463 results about "Alkaline proteinase" patented technology

The invention discloses a preparation method of an antioxidant walnut polypeptide health product. The preparation method comprises the following steps: pre-treating walnut pulp; homogenizing the walnut pulp; extracting walnut proteins; carrying out pre-treatment for enzymolysis; carrying out enzymolysis; separating; desalting; and concentrating and drying to obtain a walnut polypeptide product. Four enzymes: alkaline protease, papain, neutral protease and bromelain are sequentially added in different times in the enzymolysis link. The strength, function and synergy and the like of the effects of the four enzymes which are used for decomposing proteins into polypeptides and amino acids are comprehensively considered and the four enzymes are used for enzymolysis under the optimal enzymolysis conditions, respectively. The reducing capacity of the prepared walnut polypeptide manifests that the absorbancy floats up and down at 0.4, the hydroxyl free radical scavenging rate can reach 95%, the superoxide anion free radical scavenging rate can reach 39.5%, the protein extraction ratio can reach 98.71% and the degree of hydrolysis of the walnut polypeptide can reach 26.37%. Compared with the prior art, those items are greatly enhanced and improved relatively.

The invention provides yak bone protein peptide with DPP-IV inhibitory activity and a preparation method thereof. The yak bone protein peptide provided by the invention is optimally prepared from the enzymolysis products by conducting multiple-step enzymolysis by multilevel compound protease on the yak bone protein prepared from yak bone, and the compound protease contains alkali protease, neutral proteinase, trypsin and flavourzyme. The yak bone protein peptide provided by the invention has excellent DPP-IV inhibition and antioxidation functions, and can be used as a DPP-IV inhibitor and antioxidation raw material to be applied to special foods and nutritional foods.

A process for extracting oil and hydrolytic protein from peanut by water-enzyme method includes such steps as extracting emulsified oil by use of alkaline proteinase, and demulsifying it by freezing and thawing to obtain free oil while recovering hydrolytic protein powder in the form of micropeptide. Its advantages are high oil output and high nutritive value.

The invention relates to a method for preparing an antioxidant peptide through ultrasonic-microwave synergetic enzymatic hydrolysis. The method comprises the following steps: (1), preparing an enzymatic hydrolysis substrate; (2), adding an alkali protease for enzymatic hydrolysis; (3), carrying out ultrasonic-microwave assistant enzymatic hydrolysis; and (4), after enzyme inactivation, centrifuging and separating a reaction solution, taking supernatant, freezing and drying to obtain antioxidant peptide powder. The method has the advantages that the ultrasonic technology, the microwave technology and the enzymology biology technology are combined. Compared with the peptide prepared by the conventional method, no chemical reaction is carried out, the change rate of bioactive substances is reduced, the utilization rate of organic solvents is reduced, the enzymatic hydrolysis time is shortened after the ultrasonic-microwave assistant enzymatic hydrolysis is carried out, and a test proves that the antioxidant capacity of the salmon peptide is remarkably enhanced. The method is simple in process, can be used for industrial production and has higher economic and social benefits.

A process for preparing soybean protein oligopeptide from concentrated soybean protein, separated soybean protein, defatted soybean powder, soybean dregs, or soybean cake features the cooperative hydrolysis with alkaline proteinase, acidic proteinase and / or neutral proteinase at 30-70 deg.C for 2-24 hr. Its advantages are simple downstream steps and low cost.

The invention discloses an enzymolysis method for simultaneously extracting fucoidin, alginic acid, mannitol and seaweed dietary fiber. The method comprises the following steps of firstly performing crushing and water adding soaking on seaweed raw materials; then, adding complex enzymes A for further composite enzymolysis; then, adding complex enzymes B for two-step composite enzymolysis; performing enzyme activity inactivation; performing solid-liquid separation; obtaining solid being seaweed dietary fiber crude products; using obtained liquid for extracting alginic acid, fucoidin and mannitol, wherein the enzymes A contain any four or more than four of cellulose, hemicellulase, pectinase, amylase, xylanase and the like; the complex enzymes B contain one or any two of alkaline protease, neutral protease, papain, trypsin, acid proteinase and pepsin. The method provided by the invention has the most obvious beneficial effect that by using the special composite enzymolysis technology, four kinds of products including fucoidin, alginic acid, mannitol and functional dietary fiber can be simultaneously extracted from seaweeds.

