1036 results about "Molecular weight cut-off" patented technology

The invention provides methods of removing contaminants from a mixture of a desired product and contaminants by pH adjustments and molecular weight cut-offs. The contaminants include phosphate groups, magnesium sulfate, sodium pyruvate and tetrasodium pyrophosphate groups. The desired product includes nucleotide sugars, glycolipids, LnNT, sialyl lactose, and salts.

The present invention relates to a method of treating anemia especially in an EPO resistant hemodialysis patient, comprising hemodialysis with a high cut-off dialysis membrane, wherein the hemodialysis membrane is characterized in that it has a molecular weight cut-off in water, based on dextran sieving coefficients, of between 90 and 200 kD and a molecular weight retention onset in water, based on dextran sieving coefficients, of between 10 and 20 kD, and a ΔMW of between 90 and 170 kD. The invention further relates to a high cut-off hemodialysis membrane for the treatment of anemia in hemodialysis patients, especially EPO resistant hemodialysis patients.

A method of accurately separating immunoglobulin monomers by subjecting an immunoglobulin solution containing at least immunoglobulin monomers and immunoglobulin aggregates to cross-flow filtration using an ultrafiltration membrane, an ultrafiltration membrane module, and a cross-flow filtration apparatus. The method can separate immunoglobulin monomers by subjecting an immunoglobulin solution containing at least immunoglobulin monomers and immunoglobulin aggregates and having an immunoglobulin concentration of 1 to 150 g/L to cross-flow filtration using an ultrafiltration membrane having a molecular weight cut-off of 100,000 or more and less than 500,000 so that immunoglobulin monomers passes through the ultrafiltration membrane with a permeability of 80% or more while achieving a fractionation performance in which the permeability ratio of immunoglobulin dimers to immunoglobulin monomers that pass through the ultrafiltration membrane is 0.20 or less.

The invention discloses a method for preparing low-voltage high-flux charged nano-filtration membrane by dynamic self-assembly, which is characterized in that polymer ultra-filtration membrane is taken as a basic film; polycation electrolyte and polyanion electrolyte are alternatively and dynamically self-assembled on the surface of the basic film to gain a selective separation layer and to prepare the nano-filtration membrane of charged surface; wherein, the used ultra-filtration membrane molecular weight cutoff is less than 0.1 million; the ultra-filtration membrane material is surface-charged or modified-charged polymer. Nano-filtration membrane preparation by polyelectrolyte dynamic self-assembly has high efficiency, simple and convenient method and controllable assembly process and film structure; pure water solution is used in the whole preparation process, which is green and environmental protective; the applicable polyelectrolyte has a plurality of types; the separation films with different performances can be obtained by adjusting the types of the polyelectrolyte and the assembly conditions. Furthermore, the prepared nano-filtration membrane has low operation pressure, high removal rate on high valence inorganic salts and far greater flux than the current commercial nano-filtration membrane and the nano-filtration membrane preparation method has good application prospect.

The invention provides a process for continuously extracting sweet potato starch, sweet potato protein and dietary fibre from sweet potato specially for processing the sweet potato and belongs to the filed of food biotechnology. The sweet potato is cleaned, is added with a color protective solution, and is pulverized, ground and squeezed in order to separate sweet potato residue and cell sap; a cleaning solution of the sweet potato residue and the cell sap are mixed and are filtered through a standard sieve with 200 meshes; a filtrate is subjected to centrifugal dehydration twice and is dried to obtain starch; after starch milk is separated out, the filtrate is degraded with starch; the filtrate with molecular weight of between 5,000 and 10,000 is intercepted, ultrafiltered, condensed and dried to obtain coarse protein of the sweet potato; and the sweet potato residue is added into a biological reactor, is added with water, protease and amylase for reaction, and is subjected to filter pressing, drying and pulverization to obtain insoluble the dietary fiber of the sweet potato. The method can fully utilize organic compositions in the sweet potato, minimize the generation and emission of organic wastewater and waste residue with high concentration, realize the full-value utilization of the sweet potato, and remarkably improve the economic value of the sweet potato.

