184 results about "Starch solution" patented technology

The invention discloses an ultraviolet barrier film as well as a preparation method and application thereof. The ultraviolet barrier film is prepared from the following raw materials in percentage by weight: 20-40% of polyvinyl alcohol; 20%-30% of sodium carboxymethyl cellulose; 5%-10% of carbon quantum dots; and 30%-45% of water chestnut starch. The preparation method of the ultraviolet barrier film comprises the following steps: 1) preparing a polyvinyl alcohol solution, a sodium carboxymethyl cellulose solution, a carbon quantum dot dispersion liquid and a water chestnut starch solution; 2) preparing gelatinized mixed slurry; and 3) carrying out film casting on the gelatinized mixed slurry, and drying to obtain the ultraviolet barrier film. The ultraviolet barrier film has the advantages of being excellent in ultraviolet barrier performance, good in moisture barrier performance, high in mechanical strength, high in transparency, environmentally friendly, degradable and the like, can be used as a packaging material, and is simple in preparation method, low in production cost and suitable for large-scale industrial production and application.

The invention provides a preparation method of starch hydrogel microspheres, and belongs to the technical field of embolism microsphere manufacturing. The preparation method of the starch hydrogel microspheres comprises the following steps: adding a first cross-linking agent into a starch solution, and mixing to obtain a water-phase solution; adding the oil phase solution into the water phase solution, and mixing to obtain a mixed liquid; adding a second cross-linking agent into the mixed liquid, mixing and reacting to obtain the starch hydrogel microspheres, and the starch hydrogel microspheres prepared by the method have the advantages of long in-vivo degradation time and adjustable degradation time, and can be suitable for more disease types.

The invention discloses bacillus subtilis capable of producing beta-amylase and application of the bacillus subtilis, and belongs to the technical field of bioengineering, the bacillus subtilis is named as bacillus subtilis JXJY-0811, the bacillus subtilis is preserved in China General Microbiological Culture Collection Center (CGMCC) on June 7, 2024, and the preservation number is CGMCC NO.30886. The invention further discloses a preparation method of the bacillus subtilis capable of producing beta-amylase and application of the bacillus subtilis capable of producing beta-amylase. A strain which can secrete beta-amylase in an extracellular mode and is high in amylase activity is screened from soil through a transparent ring method, and the strain is identified as bacillus subtilis through whole genome sequencing. The appropriate temperature condition of the extracellular beta-amylase of the strain is 50-75 DEG C, the appropriate pH value is 3.5-6.5, the extracellular enzyme activity is 9640.10 U / mL, and the highest enzyme activity of the beta-amylase in a 5L fermentation tank after fermentation for 60 hours can reach 51980.36 U / mL. The beta-amylase obtained through fermentation is used for treating a soluble starch solution, the main product is maltose, and the beta-amylase can be used for producing maltose and high maltose syrup.

The invention discloses a high-strength water-resistant starch adhesive and a preparation method thereof, and belongs to the technical field of preparation of environment-friendly adhesives. The problems of strength and mildew resistance of the starch adhesive are solved. The preparation method comprises the following steps: preparing 5-10g of polyethyleneimine into a 30-60wt% solution, weighing a certain mass of urea according to a molar ratio of (1-5): 1, adding the weighed urea into the prepared polyethyleneimine solution, and reacting for 8-14 hours in an oil bath to obtain a first branched polymer; 20-50 g of dialdehyde starch and 60-90 g of polyvinyl alcohol are added into a flask to prepare a starch solution, then the reaction temperature is set, uniform stirring is performed for gelatinization treatment, a second gelatinized solution is obtained, and after mixing reaction, a prefabricated high-strength water-resistant starch adhesive is obtained; and adding 5-10 g of cassava starch filler and 5-10 g of polymethyl silicon polyphenyl isocyanate, and stirring for 10-30 minutes to obtain the high-strength water-resistant starch adhesive.