The invention belongs to the deep processing technology of shinyleaf yellowhorn, in particular to a method for extracting shinyleaf yellowhorn oil, shinyleaf yellowhorn polysaccharide and shinyleaf yellowhorn protolysate peptide from shinyleaf yellowhorn. The method comprises the following steps of: taking the kernels of shinyleaf yellowhorn, crushing the shinyleaf yellowhorn kernels, and adding water to swell; continuously treating by using microwaves, hydrolyzing by using alkali protease, separating three phases by using neutral protease, flavourzyme, cellulase and hemicellulase, concentrating through ultrafiltration by using an ultrafiltration membrane, drying the concentrated solution, and vacuum-drying and crushing the hydrolyzing residue to obtain high-grade animal feed rich in protein, fat and cellulose. In a word, the invention overcomes various defects caused by the traditional vegetable oil preparation process and adopts a brand new process for furthest extracting pollution-free shinyleaf yellowhorn oil and simultaneously acquiring shinyleaf yellowhorn polysaccharide and shinyleaf yellowhorn protolysate peptide. The whole processing process reflects continuity, rapidnessand mechanization, and production efficiency is greatly improved.

The invention belongs to the technical field of environment-friendly water treatment, particularly relates to a water purifying agent for wastewater treatment in rubber accelerator M production and further relates to a method for treating rubber accelerator M production wastewater by adopting the water purifying agent. The water purifying agent contains a flocculation water purifying agent, a microbial water purifying agent and an enzyme preparation, wherein the flocculation water purifying agent is prepared from polyaluminum chloride, polyacrylamide, ferrous sulfate and aluminum sulfate; the microbial water purifying agent is prepared from nitrobacterium powder, paracoccus denitrificans powder, thiobacterium powder, aniline degrading bacteria powder and flocculating bacteria powder; the enzyme preparation is prepared from pectinase, cellulase, oxidoreductase, lysozyme and alkaline proteinase. The water purifying agent and the method have the beneficial effects that by adopting the water purifying agent for wastewater treatment, disclosed by the invention, the water purifying effect is good, the water purifying speed is high, the safety is high, and no secondary pollution is caused; materials with adsorption capacity are used as raw materials and are assisted with microbes, so as to treat the wastewater, so that the range of use is wide, the transparency of treated water is extremely high, and recycling can be achieved.

The invention relates to a preparation method of magnetic chitosan compound microsphere immobilized marine alkaline proteinase. The magnetic chitosan compound microsphere immobilized marine alkaline proteinase is prepared from Fe3O4 magnetic chitosan compound microsphere and magnetic chitosan compound microsphere immobilized marine alkaline proteinase 894. The method further improves the using efficiency, lowers using and production cost, obtains the immobilized enzyme with stable usability, high activity recovery and long using period and has wide application on food, textile and feed.

The invention belongs to the technical field of environment-friendly water treatment, particularly relates to a water purifying agent for wastewater treatment in rubber accelerator production and further relates to a method for treating rubber accelerator production wastewater by adopting the water purifying agent. The water purifying agent contains a flocculation water purifying agent, a microbial water purifying agent and an enzyme preparation, wherein the flocculation water purifying agent is prepared from polyaluminum chloride, polyacrylamide, ferrous sulfate and aluminum sulfate; the microbial water purifying agent is prepared from nitrobacterium powder, paracoccus denitrificans powder, thiobacterium powder, aniline degrading bacteria powder and bacillus larvae powder; the enzyme preparation is prepared from pectinase, cellulase, oxidoreductase, xylanase and alkaline proteinase. The water purifying agent and the method have the beneficial effects that by adopting the water purifying agent for wastewater treatment, disclosed by the invention, the water purifying effect is good, the water purifying speed is high, the safety is high, and no secondary pollution is caused; materials with adsorption capacity are used as raw materials and are assisted with microbes, so as to treat the wastewater, so that the range of use is wide, the transparency of treated water is extremely high, and recycling can be achieved.

