192 results about "Neutral protease" patented technology

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 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 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 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 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.

The invention discloses a liver protection composition containing glutathione-rich yeast. The liver protection composition is prepared from the glutathione-rich yeast, turmeric, silybum marianum, enzymolysis polypeptide with homology of medicine and food and anti-inflammatory and anti-oxidation auxiliary components. Wherein the medicine and food homologous enzymolysis polypeptide is prepared from radix puerariae through neutral protease-cellulase double enzymolysis, the polypeptide sequence is identified as Leuu-Val-Glu-Pro-Ala, and the medicine and food homologous enzymolysis polypeptide has the capacity of remarkably inhibiting LPS-induced RAW264.7 cell NO release and removing DPPH free radicals. According to the composition, through multi-component synergism, in an anti-alcohol experiment, the blood alcohol concentration decline rate of a mouse can be remarkably increased, the MDA content of liver tissue is remarkably reduced, and no acute toxic reaction exists. The composition has the functions of protecting the liver and dispelling the effects of alcohol, is safe and effective, and is suitable for the field of health-care products or functional foods.

The invention relates to the technical field of food biology, and discloses an antiviral cubilose polysaccharide active component enriched with bound sialic acid as well as a preparation method and application of the antiviral cubilose polysaccharide active component. The weight-average molecular weight of the cubilose polysaccharide active component is 30-36 kDa, the molecular weight distribution coefficient is 1.1-1.2, the content of bound sialic acid is greater than or equal to 24.0%, and the content of total sugar is greater than or equal to 57.0%. The preparation method comprises the following steps: pretreating a cubilose raw material in a boiling water bath, and sequentially carrying out alkaline protease and neutral protease enzymolysis; carrying out alcohol precipitation on supernate, redissolving, and carrying out papain enzymolysis; and after enzyme deactivation, adjusting the ethanol concentration to 75-85%, precipitating, and drying. According to the method, the cubilose polysaccharide can be efficiently enriched, the combined sialic acid structure of the cubilose polysaccharide is reserved, and the obtained component has the effects of resisting oxidation, inhibiting pathogenic microorganisms and regulating intestinal microecology.

The invention relates to the technical field of daily chemicals, in particular to a color-protecting laundry detergent containing plant extracts and a preparation method of the color-protecting laundry detergent. The color-protecting laundry detergent is prepared from the following components in percentage by mass: 12.5 to 18.3 percent of natural anionic surfactant, 6.4 to 9.7 percent of nonionic surfactant, 3.2 to 5.8 percent of plant polyphenol extract, 3.0 to 5.2 percent of fiber affinity natural polymer, 2.1 to 4.0 percent of bio-based chelating aid, 1.8 to 3.5 percent of natural glycoside synergist, 0.9 to 2.3 percent of pH buffering agent, 0.6 to 1.4 percent of antioxidant plant essential oil and the balance of deionized water. The compound protease comprises alkaline protease, neutral protease and papain; the invention aims to solve the technical problems that the existing laundry detergent is poor in color protection effect, insufficient in environmental protection performance and large in damage to fabrics, and provides a laundry detergent product which takes natural plant extracts as core components and has an efficient color protection function.

This invention belongs to the field of alcoholic beverage processing technology, specifically relating to a high-purity ginkgo wine and its preparation method. The preparation method comprises the following steps: ginkgo slurry undergoes preliminary enzymatic hydrolysis with neutral protease and amylase, followed by secondary enzymatic hydrolysis with pectinase and sodium bisulfite; brewing yeast fermentation broth is added for pre-fermentation; glutamine transaminase, *Saccharomyces cerevisiae* fermentation broth, and *Candida valerate* fermentation broth are added for post-fermentation; and finally, distillation and filtration are performed to obtain the ginkgo wine. This invention achieves complete decomposition and fermentation of ginkgo kernels through a two-step enzymatic hydrolysis and two-step fermentation process. The preparation method has advantages such as simple process and low cost, which is beneficial for industrial production; the prepared ginkgo wine has advantages such as clarity, strong aroma, high alcohol content, and low acidity.

