154 results about "Immobilized lipase" patented technology

The invention relates to the technical field of food, in particular to diglyceride for reducing triglyceride, cholesterol and uric acid as well as a biological enzyme preparation method and application of the diglyceride. The preparation method comprises the following steps: (1) adding water and glycerol into vegetable oil, and then adding immobilized lipase to react to obtain a reactant; (2) centrifuging reactants, collecting a light-phase product, carrying out molecular distillation, and collecting a heavy-phase product to obtain diglyceride; the immobilized lipase comprises lipase and a carrier, the carrier comprises loofah sponge, soybean meal and bentonite, and the mass ratio of the loofah sponge to the soybean meal to the bentonite is 1: (2-4): (3-6). The method has the advantages that the effects of reducing triglyceride, total cholesterol and uric acid are relatively good, and the yield and the purity are relatively high.

The invention relates to the field of immobilized enzymes, in particular to immobilized lipase with graft-modified amino resin as a carrier and a preparation method thereof.The method comprises the steps that firstly, the amino resin is modified through the oxidative auto-polymerization characteristic of tannic acid, and first modified amino resin is obtained; and modifying the first modified amino resin by using fatty amine as a hydrophobic modifier to obtain second modified amino resin. Then lipase is fixed on the second modified amino resin through physical adsorption, the lipase is subjected to interfacial activation on an amphiphilic interface on the second modified amino resin, and a part of lipase is covalently bound with quinonyl in an activated state, so that the immobilized lipase with high activity and stability is obtained. The method is easy to operate, green and non-toxic, the prepared immobilized lipase is good in enzyme activity and stability, and the method can be used for preparing the immobilized lipase on a large scale, can be applied to the field of food and has industrial application potential.

The invention discloses a method for preparing immobilized lipase Janus particles by an emulsion template one-step method based on a zymoprotein directional adsorption strategy and application of the immobilized lipase Janus particles in a Pickering emulsion catalytic system. The natural hydrophilicity of lipase protein is utilized to drive the lipase protein to form directional adsorption on the surfaces of hydrophobic particles, and the Janus particles with hydrophilic and hydrophobic characteristics are constructed. Firstly, an organic phase containing hydrophobic particles and a water phase containing lipase are oscillated to form an emulsion, so that the lipase in the water phase is accurately adsorbed on the single side of the surface of the particles, and directional connection of zymoprotein and a hydrophobic matrix is realized. Afterwards, the Janus particles are used for constructing a Pickering emulsion system, and a microreactor is built, so that the catalytic efficiency of lipase in hydrolysis, ester synthesis and transesterification reaction is improved. The method is easy to operate, efficient and stable enzyme immobilization can be achieved, the obtained immobilized lipase Janus particles are remarkably superior to free enzyme in biological catalytic activity and cyclic utilization performance, and the application value of lipase in industrial large-scale production is remarkably improved.

The invention relates to the technical field of immobilized lipase, in particular to immobilized lipase taking modified nano SiO2 as a carrier as well as a preparation method and application of the immobilized lipase. The immobilized lipase sold in the market is high in price and poor in mechanical strength, the enzyme loss is too large due to shear force or carrier structure damage in the continuous production process, and the transesterification efficiency is poor. In order to solve the technical problems, the invention provides the immobilized lipase taking the modified nano SiO2 as the carrier, the immobilized lipase is obtained by sequentially grafting a modified nano silicon dioxide carrier with an amino silane coupling agent and an epoxy silane coupling agent and loading lipase on the surface of the modified nano silicon dioxide carrier, according to the method, the immobilized lipase forms an enzyme column in a chromatographic column and then serves as a reactor, damage of mechanical stirring to lipase particles is avoided, the ester exchange degree is more effectively controlled by adjusting the flow speed of a substrate, the production cost of an enterprise can be remarkably reduced, and the product quality is improved.