The invention discloses a Miichthys miiuy air bladder antioxidation peptide and application thereof. The antioxidation peptide Phe-Pro-Tyr-Leu-Arg-His (FPYLRH) is obtained through subjecting Miichthysmiiuy air bladders, which serve as a raw material, to defatting and alkaline proteinase enzymolysis to obtain an enzymolysis solution and subjecting the enzymolysis solution to ultrafiltration, anionexchange resin chromatography, gel column chromatography and out-phase high performance liquid chromatography separation and purification; proven by ESI-MS assaying, the antioxidation peptide has themolecular weight of 831.98Da. The antioxidation peptide has the beneficial effects that the prepared high-activity antioxidation peptide has a good scavenging action on DPPH free radicals and hydroxyl free radicals; meanwhile, the antioxidation peptide has a protective action on hydrogen peroxide induced human umbilical vein endothelial cell-HUVEC cellular oxidation injury and can serve as drugs,healthcare food or food additives.

The invention discloses a sea cucumber egg nutriment and a preparation method thereof. The sea cucumber egg nutriment is white or light yellow hydroscopic powder free of odor and taste and highly soluble to water and ethanol. The preparation method comprises sea cucumber egg and intestine breaking and enzymolysis, metal ion removal through ion exchange, and freeze drying, wherein the enzymolysis employs conjugated enzymes of exogenous enzymes and endogenous enzymes or single exogenous enzymes; single exogenous enzyme enzymolysis refers to the enzymolysis using single pepsinase or using the mixture of trypsinase, dispase and alkaline proteinase. The invention not only makes wastes in sea cucumber processing with traditional methods into an invigorant rich in nutrition but also reduces pollution of the wastes to the environment. The processing method is simple and reasonable and can be industrialized easily.

An alkaline protease having an amino acid with one or more amino acid residues selected from among those located at (a) position 63, (b) position 89, (c) position 120, (d) positions 63 and 187, (e) position 226, (f) position 296, (g) position 304 of the amino acid sequence of SEQ ID NO: 1, or at positions corresponding to these positions, are the following amino acid residues, respectively: (a): serine, (b): histidine, (c): arginine, (d): serine,(e): tyrosine, (f): valine, and (g): serine; and a gene encoding the alkaline protease.

The invention relates to a polypeptide production method which sequentially comprises the following steps: (1) taking a protein-containing raw material, adding water, and immersing to obtain a first solution; (2) stirring and homogenizing the first solution; (3) carrying out enzymolysis on the first solution with alkaline proteinase; (4) inactivating and centrifugating the enzymolysis solution obtained in the step (3) to obtain a supernate A and a precipitate A; (5) adding water to the precipitate A to obtain a second solution; carrying out enzymolysis on the second solution with neutral proteinase; (6) inactivating and centrifugating the enzymolysis solution obtained in the step (5) to obtain a supernate B and a precipitate B; (7) adding water to the precipitate B to obtain a third solution; carrying out enzymolysis on the third solution with acidic protease; (8) inactivating the enzymolysis solution obtained in the step (7), and centrifugating to obtain a supernate C; (9) mixing the supernate A, supernate B and supernate C to obtain a polypeptide mixed solution; and (10) removing water in the polypeptide mixed solution to obtain the polypeptide. The method can enhance the protein utilization ratio of the raw material and obtain the high-quality polypeptide product.