The invention discloses uric acid-reducing peptide goat milk powder and a preparation method thereof, and belongs to the technical field of enzymes. According to the process for preparing the uric acid lowering peptide by hydrolyzing goat milk through the compound enzyme, the total addition amount of the compound enzyme (the enzyme activity ratio of neutral protease N to neutral protease X is 1: 1) is 4000 U / g-6000 U / g, enzymolysis is conducted for 2-3 h at the temperature of 45-55 DEG C, and under the condition, the xanthine oxidase inhibition rate is 71.67 + / -1.32%-83.64 + / -0.98%. The enzymolysis goat milk containing the uric acid-reducing peptide is subjected to spray drying to prepare the uric acid-reducing peptide goat milk powder, and the storage stability of the goat milk powder is relatively good. The amino acid sequence and the source of the uric acid lowering peptide are separated and identified, the in-vitro uric acid lowering activity of the uric acid lowering peptide is verified through the solid-phase synthesized uric acid lowering peptide, and a theoretical basis and technical support are provided for development of new uric acid lowering peptide goat milk products.

This invention relates to the field of skincare technology, and in particular to a method for extracting active components from silkworm pupae and a moisturizing facial mask composition. The extraction method includes: freezing, grinding, and sieving silkworm pupae to obtain silkworm pupae powder; defatting the silkworm pupae powder in an ethanol solution and filtering to obtain defatted silkworm pupae powder; mixing the defatted silkworm pupae powder, water, and neutral protease, adjusting the pH to 6.2-7.0, and sequentially performing enzymatic hydrolysis, enzyme inactivation, centrifugation, and filtration to obtain an enzymatic hydrolysate; centrifuging, microfiltration, and fine filtration of the enzymatic hydrolysate to obtain the active components of silkworm pupae. This invention, through the synergistic effect of freezing and enzymatic hydrolysis, releases small molecule peptides, amino acids, and nucleoside active substances from silkworm pupae under mild conditions, reducing the risk of protein denaturation and inactivation; through a step-by-step physical impurity removal chain of centrifugation, microfiltration, and fine filtration, large molecule sensitizing proteins are removed without introducing organic solvents, making it more suitable for skincare products.

The invention discloses an enzyme preparation for degrading allergens of pet food and application of the enzyme preparation, the enzyme preparation is a pH-responsive acrylic resin-pectin composite double-response shell embedded enzyme-probiotic composite system, a core layer is heat-resistant neutral protease, and a middle layer is a compound of lactobacillus reuteri and bacillus subtilis. In the processing stage, the protease degrades macromolecular allergens, the composite shell in the gastrointestinal environment firstly triggers outer acrylic resin to be dissolved through weak alkalinity of the intestinal tract, then inner pectin is degraded by pancreatin, and probiotics are accurately released to metabolize residual sensitizing peptides. The enzyme preparation realizes full-chain desensitization, is high in survival rate of probiotics, is suitable for various pet foods, and is stable and reliable in desensitization effect.

The present application relates to a kind of organic water-soluble fertilizer and its preparation method, which uses fish waste and shell waste as raw material, after being crushed and sterilized, enzymatic hydrolysis is carried out using acid protease and chitinase to obtain enzymatic hydrolysate;Add molasses to the enzymatic hydrolysate, and inoculate mixed bacterial agent for primary fermentation to obtain fermentation liquor A;Add yeast, neutral protease and sodium alginate to the fermentation liquor A, and carry out secondary fermentation under stirring to obtain fermentation liquor B;After treating the fermentation liquor B, add chitosan to obtain the organic water-soluble fertilizer;The organic fertilizer prepared by the method of the present application can utilize shell waste, and the obtained organic water-soluble fertilizer can improve its water-retaining and fertilizer-retaining performance in sandy soil while meeting the standard requirements of amino acid water-soluble fertilizer.