The invention discloses immobilized lipase based on bifunctional silicon dioxide as well as a preparation method and application of the immobilized lipase. Hydrophobic modification and covalent modification are performed on the surface of mesoporous silicon dioxide to obtain a bifunctional silicon dioxide carrier; the hydrophobic modification is any one of methylation modification, octylation modification, octadecyl alkylation modification, esterification modification and bromopropylation modification. The dual-functionalized silicon dioxide carrier is used for immobilization of lipase, and the prepared immobilized lipase can be used for production of biodiesel. The immobilized lipase provided by the invention is mild in enzyme reaction condition, good in biocompatibility, relatively high in enzyme activity, and excellent in stability and repeatability. In addition, by changing the ratio of the covalent modifier to the hydrophobic modifier, the catalytic activity and stability of the immobilized enzyme and the biodiesel yield are remarkably improved.

The invention discloses a method for synthesizing ceramide NP through two-step enzyme catalysis, which comprises the following steps of: firstly, adding lipase into vegetable oil to catalyze and combine fatty acid to decompose into free fatty acid, and centrifuging to remove the lipase; a small amount of phytosphingosine is added into the hydrolyzed vegetable oil, the raw material vegetable oil is used as a solvent or a squalane system solvent for incubation, and then immobilized lipase is added for catalytic synthesis of ceramide. The invention establishes a two-enzyme method for efficiently synthesizing the ceramide NP compound, and the process is natural, environment-friendly and non-toxic. The reaction conditions are optimized through response surface analysis, meanwhile, the immobilized lipase shows excellent cycle performance, and the method is easy to operate, environmentally friendly, green and economical and has wide application prospects in the fields of cosmetics, health care products, biological medicine and the like.

The invention discloses potato starch nano-carrier immobilized lipase and a preparation method thereof, and relates to the technical field of biological catalysis. The immobilized lipase comprises a lipase and a carrier, and the lipase is immobilized on the carrier; the carrier is potato starch modified magnetic nanoparticles. The immobilized lipase provided by the invention takes the magnetic potato starch nanoparticles as a carrier and has the advantages of being green and environment-friendly and easily available in materials, and the lipase is successfully immobilized on the magnetic nanoparticles by using the potato starch and the traditional glutaraldehyde as cross-linking agents. The method not only improves the activity and stability of the immobilized enzyme, but also has good biocompatibility and safety. By optimizing parameters such as potato starch dosage, enzyme concentration and immobilization time, the obtained immobilized enzyme shows excellent storage stability and repeated utilization rate. In addition, the method provides reference for preparation of other high-performance immobilized enzymes.

The invention relates to the technical field of shoe materials, in particular to a bio-based EVA-containing composite shoe material and a preparation method thereof, and the bio-based EVA-containing composite shoe material is prepared from the following raw materials in parts by weight: a bio-based EVA polymer, bio-based TPU, a cross-linking agent, a compatilizer, a nucleating agent, filler, a foaming agent, a plasticizer, a flexible component, a biodegradation accelerant, a non-polyolefin elastomer and maleic anhydride grafted polyethylene wax. Wherein the compatilizer can be ethylene-vinyl alcohol and the like; the nucleating agent can be nanoscale talcum powder and the like; the filler can be ethyl cellulose and the like; the foaming agent is an azodicarbonamide foaming agent; the biodegradation accelerant is prepared from immobilized lipase, a tannic acid-Fe < 3 + > complex and surface carboxylated TiO2. The preparation method comprises two steps of mixing granulation and supercritical foaming. The composite shoe material provided by the invention has good biodegradability, can reduce environmental pollution, and maintains excellent physical and mechanical properties at the same time.

The invention discloses a high-activity lipase mutant and application thereof in functional grease synthesis, and belongs to the technical field of enzyme engineering and the technical field of enzyme immobilization. According to the invention, the lipase from Burkholderia B. cepacian OCRI-Lip100 screened in the early stage is truncated and mutated, and the soluble expression efficiency in Escherichia coli is improved by adding a solubilizing tag at the C end, co-expressing with folding enzyme and the like. According to the lipase mutant prepared by immobilization of the DMONs nano material, the half-life period of the obtained immobilized lipase at 60 DEG C is prolonged, the catalytic activity relative to free enzyme is improved, and the lipase mutant has good industrial application potential.

