60 results about "Dpph scavenging" patented technology

The invention relates to the production method of a bitter buckwheat product, in particular to the production process of sweet fermented bitter buckwheat, which solves the technical problems in processing sweet fermented products from the bitter buckwheat material. The production method comprises the following steps: soaking bitter buckwheat in water, steaming, cooling, adding sweet sake koji, bottling and fermenting. The sweet fermented bitter buckwheat prepared by the invention has clear liquid, aromatic flavor, sweet and sour taste, and unique flavor of bitter buckwheat. The sweet fermented bitter buckwheat contains total phenol 3.32%, total flavone 1.75% measured by spectrophotography, rutin 0.93 measured by liquid chromatography, quercetin 0.07%, isoquercitrin 0.04%, and D-chiro-inositol 0.13%. The sweet fermented bitter buckwheat has extremely high efficiency in eliminating hydroxyl radicals, hydrogen peroxide and DPPH, and the efficiency is enhanced when the concentration of the extractive liquid increases.

The invention relates to a method for increasing the contents of tanshinone and salvianolic acid in a salvia miltiorrhiza hairy root by using a transgene AtMYC2, belonging to the technical field of gene engineering. The method comprises the steps of constructing a high-efficiency expression vector of a plant by using an arabidopsis transcription factor AtMYC2, and carrying out genetic transformation on salvia miltiorrhiza leaves to obtain a gene AtMYC2 overexpressed transgenetic salvia miltiorrhiza hairy root; analyzing the expression of AtMYC2 in the transgenetic salvia miltiorrhiza hairy root and related genes in biosynthetic pathways of tanshinone and salvianolic acid through qRT-PCR; measuring the contents of tanshinone and salvianolic acid in the transgenetic salvia miltiorrhiza hairy root by using a high-performance liquid chromatography (HPLC); and measuring the antioxidant activity of tanshinone and salvianolic acid in the transgenetic salvia miltiorrhiza hairy root by using a DPPH free radical scavenging method. The invention provides the method for simultaneously increasing the contents of tanshinone and salvianolic acid in salvia miltiorrhiza hairy root and also provides a novel high-quality raw material for producing tanshinone and salvianolic acid with important clinic demands so as to have the positive promoting significance and application value for relieving the problem that the drug resources of tanshinone and salvianolic acid are short.

The invention belongs to the technology for gene engineering, and discloses a method for increasing tanshinone content of salvia miltiorrhiza hairy roots by transferring SmGGPPS gene. In the prior art, the growth cycle of the salvia miltiorrhiza is long; the tanshinone content is low, and the requirement of the human medical treatment for the tanshinone content cannot be met. The method comprisesthe following steps of: cloning a coding sequence of the SmGGPPS gene from salvia miltiorrhiza, and constructing a plant high-efficient expression vector; genetically transforming salvia miltiorrhizaleaves to obtain the salvia miltiorrhiza hairy roots with transferred SmGGPPS gene; analyzing the expression condition of the SmGGPPS gene in the transgenic salvia miltiorrhiza hairy roots by a semi-quantitative RT-PCR method; measuring the total tanshinone content including cryptotanshinone, tanshinone I and tanshinone II A of the transgenic salvia miltiorrhiza hairy roots by high performance liquid chromatography; and measuring the antioxidant activity of cryptotanshinone of the transgenic salvia miltiorrhiza hairy roots by a diphenyl picryl-hydrazyl (DPPH) method. The method has the advantages of obviously increased total tanshinone content of the salvia miltiorrhiza hairy roots, reliable effect, low cost of tanshinone, and no environmental pollution during manufacturing.

