71 results about "Endogenous enzymes" patented technology

The invention discloses a method for converting rutin into quercetin through biological catalysis, and belongs to the technical field of biological catalysis. The method comprises the following steps: mixing rutin and a solvent to obtain a quasi-solid rutin suspension; mixing the paraphlonia plant endogenous enzyme and the quasi-solid rutin suspension for enzymolysis, and then filtering, washing and drying to obtain quercetin; the solvent is methanol with the concentration of 5-50%, ethanol with the concentration of 5-50% or acetone with the concentration of 10-50%. The method is mild in biological catalytic reaction condition, does not generate pollutants such as acid waste liquid, and meets the environmental protection requirement. Efficient conversion of quercetin is realized by adopting a quasi-solid rutin strategy (rutin suspension reaction system), and the problem of substrate solubility limitation is solved. High-purity quercetin can be obtained through simple washing, the product purity is larger than 95%, and food and clinical application can be met.

The invention discloses a fresh plant directed biotransformation method based on endogenous enzyme activation and a product and application thereof. The core of the preparation method is as follows: fresh plants (tuberous roots, stems or fruits) which are harvested in a ripe state and have metabolism in a dormant state (the respiration rate is lower than 5 mg CO / kg.h) are taken as raw materials, the raw materials are treated in an environment with the specific pressure being 0.02-0.20 MPa, the temperature being 70-121 DEG C and the humidity being 50-95%, a specific impregnating compound can be selectively combined, and the raw materials can be prepared into the plant culture medium. Under the conditions that exogenous microorganisms are not introduced and plant tissue structures are not damaged, the catalytic function of an endogenous metabolic enzyme system is safely and efficiently restarted and maximally promoted, and components of a plant body are driven to realize directional biotransformation. According to the process, conversion of primary metabolites and / or secondary metabolites is remarkably promoted, the content conversion of one or more beneficial components in the primary metabolites and / or the secondary metabolites is improved, and meanwhile, the biological and pharmaceutical structures and inherent metabonomics characteristics of the plants are completely reserved. The biotransformation product can be used as a high-quality raw material to be applied to medicines, common foods, health foods, special diet foods, daily chemical products and disinfection products, and can be further prepared into traditional Chinese medicine decoction pieces, solid preparations, semi-solid preparations and liquid preparations by adding or not adding pharmaceutically acceptable auxiliary materials.

The invention discloses a method for preparing rare saponin by utilizing panax japonicus endogenous enzyme, and relates to the technical field of extraction, the panax japonicus plant material or crude extract thereof is directly taken as a starting point, the enzyme system is simple and convenient to obtain (fresh medicinal material low-temperature homogenate extraction or direct use of freeze-dried powder), the reaction system is simple, and the operation is easy. According to the preparation process provided by the invention, the catalytic action of endogenous enzyme is fully utilized, so that the introduction of exogenous substances (acid-base, protein and the like) in the extract is completely avoided; the method disclosed by the invention is high in catalytic efficiency, can quickly realize complete conversion of saponin (within 10min) under specific conditions, and has extremely high industrial application.

The invention discloses an immunostaining reagent for MHC-II expression detection of a gastric cancer biopsy sample, and belongs to the field of bioengineering. The invention establishes a preparation method of an immunohistochemical staining section. The preparation method specifically comprises the following steps: step 1, early-stage treatment: baking a tissue section, dewaxing, rehydrating, subsequently adding an antigen solution for repairing, adding an endogenous enzyme inhibitor for incubation, adding a sealing agent for sealing and the like; step 2, antibody incubation: adding a first antibody and a second antibody for incubation; and step 3, post-treatment: dyeing, re-dyeing, bluing, sealing and the like. A mixed buffer solution is used as an endogenous enzyme inhibitor, so that the background staining intensity is effectively reduced, and the staining sensitivity and specificity are improved; meanwhile, a staining result interpretation standard is established, it is proved that MHC-II expression is remarkably related to pathological remission of the gastric cancer patient, and an evaluation method is provided for pathological remission of the gastric cancer patient.