The application discloses a kind of metal-loaded starch aerogel and its preparation method and application, comprising the following steps: (1) starch and water are prepared into starch milk, starch milk is heated, and gelatinized starch solution is obtained;(2) sodium laurate is added to the gelatinized starch solution and heated to react, and after the reaction is completed, starch-sodium laurate complex solution is obtained;(3) metal nitrate solution is added to the above-mentioned complex solution, and after stirring uniformly, a reducing agent is added to reduce metal ions, and metal-loaded starch hydrogel is obtained;(4) the above-mentioned hydrogel is pre-frozen and freeze-dried to obtain metal-loaded starch aerogel.The metal-loaded starch aerogel of the application has excellent ethylene adsorption capacity, with an adsorption capacity of about 32 mL / g, good adsorption stability, and the adsorption process can be carried out at normal temperature and pressure, which can be used for fruit preservation.

The invention discloses composite hydrogel for co-embedding myricetin and epicatechin and a preparation method of the composite hydrogel, and belongs to the technical field of hydrogel microballoons.The preparation method comprises the steps that an azolla filliculoidas protein solution and a myricetin solution are self-assembled to form azolla filliculoidas protein-myricetin hydrogel; then adding an epicatechin solution into the prepared composite hydrogel, so as to form rumex hanus protein-myricetin-epicatechin composite hydrogel; and finally, adding the prepared composite hydrogel into the oxidized long-shaped rice starch solution to obtain the composite hydrogel for co-embedding the myricetin and the epicatechin. The formed composite hydrogel is relatively small in particle size and relatively high in stability, the core material embedding effect is good, and the requirement of common application of myricetin and epicatechin is met; hyaluronic acid in the dispersing agent enables particles to keep a proper distance through electrostatic repulsion, and a polylactic acid chain segment improves the steric hindrance effect, so that micelle agglomeration and precipitation are prevented, and the storage life is prolonged.

The invention discloses a preparation method of a compound microbial fertilizer, and belongs to the technical field of microbial fertilizers, the preparation method comprises the steps of starch gelatinization, strain activation, shake-flask culture, immobilization, fermentation and material mixing; the immobilization comprises the following steps: centrifuging a paenibacillus polymyxa shake-flask culture, and collecting wet thalli; mixing the wet thalli with normal saline, stirring at room temperature, adding the gelatinized starch solution, and continuously stirring to obtain a mixed bacterial solution; stirring a calcium chloride aqueous solution at 30-35 DEG C, dropwise adding the mixed bacteria solution, continuously stirring after dropwise adding, filtering, and taking filter residues to obtain immobilized paenibacillus polymyxa; the compound microbial fertilizer prepared by the invention is high in viable count, and the viable count is slightly influenced by the content of each substance in the corn steep liquor.

The invention discloses a targeted delivery system of a largemouth bass frog iridovirus oral vaccine and a preparation method of the targeted delivery system, and relates to the technical field of biological medicines.The method comprises the following steps that a starch solution and a largemouth bass frog iridovirus inactivated vaccine are stirred and mixed, then a paraffin emulsion is added, stirring and emulsifying are conducted, and a W / O emulsion is obtained; adding calcium chloride, stirring and mixing, centrifuging, and resuspending by using a PBS (Phosphate Buffer Solution) to obtain a microsphere resuspension solution; stirring and mixing with a quaternized chitosan solution, adding glutaraldehyde for crosslinking, centrifuging, and freeze-drying. The invention further discloses a targeted delivery system of the largemouth bass frog iridovirus oral vaccine prepared by the method. The vaccine is orally administered after being microencapsulated, so that the human cost is low, the stimulation to fish bodies is small, the problems of inconvenience in fish administration, low bioavailability of oral administration, instability in gastrointestinal tracts and the like are solved, and the vaccine has an excellent application prospect in the field of LMBV prevention and control.

The invention discloses a collagen membrane as well as a preparation method and application thereof, and belongs to the field of cosmetics. The preparation method of the collagen membrane comprises the following steps: pickling cow leather with lime, washing the pickled cow leather with water, then acidifying the cow leather with hydrochloric acid, washing the acidified cow leather with water, and washing away interfibrous substances until the hardness of the cow leather is 1t; the mmol / g is 0.1 to 0.3 mmol / 100g; cutting the obtained cow leather into particles, rolling the particles by a defibrator to obtain collagenous fibers, then adding a gelatinized acetate starch solution and a gelatinized chitosan solution into the collagenous fibers, and uniformly mixing and kneading to obtain collagenous fiber slurry with the water content of 95-97%; and casting the obtained collagen fiber slurry into a membrane, drying at 50-55 DEG C for 2-4 hours, soaking the membrane in a mixed solution of baking soda and glutamine transaminase for 2-3 seconds, drying at 50-55 DEG C, flushing by adopting a sodium thiosulfate solution, and washing to remove salt, thereby obtaining the collagen membrane. According to the preparation method, crosslinking among collagenous fibers is enhanced, and the structural stability of the membrane is improved.

