285 results about "Fumaric acid" patented technology

The invention relates to a carboxylic acid ligand-copper metal organic framework nano material, a preparation method thereof and an injection. The carboxylic acid ligand-copper metal organic framework nano material is of a polycrystal MOF structure formed by connecting carboxylic acid ligands and copper ions through coordinate bonds; the carboxylic acid ligand comprises at least one of dicarboxylic acid and tricarboxylic acid; preferably, the dicarboxylic acid comprises at least one of itaconic acid and fumaric acid, and the tricarboxylic acid comprises at least one of aconitic acid and citric acid; the valence states of the copper ions comprise zero valence, + 1 valence and + 2 valence; preferably, based on the total amount of the copper ions being 100 at%, the total content of Cu0 and Cu + is 85-90 at%, and the content of Cu2 + is 10-15 at%.

The invention discloses a production method of a PET composite current collector base film with high mechanical property. The base film comprises an outer surface layer, a middle core layer and an inner surface layer, the outer surface layer is composed of PET, fumaric acid, hydroxyl-terminated polybutadiene and an antioxidant; the middle core layer consists of PET (Polyethylene Terephthalate), furandicarboxylic acid, an antioxidant and a stabilizer; the inner surface layer is composed of dimethyl terephthalate, ethylene glycol, spiro diol, ethylene glycol antimony and zinc acetate. The PET composite current collector base film prepared by the preparation method disclosed by the invention has relatively high mechanical properties.

The invention discloses a preparation method of a low-chlorine composite environment-friendly coal transportation anti-freezing agent, and belongs to the technical field of anti-freezing solutions. The anti-freezing solution is used for solving the technical problems of complex components and poor anti-freezing and metal corrosion resistance of the anti-freezing solution for coal transportation in the prior art. The preparation method of the low-chlorine composite environment-friendly coal transportation anti-freezing agent comprises the following step: uniformly mixing the compound pour point depressant, the modified corrosion inhibitor, the thickening stabilizer and the industrial water to prepare the low-chlorine composite environment-friendly coal transportation anti-freezing agent. The compound pour point depressant comprises an organic pour point depressant and an inorganic pour point depressant; the organic pour point depressant is obtained by reacting unsaturated azole, sodium methallyl sulfonate and fumaric acid; the unsaturated nitrogen is obtained by reaction of an intermediate B and benzaldehyde, and the intermediate B is obtained by reaction of triazole and ethyl chloroacetate; the modified corrosion inhibitor is obtained by carrying out a reaction on potassium thiocyanate, benzoyl chloride and chitosan vanillin Schiff base. The anti-freezing solution prepared by the invention has the advantages of moderate fluidity, good metal corrosion resistance and good anti-freezing performance.

The invention discloses a preparation method of an aluminum fumaric acid desiccant rotating wheel, a desiccant rotating wheel and a dehumidifier, and relates to the technical field of dehumidification, the preparation method of the aluminum fumaric acid desiccant rotating wheel comprises the following steps: dissolving fumaric acid and sodium hydroxide in water, then adding into an aluminum sulfate solution, stirring, and after the reaction is completed, carrying out suction filtration, drying and grinding to obtain the aluminum fumaric acid desiccant rotating wheel. Aluminum fumaric acid MOF powder is obtained; uniformly mixing aluminum fumaric acid powder, a hydrophilic adhesive and water to obtain aluminum fumaric acid impregnation liquid; the preparation method comprises the following steps: impregnating inorganic fiber paper in an aluminum fumaric acid impregnation liquid, pulling, and drying with hot air at 100-150 DEG C to obtain a flaky moisture absorption material; the moisture absorption material is divided into two parts, one part of the moisture absorption material is pressed into a corrugated shape, the other part of the moisture absorption material is kept in a plane shape, the corrugated moisture absorption material is compounded on the plane-shaped moisture absorption material, and then the dehumidification rotating wheel is obtained through winding. The method is simple in step, high-temperature sintering is not needed, and the prepared dehumidification rotating wheel has a good moisture absorption effect.

