838 results about "De esterification" patented technology

The invention belongs to antibacterial materials, and particularly relates to antibacterial modified waterborne polyurethane and a preparation method and application thereof.The preparation method of the antibacterial modified waterborne polyurethane comprises the following steps that polyol and diisocyanate are mixed and subjected to a prepolymerization reaction, and a polyurethane prepolymer is obtained; mixing the polyurethane prepolymer and a chain extender, and carrying out chain extension reaction; in the chain extension reaction, adding the graft and carrying out esterification reaction to obtain a first intermediate; mixing the first intermediate with triethylamine and carrying out neutralization reaction to obtain a second intermediate; and emulsifying the second intermediate in deionized water to obtain the antibacterial modified waterborne polyurethane. Compared with the prior art, the antibacterial waterborne polyurethane has the advantages that the problems of poor intermiscibility, low durability and the like in physical addition and the problems of limited binding objects and weak antibacterial effect in covalent binding in the antibacterial waterborne polyurethane in the prior art are solved. According to the scheme, arginine and chitosan are grafted to a molecular chain of waterborne polyurethane, so that the waterborne polyurethane is endowed with a synergistic antibacterial property.

The invention provides a bio-based 1, 4-butanediol composition as well as a preparation method and application thereof, and the bio-based 1, 4-butanediol composition comprises bio-based 1, 4-butanediol, 4-hydroxybutyric acid-(4-hydroxyl) butyl ester and bis (4-hydroxyl) dibutyl ether. The total mass content of 4-hydroxybutyric acid-(4-hydroxyl) butyl ester and bis (4-hydroxyl) dibutyl ether in the bio-based 1, 4-butanediol composition is 51 to 220 ppm. The bio-based 1, 4-butanediol composition has low hygroscopicity, and can maintain low water content after long-term storage; meanwhile, when the bio-based 1, 4-butanediol composition is used for polyester synthesis, the esterification time can be shortened, the reaction efficiency can be improved, side reactions can be reduced, and a polyester product with better damp-heat resistance stability can be obtained.

The invention belongs to the technical field of grease preparation, and particularly relates to a preparation method and application of diglyceride oil with a weight reducing effect. Comprising the following steps: firstly, adding grease into a basic nutrient solution, adding strains for fermentation, and filtering to obtain a glycolysis product; adding glycerol into the glycolysis product, carrying out lipase esterification reaction, and carrying out centrifugal separation to obtain an oil phase; the method comprises the following steps: degrading triglyceride by adopting dominant strain fermentation, then adding glycerol, and carrying out esterification reaction under the action of dominant compound lipase to obtain the diglyceride oil. According to the method, the 1, 3-diglyceride can be selectively generated, the proportion of dominant grease of the 1, 3-diglyceride can be increased, and research shows that the prepared diglyceride oil has good weight reduction and fat reduction effects and has a good application prospect.

The invention relates to the field of medicines, foods or health-care products, in particular to big-fruit hawthorn heteropolysaccharide as well as a preparation method and application thereof. The large-fruit hawthorn heteropolysaccharide is prepared from galacturonic acid, glucuronic acid, mannose, xylose, arabinose, glucose, galactose, fucose and rhamnose. The weight-average molecular weight of the big fruit hawthorn heteropolysaccharide is 81.6 kDa to 157.3 kDa. The product has unique structures of complex monosaccharide composition, low molecular weight, appropriate uronic acid content, low esterification degree and the like; compared with CP which is single in structure and high in esterification, the CP is better in oxidation resistance and bile acid binding capacity; compared with hawthorn polysaccharide with low uronic acid content and high molecular weight, the hawthorn polysaccharide has the advantages that the enzyme inhibition activity is obviously enhanced, and the hawthorn polysaccharide has a wide prospect in development of functional food, health care products or medicines for regulating blood sugar / blood fat, resisting oxidation and preventing metabolic syndromes.