The invention belongs to the technical field of shortening preparation, and particularly relates to shortening base oil with low calorie and high oxidation stability and a preparation method of the shortening base oil. According to the preparation method of the shortening base oil with low calorie and high oxidation stability, provided by the invention, the novel shortening base oil with high oxidation stability, zero trans form, low cholesterol and low calorie is produced by taking palm stearin, cyperus esculentus oil and medium-carbon-chain triacylglycerol oil as raw materials and taking immobilized lipase Lipozyme RMIM as a catalyst; the problems that existing shortening is poor in oxidation stability, high in cholesterol content, excessive in trans-fatty acid content and high in long-carbon-chain saturated fatty acid content can be solved, and the low-calorie high-nutrition high-quality shortening has extremely wide application prospects in the field of preparation of low-calorie high-nutrition high-quality shortening.

The invention relates to a method for enriching EPA (eicosapentaenoic acid) ethyl ester and DHA (docosahexaenoic acid) ethyl ester, and belongs to the field of fish oil refinement, and the method comprises the following steps: taking ethyl ester type fish oil as a raw material, adding alcohol with specific molecular weight and immobilized lipase, carrying out stirring reaction at the temperature of 30-45 DEG C, and regularly detecting the contents of EPA ethyl ester and DHA ethyl ester in the fish oil, when the content of the EPA ethyl ester and the DHA ethyl ester in the total fatty acid ethyl ester is reduced, terminating the reaction, and separating the immobilized lipase; under the vacuum condition, unreacted light component alcohol substances and non-ethyl ester type fish oil ester byproducts are removed through short-path molecular distillation or thin film evaporation. The content of EPA ethyl ester and DHA ethyl ester in the obtained product can reach 85% or above. According to the method disclosed by the invention, a urea adduction method is abandoned, so that not only is environmental pollution caused by use of urea effectively avoided, but also the purity of EPA ethyl ester and DHA ethyl ester can be remarkably improved. And the method has the advantages of low energy consumption and high efficiency, and provides an efficient and green new way for fish oil refining.

The present invention provides an EPA derivative, a preparation method thereof and uses thereof. The EPA derivative is eicosapentaenoic acid-4-benzyloxybenzyl ester. The present invention belongs to the technical field of medicine and provides an EPA derivative with a novel structure. The EPA derivative is eicosapentaenoic acid-4-benzyloxybenzyl ester (abbreviated as EPA-BE), which is prepared by a one-step synthesis from 4-benzyloxybenzyl alcohol and eicosapentaenoic acid under conditions such as immobilized lipase. This derivative improves the bioavailability of EPA and enhances the therapeutic effect on atherosclerotic cardiovascular diseases.

The invention belongs to the technical field of lipase immobilization, and particularly relates to immobilized lipase and a preparation method thereof. The preparation method comprises the following two steps: (I) preparation of activated amino type silica gel resin: mixing amino type silica gel resin, a nonionic surfactant 1308 and deionized water according to a mass ratio of (1000-1100): (2000-2200): (5-8), stirring at 1-5 DEG C for 10-15 minutes, adding cyanuric chloride, dripping a 30-35 wt% sodium hydroxide solution, reacting, and centrifuging; (II) preparation of immobilized lipase: mixing the activated resin, a surfactant, deionized water and a lipase solution, dropwise adding an alkaline solution at 40-45 DEG C under the condition that the pH is 5.0-5.5, and centrifuging, washing and drying after reaction. The obtained immobilized lipase is firm in covalent binding, the enzyme activity is greater than or equal to 50% after the immobilized lipase is repeatedly used for 6 times, the acid-base tolerance and the storage stability are excellent, and the immobilized lipase is suitable for industrial catalysis in multiple industries.