The invention discloses a method for preparing antioxidant peptides from oats. Alcalase is determined to serve as the enzyme for preparation through investigating the antioxidant activities and yields of the products obtained by carrying out enzymolysis on the oat bran proteins with different proteases. Reduction of the enzymolysis speed of the Alcalase toward the oat bran proteins is determined to be mainly caused by substrate consumption and enzyme activity loss through investigating the enzymolysis speed of the Alcalase toward the oat bran proteins. Meanwhile, an enzymatic membrane reactorsystem is determined to have good retention effect on the Alcalase through studying the impact of the enzymatic membrane reactor system on the enzyme activity. The activity loss of the Alcalase is mainly caused by the damage to the enzyme in the operation process of a peristaltic pump and the adsorption of an ultrafiltration membrane toward the enzyme. By utilizing Design Expert 6.0.5 to design the response surface analysis experiment with four factors and three levels, the optimum process conditions under which the antioxidant peptides from oats can be prepared by utilizing the enzymatic membrane reactor are as follows: the substrate concentration is 3%; the enzyme addition is 3.2%; the feed flow rate is 45L / h; the operation pressure is 0.07MPa; the temperature is 55 DEG C; and the pH value is 7.3. Through verification, the DPPH scavenging rate of the products under the conditions can reach 57.39%.

The invention discloses an apple enzyme and a preparation method. The preparation method comprises the following steps: juicing apples, uniformly mixing apple juice with pure water, adding glucose which accounts for 1-5% of the total weight of the obtained raw material mixture into the raw material mixture that the volume percentage of the apple juice is 5-20%, adjusting the pH value to 5.0-7.0, sterilizing, preparing mixed bacteria from the obtained raw material liquid and a pichia pastoris bacterial liquid and a lactobacillus plantarum bacterial liquid in a volume ratio of 1:(1-5), controlling the temperature to 25-35 DEG C, performing primary fermentation for 12-48 hours, controlling the temperature of the obtained primary fermentation solution to 25-35 DEG C by using an acetic bacterial liquid, performing secondary fermentation for 12-36 hours, and sterilizing, thereby obtaining a finished product of the apple enzyme. Compared with a finished product of natural fermentation, the finished product of the apple enzyme disclosed by the invention has a remarkable antibacterial effect on propionibacterium acnes, and the removal rate IC50 of the apple enzyme on DPPH is 0.43%.

The invention relates to an enzyme product with strong antioxidant activity and a preparation method of the ferment product. The elimination rate of DPPH by the ferment product is not less than 80%, the elimination rate of superoxide anions by the ferment product is not less than 80%, and the elimination rate of hydroxy free radicals by the ferment product is not less than 80%. According to the method disclosed by the invention, one or more kinds of materials of ginger, papayas, lotus roots, Chinese yam, plums, white gourds, bitter gourds, hericium erinaceus, kiwi fruits, grapes, crystal sugar oranges, tomatoes, black beans and bananas are used as raw materials, and fermentation is performed with probiotics, so that the ferment product is prepared.

The invention relates to a technique for preparing squid skin collagen peptide through an enzymic method. The technique includes: pre-treating squid skin which is a raw material, hydrolyzing through alkaline protease, and continuing hydrolysis through composite protease to obtain collagen hydrolysate, wherein the composite protease is composed of papain and flavorzyme. The collagen peptide prepared by the technique is ideal in hydrolysis degree, DPPH removal rate and polypeptide conversion rate, molecular weight of 97.63% of collagen peptide is less than 2000 Da, and the collagen peptide is high in quality and utilization value. The technique has high theoretical guiding significance in subsequent further separation and purification and application of the squid skin collagen peptide.

The invention belongs to the technical field of developing antioxidative active peptides through the comprehensive utilization of corn proteins, and discloses a method for improving the antioxidant activity of corn peptides by aid of an irradiation aided enzymolysis technology. The key of the invention is to solve the problem that by taking corn gluten meal as a raw material, taking a hydrolysis degree as a measurement index of an enzymolysis effect and taking a DPPH clearance rate as a measurement index of antioxidant activity, by aid of single factors and a response surface experiment design method, a method for improving the antioxidant activity of corn peptides by aid of an irradiation aided enzymolysis technology is designed, and according to the method, an effect that within 3 h of enzymolysis, the hydrolysis degree can be increased to over 48.23% from 42.13%, and the DPPH clearance rate of corn antioxidative peptide meal can be increased to over 78.65% from 70.16% can be achieved. The invention aims to lay a certain preliminary technical foundation for promoting the comprehensive utilization of corn gluten meal and developing serialization products of antioxidative active peptides and industrialized demonstration researches thereof.