The invention relates to a glycosylated lactalbumin polypeptide with antioxidant activity as well as a preparation method and an application of the glycosylated lactalbumin polypeptide. According to the invention, the method for preparing the glycosylated lactalbumin polypeptide with antioxidant activity comprises the following steps: after hydrolyzing lactalbumin into protein peptide by using alkaline protease, boiling up the protein peptide and inactivating the enzyme activity of the protein peptide; cooling the protein peptide; mixing the protein peptide with sugar; stirring and heating the mixture at a certain temperature; and after carrying out Maillard reaction on the mixture for a certain time, rapidly cooling and centrifuging the mixture so as to remove precipitates, wherein a supernatant liquor can be directly frozen and dried or frozen and dried after being ultra-filtered. The glycosylated lactalbumin polypeptide obtained by using the method provided by the invention has a stronger anti-oxidation effect and obtains stronger stability than a plurality of natural antioxidants; moreover, because the used raw materials are all edible foods, high safety is obtained.

The invention relates to a biological method for extracting grease from flat almonds. The method comprises the following steps of: crushing the flat almonds in a dry way, mixing the crushed flat almond powder and water, regulating pH to 6.5-7.5 and the temperature to 50 DEG C, adding neutral proteinase accounting for 0.1-1.0% of the flat almond powder to carry out enzymolysis for 2-6 hours, reducing the temperature to 40 DEG C and regulating the pH 7.5-8.5, adding alkaline proteinase accounting for 0.1-1.0% of the raw materials to carry out enzymolysis for 2-6 hours to obtain enzymolysis liquid; directly centrifuging the enzymolysis liquid to respectively obtain free oil, emulsion, hydrolytic liquid and almond dregs from top to bottom, adding biological lipopeptid demulsifying agents accounting for 0.1-0.5% of the volume of emulsion into the emulsion, demulsifying and centrifuging again for separation to obtain free oil, and merging the free oil to obtain flat almond oil. The invention can avoid the formation of stable emulsion by adopting a dry method, the demulsifying agents are saved, and the cost is reduced; the flat almond oil prepared by the biological method can avoid problems of fat oxygenation caused by squeezing grease, and solvent remain caused by extracting oil in a lixiviation method.

The invention discloses a multipurpose surfactant-free cleaning agent for fruits, vegetables and dishes. The cleaning agent comprises purified water, a composite chelating agent, an anti-deposition agent, a composite enzyme preparation, a composite builder and a composite plant extraction liquid, wherein the composite chelating agent comprises EDTA-2Na and sodium tartrate, the composite enzyme preparation comprises alkaline proteinase, lipase, amylase and cellulose, the composite builder comprises citric acid, sodium hydroxide and sodium bicarbonate, and the composite plant extraction liquid comprises an onion extraction liquid, a garlic extraction liquid, a ginger extraction liquid, a dark tea extraction liquid, a Chinese honeylocust fruit extraction liquid and a soapberry pericarp extraction liquid. The multipurpose surfactant-free cleaning agent for fruits, vegetables and dishes can avoid secondary environment pollution generated by surfactant residues, damage to human health caused by residues of organic pesticides and the like, not only can be used for cleaning and degerming vegetables and fruits and removing the residues of pesticides, but also can be used for cleaning and sterilizing dishes; and the multipurpose surfactant-free cleaning agent for fruits, vegetables and dishes and the method for producing the multipurpose surfactant-free cleaning agent for fruits, vegetables and dishes have the advantages of less investment, easy availability of the raw materials, simple and convenient production, high cleaning rate, wide application range, and are beneficial for environment protection and human health.