This invention relates to a recombinant Halomonas strain that produces polyhydroxyalkanoates (PHA) by overexpressing endogenous enzymes encoding ADP-dependent acetyl-CoA synthase (ADP-ACS). acd This gene not only enhances the recombinant bacterium's tolerance to acetic acid but also enables it to efficiently convert acetic acid or acetate substrates into acetyl-CoA, thereby participating in the tricarboxylic acid cycle (TCA cycle) and the synthesis of PHA. The present invention also relates to a method for producing PHA using the aforementioned recombinant Halomonas bacterium employing a pH-stat strategy.

The invention discloses an enzyme-activated fluorescent molecular precursor as well as a preparation method and application thereof. The enzyme-activated fluorescent molecular precursor has a chemical structure as shown in a formula I which is described in the specification. The invention develops an enzyme-activated fluorescent molecular precursor which can be used for real-time imaging of tumors by targeting exogenous enzyme to the tumors and specifically activating a probe at the tumors; according to the invention, the exogenous enzyme is introduced as an activation trigger, and normal cells do not have the exogenous enzyme, so that the problem of co-expression of the endogenous enzyme in non-tumor tissues can be avoided, background fluorescence signals can be reduced to the greatest extent, and the imaging specificity and accuracy are remarkably improved.

In the process of producing indigo naturalis by taking strobilanthes cusia as a raw material, a very unpleasant smell is generated, a large amount of alkaline wastewater is discharged, and serious environmental pollution is caused. Therefore, development of a more environment-friendly production process and a higher value-added strobilanthes cusia extract is extremely urgent. The invention innovatively provides a green and efficient production process, namely integrally producing the indigo strobilanthes extract and the phenolic acid extract with higher additional values through endogenous enzymatic conversion coupled membrane separation and freeze drying technologies. Through an endogenous enzyme conversion process, the indigo extract with indigo content 20 times and indirubin content 1.8 times higher than that of traditional indigo can be prepared within one day. The phenolic acid extract is recovered from the indigo extract production wastewater by adopting membrane separation and freeze drying processes, and meanwhile, zero discharge of the wastewater can be realized. The prepared indigo extract shows a more excellent dyeing effect on pure cotton poplin than an Indian natural indigo extract. In addition, the prepared phenolic acid extract shows excellent inhibitory activity (IC50 = 32 [mu] g / mL) on staphylococcus aureus, and the wound healing rate of mice exceeds 98%. The method lays a foundation for high-valued and comprehensive utilization of strobilanthes cusia resources, and is of great significance to extension and sustainable and healthy development of a strobilanthes cusia industrial chain.

The invention belongs to the technical field of animal breeding, and discloses an application of N-methyltyramine hydrochloride in a breeding animal feed and the feed, the N-methyltyramine hydrochloride is added into the breeding animal feed in a mixed or mixed granulation form, and preferably, 45g of N-methyltyramine hydrochloride is added into each ton of compound feed. The N-methyltyramine hydrochloride is chemically synthesized by taking an effective stomach-invigorating component N-methyltyramine in the traditional Chinese herbal medicine immature bitter orange as a technical basis. When the N-methyltyramine hydrochloride is added into the feed for the bred animals in a proper proportion, the secretion of endogenous enzyme of the bred animals can be promoted, so that the feed reward of the bred animals is improved.