The application belongs to the technical field of biological medicine. More particularly, it relates to a collagen peptide and a preparation method and application thereof. The preparation method of the collagen peptide with anti-aging activity comprises the following steps: S1, fish scale pretreatment: washing, crushing, degreasing and removing impurities, and then washing to neutral; S2, decalcification: adding 1-4 times of pure water by weight to the pretreated fish scale, treating in a pulsed electric field for 1-5 min, then adding neutral protease for enzymolysis, and drying to obtain decalcified fish scale; S3, hydrolysis: adding plasma activated water and hydrolysis enzyme to the decalcified fish scale, water bath oscillation for 0.1-1 h, terminating the reaction, ultrafiltration, collecting the filtrate, and obtaining the collagen peptide.

The invention belongs to the technical field of medicine, and discloses an artemisia annua pollen allergen sublingual drop as well as a preparation process and application thereof.The preparation is realized through the following core processes: firstly, performing raw material screening and supercritical CO2 degreasing pretreatment on artemisia annua pollen at the full-bloom stage in North China, then performing graded ultralow-temperature freezing and crushing, and performing freeze drying to obtain the artemisia annua pollen allergen sublingual drop. The particle size D90 of the superfine powder is smaller than or equal to 4 microns; then adopting a neutral protease and pectinase composite enzymatic hydrolysis system, and combining 4 DEG C low-temperature pulse ultrasound-assisted treatment to accelerate the dissolution of allergens; carrying out tangential flow grading purification and buffer solution replacement by virtue of 100kDa and 5kDa PES (Polyether Sulfonate) ultrafiltration membranes, and introducing a compound stabilizer; and finally, performing three-stage sterile filtration, and performing encapsulation and preservation. According to the process, through multi-link collaborative optimization, the extraction efficiency and activity stability of allergens are improved, and the prepared sublingual drops have the effects of improving allergic rhinitis, allergic asthma and airway inflammation and also have excellent permeability.

The invention provides an extraction method and application of sweet potato protein, belongs to the field of agricultural product processing, protein extraction and pharmaceutical activity application, and particularly provides an extraction method of sweet potato protein, an extraction solvent is mainly water, and NaHSO3 is assisted; the sweet potato protein with a single structure and high purity is obtained through modes of cutting, crushing, centrifuging, filtering, freeze-drying and the like, and the method is suitable for industrial production and amplification; the invention further provides sweet potato protein peptide which is obtained by conducting enzymolysis on sweet potato protein through neutral protease or alkaline protease, and the obtained sweet potato protein and sweet potato protein peptide have the anti-inflammatory and anti-tumor effects.

This invention relates to the field of air pollution control technology, and in particular to a formaldehyde adsorbent from Forsythia suspensa and its application in formaldehyde adsorption. This invention uses Forsythia suspensa waste (such as withered branches) as raw material, and modifies it using a calcium chloride-assisted neutral protease method. Combined with specific preparation conditions, the resulting Forsythia suspensa formaldehyde adsorbent has a large specific surface area and a porous surface, exhibiting excellent adsorption conditions. During adsorption, -OH groups play a role; the adsorption process conforms to pseudo-second-order kinetics and the Freundlich isotherm, exhibiting a physicochemical mixed adsorption with chemical adsorption as the primary process. It involves multi-molecular layer heterogeneous site adsorption and a spontaneous endothermic reaction, achieving the national standard of 0.08 mg / m³ after 22 hours. 3 Even after eight desorption and regeneration cycles, it still retains a certain adsorption effect on formaldehyde.

This invention belongs to the field of biomedical technology, specifically relating to a Terminalia chebula active polypeptide, its preparation method, and its application. The preparation method uses Terminalia chebula slices as raw material, which are pulverized, homogenized with water, and then subjected to a series of enzymatic hydrolysis steps: a first hydrolysis with neutral protease, a second hydrolysis with pepsin, and a third hydrolysis with trypsin. Enzyme inactivation is performed after each hydrolysis. Subsequent steps include filtration, removal of alkaline proteins, ultrafiltration, and fine filtration to obtain the Terminalia chebula active polypeptide. The preparation method of this invention, through a three-step progressive enzymatic hydrolysis method, can efficiently prepare highly active Terminalia chebula polypeptides. The obtained Terminalia chebula active polypeptides have small molecular weight, are easily absorbed, and are non-toxic. These active polypeptides exhibit significant anti-tumor and liver fibrosis-improving effects, effectively reshaping the tumor microenvironment, enhancing anti-tumor immune responses, and repairing liver tissue damage. They have broad application prospects in the preparation of anti-tumor and liver fibrosis-improving drugs.