The invention relates to the technical field of liposomes, in particular to a lutein ester-fumaric acid composite liposome with high bioavailability as well as a preparation method and application of the lutein ester-fumaric acid composite liposome. The preparation method of the lutein ester-fumaric acid composite liposome comprises the following steps: mixing lutein ester with oil to obtain a phase A; adding phospholipid, cholesterol and vitamin E into the phase A, and then carrying out ultrasonic dispersion treatment to obtain a phase B; fumaric acid and water are added into the phase B, and then high-pressure homogenization treatment, high-pressure microjet treatment and freeze-drying treatment are sequentially performed to obtain the lutein ester-fumaric acid composite liposome. The lutein ester-fumaric acid composite liposome with high bioavailability has the advantages of small average particle size, high Zeta potential, high encapsulation efficiency, high bioavailability, high solubility and excellent stability, and has potential application prospects in preparation of foods, medicines or health care products with eye protection functions.

The invention discloses a vinyl copolymer pour point depressant as well as a preparation method and application thereof, and relates to the technical field of vinyl copolymer pour point depressants. Acrylamide, a methacrylate compound, a fumaric acid compound and alkyl coupling agent modified nano silicon dioxide are used as monomers, and the prepared copolymer pour point depressant has the characteristics and characteristic chemical bonds of copolymer macromolecules; due to the specific molecular chain and structure of the copolymer, the flexibility and flexibility variation range of copolymer molecules in the presence of dissolution or a solution is extremely large, crude oil can be quickly and effectively dispersed, the fluidity of the crude oil can be enhanced, blockage is reduced, and the oil production amount is increased; and the condensation point and the viscosity of crude oil can be obviously reduced under the condition of a very small amount (such as 500ppm).

The present invention relates to the technical field of post-treatment of maleic anhydride, and in particular to a device and method for obtaining maleic anhydride from a gas phase containing maleic anhydride. According to a device for obtaining a maleic anhydride product from a gas phase material flow containing maleic anhydride provided by the present invention, the objectives of simplifying the process, reducing the device investment and reducing the energy consumption can be achieved while effectively controlling the fumaric acid generation amount and the absorbent consumption.

The invention discloses a preparation method of tiamulin and tiamulin fumarate based on Bunte salt, which comprises the following steps: mixing the Bunte salt and pleuromutilin p-toluenesulfonate, reacting at 45-65 DEG C for 3-5 hours to synthesize tiamulin, preparing the Bunte salt through a reaction formula 1, and preparing the pleuromutilin p-toluenesulfonate through a reaction formula 2, the molar ratio of the 2-diethylaminoethanol to the sodium thiosulfate to the chlorination reagent in the reaction formula 1 is 1: (1-1.3): (1-1.5), and the molar ratio of the pleuromutilin to the paratoluensulfonyl chloride to the pyridine in the reaction formula 2 is 1: (1-1.2): (1-1.2); the prepared tiamulin and fumaric acid are used as raw materials for a salt forming reaction, the reaction temperature ranges from 55 DEG C to 65 DEG C, the reaction time ranges from 40 min to 80 min, and after the reaction is finished, the tiamulin fumarate is prepared through cooling, crystallization, centrifugation and drying; the tiamulin fumarate disclosed by the invention is high in content, low in total amount of impurities, few in variety and stable in quality under high-temperature and high-humidity conditions, and the preparation method is simple and easy to operate and good in product quality.

The invention provides a succinic acid composition as well as a preparation method and application thereof. The succinic acid composition comprises a combination of succinic acid and fumaric acid, and the mass content of the fumaric acid in the succinic acid composition is 10-200 ppm. The succinic acid composition provided by the invention is a biomass source and contains succinic acid and a specific content of fumaric acid, and by controlling the content of fumaric acid in the succinic acid composition, the succinic acid composition has obviously improved storage stability and long storage life, and is suitable for industrial production. And after long-term storage, the excellent quality of high succinic acid purity and low impurity content can still be maintained. The succinic acid composition is used for polyester synthesis, can effectively inhibit polymerization side reaction, improves polymerization efficiency, and obtains a high-yield and high-quality polyester product.