The invention relates to the technical field of polymer compositions, and particularly discloses a degradable bio-based food packaging material and a preparation method thereof.The degradable bio-based food packaging material is prepared from polylactic acid, ITA esterified bacterial cellulose, CSL-ITA esterified bacterial cellulose, polycaprolactone glycol, acetyl tributyl citrate, a photoinitiator and tocopherol; the preparation method comprises the following steps: esterifying bacterial cellulose hydrogel with itaconic anhydride, grafting with sodium copper chlorophyllin, dehydrating with gradient ethanol, and drying with supercritical CO2 to obtain modified powder; according to the preparation method, the interfacial compatibility of the bacterial cellulose and the polylactic acid is enhanced through ITA esterification, the illumination antibacterial function is given by utilizing CSL grafting, the polycaprolactone glycol and the acetyl tributyl citrate are synergistically used for toughening and improving the brittleness, the photoinitiator is added, the photoinitiator is added for mixing, and ultraviolet crosslinking curing is performed after film forming. The tocopherol protects the stability of the antibacterial structure of the CSL, the water resistance is improved through photo-crosslinking, and the material is degradable and meets the food packaging requirement.

The invention provides a method for preparing diglyceride oil by a solventless enzymatic method, which comprises the following steps: S1, mixing saturated fatty acid A and saturated fatty acid B to prepare a liquid eutectic mixture; s2, mixing the eutectic mixture, glycerol and lipase in a reaction system, and carrying out esterification reaction to obtain diglyceride; s3, separating the prepared diglyceride, adding the saturated fatty acid A and / or the saturated fatty acid B into the reaction system again to form a liquid eutectic mixture again, and repeating the step 2; wherein in the step S1, the saturated fatty acid A and the saturated fatty acid B are selected from C10-C20 alkanoic acid, in the step S2, the mass ratio of the eutectic mixture to the glycerol is 1: (1-5), and the temperature of the esterification reaction is 35-78 DEG C. The method solves the problem that the high-melting-point saturated fatty acid is difficult to utilize in the existing technology for preparing the diglyceride oil by the solvent-free enzymatic method.

The invention relates to the technical field of corrosion inhibitors, and discloses a preparation method of a modified imidazoline corrosion inhibitor, which comprises the following steps: carrying out quaternization reaction on tertiary amine group in an imidazoline intermediate and chlorine in benzyl chloride to generate quaternary ammonium salt, introducing hydroxyl, and continuing to carry out esterification reaction with boric acid group in 4-aminophenylboronic acid to obtain the modified imidazoline corrosion inhibitor. The modified imidazoline corrosion inhibitor is prepared by the following steps of: firstly, introducing amino groups, then carrying out amidation reaction with acyl chloride groups in 4-vinyl benzoyl chloride, introducing alkenyl groups, and finally carrying out click reaction with sulfydryl groups in DSB-TA, so as to generate the modified imidazoline corrosion inhibitor. The modified imidazoline corrosion inhibitor disclosed by the invention has a relatively good corrosion inhibition effect.

The invention discloses a functional intermediate for polycarboxylic acid synthesis modification and a preparation process thereof, the intermediate is a copolymer containing a phosphate group, an acrylate group and a hyperbranched polyether polyol chain segment, the molar ratio of all structural units is 1: (1-3): (0.5-2), and the preparation method comprises the following steps: esterification reaction; carrying out phosphorylation reaction; and carrying out gradient vacuum to remove small molecules. The intermediate is high in content of effective components, the viscosity is 500-2000mPa. S, the dispersing performance and the slump loss resistance of the polycarboxylate superplasticizer are remarkably improved through the synergistic effect of phosphate tackifying, acrylate dispersing and hyperbranched compatibilizing, the intermediate is particularly suitable for concrete construction under complex gravel geological conditions, the doping amount is reduced compared with that of traditional hydroxyethyl acrylate, and the service life of the polycarboxylate superplasticizer is prolonged. And the slump of the mother liquor can be kept lossless for a long time.

The invention discloses diglyceride prepared by an enzymic method as well as a preparation method and application thereof, and belongs to the technical field of deep processing of grease. The method comprises the following steps: adding fatty acid into a choline chloride-glycerol-urea ternary eutectic solvent, uniformly mixing, and then adding candida antarctica lipase B for esterification reaction to obtain a reaction mixture; separating the reaction mixture, and recovering an upper-layer oil phase; and separating and purifying the upper-layer oil phase to obtain the diglyceride. According to the method, the reaction rate is high, the selectivity of the diglyceride in the esterification process is high, the yield of the diglyceride can reach 65% or above by reacting for 1 h, the selectivity of the diglyceride is 75% or above, and the purity of the separated and purified diglyceride is 90% or above; in addition, the method is simple to operate, and the reaction product and the eutectic solvent can be separated through simple centrifugation after the reaction is finished; in addition, the monoglyceride content in the product is low, and the subsequent separation and purification difficulty is greatly reduced.