The invention provides an antheraea pernyi fresh-keeping method which comprises the following steps: S1, dividing a first group and a second group with different freezing response characteristics according to development biological characteristics of antheraea pernyi; the freezing response characteristic is represented by at least one parameter of tissue moisture content, methylene blue penetration depth and body wall elasticity modulus; s2, differential preprocessing is applied to the first group and the second group, so that the difference of the first group and the second group on any characterization parameter does not exceed a preset threshold value; s3, combining the two groups of tussah and freezing; in the first cooling stage, cooling from 0-1 DEG C to-10 DEG C at the speed of 0.8-1.2 DEG C / min; in the second cooling stage, cooling is conducted from-10 DEG C to-30 DEG C at the speed of 0.45-0.55 DEG C / min; in the third cooling stage, cooling from-30 DEG C to-45 DEG C at the speed of 1.8-2 DEG C / min; and S4, after freezing is completed, vacuum packaging is performed, and storage is performed at minus 45-minus 40 DEG C. According to the fresh-keeping method for the tussah, the integrity of a cell structure is maintained, juice loss is reduced, and abnormal release of endogenous enzyme is inhibited, so that nutritional ingredients are better reserved in the long-term freezing storage process, and the sensory characteristics of compact meat, uniform color and luster and no peculiar smell are maintained.

The invention relates to a method of producing an ester of a fatty acid and a C1-C4 alcohol, comprising successive steps of: cultivating cells of a microalga strain on a growth medium, harvesting the cultivated cells and concentrating them to obtain a wet cell pellet, suspending said wet cell pellet in an hydroalcoholic solution comprising said C1-C4 alcohol, incubating the cell suspension thus formed so as to form said ester of a fatty acid and a C1-C4 alcohol by transesterification and / or esterification of lipids produced by the microalga cells catalyzed by endogenous enzymes of said cells, and recovering said ester of a fatty acid and a C1-C4 alcohol from said cell suspension. The growth medium can advantageously be a dark fermentation effluent.

The invention relates to a sugar-controlling and weight-losing functional food cooperatively conditioned by endogenous enzymes of processing raw materials and a preparation method thereof, and belongs to the technical field of food. The raw materials comprise 6-10 parts of white kidney beans, 4-8 parts of lucid ganoderma, 20-40 parts of black-skin and green-kernel black beans, 3-6 parts of mung beans and 40-60 parts of wheat flour / rice flour. A dual biological activation process is adopted: white kidney beans are subjected to low-temperature enzymolysis by yeast powder and probiotic soybean enzymes (1%, 25-35 DEG C) for 2-4 hours to release an alpha-amylase inhibitor, and ganoderma lucidum is subjected to weak-base hydrolysis by sodium bicarbonate (1-3%) for 2-4 hours to activate a triterpenoid glycosidase inhibitor; and performing compound fermentation on the zymolyte and the alkaline hydrolysis product for 2-4 hours, and then adding a cereal base material to activate the endogenous enzyme activity. High fiber combination (more than 15%) is used for prolonging satiety and reducing fat absorption, resistant starch (heat is only 50% of saccharides) is used for inhibiting lipid synthesis, and quadruple synergy (enzyme inhibition is more than 90% / resistant starch / low GI / high fiber) is combined, so that dual effects of postprandial blood sugar reduction and weight control are realized.

The invention provides a pea protein high-valued preparation method and system based on molecular level structure regulation and enzymolysis targeting synergy, and belongs to the field of vegetable protein functional processing. Pure natural pea meal is taken as a raw material, a porous structure is directionally generated through a superheated steam instantaneous phase change blasting mechanism, and phytic acid inactivation and endogenous enzyme retention are synchronously realized; by combining alpha-amylase to precut starch, alpha-galactosidase to degrade oligosaccharide in a targeted manner and a double-enzyme gradient time sequence activation mechanism, the enzymolysis competitive inhibition problem is solved; and finally, the protein dissolution index and digestibility are improved through microporous nanofiber compounding and a multi-scale structure interaction mechanism, and a steam-enzymolysis collaborative module is integrated in the system, so that an innovative solution is provided for natural plant protein processing. The obtained thin bean flour has breakthrough integration of nutritional advantages of pea protein and natural viscoelasticity regulation and control characteristics, has cold and hot double-soluble quick-acting property, low sensitization and long-term preservation property, and can be expanded to the field of precise nutritional food development.