This invention discloses a multi-enzyme preparation for industrial cell dissociation, its usage method, and applications, belonging to the field of seed cell extraction technology for industrial meat culture. The invention employs a multi-enzyme preparation composed of component 1 and component 2; component 1 includes neutral protease, hyaluronidase, and elastase; component 2 includes matrix metalloproteinase, papain, and plasmin. The invention also discloses the preparation method and applications of the multi-enzyme preparation. The rational enzyme ratio and optimized treatment conditions of this invention help protect cell membrane integrity, maintain high cell activity, and significantly improve dissociation efficiency and cell recovery. The compound enzyme preparation is highly adaptable, applicable to various tissue types and dissociation requirements, and facilitates standardized and large-scale production. Combined with automated dissociation equipment, the compound enzyme preparation enables efficient and stable industrial operation, providing important technical support and broad application prospects for the cultured meat industry, tissue engineering, and cell therapy.

The invention discloses a fattening feed additive composition for old cattle and a fattening method, and belongs to the technical field of feed. The additive composition comprises the following components in parts by weight: 13-20 parts of a rumen function regulator, 4-10 parts of an intestinal repair agent, 10-20 parts of a rumen bypass compound enzyme preparation, 5-10 parts of a muscle-increasing growth-promoting composition, 5.5-7.3 parts of a functional trace element composition and 32.7-62.5 parts of a carrier. Wherein the rumen function regulator is compounded by a coated saccharomyces cerevisiae culture and bacillus subtilis; the rumen bypass compound enzyme preparation comprises acid protease, neutral protease and cellulase; the muscle-building and growth-promoting combination is coated guanidinoacetic acid. Through regulation and control of a rumen-intestinal tract-tissue three-level linkage network, the rumen fermentation function of the old cattle is remarkably improved, the feed conversion rate is increased, and meanwhile muscle hyperplasia and meat tenderization are achieved. By means of the fattening method, the average daily gain of the old cattle is increased by 22.8% or above, the muscle shear force is reduced by 29.6% or above, the feed conversion ratio is reduced by 17.1% or above, and green and efficient fattening is achieved.

The present invention relates to a method for modifying meat, including bringing the meat in contact with a Bacillus amyloliquefaciens-derived neutral protease having the following properties (a) to (e), and thermolysin; (a) being an enzyme that hydrolyzes a substrate having a peptide bond to release the peptide, (b) having an optimal pH of 7, (c) being stable at pH=5 to 7, (d) having an optimal temperature of 50°C to 55°C, (e) being a metal protease inhibited by ethylenediaminetetraacetic acid (EDTA), and a composition for modification, containing said neutral protease and thermolysin. According to the present invention, meat can be tenderized conveniently in a short time, and ease of loosening can be imparted to the meat.

The present application belongs to the technical field of nutritional functional food and health food, and particularly relates to a preparation method of marine fish skin collagen oligopeptide beneficial to promoting skin health, and a product and application thereof. The method comprises the following steps: after deep sea fish skin is pretreated by salt dissolution with a NaCl solution, trisodium citrate is added as an enzymolysis aid, and neutral protease (from Trichoderma reesei) and papain are sequentially used for two-step enzymolysis, and after enzyme inactivation, impurities are removed, sterilization is performed, and concentration, drying are performed to obtain the product. In vitro cell experiment verification shows that the product can significantly promote human skin fibroblast proliferation; in vivo animal experiment verification shows that the product can significantly increase skin moisture content, reduce transdermal water loss, increase hydroxyproline content, improve SOD activity and reduce MDA content. The product is suitable for the field of nutritional functional food and health food, and has a good application prospect in promoting skin health.