The invention relates to a method for preparing an electrical equipment insulating liquid from waste edible oil methyl ester with an improved pour ignition point characteristic, and belongs to the technical field of insulating liquids. Distilling the waste edible oil methyl ester to obtain distilled waste edible oil methyl ester; the method comprises the following steps: adding a molecular sieve, immobilized lipase IM-100, neopentyl glycol, distilled waste edible oil methyl ester and methyl nonanoate into a reaction vessel, reacting for 72-96 hours under the conditions that the temperature is 40-50 DEG C and the stirring rotating speed is 120-130 rpm, and separating out the molecular sieve and the immobilized lipase IM-100 to obtain waste edible oil-nonanoate neopentyl glycol diester; and carrying out adsorption, vacuum drying and filter membrane filtration on the obtained waste edible oil-nonanoic acid-based neopentyl glycol diester to generate the waste edible oil-nonanoic acid-based neopentyl glycol diester insulating liquid. The obtained waste edible oil-nonanoic acid neopentyl glycol diester insulating liquid has an excellent low-temperature flow characteristic, and the ignition point also reaches the fireproof safety standard of K-grade insulating oil, so that the risk of accidents of power equipment such as a transformer and the like under severe environment conditions is reduced to a great extent; the vacancy of the insulating liquid in high-safety application places such as offshore wind power and the like is supplemented, and more choices are provided for the application of the insulating liquid.

The application discloses a green preparation method of a medium-chain acylated hydroxytyrosol lipoid-triphenylphosphine derivative and application of the derivative in mitochondrial-targeted antioxidation, and relates to the following steps: taking hydroxytyrosol and saturated halogenated fatty acids with medium-chain length C8-C12 as raw materials, and synthesizing a medium-chain hydroxytyrosol lipoid compound through a low-field ultrasonic coupling immobilized lipase synergistic directional alcohol hydroxyl acylation reaction; and further synthesizing the lipoid compound through high-speed stirring reaction with a triphenylphosphine compound to obtain a medium-chain acylated hydroxytyrosol lipoid-triphenylphosphine derivative. The derivative has the antioxidation effect of mitochondrial-targeted enrichment and active oxygen radical scavenging. The hydroxytyrosol derivative prepared by the application has the characteristics of green efficiency, directional bonding and simple operation. The acylation reaction of hydroxytyrosol does not need to involve flammable and explosive, easily oxidized and corrosive concentrated sulfuric acid and concentrated nitric acid, and the medium-chain acylated hydroxytyrosol lipoid-triphenylphosphine derivative has mitochondrial targeting, can be used as a potential mitochondrial nutritional supplement product, and has a wide application prospect in the health care functions of anti-aging, cardiovascular protection, diabetes prevention and the like.

The application discloses a hot air pretreatment method for extracting oat oil and belongs to the technical field of oil extraction. The application solves the technical problems of low extraction efficiency, easy oxidation of oil and large solvent consumption existing in the prior art. The method comprises the following steps: a. oat bran is dried by hot air at 130-150 DEG C for 15-20 min; b. the oat bran is placed in a negative pressure environment, and ethanol vapor flash treatment is performed for 5-15 min; c. the oat bran is mixed with a mixed solvent of petroleum ether and ethanol, immobilized lipase and natural antioxidant are added, and extraction is performed for 8-12 h, and then filtration separation is performed; d. the first residue is mixed with the mixed solvent, extraction is performed for 4-6 h, and then filtration separation is performed; e. the first supernatant and the second supernatant are combined, the solvent is recovered by reduced pressure distillation, and oat crude oil is obtained; and f. the immobilized lipase is recovered. The method is mainly used for efficiently extracting high-quality oat oil from oat bran.

The invention relates to the technical field of pure biodiesel preparation, and particularly discloses a method for continuously preparing pure biodiesel from kitchen waste oil based on immobilized enzyme. The invention discloses a method for continuously preparing pure biodiesel from kitchen waste oil based on immobilized enzyme. The method comprises the following steps: filtering, dehydrating and degumming the kitchen waste oil to obtain pretreated kitchen waste oil; mixing the pretreated kitchen waste oil with an acyl acceptor to obtain a reaction substrate; and feeding the reaction substrate into an enzyme reactor filled with the immobilized lipase catalyst, carrying out transesterification, collecting reaction effluent, and carrying out separation and purification to obtain pure biodiesel. According to the continuous production technology, separation of the catalyst and the reaction substrate is achieved, the catalyst can be recycled, the immobilized lipase catalyst prepared through the covalent binding method has high stability and activity, and the yield of pure biodiesel can still reach 84% or above after continuous operation exceeds 200 hours.