The present application relates to a freshness indicator protein related to quality traits of low-temperature stored Siniperca chuatsi, endogenous proteases and applications. The freshness indicator endogenous proteases are related to postmortem proteolysis and meat softening of Siniperca chuatsi, including cathepsin B, cathepsin L and calpain. The freshness indicator proteins are related to quality changes occurring during postmortem cold storage of Siniperca chuatsi, including myoactin 1, myosin binding protein, LDB protein, actin-related protein, etc. The present application determines the change rule of endogenous protease activity of Siniperca chuatsi at different storage stages, and the dynamic influence on muscle proteolysis and muscle degradation of Siniperca chuatsi, and reveals the internal relationship with fish meat sensory quality and processing characteristics, and clearly defines the "critical point" of quality deterioration of Siniperca chuatsi. It provides clear guidance for the control of endogenous enzyme-mediated quality deterioration in the processing and storage process of Siniperca chuatsi.

The invention belongs to the technical field of food processing, and particularly relates to a garlic pickling method capable of promoting nutrient absorption, which comprises the following steps: S1, performing micropore puncture pretreatment on carefully selected complete garlic bulbs to form through pore channels in specific directions so as to establish rapid permeation channels of subsequent treatment substances; s2, sequentially immersing the garlic bulbs punctured by the micropores into a low-concentration and low-temperature first ethanol solution and a high-concentration and high-temperature second ethanol solution for gradient ethanol dehydration, then carrying out heat treatment to remove part of water, carrying out primary sterilization and activating the endogenous enzyme activity of the garlic bodies. According to the invention, physical pretreatment, gradient dehydration, heat treatment activation and compounding of absorption-promoting pickling liquid are combined with a dynamic alternate pickling process to synergistically destroy garlic cell barriers, activate endogenous enzyme conversion and introduce absorption-promoting functional components, so that the pickled garlic product with good flavor and nutrition easier to absorb by human bodies is prepared within a short time.

This invention relates to the field of grain processing technology, and in particular to a method for improving the nutritional value of brown rice and reducing its glycemic index. The invention uses brown rice as raw material, processing it through a process of mist-wetting for nutrient enrichment, integrated microwave gelatinization and drying, tempering, and milling to produce semi-cooked rice (parboiled rice). The brown rice processed by the method provided by this invention is clean and odorless, slows down the rate of water penetration, prevents grain cracking, reduces the rate of broken rice during subsequent milling, and, under the action of endogenous enzymes, enriches nutrients such as GABA, flavonoids, and free amino acids. Furthermore, the bran layer of the dried brown rice is easily separated.

This invention relates to the field of feed additive technology, specifically to a feed additive that promotes digestion and absorption and its preparation process. The preparation process of a feed additive that promotes digestion and absorption includes: preparing antioxidant-modified chicken fat; preparing an extract; preparing a composite oil phase; and preparing the feed additive. In this invention, the extract of Shenqu (a type of fermented wheat) can directly compensate for insufficient endogenous enzyme secretion in laying hens, rapidly decomposing starch in feed and chicken fat in plant proteins, laying the foundation for subsequent absorption. The extract of Zhishi (a type of immature bitter orange) accelerates gastrointestinal motility and digesta emptying, while also promoting bile and pancreatic juice secretion, further improving the digestibility and utilization rate of fat-soluble components in laying hens. The extract of pine pollen can repair the intestinal mucosa, increase intestinal villus height, increase the nutrient absorption area, and regulate the intestinal microecology, reducing nutrient loss and intestinal stress. The combined use of these three ingredients synergistically promotes the digestive and absorptive capacity of laying hens.

The present invention relates to a cleaning composition, preferably a cleaning composition for use in automatic dish washing and / or laundry washing, which cleaning composition comprises an Alkalitalea saponiacus endogenous enzyme or a variant thereof. The invention also relates to a method of cleaning using the composition of the invention and to the use of an enzyme in a cleaning composition.