The invention relates to a method for obtaining active polypeptide by carrying out multi-strain compound solid state fermentation on common rapeseed meal. The common rapeseed meal is taken as raw material, plant lactic acid bacteria, bacillus subtilis and aspergillus oryzae are screened for carrying out mixed bacterium solid state fermentation, and concrete fermentation steps are as follows: inoculating in the ratio of plant lactic acid bacteria to bacillus subtilis to aspergillus oryzae being (1-5): (1-3): (1-3), wherein concentration of inoculated bacterium suspension is 108 / mL, after inoculation, fermenting in a fermentation bin, and drying at the temperature of 55 DEG C, thus obtaining the active polypeptide. By adopting the method disclosed by the invention, after fermentation, crude protein content is improved by 10%, polypeptide content is increased by more than 6%, clearance rate of the polypeptide to hydroxyl radical is improved by 14 times, the clearance rate of the polypeptide to superoxide anion is improved by 17 times, and the clearance rate of the polypeptide to DPPH (1,1-diphenyl-2-picrylhydrazyl radical) is improved by 12 times.

The invention belongs to the technical field of the deep-processing of egg products and the comprehensive utilization of side products, and discloses an egg white source antioxidant peptide powder and a preparation method thereof. The egg white source antioxidant peptide powder can be prepared by taking hydrolyzed egg white protein as a raw material and DPPH (1,1-diphenyl-2-picryhydrazyl) free radical scavenging rate and reducing power as antioxidant activity evaluation indexes through using an ultrafiltration device, a vacuum rotating concentration instrument, a column chromatography cabinet system and a vacuum freeze-drying technology. In the egg white source antioxidant peptide powder, the molecular weight is 300-600Da, the protein content is 94.28%, the DPPH scavenging rate is 90.2%, the reducing power is 1.8, and the moisture content is 1%-3%. According to the preparation method, the antioxidant activity of the egg white source antioxidant peptide can be improved, the DPPH scavenging rate is improved to 90.2% from 50%, the reducing power is improved to 1.8 from 1.46, and the research and development level of egg resources on comprehensively utilizing and developing functional products can be beneficially improved.

The invention relates to a micro-molecule polypeptide with a function of removing free radicals. In the biological field related to removal of free radicals, earthworm is a novel high-protein source and is high in content of protein and rich in types of amino acids; an earthworm proteinase product prepared by autolysis of the earthworm or degradation of exogenous proteases has an excellent function of removing free radicals. The micro-molecule polypeptide is extracted from the earthworm and is prepared by the following steps: dispersing the earthworm into slurry, carrying out enzymolysis on the slurry by using different hydrolytic enzymes, carrying out suction filtration and ultrafiltration on enzymatic hydrolysate, concentrating and drying to obtain the micro-molecule polypeptide. The micromolecule polypeptide is low in molecular weight and low in sensitization; the total content of polypeptide with the molecular weight being smaller than 1000Da is over 90%; by virtue of detection of the capability of removing DPPH, the micro-molecule polypeptide has the excellent function of removing the free radicals.

The invention belongs to the technical fields of agricultural product deep processing and comprehensive utilization of byproducts thereof, and relates to a pine nut protein source anti-oxidation peptide and a preparation method thereof. The pine nut protein source anti-oxidation peptide having a molecular weight of 1000-3000Da, a protein content of 95.0-98.0%, an ash content of 0.5-2.5% and a DPPH clearance rate of 80-90% is obtained through carrying out immersion, crushing, homogenizing, protein denaturation, enzymatic hydrolysis, centrifugation, ultrafiltration, concentration and vacuum freeze-drying processes of pine nut meal as a raw material. The raw material is pine nut meal, is processed through using a cold squeezing technology, and does not contact with any organic extraction solvents, so the raw material is unpolluted, and the original quality and functions of pine nut proteins are reserved; and the pine nut protein source anti-oxidation peptide is obtained through efficiently utilizing high-quality proteins in pine nuts on the precise of the low cost and easy obtaining of the raw material, so the environment is protected, the effective value increment utilization of the high-quality protein sources is relied, and the added values of pine nut products are improved.