The invention relates to the field of yeast extracts, in particular to a yeast extract containing arginine as well as a preparation method and application of the yeast extract. Wherein the content of arginine in the yeast extract containing arginine is greater than or equal to 6%, and the preparation method comprises the following steps: step 1, culturing a strain to obtain yeast milk; 2, extracting the yeast milk obtained in the step 1, and performing solid-liquid separation to obtain supernate; step 3, performing enzymolysis on the supernate obtained in the step 2, and performing solid-liquid separation to obtain a yeast extract containing arginine; wherein in the step 3, the enzyme used for enzymolysis comprises one or more than two selected from a substance group consisting of papain, alkaline protease and neutral protease. By adopting the preparation method disclosed by the invention, the arginine in the yeast can be more effectively enriched and can be up to 7.35% at most, and the method can be widely applied to the fields of preparing flavor modifiers of foods or human nutrition supplements and the like.

The invention belongs to the technical field of collagen peptide preparation, and particularly relates to a proline aminopeptidase mutant and application thereof in collagen peptide preparation. The amino acid sequence of the proline aminopeptidase mutant is as shown in SEQ ID NO. 2. The proline aminopeptidase mutant provided by the invention has the advantages of high enzyme activity, wide temperature and pH adaptation range, capability of adapting to a long-time high-temperature environment of collagen enzymolysis and the like, and is suitable for deep hydrolysis of collagen. Through cooperation with neutral protease, papain and collagenase, collagen raw materials from fish skin can be effectively degraded, the yield of low-molecular-weight peptide is increased, and collagen peptide with the molecular weight smaller than 1000 Da and accounting for 90% or above, collagen tripeptide accounting for 39% or above, collagen dipeptide accounting for 2% or above and the content of characteristic dipeptide Hyp-Gly being remarkably increased is generated. The method has important application value in the field of oriented preparation of collagen dipeptide.

The invention discloses a method for extracting fish oil from viscera of freshwater fish, which comprises the following steps: removing gall bladder, swim bladder and intestinal digests in the viscera of freshwater fish, cleaning, draining, and crushing to obtain viscera paste; putting the minced viscera into deionized water, carrying out microwave treatment, then adjusting the pH value to 6.5-7.5, and then adding neutral protease and an antioxidant to carry out enzymolysis reaction, so as to obtain an enzymolysis mixture; and performing centrifugal layering on the enzymolysis mixture, collecting a fish oil layer, and performing distillation purification to obtain the fish oil. According to the extraction method disclosed by the invention, a microwave-assisted enzymolysis technology is adopted to accelerate a reaction process, an oil-soluble natural antioxidant in-situ antioxidant technology is combined to inhibit fat oxidation, and the fish oil is purified by a molecular distillation technology, so that the product quality is improved; the technology can improve the fish oil extraction efficiency, reduce the production cost, reduce the environmental pollution, and ensure the high quality and high purity of the fish oil.

The invention relates to the technical field of food colloid modification and food processing, in particular to a modified gelatin raw material, a preparation method and application of the modified gelatin raw material in soft sweets. The preparation method of the modified gelatin raw material comprises the following steps: mixing a gelatin base material with water to prepare a gelatin solution, and adding neutral protease for enzymolysis to obtain enzymatic hydrolysate; cooling the enzymatic hydrolysate, adding glutamine transaminase, and stirring for reaction to obtain a mixture A; the mixture A is subjected to spray drying, powder is collected, smashed and sieved, and the modified gelatin raw material is obtained. Through composite modification, high gel strength (250-280 Bloom), excellent emulsion stability (greater than or equal to 95%) and fresh and cool taste (low stickiness) are simultaneously realized on the basis of a single gelatin raw material, and the performance indexes are comprehensively superior to those of unmodified and single modified gelatin; the soft sweets prepared from the modified gelatin material are good in elasticity, not sticky to teeth and good in flavor release.