This invention discloses a cooking utensil and a method for preparing sleep-enhancing factors enriched therein, belonging to the field of household appliances. The method for preparing sleep-enhancing factors enriched in the cooking utensil includes a stress enzymatic hydrolysis process and a baking process. The stress enzymatic hydrolysis process refers to pre-treating the ingredients to activate their endogenous enzymes. Pre-treatment includes at least one of the following: steam heating and humidification treatment, periodic heating-cooling treatment, low-temperature treatment, low-oxygen treatment, negative pressure treatment, high-pressure treatment, ultrasonic treatment, pulsed light treatment, and plasma treatment. The baking process refers to baking the ingredients treated with the stress enzymatic hydrolysis process. The preparation method of this invention can significantly increase the GABA content of the ingredients, while also improving the bitter taste and enhancing the aroma. In other words, this invention solves the problem that existing cooking methods cannot simultaneously achieve good taste and high nutritional value.

The application provides an edible mushroom culture medium prepared from yellow water, a preparation method and application thereof. The preparation method comprises the following steps: subjecting yellow water to a variable-temperature process; adding a compound enzyme to the yellow water subjected to the variable-temperature process for compound enzymolysis treatment; adjusting the pH of the yellow water subjected to the compound enzymolysis treatment to 7.0, collecting the precipitate by centrifugation, and drying to obtain a solid powder; and adding an auxiliary material to the solid powder, and stirring uniformly to obtain the edible mushroom culture medium. The method of the application activates the endogenous enzyme of the bacteria in the yellow water through a variable-temperature process, and then adds a compound enzyme for compound enzymolysis, so that the bacteria in the yellow water are fully lysed, and the bacteria in the yellow water release more efficiently organic nitrogen sources, carbon sources and organic small molecules and other nutrients, the obtained culture medium has more abundant nutrient components, is more suitable for the culture of edible mushrooms, can effectively improve the yield of the cultured edible mushrooms, and shortens the culture period and reduces the production cost.

The disclosure relates to the field of chronic pain and the treatment thereof. The disclosure involves antisense oligonucleotides and the use thereof in pre-mRNA and mRNA modulation, in one aspect related to RNA editing using endogenous ADAR enzymes, in targeting an adenosine in a (pre-) mRNA for human Nav1.7, preferably to change from a lysine residue to an arginine residue in the protein at position 1406 (K1406R), thereby impairing the ability of the Nav1.7 protein to act as a sodium ion channel. In another aspect the disclosure relates to exon skipping wherein antisense oligonucleotides are used to induce skipping of exon 23 in the generation of human SCN9A mRNA thereby generating a shortened Nav1.7 protein with an impaired ability to act as a sodium ion channel. The disclosure relates to methods and means to alter the Nav1.7 protein in cells of the peripheral nervous system, preferably large nociceptor cells (type Aα / Aβ), to provide a treatment of chronic pain.

The invention discloses a tea enzyme activation fermentation method which comprises the steps of fresh leaf pretreatment, ultrasonic-assisted low-temperature cold beating, gradient variable-temperature circulating cell breaking, multi-stage enzyme activation fermentation, activity locking storage, secondary drying, quality fine adjustment and finished product grading and packaging. By optimizing a low-temperature treatment process, introducing an ultrasonic-assisted technology and designing a multi-section temperature-humidity coupling regulation system, accurate activation of endogenous enzyme activity of tea and controllable regulation of a fermentation process are realized, so that a tea product which is rich in flavor level, high in freshness and capable of realizing customized fermentation is prepared.

This invention discloses a food-medicine homology composition and its application in black bean products, belonging to the field of food processing technology. First, black beans are washed and frozen, then rinsed with warm water to obtain broken-cell black beans. The broken-cell black beans are then mixed with dried angelica slices and stacked to balance the moisture content and promote the migration of angelica components and endogenous enzymatic hydrolysis of the black beans, resulting in a mixture. Finally, the mixture is placed in a wok with rock sugar and stir-fried using a stepped heating and stirring process to allow the rock sugar to melt and penetrate into the cracks of the black beans and cause the seed coat to wrinkle, thus obtaining the food-medicine homology composition. This achieves a food-medicine homology product with high active ingredient content, strong antioxidant capacity, and excellent sensory quality.