The utility model belongs to the technical field of ethylene glycol preparation, and particularly relates to an esterification purge gas treatment device in a process of preparing ethylene glycol from synthesis gas, which comprises an MN recovery tower, a gas mixer, a tail gas heater, a tail gas reactor, a cooler and a tail gas absorption tower, tower top outlet gas of the MN recovery tower and purge gas from PSA desorption gas of a hydrogenation unit enter a gas mixer, are mixed in the gas mixer, then enter a tail gas heater to be heated and then enter a tail gas reactor to react, an outlet of the tail gas reactor is connected with an inlet of a cooler, an outlet of the cooler is connected with a tail gas absorption tower, and an outlet of the tail gas absorption tower is connected with an outlet of the MN recovery tower. The tail gas absorption tower is connected with a spray water inlet pipe and a waste gas discharge pipe; and the tail gas reactor is a fixed tubular reactor. According to the device, nitrogen oxide which cannot be directly discharged in esterification purge gas can react to generate harmless gas such as nitrogen and nitrogen dioxide, environmental pollution is avoided, the device can adapt to the shutdown working condition of an esterification system, air does not need to be supplemented to the MN recovery tower, and the technological operation risk is reduced.

The invention belongs to the technical field of organic synthesis, and provides a preparation method of a cationic lipid compound, which comprises the following steps: (1) reacting 1, 5-dihalopentane, 2-tert-butyl glycolate and alkali to obtain a product G; (2) hydrolyzing the product G under an acidic condition to obtain a product H; (3) carrying out esterification reaction on the product H, the raw material C, 4-dimethylaminopyridine and a condensing agent in dichloromethane to obtain a product J; and (4) carrying out amination reaction on the product J, the raw material L and alkali in acetonitrile to obtain the cationic lipid compound. Compared with the prior art, the method has the relatively remarkable advantages that when the first part of halogenated long-chain alkyl ester H is synthesized by the method, 1, 5-dihalopentane and 2-tert-butyl glycolate are used as raw materials, the halogenated long-chain alkyl ester J is synthesized by a simple method, the product is obtained at a higher yield in synthesis, and the method is suitable for kilogram-level production. The route synthesis only comprises four steps of chemical reactions, and is suitable for industrial production.

The invention relates to the technical field of organic synthesis, and particularly discloses a synthesis method of bis-diglycerol polyacyl adipate-2, which comprises the following synthesis steps: S1, stirring and mixing isostearic acid, caprylic capric acid, stearic acid and 12-hydroxystearic acid to obtain total fatty acid; s2, stirring and mixing dipolyglycerol, adipic acid, total fatty acid and an organic tin catalyst, and starting to heat; s3, the initial reaction temperature is controlled to be 140-150 DEG C, the reaction vacuum degree is 0.04 MPa, the heating rate is controlled to be 2-10 DEG C / h in the reaction process, the temperature is increased to 190-210 DEG C, then the reaction vacuum degree is converted into 0.1 MPa, and the heat preservation reaction is conducted for 4-10 h; after the reaction is completed, sampling and measuring an acid value; and S4, after the acid value reaches the standard, carrying out heat preservation reaction for 2-5 hours under a high-vacuum condition, cooling, and filtering to obtain the product. The organic tin catalyst is used, the esterification period is shortened, the conversion rate is increased, and the production cost is reduced.