The invention provides a joint production process and application of monoglyceride and diglyceride, and belongs to the technical field of organic synthesis. The joint production process comprises the following steps: (1) dissolving a reaction substrate in a certain volume of solvent, and uniformly mixing to obtain a mixed substrate; (2) transferring the mixed substrate in the step (1) into a packed bed enzyme reactor filled with immobilized lipase, and reacting under a vacuum condition to obtain a reaction product; (3) carrying out molecular distillation on the reaction product in the step (2), and separating to obtain monoglyceride and diglyceride; according to the invention, a mixed solution of tert-butyl alcohol and propylene glycol monomethyl ether is used as a solvent, a mixture of microbial lipase-candida rugosa and commercial immobilized lipase Lipozyme RM IM is used as a lipase system, and the ratio and reaction temperature are controlled, so that the mixed enzyme can show better catalytic efficiency and enzyme stability; and the monoglyceride and diglyceride with high yield and high purity are further obtained.

The invention discloses a method for extracting bioactive substances from sheep placenta, and relates to the technical field of animal placenta extraction. The method uses immobilized lipase to enzymolyze the crushed fresh sheep placenta, then adds protease to continue enzymolysis, and after the enzyme is inactivated, the purified bioactive substances have a high yield; and the immobilized lipase prepared by the chitosan derivative modified by the thiazole group has good application stability; in addition, the present invention also uses S-benzyl-L-cysteine ​​methyl ester hydrochloride to undergo a substitution reaction with a polyamide nanofiltration membrane, and the obtained nanofiltration membrane is used in the purification process of the bioactive substance, which has a good decolorization effect.

The application discloses a preparation method of medium and long chain fatty acid triglyceride, and belongs to the technical field of oil deep processing. Firstly, plant oil and medium chain fatty acid triglyceride are used as substrates, a low eutectic solvent is used as a reaction medium, and an ester exchange reaction is carried out under the catalysis of immobilized lipase; after the reaction is completed, centrifugal treatment is carried out, and the low eutectic solvent, the immobilized lipase and the reaction product are recovered respectively; the recovered low eutectic solvent and the immobilized lipase are used for the next batch of reaction, and the recovered upper oil phase is the reaction product. The application uses immobilized lipase to catalyze ester exchange to prepare medium and long chain fatty acid triglyceride in a low eutectic system, the substrate conversion rate and the product generation amount are high, the product separation is easy, further separation and purification are not needed, the low eutectic solvent is green, environment-friendly and reusable, and the method has good ecological, economic benefits and industrialization application prospects.

The invention belongs to the technical field of fat synthesis, and particularly discloses a method for synthesizing 1, 3-dilinoleic acid-2-palmitic acid triglyceride, which comprises the following steps: S1, dissolving palm stearate in a solvent, and purifying to obtain PPP; s2, mixing the PPP purified in the step S1 with LA, dissolving, and adding immobilized lipase ANL-MARE to carry out primary reaction; after the primary reaction is completed, carrying out acid removal; and then adding LA again to carry out secondary reaction, filtering to remove enzyme after the reaction is completed, and separating and purifying to obtain the LPL structure lipid. According to the method, PPP-rich palm stearin and linoleic acid are used as raw materials, and immobilized lipase is utilized to catalyze two-step acidolysis reaction in a solvent-free system to synthesize the structured triglyceride rich in LPL. Compared with a common one-step acidolysis method, the method has the advantages that the relative content of LPL is increased by 10.27%, the relative content of sn-2PA is kept unchanged, the usage amount of enzyme is effectively reduced, and the LPL efficiently synthesized through enzymatic catalysis of the method has the potential of being used for production of human milk fat substitutes.