The present application relates to a kind of frozen pre-made grass carp fillets method, belong to food preservation technical field.The frozen pre-made grass carp fillets method disclosed in the present application, mainly using quality improvement liquid (including: 3~4% collagen gel liquid, 0.4~0.6% glutamine transaminase (TG enzyme), 2~4% salt according to weight percentage) is injected into fish meat to be pickled.Then subsequent processing can be done, the salt in the quality improvement liquid can promote the unfolding of myofibrillar protein structure in fish meat, collagen gel liquid can fill the intercellular pores left after myofibrillar protein structure changes, glutamine transaminase can regulate the crosslinking degree and thermal stability of collagen gel to make it have the characteristics of intermuscular matrix protein, the above effects can inhibit the damage of fish meat cells and protein structure caused by endogenous enzymes and ice crystals during freeze-thaw process.The method used in the present application can reduce the quality deterioration of fish meat during freeze-thaw process, so that the fish meat can maintain better taste after frozen storage.

The invention discloses a method for evaluating the quality of surimi on the basis of muscle tissue microstructure and endogenous enzyme activity, which comprises the following steps: acquiring the muscle joint length of raw material fish muscle tissue and the activity data of muscle fiber-bound cathepsin L, and constructing a correlation model between the muscle joint length and the activity data of muscle fiber-bound cathepsin L and the gel strength of surimi; and predicting to obtain the gel strength after the raw material fish is processed into the gel, so that the special raw material fish for surimi is classified and screened. According to the method disclosed by the invention, the sarcomedo length and the activity of the muscle fiber-bound cathepsin L are selected to have significant correlation with the quality of the minced fillet gel, and the parameter combination provides objective and reliable data support and decision basis for raw material screening and quality control; besides, the method can realize rapid prediction of the gel quality based on the raw material fish without preparing the minced fillet gel, greatly simplifies the process, saves time, cost, raw materials and the like, has important application value and wide popularization prospect, and can provide reliable quality prediction technical support for the minced fillet product industry.

The invention relates to the technical field of biological fermentation, and discloses a functional fermentation product preparation process based on directional conversion of bean dregs, and the preparation process comprises the following steps: firstly, performing autolysis pretreatment on the bean dregs through an osmotic pressure regulator, activating an endogenous enzyme system, and releasing soluble nutrient substances; then, in the solid state fermentation stage, a composite stress factor composed of short-chain inulin and sorbitol is added, aspergillus oryzae is induced to form a loose and porous hypha network skeleton, and the ventilation and mass transfer efficiency of a fermentation substrate is remarkably improved. Then, regulating and controlling a cooling time sequence, adding L-glutamic acid as a metabolism inducer, and accurately receiving a metabolism path of bacillus megaterium to realize directional enrichment of functional products. The method effectively solves the problem that the physical structure is not matched with microbial metabolism in solid fermentation of the bean dregs, and improves the yield of functional fermentation products and the resource utilization value of the bean dregs.

This invention belongs to the field of whole grain deep processing technology, and relates to a high-resistant starch whole grain powder and its preparation method. The raw materials of the high-resistant starch whole grain powder include the following components by weight: chickpeas 25-45 wt%, quinoa 20-30 wt%, brown rice 10-20 wt%, pea protein isolate 10-20 wt%, hemp seed protein 1-10 wt%, fructooligosaccharides 1-5 wt%, and compound nutrients 0.5-4 wt%. The high-resistant starch whole grain powder has a resistant starch content ≥35 (g / 100g starch), a GI value ≤55, and a powder particle size ≤100μm. This invention significantly increases the resistant starch content of the obtained whole grain to over 35% through the synergistic effects of germination activating endogenous enzymes, fermentation promoting starch molecule rearrangement, and aging-induced retrogradation. The product has a GI value ≤55, a natural fermented aroma, and a fine, easily reconstituted texture.