The invention discloses a bio-based recoverable high-thermal-conductivity dynamic ordered network composite material and a preparation method thereof, and is characterized in that the material takes a bio-based multifunctional epoxy system and a carboxylic acid compound containing disulfide bonds as reaction monomers, and the reaction monomers are reacted under the conditions of high temperature and metal salt catalyzed epoxy-carboxylic acid esterification reaction to obtain the bio-based recoverable high-thermal-conductivity dynamic ordered network composite material. A dynamic ordered network structure simultaneously containing disulfide bonds and beta-hydroxyl ester bonds is constructed, and the dynamic ordered network can be used as a springboard for phonon transmission, serves as an efficient'thermal bridge ', and plays a role similar to an ordered'crystal domain', so that higher heat-conducting property is shown when heat-conducting filler is not introduced, high flexibility and intrinsic heat conduction are realized, and the service life of the material is prolonged. And the material is endowed with reprocessing and recycling characteristics. Due to the synergistic existence of carboxyl, hydroxyl generated by epoxy ring opening and metal coordination in the system, and in combination with electrostatic interaction, Van der Waals force and hydrophobic interaction, the material has the adhesion characteristic suitable for a thermal interface at the same time.

The invention relates to a synthetic method of a refined dimethenamid intermediate, which comprises the following steps: adding methanol and L-alanine into a reaction flask, starting to heat, dropwise adding an esterification reagent at a certain temperature while keeping the temperature, reacting at the same temperature while keeping the temperature after dropwise adding is finished, and after the reaction is finished, carrying out post-treatment to obtain a crude product of (S)-2-amino methyl propionate; adding a solvent and a first reducing agent into the reaction flask, dropwise adding the (S)-2-methyl aminopropionate crude product and a second reducing agent at low temperature, and after dropwise adding, carrying out heat preservation reaction for a period of time at the same temperature; and raising the reaction temperature, carrying out high-temperature heat-preservation reaction for a period of time, and carrying out post-treatment to obtain the refined dimethenamid intermediate (S)-(+)-1-methoxy-2-propylamine. When the method is used for preparation, the product can be obtained only by esterifying and reducing the raw materials, the steps are simple, the raw materials are cheap and easy to obtain, and the yield is greater than 90%.

The invention discloses a preparation method of linolenic acid structural ester with synergistic biological activity, and relates to the technical field of linolenic acid structural ester preparation.The preparation method comprises the steps that specific lipase is prepared through rhizopus wei, and after an SBA-15 molecular sieve is treated, the lipase is fixed to prepare a composite catalyst; the preparation method comprises the following steps: after hydroxyl protection of quercetin, esterifying quercetin with EPA to obtain quercetin-EPA ester; esterifying glycerol and linolenic acid in the presence of a composite catalyst and microwaves, and purifying to obtain an intermediate product; carrying out microwave catalytic ester exchange on the intermediate product and quercetin-EPA ester in tert-butyl alcohol through a composite catalyst to obtain a crude product; and removing impurities from the crude product by a urea adduction method, and carrying out molecular distillation graded purification, column chromatography, deodorization and filtration to obtain a final product. According to the invention, linolenic acid, quercetin and EPA are combined through molecular design to form a compound structure ester with a multi-target effect, and the linolenic acid, quercetin and EPA achieve functional complementation through a synergistic effect, so that the biological activity of the compound structure ester is enhanced.

The invention provides a molecular modification design method for improving esterification activity of lipase. The method comprises the following steps: calculating a channel structure of lipase to be modified through CAVER ANALYST 2.0, determining a modification site through comprehensive measurement of other calculation tools, establishing a mutant library by adopting NNK degenerate codons for site-saturated mutation, and screening out excellent mutants with improved esterification performance by adopting a microwell plate screening method based on a copper soap complexing method. According to the candida antarctica lipase B mutant M5 disclosed by the invention, in various different types of esterification reactions, the catalytic efficiency of the mutant M5 is improved by 4.5 times or more than that of a wild type. The molecular modification design method disclosed by the invention can be used for improving the esterification performance of the lipase and has relatively wide esterification reaction application applicability, so that the lipase mutant can play an important role in industrial application in the fields of foods, medicines or biodiesel and the like.

The invention relates to a preparation method of (S, S)-2, 8-diazabicyclo [4, 3, 0] nonane and an intermediate of the (S, S)-2, 8-diazabicyclo [4, 3, 0] nonane. Specifically, the invention discloses a method for preparing (S, S)-2, 8-diazabicyclo [4, 3, 0] nonane from a cheap raw material 2-chloronicotinic acid through an esterification reaction, a substitution reaction, a reduction reaction and an asymmetric hydrogenation reaction, and the method is novel in route, simple to operate, high in product yield, good in purity, safe, environment-friendly and very suitable for industrial production.