The present invention discloses an enzymatically modified starch adsorbent and a preparation method thereof, and relates to the field of adsorbent technology. The method comprises the following steps: adding corn starch to deionized water and performing gradient temperature-ultrasound synergistic treatment, first subjecting the pretreated starch solution to cold plasma treatment under a nitrogen atmosphere, adjusting the pH, heating, and then adding a complex enzyme for enzymatic hydrolysis, adding modified sulfonic acid sodium alginate for reaction, and then adding epichlorohydrin and stirring the reaction; then subjecting the solution to cold plasma treatment under a nitrogen atmosphere, adding pretreated attapulgite for reaction, adding ammonium sulfate and acrylamide and excluding air, and then filtering, washing, and drying the solution after the reaction to obtain an enzymatically modified starch adsorbent. The pretreatment of corn starch by the present invention effectively improves the reactivity of starch granules; the introduction of ingredients such as pretreated attapulgite further improves its adsorption capacity and adsorption capacity stability. Therefore, the adsorbent of the present invention has a wider application prospect.

The invention discloses a method for improving the moisture infiltration capacity of urban green land soil. The method comprises the following steps that S1, according to design requirements, a foundation is excavated, earthwork is cleaned, the foundation is leveled and divided in a checkerboard mode, and an air pump device is used for aerating the foundation in checkerboard checks; s2, crushing the construction waste: crushing the engineering muck, the engineering slurry, the engineering waste, the demolition waste and the decoration waste into coarse grains with the grain size of 30-50mm, removing metal in the coarse grains, paving the coarse grains on a foundation, and leveling and compacting to form a permeable layer; s3, a starch solution is injected into the permeable layer, glucose is formed after the starch solution is hydrolyzed in the permeable layer, acetic acid is formed after the glucose is alcoholized, hydroformylated and acidified, and the acetic acid reacts with carbonate in the permeable layer to generate water-soluble substances which are consumed, so that the porosity of the permeable layer is improved. The problem that urban inland inundation is prone to occurring due to the fact that urban green land permeability is poor can be solved.

The invention belongs to the technical field of functional emulsion and food processing, and particularly relates to temperature response type high internal phase emulsion and a preparation method and application thereof. The preparation method comprises the following steps: stirring and mixing a starch aqueous solution and an OSA alcoholic solution for reaction to obtain OSA-starch; the preparation method comprises the following steps: dissolving OSA-starch in distilled water to obtain an OSA-starch solution, and then heating and uniformly mixing the OSA-starch solution with a glycyrrhizic acid solution to obtain a water-phase solution; and carrying out high-speed homogenization treatment on the obtained water-phase solution and vegetable oil to obtain the temperature-responsive high-internal-phase emulsion. According to the invention, an aqueous phase solution prepared from OSA-starch and glycyrrhizic acid is introduced into vegetable oil to form the temperature-responsive high-internal-phase emulsion, the prepared temperature-responsive high-internal-phase emulsion has high safety and good stability, rheological properties can be regulated and controlled through temperature, a solution is provided for food system individuation, and the temperature-responsive high-internal-phase emulsion has good application prospects. The method has a good application prospect in the food industry and related fields.

The invention relates to agricultural production, in particular to a method for evaluating technologies for treating fibrous cotton seeds against disease, and can also be used to create methods for evaluating technologies for treating seeds of other agricultural plants. The essence of the invention is that in the method of assessing the resistance of cotton plants to disease, which consists in cultivating seed materials in an area artificially infected with the pathogen and isolated with polyethylene coating, fibrous cotton plants, on whose outer surfaces a thin coating is created by sequentially applying starch and fungicide and / or fungicide and starch solutions, are cultivated in an artificially infected area.