The invention discloses a fermentation method of a noni enzyme. The fermentation method comprises the following steps: firstly, screening fresh noni fruits, soaking the fresh noni fruits in a dilute acetic acid solution, performing steam explosion and ultra-high-temperature instant sterilization treatment, adopting primary fermentation and secondary fermentation combined with deep fermentation byadopting different compound fermentation agents in different stages and controlling the dosages of the different compound fermentation agents for sufficiently improving the fermentation effects, and then performing centrifugation and pasteurization to obtain the high-quality noni enzyme. The fermentation method disclosed by the invention reserves the nutritional components of the noni fruits to the maximum extent and improves the dissolution rate of the effective components in the noni fruits, so the prepared noni enzyme contains rich SOD, flavonoids and polyphenol substances, has a high DPPHclearance rate and a high hydroxyl radical clearance rate and thus has the effects of improving multiple symptoms including insomnia, obesity, constipation, and hypertension, and the total effective rate is as high as 100%.

The invention belongs to the technical field of microorganisms, and discloses streptococcus thermophilus and an enrichment culture method and application thereof. A strain DMST-H2 is separated from homemade yogurt of the Inner Mongolia family, and is preserved in the Guangdong microbial culture collection center (GDMCC) at April 16, 2019, and the preservation number is GDMCC 60642. By optimizing an enrichment culture medium, the viable count of the strain can be increased to 10<9> CFU / mL or above. The viable count under optimal conditions can reach 4.2*10<9> CFU / mL, and is 37.8 times that before the conditions are optimized. The strain is more suitable for intestines of Chinese, and lower in cost. In addition, the strain has the capacity of resisting acid, cholate and artificial gastrointestinal fluid, and meanwhile has the outstanding antioxidant capacity, especially DPPH removal capacity.

The invention discloses an extracellular polysaccharide producing space plant lactobacillus SS18-33 and application thereof to organism anti-oxidization activity improvement. The space plant lactobacillus SS18-33 disclosed by the invention is collected in CGMCC (China General Microbiological Culture Collection Center), and has the preservation number of CGMCC No.15151. The extracellular polysaccharide produced by the space plant lactobacillus SS18-33 has the DPPH clearing capability, superoxide anion free radical (O<2->.) clearing capability, Fe<2+> chelation capability, total reduction capability for blocking peroxide formation on provided hydrogen atom substances or total anti-oxidization capability. In addition, the strain also has the characteristic of gastrointestinal tract inverse environment tolerance; the practical basis is provided for the application of the extracellular polysaccharide to the organism anti-oxidization activity improvement. The extracellular polysaccharide producing space plant lactobacillus SS18-33 fills the study blank of space food microbial engineering bacteria.

The invention relates to the field of milk product processing, and especially relates to antioxidant Cheddar cheese containing lactobacillus plantarum and lactobacillus casei, as well as a preparation method thereof. According to the preparation method, two strains with antioxidant properties, namely the lactobacillus plantarum and the lactobacillus casei, are added into the Cheddar cheese as working ferments so as to increase qualities and antioxidant properties of the Cheddar cheese. The production method of the antioxidant Cheddar cheese containing the lactobacillus plantarum and the lactobacillus casei is characterized in that the Cheddar cheese of which the viable count is up to 6.0 multiplied by 10<7> cfu / ml and the DPPH scavenging capacity up to 51.72% can be prepared by the production method. Integrated functional properties of the Cheddar cheese and the two stains of the probiotics can be simultaneously played so as to effectively solve the problems of oxidation posed to human human health and food preservation.