The invention discloses an oral liquid containing soybean peptides and fungi polysaccharides and a preparation method thereof, and belongs to the technical field of non-alcoholic beverages, wherein the soybean peptides contain oligopeptides, short peptides and polypeptides mixtures. The oral liquid comprises the following raw materials in percentage by weight: soybean peptides containing oligopeptides, short peptides and polypeptides mixtures 2-12%, lentinan or ganoderma polysaccharide 0.03-0.1%, citric acid 0.1-0.15%, malic acid 0.1-0.15%, xylitol 5-10%, brown sugar 5-7%, honey 1-3%, CMC 0.2%, various kinds of vitamins, and the balance of water. The soybean protein powder which has been completely deodorized and one of akaline proteinase and flavor proteinase are treated at 55 DEG C and at the pH value of 9.0, and then centrifuged at 3000rpm. The supernatant is subjected to spray drying, so as to obtain the soybean polypeptide powder, and the soybean polypeptide powder is mixed with different kinds of fungi polysaccharides and the other raw materials such as citric acid, so as to prepare the oral liquid. The oral liquid has very good physiological and nutritive function, and the oral liquid and the preparation method develop a new way for deep processing of soybeans.

The invention discloses a preparation method of cordyceps militaris polypeptide. The preparation method comprises the steps of: based on fresh cordyceps militaris as a raw material, preparing cordyceps militaris homogenate liquid by crushing, grinding, freeze thawing and homogenizing; carrying out enzymolysis of compound enzymes consisting of plasmase and pectinase, the enzymolysis of papain, the enzymolysis of alkaline proteinase and the enzymolysis of flavourzyme on the cordyceps militaris homogenate liquid; and finally carrying out enzyme inactivation, filtering by utilizing a molecular film filter and spray-drying on the cordyceps militaris homogenate liquid, so as to obtain cordyceps militaris polypeptide powder. The preparation method can be carried out at normal temperatures and pressures and has the advantages of simple operation method, energy conservation and environmental friendliness, low cost, high extraction efficiency of the cordyceps militaris polypeptide and high polypeptide contents of products.

The invention discloses a bacillus licheniformis and a method for utilizing the sludge as raw material for producing alkaline protease. The bacillus licheniformis is gram-positive bacteria and is shaped like a straight rod, and the collection number is CGMCC 1970. The method for utilizing the bacillus licheniformis for producing the alkaline protease includes (1) the conditioning of a culture medium; (2) shaking culture; (3) the fermentation by a fermentation tank; and (4) the purification of the protease. The bacterial strain of the invention is utilized for producing the alkaline protease, which can not only dispose sludge, but also obtain the alkaline protease product with high additional value and lower cost. The method uses urban waste sludge to replace the traditional food culture medium for producing the alkaline protease product, which not only provides a new way for the resource disposal of urban sludge, but also can greatly reduce the price of the product and promote the industrial production and application of protease preparations.

The invention discloses a making method of chondroitin sulfate, which comprises the following steps: grinding chondroitin sulfate; enzymolyzing through 2709 alkaline proteinase; filtering; decoloring; sedimenting liquid through cetylpiridinium chloride; dissociating the sediment; sedimenting through alcohol; drying; obtaining the product.

The invention discloses a method for preparing protein hydrolyzate from abalone viscera through complex enzyme hydrolysis, bitterness shielding and other technologies. Complex enzymes comprise alkali protease and papain. The protein hydrolyzate is prepared from abalone viscera by cleaning, pulping, hydrolyzing with the enzymes, inactivating the enzymes and shielding bitterness by using ethyl maltol in sequence. The method effectively utilizes a side product, namely viscera, generated during abalone processing, and the bitterness of the protein hydrolyzate is avoided; the prepared protein hydrolyzate has high content of free amino acid, high absorptivity of human body, rich nutrition and delicious flavor, and can be used as an additive to be widely applied to products such as cans, sauces,fodders, plant nutrient solutions and the like.