The invention provides a preparation method of protein short peptide chelated calcium. The method includes the steps of: refinement treatment and sterilization of mixed raw material containing protein and water, a first hydrolysis by adding proteolytic enzyme, ultrafiltration of the liquid portion separated after the first hydrolysis using a ultrafilter membrane whose retention molecular weight is in the range of 1000-6000 Da, mixing of the macro-molecule peptide liquid which does not permeate the ultrafilter membrane and the solid phase portion separated by the first hydrolysis, a second hydrolysis by adding proteolytic enzyme, purification of micromolecule oligopeptide liquid after twice hydrolysis ultrafiltrations, chelating by adding calcium hydrate or calcium chloride, complete reaction of quantitive sodium carbonate when the pH valve is neutral, filtering for removing deposition, desalination by the nanofiltration membrane, sterilization, condensation and obtaining of the protein short peptide chelated calcium product. The preparation method can substantially improve the protein short peptide obtaining rate and the raw material protein utilization rate, and reduce production cost, so the obtained protein short peptide chelated calcium product has a good quality and high production safety.

The invention provides a preparation method of cyaniding-3-O-glucoside chloride. Specifically, the method comprises the steps of: subjecting purple crops as the raw materials to an extraction with an extract of ethanol water solution with a volume fraction of 30-80% and a pH value of 1-4, leaving the obtained anthocyanidin crude extract to an ultrafiltration treatment through an ultrafilter membrane with a molecular weight cut-off of 1000-5000 D, and freeze drying the filtrate so as to obtain filtrate dry powder with a molecular weight less than 1000-5000 D, preparing a column-loading solution of 0.05-5wt% with the filtrate dry powder and water, purifying the filtrate dry powder preliminarily on a gel chromatographic column, conducting elution and collecting the eluent located at a position of 520nm and with an absorption peak, and reserving fractions containing cyaniding-3-O-glucoside chloride; purifying the fractions containing cyaniding-3-O-glucoside chloride further with preparative HPLC (high performance liquid chromatography), and collecting cyaniding-3-O-glucoside chloride absorption peaks. According to the invention, by improving the conditions and operations of extraction separation and purification, sugar, protein, other types of anthocyanin and flavonoid pigments in extracts can be effectively removed. Meanwhile, with simple steps and safe reagents, the method of the invention is beneficial for obtaining high purity cyaniding-3-O-glucoside chloride products.

The invention discloses a method for preparing a novel biological microcapsule for a biological fluidized bed. The microcapsule is prepared through treating sodium alginate, powdery active carbon, calcium chloride and chitosan as capsule materials, and a dominant degradation bacterium as a capsule core, preparing calcium alginate gel beads through carrying out ion exchange on sodium alginate and calcium chloride, coating the surface of the gel beads with chitosan, liquefying the gel beads in sodium citrate, and coating the gel beads with sodium alginate. The diameter of the prepared microcapsule is 3.0-4.0mm, the membrane thickness of the prepared microcapsule is 10-20mum, the density of the prepared microcapsule is 1.05-1.08g/mL, and the maximum interception molecular weight of the prepared microcapsule is about PEG 4000, so a micromolecular substance with the relative molecular weight of less than PEG 1500 can freely go through the capsule membrane. Acidic conditions and most divalent cations allow the microcapsule to be stable, and monovalent cations and most anions are bad for the stability of the microcapsule.

The invention provides a preparation method and application of a separation film with a nano composite cortical layer. The separation film comprises a non-woven fabric layer, two porous support layers and a desalination layer, and is characterized in that the lower layer of the two porous support layers is a porous body layer containing polymers and/or nano particles, and the upper layer of the two porous support layers is a porous cortical containing polymers and nano particles. The preparation method includes coating the upper layer and the lower layer of the non-woven base material by means of a double-layer coating technology. An ultrafilter support layer of the composite separation film prepared by the preparation method is good in surface evenness, hight water flux is kept in the meantime of keeping higher cutoff rate, and the separation film can be directly used as an ultrafiltration film or can be used as a basic porous support layer to further prepare a composite forward osmosis, reverse osmosis and nanofiltration film. The preparation method can be applied to preparing the reverse osmosis film and the nanofiltration film which are good in performance, and a composite ultrafiltration film with low molecular weight cutoff.