Provided are a metal-organic framework nanomaterial, a preparation method therefor, and a use thereof, belonging to the technical field of bionanomaterials, and resolving the technical problem of inhibiting atherosclerosis using biomimetic metal-organic framework nanoenzymes. The solution is: the components of the of the metal-organic framework nanomaterial and the ratio thereof are: metal ions Ce4+ and a ligand fumaric acid in a molar ratio of 1:5. The preparation method therefor is: measuring an FA regulator and water to prepare a mixed solution, then adding fumaric acid and cerium ammonium nitrate dropwise into the mixed solution, stirring at room temperature, centrifuging, repeatedly washing alternately with water and ethanol, and finally drying overnight in a vacuum oven. A simple, efficient and convenient method for synthesizing the metal-organic framework nanomaterial is provided. The synthesized metal-organic framework nanomaterial has excellent CEH-like enzyme activity and intrinsic antioxidant activity, and can be used to increase lipid efflux and reduce lipid uptake, and decrease ox-LDL-induced foam cell formation, thereby alleviating atherosclerosis.

Provided is a dispersant for hydraulic compositions that has dispersing properties and can reduce the viscosity of hydraulic compositions. [Solution] A dispersant for hydraulic compositions, comprising a polymer (P) having a structural unit (1) formed from a compound represented by general formula (1), a structural unit (2) formed from a compound represented by general formula (2), and a structural unit (3) formed from at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, and salts thereof, wherein the mass average molecular weight of this polymer (P) is 5,000 to 5,000,000.

The invention discloses an automatic control method and system for fumaric acid production. The method comprises the following steps: collecting process variables in a fermentation process; constructing a soft measurement model fusing physical modeling and a residual neural network to obtain an acid production rate prediction value and prediction confidence; calculating a feed-forward control quantity, and adjusting the weight according to the prediction confidence to obtain a feed-forward control output; constructing a state vector, and establishing a Markov decision process; training a neural network control strategy by adopting a near-end strategy optimization algorithm, and outputting a proportionality coefficient, an integral coefficient and a differential coefficient; calculating feedback control quantity, fusing the feedback control quantity with feed-forward control output, and applying change rate and amplitude limitation to obtain final control output; and switching to a feedback priority control mode under a specific condition, and regularly updating a soft measurement model and a control strategy parameter. According to the invention, high-precision stable control of pH in the fumaric acid fermentation process is realized, the production efficiency and the process robustness are improved, and the method is suitable for automatic control of the large-scale fermentation process.

The invention relates to the technical field of building materials, and discloses a mortar containing a nanometer material and a preparation method thereof, the mortar comprises 70-80 parts by weight of cement, 8-12 parts by weight of fly ash, 0.4-0.5 part by weight of a polycarboxylic acid water reducer, 0.4-0.6 part by weight of hydroxypropyl methyl cellulose, 1-2 parts by weight of the nanometer material, 2-3 parts by weight of modified silk fibroin and 40-50 parts by weight of water. Wherein the modified nano silicon dioxide is modified by gamma-aminopropyltriethoxysilane, the modified cubic nano calcium carbonate is subjected to compound modification by fumaric acid, sodium stearate and palmitic acid, and the modified silk fibroin is prepared by grafting modification by bis-aminopropyl terminated polysiloxane. According to the mortar, through optimization of component matching and modification treatment of the nano material and the silk fibroin, the mechanical property, durability and crack resistance of the mortar are remarkably improved, and the cost is controllable.

This invention belongs to the technical field of medicinal chemistry, specifically relating to a novel crystal form of cariprazine, specifically the cariprazine-4-hydroxybenzoic acid-methanol-hemihydrate crystal form and its preparation method. The novel cariprazine-fumaric acid crystal form provided by this invention comprises a basic unit of one molecule of cariprazine, one molecule of 4-hydroxybenzoic acid, one molecule of methanol, and 0.5 molecules of water. Its preparation method is simple to operate, the crystallization process is easy to control, and it has good reproducibility. The formation of a eutectic significantly enhances the solubility of cariprazine, exhibiting strong pharmaceutical value.

The invention discloses a sheet molding compound for a torrent swimming pool wall. The sheet molding compound is prepared from the following raw materials: isophthalic resin, hyperbranched unsaturated polyester, a low-shrinkage additive, a curing agent, a release agent, a polymerization inhibitor, a thickening agent, a diluent, fibers and filler, the isophthalic resin is prepared from isophthalic acid, fumaric acid, neopentyl glycol and 1, 2-propylene glycol through a two-step process under the action of a catalyst and an initiator; the hyperbranched unsaturated polyester is obtained by sequentially grafting pentaerythritol serving as a central monomer with bis (hydroxymethyl) propionic acid serving as a branched monomer and lauric acid for low viscosity and carrying out end-capping modification with acrylic acid. The mechanical property and the water resistance of the isophthalic resin are optimized through the compounding and preparation steps of the isophthalic resin raw materials; the hyperbranched unsaturated polyester and the isophthalic resin have good compatibility in compounding, the viscosity of the raw materials is adjusted, and the mechanical property and the heat resistance of the product are further optimized after crosslinking.