The invention provides a preparation method of dehydronandrolone acetate, and relates to the technical field of medicine synthesis. The dehydronandrolone acetate is prepared by carrying out oxidation reaction on etherates; wherein the preparation of the etherate comprises the following steps: step 1, carrying out esterification reaction on nandrolone to obtain an ester; and 2, carrying out an etherification reaction on the esterified product obtained in the step 1 to obtain an etherified product. According to the method for preparing the dehydronandrolone acetate, the dehydrogenation reaction can be completed at normal temperature, and compared with the prior art, the energy consumption and the operation complexity are remarkably reduced. The method disclosed by the invention is safe and environment-friendly, is convenient for recycling, reduces the recycling cost, avoids the problem of generating high-risk nitrosamine genotoxic impurities, and meanwhile, the chloranil is used as the dehydrogenating agent, and the reduction product is easy to recycle and reuse, so that the production cost is further reduced, and the generation of wastes is reduced.

The present invention provides a paroxysmal hemoglobinuria indication drug ipropam key intermediate synthesis method, and relates to the technical field of ipropam, the method comprises: taking p-bromobenzaldehyde as an initial raw material, adopting an S-configuration catalyst to obtain an intermediate 03, carrying out protection group removal on the intermediate 03, carrying out automatic ring closing to obtain an intermediate 04, and carrying out post-treatment to obtain the paroxysmal hemoglobinuria indication drug ipropam key intermediate. Reducing the intermediate 04 with sodium borohydride to obtain a single cis-configuration intermediate 05, then carrying out a chiral flip reaction and hydrolysis to remove p-nitrobenzoic acid, then carrying out an etherification reaction with diethyl sulfate to obtain an intermediate 08, reducing amide of the intermediate 08 with sodium borohydride and boron trifluoride diethyl etherate to obtain an intermediate 09, then carrying out an acetylation reaction to protect amino, and finally carrying out a reaction to obtain the chiral cis-configuration intermediate 03. Cuprous cyanide is subjected to a cyanation reaction and a hydrolytic esterification reaction to obtain the ipropam key intermediate TM. The method is low in raw material price, high in chiral control selectivity, easy in reaction condition control and low in equipment requirement, avoids column chromatography and other operations, and is more suitable for industrial production.

The invention relates to a saccharomycetes strain with high yield of esterifying enzyme and application thereof, the classification name of the saccharomycetes strain is Wickerhamomyces anomalus, the saccharomycetes strain is preserved in China General Microbiological Culture Collection Center on March 21, 2025, the preservation number is CGMCC 33925, and the address of the preservation unit is No.3, Yard 1, Beichen West Road, Chaoyang District, Beijing. The strain screened by the invention has the ability of high yield of esterifying enzyme, and can synchronously catalyze synthesis of a plurality of key esters such as ethyl acetate, ethyl hexanoate, ethyl lactate and the like. Through the synergistic effect of polyesters, the flavor level of the liquor body is richer, and the liquor body is close to the composite aroma characteristic of the traditional solid fen-flavor liquor. The strain is naturally adapted to brewing of fen-flavor liquor and intensified application of medium and low temperature yeast, exogenous enzyme dependence is reduced, and the esterification capacity of yeast is improved.

The invention discloses a method for purifying fructus mali pectin and application of the fructus mali pectin in ulcerative colitis, and belongs to the related technical field of separation and purification of natural product bioactive substances and the field of biological medicine. According to the purification method, impurities in the fructus mali pectin can be effectively removed, meanwhile, the structure of the fructus mali pectin cannot be remarkably changed, and the content of galacturonic acid and the esterification degree of the pectin obtained through purification are high. The fructus mali pure pectin can significantly reduce the serum proinflammatory factor level of DSS-induced ulcerative colitis mice, improve the expression of anti-inflammatory factors, and effectively improve the pathological injury of intestinal tissues. According to the invention, a high-efficiency pectin purification system based on macroporous adsorption resin is constructed, and an industrial solution is provided for separation of natural products; meanwhile, the anti-inflammatory mechanism of the fructus mali pure pectin disclosed by the invention lays a scientific foundation for developing medicines and functional foods for treating ulcerative colon.