The invention discloses a new process utilizing enzymolysis and microbiological fermentation to improve the feeding nutritional value of rapeseed meal. The method is characterized in that: the process combining the enzymolysis of exogenously added alkaline protease and microbial two-step anaerobic fermentation is employed to prepare a high value-added fermented rapeseed meal product that has high protein content, is rich in polypeptide, small peptide, amino acid, organic acid, probiotics and other nutrients, and has low content of phytic acid, tannin and other antinutritional factors. The fermented rapeseed meal product has a crude protein content of more than or equal to 50%, an acid soluble protein content of greater than or equal to 10%, a degree of hydrolysis of more than or equal to 35%, an organic acid content of more than or equal to 5%, a phytic acid content of less than or equal to 0.1%, and a volatile basic nitrogen content of less than or equal to 100mg / 100g, the feed utilization rate is improved, and the culture cost is reduced. The fermented rapeseed meal can be applied to aquatic feed, enhances the adding amount of fermented rapeseed meal in aquatic feed, and can partially replace the application of fish meal, soybean meal and the like. In addition, the method provided by the invention adopts solid static fermentation, also the fermentation process has no need for sterilization, the production process is simple, the production cost is low, and the industrial production prospect is broad.

A composite enzyme as the treating agent of leather collegen contains at least two of neutral proteinase, alkaline proteinase and acidic proteinase, pH-buffering agent and additive. It can be used for hydrolysis and softening of leather collegen.

The invention provides a method for preparing an intestine nutritive peptide by using wheat, and belongs to the technical field of deep processing of wheat protein. The method comprises the following steps: (1) pre-mixing the wheat with polysaccharide and adding water for dispersion, so that wheat protein suspension liquid solubilized through the polysaccharide is obtained; (2) selecting protamex<TM> to perform restriction enzymolysis on the wheat protein step by step, wherein the substrate obtained in the later step is a precipitate produced through enzymolysis in the step (1), the times for enzymolysis are controlled to be 3-4, and when the protein content in the final precipitate is less than 5% (dry basis), the enzymolysis is stopped; (3) using a continuous enzymolysis-membrane separation coupling system for treating a supernatant centrifuged through enzymolysis in the above steps, adding a certain amount of alcalase in the system for enzymolysis for a certain time, and then desalting permeating liquid through nanofiltration, so that wheat oligopeptide with high glutamine is obtained. The wheat active peptide prepared through the method can alleviate injury degree of enteritis rat intestinal mucosa, and promote the synthesis of intestinal mucosa protein and DNA, and has an obvious efficacy of enteral nutrition.

The invention discloses a preparation method of whitening complex protein peptide enzymatic hydrolysate. The preparation method includes the following steps: (1) preparing raw materials; (2) preparingprotein enzymatic hydrolysate, and performing enzymolysis by using alkaline protease, papain and neutral protease through two steps, wherein the using amount of the alkaline protease is 1-3% of the dry weight of material liquid, the using amount of the papain is 0.5-1.5% of the dry weight of the material liquid and the using amount of the neutral protease is 1-3% of the dry weight of the materialliquid; (3) performing centrifugation; (4) performing decolorization; and (5) performing filtering so as to obtain the whitening complex protein peptide enzymatic hydrolysate. The full enzymolysis ofeach protein can be achieved through the preparation method, and active peptide can be reserved, so that the obtained complex protein peptide can be easily and rapidly absorbed, nutrition can be rapidly supplemented, and the complex protein peptide has the functions of promoting skin whitening. A whitening complex protein peptide beverage containing the whitening complex protein peptide enzymatichydrolysate and a preparation method of the whitening complex protein peptide beverage are also provided. The whitening complex protein peptide beverage has the effects of significantly promoting skin whitening and is tasty.