The present invention discloses an immobilized lipase and its application in catalytic preparation of monoglyceride and diglyceride. The preparation method of the immobilized lipase comprises the following steps: S1. 3 O 4 The magnetic nanoparticles react with a glutaraldehyde solution to obtain a magnetic nanoparticle composite carrier; S2. The magnetic nanoparticle composite carrier is activated by an activator, and then reacted with a lipase solution and a glutaraldehyde solution to obtain an immobilized lipase. The present invention immobilizes the lipase in the magnetic nanoparticle composite carrier, and the magnetic nanoparticle composite carrier is activated to obtain an immobilized lipase; the immobilized lipase is used to catalyze the reaction of glycerol and triglyceride, and can greatly improve the conversion rate of enzymatic hydrolysis of triglyceride to generate monoglyceride and diglyceride.

The utility model relates to the technical field of enzyme reaction equipment, and provides an enzyme hydrolysis device aiming at the problems of non-uniform mixing and inconvenience in repeated utilization of enzyme in the conventional hydrolysis tank, which comprises a tank body, and the tank body is provided with a sealing cover, a feeding and discharging assembly, a mixing assembly and a heating assembly for enabling the inside of the tank to reach a proper reaction temperature, the sealing cover is movably connected with the top of the tank body; and an enzyme filling assembly comprising a mounting plate and a plurality of enzyme filling columns is arranged in the inner cavity of the tank body. After being conveyed to the inner cavity of the tank body through the feeding and discharging assembly, the waste grease raw material enters the enzyme filling column through the first through hole, the waste grease raw material and immobilized lipase are subjected to full contact reaction through the mixing assembly, and the hydrolysis effect is good; and the immobilized lipase is filled in the enzyme filling column, cannot be discharged along with a product and can be remained in the tank body to continuously participate in the reaction, and when the enzyme activity is reduced, the enzyme filling column can be taken out from the mounting plate by opening the sealing cover, so that the immobilized lipase is convenient to recycle, and the device is economical and practical.

This invention relates to the technical field of imiquimod synthesis, specifically to catalysts, methods, and applications for imiquimod synthesis. The invention employs a lipase-immobilized lipase complex carrier to catalyze a transesterification reaction, using vinyl isobutyrate as the acyl donor and tert-butanol as the solvent. The hydroxyl group of 3-(4-amino-1H-imidazo[4,5-C]quinoline-1-yl)-2-methylpropane-1-ol is converted to an isobutyl side chain. Following enzymatic catalysis and pH adjustment, hydrolysis is performed to release the isobutyl group, further generating imiquimod and isobutyric acid. The lipase selectively catalyzes transesterification, avoiding side reactions, and the ester bond is rapidly hydrolyzed to the target product under acidic conditions.

The invention provides a preparation method of a mesoporous MOFs (Metal-Organic Frameworks) material with water-acid dual stability and application of the mesoporous MOFs material in high-value conversion of grease. The preparation method comprises the following steps: firstly, preparing a mesoporous MOFs material of which the average pore size is greater than 10nm by a lauryl sodium sulfate mediated soft template method, and then dissociating an outer layer by using sodium citrate to increase the outer specific surface area of the outer layer, so as to obtain the mesoporous MOFs material (Meso-MIL-88A) with water-acid dual stability. The adsorption isotherm of the Meso-MIL-88A accords with a Langmuir model, the adsorption of macromolecular lipase belongs to single-molecule adsorption, and the defect that the specific enzyme activity is reduced due to enzyme accumulation caused by the fact that a macroporous material serves as an enzyme immobilization carrier is fundamentally avoided. The Meso-MIL-88A can be used for efficiently immobilizing lipase and synthesizing structural phospholipids, and has a good application prospect in the field of lipase-mediated grease high-valued treatment.