The invention discloses a method for preparing active peptide from waste fermented grains. The method comprises steps of pre-processing raw materials, enzymatically hydrolyzing waste fermented grain protein and purifying the active peptide; the active peptide, which is low in molecular weight and high in activity, is prepared by virtue of a selective enzymatic hydrolysis technology and 3kDa membrane ultrafiltration; the active peptide is highly purified by virtue of gel filtration chromatography and high performance liquid chromatography two-step separation technology; the ACE inhibitory activity IC50 of the active peptide is 1.14 mg / ml; DPPH scavenging capacity EC50 is 1.42 mg / ml, ABTS scavenging capacity EC50 is 2.56 mg / ml, reducing power (A700nm=0.5) is 375.48 [mu]g / ml, and purity reaches 92.1% or above. The method provides by the invention adopts the waste fermented grains of Daqu liquor, Xiaoqu liquor, mould bran liquor and the like as the raw materials; the method is applicable to industrial production and strong in operability, and a target object is low in molecular weight and high in purity; and the method is capable of promoting the development and the utilization of by-product resources of liquor-making industry in China and achieving the efficient preparation of the active peptide.

The present invention discloses a method for enhancing an efficacy of an enzyme by using lactobacillus bulgaricus and belongs to the technical field of fermented food. Saccharomyces cerevisiae N85, acetobacter gluconicum Q1 and lactobacillus delbrueckii subsp. bulgaricus B1 are added into fruit and vegetable raw materials, and the health preserving efficacy of the enzyme is enhanced, so that the prepared enzyme has a reducing power increased by 43.3% compared with that in the control group, a DPPH clearance rate also increased from 88.25% to 93.09%, a lactic acid content increased by 36.1%, anacetic acid content increased by 35.2%, and a protease activity increased by 11.9% compared with that in the control group, increases a content of volatile substances, has an ethyl acetate content increased by 85.1% and an amyl acetate content increased by 89.1%, has a special fruit aroma, and is increased in enzyme antibacterial ability.

The invention discloses a ginkgo leaf and flos sophorae compound drink and a preparation method thereof. The compound drink includes the following specific components in parts by mass: 50-80 parts of flos sophorae extract liquid, 70-100 parts of ginkgo leaf extract liquid, 2-4 parts of aspartame and 0.8-1.2 parts of citric acid. The preparation method is as follows: (1) preparing the flos sophorae extract liquid; (2) preparing the ginkgo leaf extract liquid; and (3) mixing the flos sophorae extract liquid, the ginkgo leaf extract liquid, the aspartame and the citric acid in proportion for 20-40 min so as to obtain the compound drink. The compound drink provided by the invention has a soothing effect on the human cardiac and cerebral blood vessels, has a relatively high TBA inhibition ratio, a relatively high hydroxyl free radical clearance ratio and a relatively high DPPH free radical clearance ratio and also meets the standard of low energy.

The invention discloses a preparation method of isaria cicadae miq rice wine, glutinous rice as a main fermentation substrate is added with isaria cicadae miq powder and sweet wine yeast for collaborative frequency sweep ultrasonic fermentation for preparation of the isaria cicadae miq rice wine. The isaria cicadae miq rice wine can realize the effective extraction of sedative hypnotic components of isaria cicadae miq, has very good sedative and hypnotic effect, is stronger than the pure isaria cicadae miq water extract, after 5 times of dilution, still has 40-63% DPPH (1,1-diphenyl-2-picryl-hydrazyl) removal rate, has strong free radical scavenging effect, plays the anti-aging and disease prevention roles to a certain extent, and has the important meaning to improve the added value of the isaria cicadae miq.

The invention relates to an antioxidant and application thereof, and relates to application of chlorella polysaccharides in preparation of plant green pesticides and food additives. The chlorella polysaccharides are a group of polysaccharides with a molecular weight of 10.6-13.6kDa, and are prepared from water-insoluble chlorella part (algal residue) by enzymolysis, deproteinization and alcohol precipitation, and the monosaccharide is mainly composed of glucose, galactose, arabinose, fucose and rhamnose. The chlorella polysaccharides can significantly improve plant cell antioxidase (SOD, POD and CAT) (superoxide dismutase, peroxidase and catalase) and in-vitro hydroxyl free radical clearance rate, reducing power, DPPH (1,1-diphenyl-2-picrylhydrazyl radical) clearance rate and other activity, and can be used as a plant growth regulator and a natural food additive.