The utility model discloses a centrifugal screen for separating fiber from starch aqueous solution, and relates to the technical field of centrifugal screens, the centrifugal screen for separating fiber from starch aqueous solution comprises a screen box, the bottom end of the screen box is provided with a motor, and the centrifugal screen is provided with a support, an electric push rod and a push plate. In the separation process of starch and fibers, an electric push rod installed on the bottom end face of a support can be started to push a push plate to the lower side, and the push plate is synchronously utilized to move to the lower side to rapidly push and scrape away the fibers attached to the inner wall of a screen drum. The screen drum is connected with the connecting block fixedly connected to the output shaft at the top end of the motor, and when the screen drum needs to be cleaned, the screen drum can be detached from the connecting block fixedly connected to the output shaft at the top end of the motor, so that the cleaning efficiency can be remarkably improved when the screen drum is cleaned.

The invention provides a fully degradable nanocellulose composite liquid mulching film and a preparation method thereof, and the preparation method comprises the following steps: adding hexadecyl trimethoxysilane into a nanocellulose solution, mixing and heating to obtain a hydrophobically modified cellulose solution; adding citric acid and sodium hypophosphite into the starch solution, mixing and heating for esterification reaction to obtain an esterification product, and adding deionized water after the esterification product is cooled to room temperature to obtain a product solution; mixing and stirring a gelatin solution and a dopamine solution to obtain a modified gelatin solution modified by polydopamine; mixing the modified gelatin solution with the product solution to obtain composite gel; mixing, shearing and emulsifying the modified cellulose solution, the composite gel, an emulsifier, a plasticizer and a water-retaining agent to obtain a composite emulsion; alkali liquor is dropped into the composite emulsion to adjust the pH value, then a cross-linking agent is added, and the composite liquid mulching film is obtained after mixing and heating.

The invention belongs to the field of microbial preparations, and particularly relates to a protection method of a microzyme freeze-dried fungicide based on low-liquefied starch. On one hand, the invention provides a freeze-drying protective agent. The freeze-drying protective agent is obtained by carrying out enzymolysis on a starch solution with amylase for 20-200 minutes, centrifuging and freeze-drying. On one hand, the invention provides a protection method of a saccharomycetes freeze-drying bacterial agent, which comprises the following steps: adding the freeze-drying protective agent into saccharomycetes resuspended thalli, standing, removing supernatant to obtain paste, and freeze-drying the paste. By using the freeze-dried microbial inoculum provided by the invention, the survival rate of the saccharomycetes freeze-dried microbial inoculum is remarkably improved.

The application discloses modified emulsified starch and a preparation method thereof and application of the modified emulsified starch to health products for the elderly, and relates to the technical field of starch modification. The preparation method of the modified emulsified starch comprises the following steps: high-temperature liquefaction is performed on starch milk to obtain a liquefied starch solution; the pH of the liquefied starch solution is adjusted, starch amylase is added to perform an enzymolysis reaction, then the residual starch amylase is inactivated to obtain an enzymolysis product; the pH of the enzymolysis product is adjusted, octenyl succinic anhydride is added to perform an esterification reaction, and an esterification modified solution is obtained; and the esterification modified solution is washed and spray-dried to obtain the modified emulsified starch. The modified emulsified starch has a high coating rate for vitamin C, can prevent photo-oxidation of vitamin C, has a good dissolution effect, and is convenient for the elderly to absorb and utilize vitamin C.

The present invention discloses a method for preparing corn starch nanocrystals by pulsed electric field-assisted acidolysis. First, the starch solution is treated with a pulsed electric field of 1-12 kV / cm, and then acidolysis is carried out to prepare starch nanocrystals. It is simple and efficient, which can not only significantly reduce the reaction time and prepare corn starch nanocrystals in a short time, but also has higher safety performance, low energy consumption due to mild reaction conditions, and avoids the adverse effects of instantaneous temperature rise on starch acidolysis. While improving the crystallinity, corn starch nanocrystals with smaller sizes are obtained, which can be used as fillers for composite materials to improve their mechanical properties and barrier properties, and are suitable for use as emulsion or embedding materials in the food or daily chemical fields.