This application relates to the field of feed processing technology and discloses a highly absorbable feed composition for nursery pigs containing compound probiotics. The composition includes the following ingredients: a basal diet, a live bacteria compound powder composed of freeze-dried *Lactobacillus plantarum* powder and freeze-dried *Bacillus coagulans* powder, medium-chain triglycerides, a PIT-responsive compound emulsifier composed of polysorbate-80 and sorbitan monooleate, anhydrous trehalose, glycerol, a micron-sized confinement carrier, which is a porous carrier obtained by high-temperature expansion and vacuum degassing of perlite powder, and fumaric acid. This invention employs anhydrous trehalose and glycerol to construct a high-permeability system, combined with medium-chain triglycerides and a compound emulsifier to form an oil-phase encapsulation, achieving the technical effect of effectively blocking external moisture penetration and improving the heat resistance of the bacteria.

The invention discloses a eutectic of a compound as shown in a formula (I) and fumaric acid, a pharmaceutical composition and application of the eutectic. Specifically, the invention discloses a eutectic formed by a compound shown as a formula (I) and fumaric acid in a molar ratio of 1: 0.4-0.6, and the structure of the eutectic is shown as a formula (II), the invention also relates to a preparation method of the eutecticum of the compound as shown in the formula (I) and fumaric acid.

The invention discloses vonoprazan fumarate, intragastric retention tablets of the vonoprazan fumarate and application of the vonoprazan fumarate to gastrointestinal tracts, and relates to the technical field of medicines.The vonoprazan fumarate is prepared through a synthesis method comprising the following steps that in the presence of an organic solvent and alkali, 5-(2-fluorophenyl) pyrrole-3-formaldehyde and pyridine-3-sulfonyl chloride are subjected to a reaction, and the vonoprazan fumarate is obtained. Hydroxypropyl-beta-cyclodextrin is added into a reaction system, and a compound WNLZ-1 is generated; reacting the compound WNLZ-1 with methylamine, and then reducing to obtain a compound WNLZ-3; the compound WNLZ-3 and fumaric acid are subjected to a salt forming reaction, and vonoprazan fumarate is obtained. According to the preparation method, hydroxypropyl-beta-cyclodextrin is introduced as a reaction accelerant in the synthesis step, the yield and purity of an intermediate are improved, meanwhile, hydroxypropyl-beta-cyclodextrin and xanthan gum are jointly used in the preparation, and the whole process optimization from raw material medicine synthesis to preparation performance is achieved.

The invention relates to the field of chemical raw materials, in particular to an organic acid salt of nicotinamide ribose, a crystal form and a preparation method thereof. The invention discloses an organic acid salt of nicotinamide ribose, and in the organic acid salt of nicotinamide ribose, organic acid is selected from acetic acid, citric acid or fumaric acid; the molar ratio of the nicotinamide ribose to the organic acid is 1: (1-1.5). The invention also discloses a preparation method of the organic acid salt of nicotinamide ribose. The invention also discloses a crystal form A and a crystal form B of the nicotinamide ribose hydrogen fumarate. The nicotinamide ribose hydrogen fumarate in two crystal forms is good in flowability, low in hygroscopicity, good in stability, free of color change, capable of keeping a solid form, low in effective concentration, capable of reducing the use cost, more suitable for batch production and wider in application scene.

The application relates to the field of pharmaceutical chemistry and provides a preparation method of a key intermediate of fumaric acid vorolanib. The method is to prepare the key intermediate 5-(2-fluorophenyl)-1H-pyrrole-3-formaldehyde from 5-(2-fluorophenyl)-1H-pyrrole-3-formaldehyde through two-step procedures, the key intermediate of fumaric acid vorolanib is prepared through an economic, green and safe method, the operation is simple, the condition is mild, and the product can be obtained at a high yield and high purity.