The invention relates to the technical field of catalysis, and particularly discloses a method for preparing pure biodiesel from kitchen waste oil through enzyme catalytic desulfurization. The method comprises the following steps: adding a Sm2O3 / ZrO2 solid acid catalyst into the kitchen waste oil for pretreatment to obtain pretreated waste oil, and then adding lipase into the pretreated waste oil for catalyzing transesterification to obtain the biodiesel. According to the method for preparing the pure biodiesel from the kitchen waste oil through enzyme catalytic desulfurization, in-situ esterification and synchronous desulfurization of free fatty acid can be completed in a single-step reaction, the stability of a conversion reaction is effectively improved, the production process is simplified, and the conversion efficiency of preparing the biodiesel from the kitchen waste oil is improved.

The invention belongs to the technical field of sewage biochemical treatment, and particularly relates to an internal circulation anaerobic reaction tower and an esterification wastewater treatment method.The internal circulation anaerobic reaction tower comprises a tower body, a rotary water distributor is arranged at the bottom in the tower body, two three-phase separators are arranged in the tower body in the height direction at intervals, and the two three-phase separators communicate with a gas-liquid separation cavity through ascending pipes; the gas-liquid separation chamber is located at the upper end of the tower body, a gas-liquid separation assembly is arranged in the gas-liquid separation chamber, the gas-liquid separation chamber is communicated with one end of the sinking pipe, the other end of the sinking pipe is located above the rotary water distributor, a gas-liquid mixture enters the gas-liquid separation chamber through the ascending pipe by virtue of the three-phase separator, and granular sludge settles and flows back under the action of gravity; after a gas-liquid mixture is stirred by the gas-liquid separation assembly, gas rises and is discharged out of the system, liquid flows back to the position above the rotary water distributor through the sinking pipe under the action of self gravity, stable internal circulation is formed, efficient backflow of sludge can be achieved without additional power, and the reaction efficiency and the treatment capacity are greatly improved.

The invention discloses application of low-esterification pectin in preparation of intelligent nanoparticles for oral delivery of insulin. The application comprises preparation of pectin with different esterification degrees, subcritical water treatment of pectin and preparation of pectin-based intelligent nanoparticles. According to the invention, through esterification degree regulation and control of pectin, a subcritical water treatment process and use of appropriate auxiliary materials, the embedding efficiency of insulin and the stability of nanoparticles are remarkably improved, the degradation of insulin in a gastrointestinal tract environment is reduced, and the oral bioavailability of drugs is improved.

The invention discloses a chemical-enzymatic coupling synthesis method of oseltamivir phosphate, which comprises the following steps: by taking monasic acid OS-01 as a substrate, sequentially carrying out S1 esterification, S2 ketalation, S3 selective ring opening, S4 TEMPO oxidation, S5 primary transaminase reaction, S6 acetylation, S7 secondary transaminase reaction and S8 phosphorylation reaction to obtain the final product oseltamivir phosphate OS-09. According to the method, the step of sodium azide required by a traditional route is avoided, the production safety and the industrialization possibility are enhanced, two different transaminases are used for respectively constructing different chiral centers, the steps of protecting groups and deprotecting groups on the traditional route are not needed, the overall route is short, the used chemical reagents are few, the yield is high, and the method is suitable for industrial production. The industrial requirements of environmental protection and low cost are met.

The invention discloses a platinum (IV)-pirfenidone compound prodrug, a preparation method and microenvironment remodeling anti-tumor application, and belongs to the field of medical technology and drug synthesis. A series of molecules are characterized by being platinum prodrugs modified by pirfenidone derivatives. The synthesis method sequentially comprises the following steps: oxidizing platinum drugs, modifying hydroxyl groups, and introducing pirfenidone derivatives through esterification reaction. A series of molecules are reduced into Pt (II) drugs at the focus to kill cancer cells, and meanwhile, the released pirfenidone derivative can remodel the tumor microenvironment. The platinum prodrug disclosed by the invention not only has excellent cancer cell killing ability, but also is relatively low in drug resistance and excellent in safety, can trigger immunogenic cell death, and is a brand new chemotherapy-immunotherapy method. A series of molecules are convenient to synthesize, the preparation process is simple, and the amphipathicity is excellent, the anti-cancer capability is excellent, the drug resistance and toxicity are low, and the clinical application prospect is good.