The application discloses a preparation method of starch-unsaturated fatty acid compound. The method comprises the following steps: starch is pretreated by a debranching enzyme to obtain a debranched starch solution, the debranched starch solution is mixed with unsaturated fatty acid, an ethanol-water solution is added as a ball milling medium, a multi-stage ball milling parameter dynamic regulation process is adopted, and low-temperature protection, medium-temperature complexing and cooling solidification stage ball milling reactions are sequentially carried out, and finally, drying, crushing and sieving are performed to obtain the starch-unsaturated fatty acid compound. Through the synergistic effect of debranching enzyme pretreatment and multi-stage ball milling, the starch and the unsaturated fatty acid are efficiently compounded under mild conditions. The obtained compound has high compounding rate, high resistant starch content and excellent antioxidant stability. The compound can be used as a low-glycemic index functional food raw material and is used for preparing blood glucose management, weight control or antioxidant functional food. The method is mild, controllable and reproducible, does not need high temperature and high pressure, and meets the clean label consumption trend.

The application provides a wet starch preparation and automatic adding system, which comprises a clean water tank, a starch preparation tank, a quantitative adding system, a ton bag hoisting system and a control system, wherein the water outlet of the clean water tank is connected with the water inlet of a starch water inlet pump through a first pipeline; the water inlet of the starch preparation tank is connected with the water outlet of the starch water inlet pump through a second pipeline; the quantitative adding system is used for adding starch into the starch preparation tank; the ton bag hoisting system is arranged above the quantitative adding system and is used for hoisting and conveying a ton bag of starch to add the starch into the quantitative adding system; the water inlet of a starch water outlet pump is connected with the starch solution outlet of the starch preparation tank; the water outlet of the starch water outlet pump is connected with the starch solution inlet of a mixing machine through a starch solution conveying pipe; and the control system is electrically connected with the starch water inlet pump, the quantitative adding system, the ton bag hoisting system and the starch water outlet pump respectively. The system can effectively realize wet addition of the starch in the process of the gypsum board production, stabilize the production and improve the product quality.

This application relates to the field of papermaking technology, and more particularly to a cationic cassava starch and its preparation method, apparatus, and application. The preparation method involves repeatedly statically mixing 60%–69% etherifying agent with 5%–15% caustic soda solution, adding 35%–42% cassava starch solution within 10–30 seconds, mixing, sieving, and then undergoing an etherification reaction to obtain cationic cassava starch. The apparatus includes an etherifying agent storage unit, a caustic soda solution storage unit, a raw material mixing unit, a cassava starch solution supply unit, a mixing and sieving unit, a reaction unit, controllable valves, a timer, and a control unit. Two storage units are connected to the raw material mixing unit, which is connected to the mixing and sieving unit via valves. The starch solution supply unit is also connected to it, and subsequently to the reaction unit. The control unit regulates the opening and closing of the valves to ensure the mixing of the solution is completed within 10–30 seconds. The application is the use of cationic cassava starch in papermaking. It is evident that the preparation method of this application can avoid gelatinization caused by excessively high local concentration when starch is mixed with alkali solution, and reduce the generation of impurities; the wet process can flexibly control the degree of substitution to adapt to paper machine production, eliminate the drying process, and produce wet cationic tapioca starch with stable degree of substitution, excellent quality, which can be directly supplied to paper machines and has good retention and filtration effects.

The invention discloses a wood fiber-based composite material with a tough interface structure and a preparation method thereof, and the preparation method comprises the following steps: 1) mixing a gelatinized starch solution and a waterborne polyurethane emulsion to form a dynamically stable flow equalizing agent; 2) adding the wood fiber and the coconut shred fiber into hydrogen bond alkalinity beta gt; carrying out colloid milling in 0.5 of a solvent to obtain mixed fibers; and (3) uniformly mixing the flow equalizing agent obtained in the step (1) and the mixed fiber obtained in the step (2) by using a kneading machine, putting the mixture into a mold, and carrying out hot press molding to obtain the composite material. The starch solution and the waterborne polyurethane are prepared and compounded to form the flow equalizing agent, the flow equalizing agent is mixed with the pretreated fibers, and the binding material with high strength and high toughness is prepared through kneading and mold forming. The adhesive combines the adhesion of natural starch and the flexibility of waterborne polyurethane, realizes multi-component synergistic enhancement, and has excellent mechanical properties and environmental protection characteristics.