The invention discloses a rapid hemostatic material, and belongs to the technical field of hemostatic materials, and the hemostatic material has low toxicity, low heat release and structural stability. The hemostatic material comprises a metal organic framework material or a mixture of a plurality of metal organic framework materials; the metal organic framework material is obtained by coordination of metal aluminum ions and organic ligands, and the organic ligands are selected from one or more of phthalic acid, isophthalic acid, trimesic acid, fumaric acid and other substances and derivatives thereof. Compared with a zeolite hemostatic material, the hemostatic material disclosed by the invention has the advantages of high hemostatic speed, mild hemostatic reaction and less heat release; compared with other metal organic framework hemostatic materials, the hemostatic material disclosed by the invention has the characteristics of high structural stability and high biocompatibility.

The application discloses a microbial fermentation process for improving coffee fruit acid flavor and belongs to the technical field of coffee processing. The coffee fermentation process is scientific and reasonable to improve the fruit acid flavor of roasted coffee by additionally adding screened strains under the condition of reserving original bacteria of coffee. The fermentation can improve the organic acid content of roasted coffee, wherein the content of citric acid is 8861.58 mu / g, the content of quinic acid is 9291.51 mu / g, the content of maleic acid is 204.32 mu / g, the content of fumaric acid is 190.23 mu / g, the content of succinic acid is 150.69 mu / g, and the content of nicotinic acid is 50.89 mu / g. The coffee fermentation process can improve the coffee bitterness and quality, and the total score of coffee reaches the level of high-quality coffee.

The invention relates to the field of battery materials, in particular to a binder and a preparation method thereof, a negative plate and a lithium ion battery. According to the preparation method of the adhesive provided by the invention, a monomer 1 (an itaconic acid-based monomer and / or a fumaric acid-based monomer) is adopted as a main flexible monomer and is copolymerized with conjugated diene, a monomer 2 (a carboxylic acid-based monomer shown in a formula (2)) and a cross-linking monomer, and meanwhile, an amino polyoxyethylene ether nonionic emulsifier is introduced, so that the adhesive is prepared. And by means of a pre-emulsification process, monomer ratio regulation and control, pre-lithiation realized by using lithium alkali in the later stage and the like, a low swelling rate is realized, so that the bonding strength of the material and high conductivity of electrode electrons and ions are ensured, and excellent low-temperature performance is also realized.

This invention belongs to the field of pharmaceutical crystallization technology, specifically relating to a crystallization process for small-particle-size azithromycin fumarate with low solvent residue. In existing processes, azithromycin fumarate crystallizes in alcohol solvents, often resulting in residual ethanol. This invention provides a crystallization process for azithromycin fumarate by adding a portion of fumaric acid to azithromycin, then adding azithromycin fumarate seed crystals, inducing crystallization through ultrasonication, continuing to add fumaric acid, and then concentrating under reduced pressure for isothermal crystal growth. The azithromycin fumarate crystals prepared by this method have a particle size distribution range of 15-30 μm, and the ethanol residue is reduced to below 0.5%, allowing for direct use in pharmaceutical preparations without further purification. This results in a high-quality, economically viable active pharmaceutical ingredient.

By using a resin composition having excellent retardation properties and transparency, a film having excellent adhesion to a substrate is provided. [Solution] A resin composition containing 80.0 to 99.9 wt % of a fumaric acid ester-based polymer containing a fumaric acid diester residue and 0.1 to 20.0 wt % of an aromatic hydrocarbon resin having a weight-average molecular weight of 5,000 or less and containing a residue unit represented by the following general formula (2): JPEG2026043089000008.jpg4769 (wherein, each R3 independently represents hydrogen or an alkyl group having 1 to 12 carbon atoms, and R4 represents hydrogen or a methyl group).