The invention belongs to the technical field of biology and in particular relates to a method for preparing an antioxidant pine pollen peptide by utilizing pine pollen meal. According to the method disclosed by the invention, lots of pine pollen meal residues and wastes are reutilized in the process of preparing aqueous extract of pine pollen, lots of high-quality protein resources in the residuesare fully utilized, and the environment stress is relieved. The prepared pine pollen peptide with antioxidant activity has the characteristics of being high in safety, reasonable in amino acid ratioand the like, and has wide market prospects in the field of foods. The provided preparation method is simple in process and low in reaction temperature, the oxidation resistance of pine pollen proteins can be improved, and the pine pollen peptide prepared under the optimal process condition has a superoxide anion inhibition rate of 18.7%, reaches a DPPH (1,1-diphenyl-2-picryl-hydrazyl) removal rate of 76.8%, reaches a hydroxyl radical inhibition rate of 94.6%, and provides high-quality natural antioxidants for industries of foods, medicines and the like.

The invention discloses a method for rapid activation of antioxidant activity of a 1,000-10,000Da egg white peptide component, belongs to the technical field of subsidiary agricultural products deep processing and comprehensive utilization of byproducts thereof, and relates to a method for rapid activation of antioxidant activity of a 1,000-10,000Da egg white peptide component using a high-voltage pulse electric field technique. The method uses a 1,000-10,000Da egg white peptide component with a DPPH (1,1-diphenyl-2-picrylhydrazyl) scavenging rate of 30% as a raw material, adopts a high-voltage pulse electric field technique, realizes the key technical invention for peptide activation by electrodes within 2,500mus and rapid increase of the DPPH free radical scavenging rate up to over 70% through preparation of egg white antioxidant peptide liquid, regulation of high-voltage pulse electric field device activation parameters, regulation of peptide liquid constant flow rate, high-voltage pulse electric field activation treatment and vacuum freeze drying processes, and can open a new route for comprehensive utilization of egg white resources.

The invention discloses a method for quickly improving anti-oxidation activity of a 10-30kDa egg white protein peptide, belonging to the technical field of fine deep processing of agricultural sideline products and comprehensive utilization of by-products, particularly relating to a technique with high-voltage pulse electric field treatment as a core. With 10-30kDa egg white protein peptide as a research object and a DPPH (1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl) clearance rate and an FRAP (Fluorescence Recovery After Photobleaching) value as main indexes for balancing the anti-oxidation activity, the time that a material flow passes through double electrodes of a high-voltage pulse electric field is optimized to be within 50-2,000 microseconds depending on the high-voltage pulse electric field technique, thus the DPPH clearance rate of the anti-oxidation activity of the egg white protein peptide is improved from 64% to 80.4%, the FRAP value of the egg white protein peptide is improved from 1.32 to 1.52, the stability of the egg white protein peptide is prolonged from 3h to 8h, and the purposes of quickly improving the anti-oxidation activity and reinforcing the stability are realized. The method for quickly improving the anti-oxidation activity of the 10-30kDa egg white protein peptide, disclosed by the invention, not only provide a new idea for the technical research on quick improvement of the anti-oxidation activity of the egg white protein peptide, but also provides a new way for development and application of high-activity egg white protein peptide series products.

The present invention belongs to the field of processing of dendrobium officinale kimura et migo, and particularly relates to a method for preparing dendrobium officinale kimura et migo oligosaccharide having an in vitro anti-oxidation activity. According to the present invention, the dendrobium officinale kimura et migo oligosaccharide is prepared by using the enzymolysis method, the method is simple and has the strong practicality, and the prepared dendrobium officinale kimura et migo oligosaccharide has the DPPH removal rate of 23.7% and the total anti-oxidation activity of 0.65 U / mL.