The invention relates to a process of continuous production of casein bioactive peptide by enzymolysis and filtering membrane concentration which comprises, using caseinum as raw material and at least one prolease action, obtaining biologically active polypeptides having multiple functions in multi-stage enzyme membrane reactor combined from enzymolysis tank and hyperfiltration, nano filter membrane of dissimilar entrapment molecular weight.

A process for the preparation of white and brown sugar from raw diffuser beet juice. The juice is purified by membrane filtration at 70-95° C. on a filter having a molecular weight cut-off between 2,000 and 500,000 Dalton and evaporated to a dry matter content of between 60 and 80% by weight under vacuum to a thick juice. A conventional multi-step evaporative crystallisation of the thick juice gives crops of white and brown sugar crystals. The brown sugar obtained have valuable organoleptic properties.

The invention provides a preparation method for a low-toxic fluorescence carbon point. The method comprises the steps as follows: a washed carbon electrode is added into an electrolyte liquid and oxidation is carried out on the carbon electrode by a constant potential electrolytic oxidation method at a more positive potential position; then the carbon electrode after being oxidized is washed by ultra-pure water; the water liquid after washing is collected; the electrolyte liquid and the water liquid after washing are combined and centrifugated for collecting supernatant and removing the deposits; finally the collected supernatant is filtered in sequence by ultrafilter pipes the retained molecular weights of which are respectively 30, 10 and 5kDa; the components with the retained molecular weights of 5-10kDa and less than 5kDa are collected, wherein, the component of the retained molecular weight of 5-10kDa is the carbon point which gives out yellow fluorescence; and the component less than 5kDa is the carbon point which gives out blue fluorescence. The method is simple and easy to carry; the material resources are broad and cheap; and the obtained carbon points do not have cytotoxicity and resist light bleaching.

The invention belongs to technical field of nanomaterials and discloses a method for solvothermal preparation of fluorescent carbon nitride quantum dots by adoption of melamine as a raw material. The method includes steps: a) calcining melamine in a muffle furnace at a high temperature, and grinding products into yellow graphite-phase carbon nitride powder; b) scattering the graphite-phase carbon nitride powder into an alcohol solvent, adding a certain amount of alkali liquor, dissolving ultrasonically, sealing in a reaction kettle, and reacting for a while at a high temperature; c) cooling to the room temperature, collecting filtrate after vacuum filtration, and dialyzing the filtrate in a dialysis bag with a certain molecular weight cutoff until the filtrate is neutral, so that the fluorescent carbon nitride quantum dots are obtained. The method is simple in process, easy in operation, low in cost and environment friendly, and the prepared fluorescent carbon nitride quantum dots are high in purity and yield, excellent in dispersity and stability and high in fluorescence intensity and have a potential application prospect in fields of bioimaging, solar cells and the like.

The invention provides 'high-quality seafood peptide' for preparing a natural peptide-rich flavor enhancer and a preparation method thereof. The preparation method mainly comprises the following steps of: raw material pretreatment; controllable enzymolysis: mixing serum, adding water to regulate the serum till the concentration of the mixed serum is 30 to 50 weight percent, regulating the pH value to between 6.0 and 8.0, adding papain to perform hydrolysis, regulating the pH, heating the mixture, adding composite flavor protease into the mixture, hydrolyzing the mixture, controlling the solid concentration to be between 10 and 15 percent, and inactivating the enzyme after the enzymolysis is finished to obtain a hydrolysis product; centrifuging and filtration; fermentation and fishy smell removal: sterilizing the enzymolysis solution, then cooling the enzymolysis solution to room temperature, inoculating lactic acid bacteria according to the weight of the enzymolysis solution, and fermenting the solution to obtain fermentation solution without fishy smell; ultra-filtration: diluting the fermentation solution till the solid concentration is 2 to 5 percent, and obtaining a short peptide-rich product with a molecular weight of below 6,000Da through an ultra-filtration membrane with a cut-off molecular weight of 6,000Da; concentration; high-pressure homogenization; and spray drying. The prepared flavor enhancer has double effects on flavor and nutrition, and can be widely applied to the food field of condiments, meat products, quick-frozen products, instant noodles, expanding leisure food and the like.