The utility model relates to the technical field of reaction kettles, and particularly discloses a sodium carboxymethyl cellulose esterification synthesis reaction kettle which comprises a reaction kettle body, a heating mechanism is arranged on one side of the reaction kettle body, a stirring mechanism is connected in the reaction kettle body and comprises a stirring shaft, a centrifugal disc is fixedly connected to the upper portion of the stirring shaft, and the centrifugal disc is fixedly connected to the lower portion of the stirring shaft. The heating mechanism comprises a heating box, a water inlet pipe and a water outlet pipe are respectively communicated between the upper part and the lower part of one side of the heating box and the reaction kettle, and a spiral pipe is connected between the water inlet pipe and the water outlet pipe; the spiral pipe is embedded in the reaction kettle, and the cross section of the spiral pipe is flat; according to the reaction kettle, the stirring sufficiency and the heating uniformity of raw materials can be improved, the layering phenomenon of the raw materials during reaction or the local high temperature or low temperature condition in the reaction kettle is avoided, and the reaction effect is ensured.

The invention belongs to the technical field of food functional ingredients, and particularly discloses a preparation method and application of low-ester pectin with a saltiness increasing effect. According to the method, high-esterification-degree citrus pectin is taken as a raw material, a degreasing reaction is optimized by regulating and controlling the concentration of alkali liquor, the reaction temperature, the reaction time and the reaction termination pH value, and dialysis, rotary evaporation and freeze drying processes are combined to prepare the low-ester pectin with a remarkable saltiness increasing effect. The prepared low-ester pectin with the esterification degree lower than 30% adsorbs Na < + > by utilizing enhanced electronegativity to generate a counter ion coagulation effect, and the retention time of Na < + > on the tongue surface is remarkably prolonged, so that the salty taste perception is effectively enhanced, and the purposes of increasing the salty taste and reducing the salt content are achieved. The low-ester pectin can be used as a salty taste enhancer to be added into food to achieve the effects of increasing salty taste and reducing salt, no peculiar smell is introduced, and the low-ester pectin has a potential health effect.

The invention provides a method for regulating and controlling growth and metabolism of caproic acid bacteria by using marine active peptides in a baijiu fermentation process. According to the method, the marine active peptides are added in an anaerobic fermentation stage of baijiu preparation to regulate and control the growth and metabolism of the caproic acid bacteria; wherein the marine active peptide is chlorella pyrenoidosa peptide, schizochytrium limacinum peptide, fish albumin peptide or euphausia superba peptide. According to the method, active peptides with specific sources are added into an anaerobic culture system, so that the growth of caproic acid bacteria can be promoted, energy metabolism can be enhanced, and the activity of key enzymes such as caproic acid dehydrogenase and caproic acid synthase can be activated, and therefore, the generation amount of flavor acids such as caproic acid and butyric acid can be increased, the fermentation quality can be improved, and the flavor level and esterification precursor substance content of Baijiu can be improved.

The utility model discloses an esterification reaction dehydration device for producing an amino acid surfactant. The esterification reaction dehydration device comprises a reaction kettle, a steam pipe, a gas drying chamber, a condensation pipe and a liquid drying chamber with a siphon on the side surface, a steam outlet and a feed port are formed in the top of the reaction kettle, a discharge port is formed in the bottom of the reaction kettle, an inorganic salt dehydration device is fixedly arranged in the reaction kettle, and the steam outlet is connected with a gas inlet of the gas drying chamber through a steam pipe; a gas outlet of the gas drying chamber is connected with a valve interface of the liquid drying chamber; a condenser pipe is arranged at the top of the liquid drying chamber; the siphon inlet is connected with the bottom of the liquid drying chamber; an outlet of the siphon is connected with the reaction kettle; the inorganic salt dewatering device is a heat-resistant pipeline with one end blocked and small holes distributed in the periphery, and water-absorbing inorganic salt is placed in the pipeline after being packaged by a filter bag. The problems that in the prior art, a high-boiling-point toxic dehydrating agent is used, a water segregator is poor in water segregation effect, and the esterification rate is low are solved.