The invention relates to the technical field of medicines, and particularly discloses a polypeptide Loni-P extracted from traditional Chinese medicine honeysuckle, and the amino acid sequence of the polypeptide Loni-P is SEQ ID No.1. The polypeptide can be prepared from honeysuckle through the steps of ultrasonication, enzymolysis, purification and the like. Experiments show that the inhibition rate of Loni-P to malassezia under the concentration of 2 mu g / mL reaches 86 + / -5.29%, which is similar to that of positive control ketoconazole (92 + / -9.17%). The invention further provides a medicated bath component containing Loni-P. The medicated bath component is composed of polypeptide, beta-cyclodextrin, chitosan, fumaric acid, sodium hydroxide and other auxiliary materials and is matched with 200 L of medicated bath water. Clinical experiments show that the medicated bath can remarkably relieve itching, skin lesion area and shape of a chronic eczema patient, and after 30 days of treatment, the score of an experimental group is reduced from 7.93 to 4.0 (a control group has no remarkable change). The polypeptide is natural in source and high in safety, and a new strategy is provided for eczema treatment.

This invention relates to a catalyst for degrading polysaccharides, its preparation method, and its application, belonging to the field of polysaccharide degradation technology. The invention provides a method for preparing a catalyst for degrading polysaccharides, comprising: weighing fumaric acid and hydrogen peroxide, mixing them, and preparing the catalyst. The molar ratio of fumaric acid to hydrogen peroxide is 0.5–2:0.5–2. The invention also provides a catalyst for degrading polysaccharides, obtained by the above preparation method. The catalyst prepared by this invention using fumaric acid and hydrogen peroxide for the degradation of galactomannan can improve the polysaccharide degradation efficiency, resulting in high yields of low molecular weight galactomannan and galactomannan oligosaccharides, thus increasing productivity.

The invention discloses application of aloe polysaccharide to improvement of solubility and storage stability of insoluble substances. The aloe polysaccharide can be used as a solubilizer of insoluble substances, and the preparation method of the aloe polysaccharide comprises the following steps: removing two ends of fresh aloe barbadensis leaves, and soaking the fresh aloe barbadensis leaves in pure water for 1-2 days; washing with water and removing skin to obtain aloe gel to be ground; the aloe gel to be ground is ground, and aloe polysaccharide feed liquid is obtained; and putting the aloe polysaccharide feed liquid into a stirring tank, stirring at 4-15 DEG C, carrying out light treatment for at least 24 hours, and then collecting the aloe polysaccharide pervaporation membrane on the surface of the liquid in a high-temperature membrane forming tank at 75-95 DEG C, thereby obtaining the aloe polysaccharide pervaporation membrane. According to the present invention, the aloe polysaccharide pervaporation membrane can be used for improving the solubility and the stability of the insoluble substance (such as fumaric acid) at the normal temperature so as to avoid the storage precipitation;

The present invention provides a dispersant for hydraulic compositions that exhibits high dispersibility and can reduce the viscosity of hydraulic compositions. [Solution] A dispersant for hydraulic compositions comprising a polymer (P) having a constituent unit (1) formed from a compound represented by general formula (1), and a constituent unit (2) formed from a compound containing at least one selected from acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, and salts thereof, and an ether compound (A) which is a compound obtained by adding 1 to 500 moles of alkylene oxide having 2 to 4 carbon atoms to 1 mole of a 1 to 4 valent aliphatic alcohol having 2 to 24 carbon atoms, wherein the mass average molecular weight of the polymer (P) is 5,000 to 5,000,000, and the mass ratio value (A / P) of the ether compound (A) to the polymer (P) is greater than 0 and 0.25 or less.

The invention discloses a high-purity DL-malic acid production method, which belongs to the technical field of DL-malic acid purification, and comprises the following steps: carrying out high-temperature and high-pressure hydration reaction on maleic acid, fumaric acid and water to obtain a DL-malic acid reaction solution; carrying out first cooling crystallization and then carrying out first solid-liquid separation to obtain first reaction mother liquor and wet solid-phase fumaric acid; adding an isomerization catalyst, carrying out an isomerization reaction, and converting residual fumaric acid in the first reaction mother liquor into maleic acid to obtain an isomerization reaction solution; sequentially carrying out filtration, ion exchange, decolorization treatment, vacuum concentration and secondary cooling crystallization, and then carrying out secondary solid-liquid separation to obtain a second reaction mother liquor and a DL-malic acid wet solid phase; and washing and drying to obtain a finished product DL-malic acid. According to the high-purity DL-malic acid production method provided by the invention, maleic acid and fumaric acid can be removed to obtain a high-purity DL-malic acid product, and the application of the DL-malic acid in high-standard strict-requirement industries such as food and medicine is met.