The invention discloses a method for catalytically synthesizing a dabigatran intermediate based on immobilized lipase. The method comprises the following steps: firstly, immobilizing optimized CALB lipase with an amino acid sequence as shown in SEQ ID NO: 2 by taking a dimethyl sulfoxide-resistant carrier comprising silanization modified mesoporous SiO2, polyvinylidene fluoride, polymethyl methacrylate and the like as carriers to obtain immobilized lipase, and then, carrying out a reaction on a compound II serving as a substrate in a DMSO organic phase, so as to obtain the immobilized lipase. The immobilized lipase is utilized to catalyze a compound II and a compound III to perform an addition reaction, and a dabigatran key intermediate compound I is efficiently and highly selectively generated; the immobilized carrier adopted by the invention can effectively tolerate a DMSO solvent, is firm in enzyme binding, can be repeatedly used for more than 10 times, has good activity retention, solves the problem that a biocatalyst is easy to inactivate and difficult to recover in a strong polar solvent, has the advantages of high conversion rate, good stereoselectivity, low production cost and environmental protection, and has a good industrial application prospect.

The invention relates to the technical field of biological catalysis, in particular to cyclodextrin-metal organic framework immobilized lipase, a preparation method and application of the cyclodextrin-metal organic framework immobilized lipase in grease catalysis. The cyclodextrin-metal organic framework immobilized lipase provided by the invention is simple in preparation process and controllable in cost, and has the advantages of high catalytic efficiency, good stability, strong reusability and the like; when the catalyst is applied to a grease catalytic reaction, the reaction condition is mild, the product is easy to separate, and the catalyst can be widely applied to the industrial fields of food processing, biodiesel preparation, fine chemical engineering and the like, and has remarkable economic value and social benefit.

The invention discloses a method for continuously catalyzing grease deacidification, which comprises the following steps: mixing a deep eutectic solvent, crude oil and immobilized lipase, homogenizing into an emulsion, continuously supplementing the crude oil, and carrying out esterification deacidification reaction, the immobilized lipase is obtained by carrying out immobilization by taking silane modified silicon dioxide as a carrier. According to the method, grease deacidification can be continuously catalyzed, the cost of enzymatic deacidification is reduced, the grease yield is increased, better economical efficiency and environmental friendliness are achieved, the industrial application potential is high, and after crude oil is deacidified through the method, the acid value is low, the deacidification rate is high, the neutral oil loss is small, and the oil product stability is good.

The invention relates to a rosin-free depilatory hot wax and a preparation method thereof, and belongs to the technical field of depilatory hot wax. The depilatory hot wax comprises the following raw materials by weight: 30 to 70 parts of wax-based substances, 1 to 5 parts of carboxylated cellulose nanocrystals, 3 to 7 parts of coconut oil-based wax esters, 0.1 to 1 parts of depilatory proteases, 5 to 10 parts of modified polyols, 3 to 5 parts of polyurethane dispersions and 0.3 to 2 parts of colorants; wherein the coconut oil-based wax esters are synthesized from coconut oil, coconut alcohol and immobilized lipase; the modified polyols are synthesized from triglycerides after epoxidation reaction and then hydroxylation reaction. The depilatory hot wax of the invention does not add any additives containing any rosin or rosin derivatives with rosin as raw material, thus avoiding the occurrence of users being allergic to rosin and its derivatives, and has high depilatory efficiency, low drop melting point, can significantly reduce skin pain, and has good film-forming properties and is easy to tear.

The invention relates to the technical field of organic synthesis and biochemical engineering, and discloses a preparation method of 3-o-ethyl ascorbic acid, which comprises the following steps: (1) carrying out pre-acetylation reaction on ascorbic acid and vinyl acetate under the catalysis of lipase to obtain 6-acetyl ascorbic acid; (2) carrying out ethylation reaction on the product in the step (1) and diethyl carbonate by taking ionic liquid as a catalyst; (3) purifying the product by combining supercritical COextraction with membrane filtration; according to the preparation method of the 3-o-ethyl ascorbic acid provided by the invention, the purity and the yield of the product are remarkably improved through a synergistic process of lipase pre-acetylation, ionic liquid catalytic ethylation and supercritical COextraction combined with membrane filtration and purification; 6-hydroxyl of ascorbic acid can be selectively protected. The step utilizes the specific catalysis function of the enzyme to avoid the non-selective reaction of other hydroxyl groups.