The invention relates to the technical field of plant extraction, and particularly discloses quinoa peptide with whitening and antioxidant activity as well as a preparation method and application thereof. Alkaline protease, papain and acid protease are adopted to form specific compound protease for performing graded enzymolysis on quinoa protein, wherein the alkaline protease is added for enzymolysis under certain pH and temperature conditions firstly, then the pH and temperature conditions are adjusted, the papain is added for enzymolysis, then the pH and temperature conditions are further adjusted, the acid protease is added for enzymolysis, and the quinoa peptide is obtained. The quinoa peptide disclosed by the invention is small in molecular weight, relatively high in hydroxyl radical scavenging rate, DPPH scavenging rate and tyrosinase inhibition rate, and has the effects of whitening and resisting oxidation. Therefore, the quinoa peptide prepared by the invention can be used in cosmetics, health care products or foods. The method disclosed by the invention is simple to operate, high in safety and easy to industrialize, and has important significance on fully utilizing quinoa resources and developing functional products.

The invention discloses a method for preparing antioxidant peptides from oats. Alcalase is determined to serve as the enzyme for preparation through investigating the antioxidant activities and yields of the products obtained by carrying out enzymolysis on the oat bran proteins with different proteases. Reduction of the enzymolysis speed of the Alcalase toward the oat bran proteins is determined to be mainly caused by substrate consumption and enzyme activity loss through investigating the enzymolysis speed of the Alcalase toward the oat bran proteins. Meanwhile, an enzymatic membrane reactorsystem is determined to have good retention effect on the Alcalase through studying the impact of the enzymatic membrane reactor system on the enzyme activity. The activity loss of the Alcalase is mainly caused by the damage to the enzyme in the operation process of a peristaltic pump and the adsorption of an ultrafiltration membrane toward the enzyme. By utilizing Design Expert 6.0.5 to design the response surface analysis experiment with four factors and three levels, the optimum process conditions under which the antioxidant peptides from oats can be prepared by utilizing the enzymatic membrane reactor are as follows: the substrate concentration is 3%; the enzyme addition is 3.2%; the feed flow rate is 45L / h; the operation pressure is 0.07MPa; the temperature is 55 DEG C; and the pH value is 7.3. Through verification, the DPPH scavenging rate of the products under the conditions can reach 57.39%.

The invention discloses a method for extracting flavone substances in Camellia nitidissima. The method includes the steps of a, drying the Camellia nitidissima, and crushing to obtain a product A; b,extracting the product A with ethanol to obtain Camellia nitidissima flavone substance extract, wherein the volume fraction of the ethanol during extraction is 50-90%, the solid-liquid ratio of the product A to the ethanol is 1:(10-50)g / mL, extraction temperature is 40-80 DEG C, and extraction time is 40-80 minutes. The method is high in Camellia nitidissima flavone substance extraction rate, theextraction rate of the optimal extraction process is 5.99%, the extracted flavone substances are good in oxidation resistance and good in eliminating ability, the DPPH eliminating rate of the extracted flavone substances can reach 80%, the ABTS eliminating rate of the extracted flavone substances can reach 85%, and the method is of great significance to the increasing of the additional value of the Camellia nitidissima and can provide a certain theoretical foundation for the further increasing of the comprehensive utilization value of the Camellia nitidissima.

The invention relates to the technical field of active protein peptides, in particular to a snake skin collagen peptide and preparation and application thereof. According to the snake skin collagen peptide, purified snake skin collagen is adopted as an enzyme cutting raw material; through single enzyme digestion and combined multi-enzyme digestion, the snake skin collagen peptide with the molecular weight of 100 Da-20 KDa is obtained. The snake skin collagen peptide has high antioxidant activity, the DPPH clearance rate of the snake skin collagen peptide with the concentration of 1 mg / ml reaches 49.36%, and the clearance rate of superoxide anions reaches 51.12%. A provided preparation method of the snake skin collagen peptide has the advantages of being simple in enzymolysis process, highin enzyme digestion efficiency and short in production cycle, the yield of the snake skin peptide is higher than 52%, and the antioxidation activity is high. When the snake skin peptide is applied tothe cosmetic field, a cosmetic capable of resisting skin aging is obtained and has remarkable antioxidation activity.