Provided is a mutated lysophospholipase. Further provided are a gene encoding the lysophospholipase, and a vector and a host cell comprising the gene. In addition, further provided is a use of the lysophospholipase. The present invention also provides a mutated Aspergillus niger strain and a use thereof. Specifically, the present invention provides a mutated Aspergillus niger strain, which is an orotate phosphoribosyltransferase auxotrophic strain, and has improved production capacity of endogenous enzymes, preferably lysophospholipase, with respect to an unmutated strain. The present invention further provides uses of the strain. For example, the strain can be used for expressing the mutated lysophospholipase of the present invention.

This invention discloses a method for the targeted conversion and synthesis of rare ginsenosides Rg3 and Rh2. Specifically, fresh Panax notoginseng leaves are microwave-dried for 1-3 minutes to inactivate their endogenous β-glucosidase. The dried Panax notoginseng leaves are extracted with anhydrous methanol, and the extract is resuspended in an acetate-sodium acetate buffer solution after drying. α-arabinofuranase, β-xylosidase, and β-glucosidase are added to the resuspended solution, and an enzymatic reaction is carried out at 35-40℃ to directionally convert the original ginsenosides into rare ginsenosides Rg3 and Rh2. This method can achieve the inactivation of endogenous enzymes and the stable retention of original saponins in Panax notoginseng leaves in a very short time. Compared with the natural drying combined with exogenous enzymes, the conversion ratios of Rg3 and Rh2 are increased by 3.14 and 2.4 times, respectively. Compared with fresh Panax notoginseng leaves, the contents of Rg3 and Rh2 are increased by 20.6 and 8.7 times, respectively. This method is suitable for the high-value utilization of Panax notoginseng leaf waste resources and the large-scale preparation of rare saponins.

The invention relates to a soybean folic acid extract and a preparation method thereof, and the preparation method comprises the following steps: selecting sprouted soybeans as a raw material, spraying a culture solution containing Mg < 2 + >, Zn < 2 + > and serine in the soybean sprouting process, activating an endogenous enzyme system of sprouted seeds, and increasing the enrichment amount of soybean folic acid (5-CH3-THF); 5-CH3-THF is separated by adopting a supercritical CO2 extraction technology, preliminary purification of an AB-8 macroporous adsorption resin column and secondary purification of an ultrafiltration membrane; ascorbic acid and EDTA-2Na are added into the extracting solution, and the stability of soybean folic acid is further improved after freeze drying. According to the technical scheme, the characteristics of the germinated soybeans are deeply excavated and efficiently utilized, and a technical foundation is laid for production and popularization of natural folic acid.

The invention discloses an EPSF / polygonatum sibiricum polysaccharide / casein submicron composite preservative as well as a preparation method and application of the EPSF / polygonatum sibiricum polysaccharide / casein submicron composite preservative. The compound is prepared by compounding EPSF, polygonatum polysaccharide and sodium caseinate according to a mass ratio of 1: (0.2-0.8): (2-8), wherein the EPSF is synthesized by catalyzing an endogenous enzyme from aspergillus niger, and the compound is prepared by ultrasonic treatment and freeze-drying. The compound has excellent oxidation resistance, the superoxide anion clearance rate is as high as 88.36%, meanwhile, the compound preservative has broad-spectrum antibacterial activity, and the diameter of an inhibition zone is as high as 23.25-26.5 mm. When being applied to fresh-keeping of fruits and vegetables such as fresh-cut apples and potatoes, the fresh-keeping agent can remarkably inhibit browning, the browning index is reduced by about 60-80%, the weight loss ratio is reduced by 20-30%, and the fresh-keeping agent has the advantages of maintaining hardness, effectively prolonging the fresh-keeping period, being efficient, safe, nutritional and the like.