps: preparing the black-bone chicken liver into meat paste, mixing the meat paste with water to obtain a liquid material, heating the liquid material, adding alkaline protease to carry out enzymolysis, carrying out enzyme deactivation, centrifugally collecting supernate, and freeze-drying to obtain the black-bone chicken liver hydrolyzed peptide. According to the invention, a formaldehyde titration method is adopted to detect the degree of hydrolysis, SDS-PAGE electrophoresis and Tricine-SDS-PAGE electrophoresis are adopted to detect the molecular weight, LC-MS / MS is adopted to carry out sequence analysis, a database is adopted to predict the biological function of a peptide fragment, an in vitro experiment is adopted to detect the antioxidant and antihypertensive ability of the black-bone chicken liver peptide, and a mouse experiment is adopted to detect the colitis improvement effect of the black-bone chicken liver peptide. The result shows that the black-bone chicken liver peptide prepared by the invention has the advantages of resisting oxidation, reducing blood pressure and improving ulcerative colitis.

The invention relates to a method for reducing the anaphylaxis of natural latex by multi-enzyme cascade catalysis of rubber protein. The invention relates to the technical field of catalysis of rubber protein hydrolysis, in particular to a method for reducing the anaphylaxis of natural latex by thoroughly hydrolyzing rubber protein through multi-enzyme cascade catalysis. The method for reducing the anaphylaxis of the natural latex by catalyzing the rubber protein through the synergistic effect of multiple enzymes from the perspective of industrial production comprises the following steps: adding an enzyme A and an enzyme B into the natural latex for reaction so as to reduce the anaphylaxis of the natural latex, the enzyme A is alkaline protease; and the B enzyme is at least one of aminopeptidase, carboxypeptidase B, carboxypeptidase A and carboxypeptidase Y. According to the method disclosed by the invention, the enzyme A-endopeptidase and the enzyme B-exopeptidase are subjected to multi-enzyme-stage combined treatment and concerted catalysis, so that the enzyme A-endopeptidase and the enzyme B-exopeptidase are completely hydrolyzed or are completely hydrolyzed into more amino acid substances and short-chain peptides (oligopeptides) as far as possible, and the amino acid substances and the short-chain peptides (oligopeptides) are retained in latex. Protein is highly hydrolyzed into amino acid with higher safety, so that the possibility of I-type anaphylactic reaction caused by protein allergens is greatly reduced or even eliminated.

The invention discloses camellia seed meal oligopeptide as well as a preparation method and application thereof. The method comprises the following steps: S1, pretreating camellia seed meal to obtain a pretreated substance; s2, performing enzymolysis and wall breaking to obtain first enzymatic hydrolysate; wherein the enzymolysis wall breaking adopts a mixed enzyme, and the mixed enzyme comprises amylase and cellulase; s3, extracting crude protein to obtain crude protein; s4, carrying out crude protein enzymolysis on the crude protein to obtain a second enzymatic hydrolysate; wherein the crude proteolysis adopts mixed protease, and the mixed protease comprises first protease and second protease; wherein the first protease is one or more of alkaline protease, neutral protease and acid protease; the second protease is papain; and S5, purifying the second enzymatic hydrolysate to obtain the camellia seed meal oligopeptide. The average molecular weight of the obtained product is smaller than 1000 Daltons, and the product has biological activity and high application value in the fields of cosmetics and functional food.

The invention belongs to the technical field of microbial protein separation and extraction, and particularly relates to soluble microbial protein and a preparation method thereof. The method comprises the following steps: fermenting and culturing microbial thalli to a logarithmic phase, and centrifuging to obtain mycelia; the mycelium is freeze-dried and then smashed, and mycelium powder is obtained; the mycelium powder is placed in water to be dispersed and homogenized, and homogenized homogenate is obtained; finally, alkaline protease is added into the homogenate for enzymolysis and enzyme deactivation, and the soluble microbial protein is obtained. On one hand, microbial cell walls are directly destroyed through mechanical shearing force and collision action generated by high-speed rotation of the wall breaking machine, and intracellular proteins and active ingredients are released; on the other hand, high-pressure homogenization is combined, mechanical shear force and cavitation effect are utilized to destroy a protein compact structure and expose restriction enzyme cutting sites, and alkaline protease is combined for directional hydrolysis, so that the enzymolysis time is greatly shortened, the efficiency is improved, and the extraction rate is greatly improved.

The invention belongs to the field of biological material extraction, and particularly relates to a method for extracting collagen peptide from marine organisms, which comprises the following steps: S1, crushing marine organism raw materials, soaking the crushed marine organism raw materials in a citric acid buffer solution containing alginate oligosaccharide for swelling treatment, and then performing high-voltage pulse electric field treatment to obtain pretreated collagen slurry; and S2, carrying out first-stage enzymolysis treatment on the pretreated collagen slurry through alkaline protease, and then carrying out second-stage enzymolysis treatment through collagenase and flavourzyme. S3, performing separation treatment through a first ultrafiltration membrane to obtain first filtrate, performing deodorization treatment on the first filtrate through a first nanofiltration membrane of which the surface is coated with a beta-cyclodextrin adsorbent to obtain second filtrate, and performing separation treatment on the second filtrate through a second nanofiltration membrane to obtain third filtrate. And S4, concentrating, desalting and drying the third filtrate to obtain collagen peptide powder. Through the synergistic effect of multiple steps, the concentration of the molecular weight of the collagen peptide and the efficient deodorization are realized on the basis of retaining the active structure of the collagen.