The invention discloses an antioxidant active peptide and a preparation method thereof. The antioxidant active peptide is characterized by taking decapterus fish protein as the raw material, alkaline protease generated by bacillus subtilis 2709 is adopted for hydrolysis, after enzyme deactivation of the hydrolysate, the hydrolysate is separated through centrifugation, ultra-filtration, gel chromatography and reverse phase high performance liquid chromatography so as to determine the structures of two natural antioxidant peptide, the amino acid sequences are His-Asp-His-Pro-Val-Cys (histidine-aspartic acid-histidine-proline-valine-cysteine) and His-Glu-Lys-Val-Cys(histidine-glutamic acid-lysine-valine-cysteine), the concentration (EC50) for eliminating DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical of 50% are 0.0310+ / -0.0011mu M and 0.0677+ / -0.0012mu M, the concentration for eliminating superoxide anion (O2-) radical of 50% are 0.3814+ / -0.0017mu M and 0.3744+ / -0.0021mu M, and the antioxidant active peptide has good antioxidant activity.

The present invention belongs to the field of food-derived peptides and discloses a collagen peptide, a production method, a production device and an application thereof. The production method of thecollagen peptide comprises steps of coarse collagen solution heating, cooling, high-efficiency compound enzyme preparation enzymatic hydrolyzing, membrane filtering, concentrating, ultra-high pressurehomogenizing, and ultra-high temperature instantaneous sterilizing and drying. The high-efficiency compound enzyme preparation enzymatic hydrolyzing uses a compound enzyme preparation comprising compound protease, alkaline protease, neutral protease, flavor protease, animal proteolytic enzyme and an enzyme activator, and the enzyme activator is dithiothreitol and / or beta-mercaptoethanol. The provided method does not need to adjust pH value of the enzymatic hydrolyzing, does not need to control enzymatic hydrolyzing temperatures, is short in enzymatic hydrolyzing time and small in enzyme addition amount, and enables the enzymatic hydrolyzed product to be low and concentrated in molecular weight. The prepared collagen peptide powder is free of fishy smell, extremely excellent in water resolubility and also not liable to absorb moisture and agglomerate during storage process, and can be used in solid beverages, effervescent tablets, chewable tablets, health-care foods and feature-beautifying and skin-protecting products.

The invention discloses an antifreeze polypeptide for protecting bacteria from low temperature freeze-thawing damage and a preparation method thereof. The preparation method is characterized by using fish-derived collagens as raw materials, adopting alkaline protease to carry out enzymolysis on the fish-derived collagens and carrying out separation and purification and freeze drying, thus obtaining the antifreeze polypeptide for protecting bacteria from low temperature freeze-thawing damage. The amino acid complete sequence of the antifreeze polypeptide is Gly-Gln-Arg-Gly-Gly-Arg-Gly-Leu-Pro-Gly-Glu-Arg-Gly-Arg-Val-Gly-Pro-Ser-Gly-Pro-Ala-Gly-Ala-Arg-Gly-Ala-Asp-Gly. By adopting the antifreeze polypeptide and the preparation method, the research ideas and methods of antifreeze proteins (polypeptides) existing at home and abroad are broken through, limitation of the quantity of the antifreeze proteins purified form natural organisms and considerations of international FDA (food and drug administration) for security of transgenic antifreeze proteins in food application are overcome, an efficient antifreeze polypeptide based on food sources is obtained, and a theoretical foundation is laid for developing the antifreeze polypeptide based on food sources and exploring extensive application of the antifreeze polypeptide to food and medicines.

The invention provides a yak bone protein peptide with an ACE inhibiting function and a preparation method and application thereof. The yak bone protein peptide is prepared from enzymatically hydrolyzed yak bone protein by multiple-step enzymatic hydrolysis by compound protease, and the compound protease consists of alkali protease, papain, trypsin and flavourzyme. The yak bone protein peptide provided by the invention has an excellent ACE inhibiting function, the ACE inhibiting activity (IC50 value) is smaller than 0.32mg / mL, and the yak bone protein peptide can be used as an ACE inhibitor to be applied to special foods and nutritional foods. The preparation method of the yak bone protein peptide provided by the invention is simple, the whole processing course is not added with acid or alkali for regulating the pH value, and the product maintains good functional characteristics and is easier to realize industrialized production.