The invention relates to a preparation method of giant salamander skin collagen peptide. The method comprises the steps that degreasing and deodorization are conducted simultaneously on a giant salamander skin, black skin and impure protein are removed through alkali liquor, under the condition that the temperature ranges from 20 DEG C to 25 DEG C and the pressure ranges from 150 MPa to 300 MPa, pressure maintaining is conducted for 10-60 min, pH of the giant salamander skin processed through ultrahigh pressure is regulated to 8-10, alkaline protease with the weight of 2%-3% of the skin is added, at the temperature of 45-50 DEG C, continuous stirring and enzymolysis are conducted for 3-6 hours, the mixture is boiled for 1-2 min and cooled to 40 DEG C, pH of the mixture is regulated to 4-5, activated carbon with the mass of 1% of the mixture is added, and stirring and decoloration are conducted; under the condition that the rotating speed is 3000-4500 r/min, centrifugation is conducted on the processed mixture for 10-15 min, microfiltration through a filter membrane with the thickness of 0.45 micron, ultrafiltration through an ultrafiltration membrane with the molecular weight cut-off of 4-5 kD and nanofiltration through a nanofiltration membrane with the molecular weight cut-off of 2-3 kD are conducted on the mixture in sequence to obtain filter liquor, the filter liquor is concentrated to be one half of an original sample, and the concentrated liquor is freeze-dried and smashed to obtain giant salamander skin collagen powder. According to the preparation method of the giant salamander skin collagen peptide, the molecular weight of the collagen peptide is small, and over 90% of the molecular weight is smaller than 1000 Dalton.

The invention discloses a recovery processing method of protein waste water, belonging to the field of food waste water processing. The processing method is as follows: after early-day preprocessing, protein waste water passes through an ultrafiltration system; after passing through a filtration membrane with different cut-off molecular weight ranges, separated and purified protein is obtained by recovering from concentrated cut-off liquid; ultrafiltration permeate passes through a nanofiltered system or a reverse osmosis system; on one hand, other micromolecule useful substance can be further recovered from the concentrated cut-off liquid, on the other hand, permeate can be directly discharged or serves as process water to be recovered; or preprocessing protein waste water is directly processed by a nanofiltered membrane or a reverse osmosis membrane, and useful substance is recovered. The invention realizes the recycling recovery processing of protein waste water, solves the problems of high treatment cost and environment pollution due to hard processing of protein waste water and has wide adaptability, simple technology, easy operation and low operation cost.

The invention discloses a method for grading the molecular weight of anglerfish skin collagen peptide. The method comprises the following steps: soaking anglerfish skin in dilute alkaline liquid; taking out, then washing with water and draining; performing enzymolysis on the anglerfish skin; after deactivating enzyme, adding active carbon for debitterizing and decoloring; entrapping collagen peptide with the molecular weight being more than 10,000 Daltons from the filtrate obtained after the active carbon is filtered out, by a first-level plate type ultrafiltration membrane; entrapping collagen peptide with the molecular weight being more than 2,000 Daltons by a second-level roll type ultrafiltration membrane; and entrapping collagen peptide with the molecular weight being more than 200 Daltons by a roll type ultrafiltration membrane. According to the method, the anglerfish skin is hydrolyzed by using pepsase and flavourzyme step by step during enzymolysis, and the collagen peptide with the molecular weight in broad distribution is subjected to effective molecular weight grading processing after enzymolysis, so the collagen peptide with different molecular weight segments can be obtained and can be effectively utilized.

The invention discloses a method for recycling active ingredients in the amoxicillin mother liquor synthesized by an enzymatic method. The method includes synthesizing the amoxicillin mother liquor by the enzymatic method; separating the amoxicillin mother liquor through a macro-porous resin column, eluting the separated amoxicillin mother liquor by deionized water, and collecting an eluant rich in D-4-Hydroxyphenylglycine and an eluant rich in 6-amino penicillanic acid (APA) respectively; filtering the eluant rich in D-4-Hydroxyphenylglycine with Daltonian ultrafiltration membranes with a cutoff molecular weight of 150 to 200; performing nanofiltration concentration on the Daltonian ultrafiltration membranes for the filtered liquor with the cutoff molecular weight of 150 to 200, and standing, crystallizing and filtering the concentrated liquor to obtain solids, and drying the solids to obtain the D-4-Hydroxyphenylglycine. According to the method, the technological design is reasonable, the operation is convenient, the recycling effect is good, and energy is saved and the environment is protected.