The present invention belongs to the technical field of biomass extraction. More specifically, it relates to a production process of tea seed essence. The production steps of the present invention include: mixing camellia seed meal and water, and performing ultrasonic impregnation to obtain an impregnation solution; mixing starch and water and gelatinizing to obtain a gelatinized starch solution; adding the gelatinized starch solution to the impregnation solution, mixing evenly, and freezing to obtain a solid mixture; performing cryogenic grinding on the solid mixture to obtain a ground material; completely thawing the ground material to obtain a ground slurry; adding a gelatin solution to the ground slurry and stirring and mixing evenly to obtain a mixed slurry; adjusting the pH of the mixed slurry to obtain an acidified mixed slurry; adding a composite enzyme solution to the acidified mixed slurry, performing an enzymatic hydrolysis reaction, then adding an amylase solution, continuing to keep warm for the enzymatic hydrolysis reaction, inactivating the enzyme, separating, and taking the supernatant; purifying and drying the supernatant to obtain the tea seed essence.

The invention discloses modified emulsified starch, a preparation method of the modified emulsified starch and application of the modified emulsified starch to health-care products for old people, and relates to the technical field of starch modification. The preparation method of the modified emulsified starch comprises the following steps: liquefying starch milk at high temperature to obtain a liquefied starch solution; adjusting the pH value of the liquefied starch solution, adding amylase to carry out an enzymolysis reaction, and then inactivating the residual amylase to obtain an enzymolysis product; adjusting the pH value of the enzymolysis product, and adding octenyl succinic anhydride for esterification reaction to obtain esterification modified feed liquid; and washing and spray-drying the esterified modified feed liquid to obtain the modified emulsified starch. The modified emulsified starch provided by the invention has a high coating rate on vitamin C, can prevent photooxidation of vitamin C, has a good dissolution effect, and facilitates absorption and utilization of vitamin C by old people.

The invention discloses a preparation process of a preserved Guo dish, and belongs to the technical field of food processing. The preparation process comprises the following steps: pre-treating the sweet potato leaves and the chicken, respectively blanching the sweet potato leaves and the chicken with soda, cleaning for multiple times, crushing and filtering, and separating filtered juice and filter residues; steaming straw mushrooms and extracting normal juice; mixing the sweet potato leaf filtered juice, the filter residues and the straw mushroom normal juice, adding the mixture into the soup-stock for cooking, and adding water starch for thickening after boiling; chicken oil, salt and soup-stock are added into the chicken filtered juice and the filter residues for cooking, and water starch is added for thickening after boiling; and performing pasteurization and quick-freezing preservation at-18 DEG C on the cooked Guangdong dish. The prepared Guangdong dish retains the fine taste and traditional flavor of the Guangdong dish, prolongs the shelf life, can be preserved for a long time, and is suitable for large-scale processing of the pre-prepared dish.

The invention discloses an antibacterial packaging material as well as a preparation method and application thereof. The antibacterial packaging material is prepared from pineapple leaf fiber carboxymethyl cellulose, carboxymethyl cellulose, cationic starch, 3-hydroxyl octoate, alpha-tocopherol, dimethylbiguanide hydrochloride, a plasticizer, nitrogen-doped carbon quantum dots, plant essential oil, nano zeolite powder, carvacrol and citric acid. The preparation method comprises the following steps: dispersing the cationic starch in the deionized water, dispersing the pineapple leaf fiber carboxymethyl cellulose and carboxymethyl cellulose in the deionized water, completely dissolving, adding into a starch solution, sequentially adding the rest components, uniformly mixing, heating, reacting, forming a film, and drying to obtain the packaging material. According to the antibacterial packaging material, the cationic starch, the carbon quantum dots, the plant essential oil and other related components are combined for the first time to form a novel antibacterial packaging material, the antibacterial performance is remarkably improved and kept for a long time through the synergistic effect of all the components, and the antibacterial packaging material is high in material stability, simple and convenient in preparation process, low in cost and high in application and popularization value.

The invention discloses a pore diameter regulation and control method of a carbon-sequestration environment-friendly composite insulating dielectric with a three-dimensional nano-porous structure. The pore diameter regulation and control method comprises the following steps: S1, preparing a starch solution; s2, preparing a precursor solution; s3, preparing composite wet gel; and S4, aging and drying to obtain the PNBIM. And regulating and controlling the aperture of the PNBIM based on the regulation and control of the starch concentration in the step S2. The polysiloxane-nano porous biopolymer insulating material prepared by the invention is combined with carbon dioxide (CO2) in the atmosphere to form a novel gas-solid composite insulating material. The material shows remarkable advantages in multiple aspects, including high insulativity, low dielectric loss, light weight, reproducibility, environmental protection, carbon sequestration and the like, and a new way is provided for miniaturization and environmental upgrading of electrical equipment.

The chemical formula of a metal organic framework 2D-NCM (Fe) in the magnetic metal-organic framework mediated multi-enzyme nano material GOx-GAA at 2D-NCM (Fe) is Fe3O6Co2Ni2C3N0.4, Gox is glucose oxidase, and GAA is glucosidase. The invention also provides a method for efficiently and quickly measuring the activity of alpha-amylase, which comprises the following steps: acquiring a to-be-measured sample solution containing alpha-amylase, and carrying out enzymolysis on the to-be-measured sample solution and a starch solution at a first preset temperature for a first preset time to obtain a first reaction solution, after the enzymolysis reaction is finished, adding a first solution containing a magnetic metal-organic framework mediated multienzyme nanomaterial GOx-GAA at 2D-NCM (Fe) and a 3, 3 ', 5, 5'-tetramethyl benzidine solution into the first reaction solution, and reacting for a second preset time to obtain a second reaction solution; measuring the absorbance of the second reaction liquid at 652 nm; and obtaining the enzymatic activity of the alpha-amylase in the to-be-detected sample solution containing the alpha-amylase according to a standard curve of association between the absorbance at 652nm and the enzymatic activity of the alpha-amylase.

The present invention discloses a strain of bacillus subtilis producing beta-amylase and its application, belong to the field of bioengineering technology, the bacillus subtilis is named as bacillus subtilis (Bacillus subtilis) JXJY-0811, has been deposited in the General Microbiology Center of China National Committee for the Collection of Microorganisms on June 7, 2024, and the deposit number is CGMCC NO.30886. The present invention uses the clear circle method to screen from soil and obtain bacterial strains that can secrete beta-amylase and amylase activity extracellularly, and is identified as bacillus subtilis through whole genome sequencing. The extracellular beta-amylase suitable temperature conditions of the strain are 50-75 DEG C, suitable pH value is 3.5-6.5, and extracellular enzyme activity is 9640.10U / mL, and after 60 hours of fermentation, the highest enzyme activity of 5L fermentation tank beta-amylase can reach 51980.36U / mL. The beta-amylase obtained by fermentation is used to process soluble starch solution, and the main product is maltose, which can be used for the production of maltose and high maltose syrup.

The invention discloses a starch-based medical adhesive as well as a preparation method and application thereof, and particularly relates to the technical field of biomedical materials. The method comprises the following steps: firstly, adding modified starch 1 into water, and heating, stirring and gelatinizing in an oil bath pan to obtain a modified starch 1 solution; adding the modified starch 2 into water, and heating, stirring and gelatinizing in an oil bath pan to obtain a modified starch 2 solution; mixing the modified starch 1 solution and the modified starch 2 solution, and uniformly stirring to obtain a modified starch compound; and finally, performing low-temperature freezing treatment on the modified starch compound, performing freeze-drying treatment, and crushing the freeze-dried modified starch compound to obtain the starch-based medical adhesive. The medical adhesive disclosed by the invention has good biocompatibility, can be degraded into a non-toxic and harmless product in an organism, has relatively strong wet tissue adhesion strength and good tissue compliance, is simple in process, can directly act on skin wounds, deep wounds and wounds which are difficult to reach by an operation, and is simple and convenient to use.