The invention relates to the field of membrane technology, in particular to a high-temperature-resistant precision molecular weight cut-off ultrafiltration membrane and a preparation method thereof. The composition of raw materials and the definition of parameters in the preparation process of the base film ensure that the performance of the prepared wet base film is stable after the subsequent modification treatment, and can effectively improve its high temperature resistance; at the same time, combined with the modification process The definition of time, temperature and treatment method in the process makes the rejection rate of the ultrafiltration membrane to the molecular weight range of 2000-4000 reach more than 90%, which effectively improves the interception of the ultrafiltration membrane to low molecular weight substances and improves the quality of the filtration product .

The invention provides a method for advanced treatment and reuse of wastewater. The method is characterized in that a biochemical device adopting a biological aerated filter comprises a water inlet pipe, a backwashing water inlet pipe, a backwashing air inlet pipe, an aerator pipe, a backwashing drain pipe, a water outlet pipe, water distributors, supporting fillers, ceramic fillers, a cell body and a filter plate, wherein energy consumption is only 60% of that of a contact oxidation method after secondary wastewater is subjected to biochemical treatment in the biological aerated filter and organic pollutants are removed; a separation device of an ultrafiltration pressing film comprises a biological aerated filter water discharging tank, a lift pump, a safety filter, ultrafiltration films, an ultrafiltration water production pipe and an ultrafiltration concentrated water pipe, wherein the ultrafiltration films can be used for intercepting matters with molecular weights of 3*10000-1*10000 and removing most colloidal silicon and organic matters in the water; and an electric-absorption desalting device comprises an ultrafiltration device water discharging tank, a water supply pump, a filtering device, an electro-adsorption module, a water production pipe, a reuse water tank, a regenerative pump and a regenerative water outlet, wherein raw water lifted by the regenerative pump is flushed by a short-circuited and standing module so as to regenerate an electrode, and a pollution discharge process is a backwashing process of the module.

The invention discloses a purely physical preparation method of vegetal and microbial polysaccharides. The purely physical preparation method comprises the following steps of drying a sample, crushing the dried sample, sieving the sample powder by a sieve of 60 to 80 meshes, uniformly mixing the sample powder and water, pouring the mixture into a high pressure homogenizer, carrying out homogenization under certain pressure, carrying out centrifugation, collecting a supernatant, carrying out separation of the supernatant by an ultrafiltration membrane of which molecular weight cut-off is 2-5 times higher than molecular weight of vegetal or microbial active polysaccharides to obtain a penetrating fluid, carrying out separation of the supernatant by an ultrafiltration membrane of which molecular weight cut-off is 1/5-1/2 of molecular weight of the vegetal or microbial active polysaccharides to obtain a trapped fluid, concentrating the trapped fluid, and carrying out freeze drying to obtain an active polysaccharide sample. The purely physical preparation method has a high polysaccharide extraction ratio, short time consumption, protein-removal effects superior to those of the traditional sevage method, does not utilize any organic reagent in polysaccharide extraction, and has a low production cost and no pollution.

The invention discloses an oyster polysaccharide (alpha-1, 4; 1, 6-gluglucosan and beta-1, 6-gluglucosan with relative molecular weight at 4000-6500Da) and making method and application in the cosmetics, which comprises the following steps: washing Dalian bay oyster or Atlantic oyster through water at 0-10 deg.c; boiling oyster at 70-80 deg.c under 0.3-0.5 Mpa for 20-45min; filtering; collecting supernatant; centrifuging to remove sediment; adjusting pH value of supernatant to 5-6 through acetic acid; acidolyzing for 1-3h; intercepting material with molecular weight less than 30000Da through film separator; adjusting pH value of filtrate over 30000Da to 6-8 through NaOH; centrifuging to remove sediment; dialyzing supernatant in the distilled water; passing tomographic column of Sephadex G-100 molecular sieve; collecting material at adsorbing peak with OD at 280 nm; freezing; drying.