314 results about "Curdlan" patented technology

In order to provide a composition having a long gastroduodenal residence time and exhibiting an improved efficacy, is provided a gastrointestinal mucosa-adherent composition comprising an active ingredient and a material which swells a viscogenic agent capable of being viscous with water a (e.g. curdlan and / or a low-substituted hydroxypropylcellulose etc.).

The invention discloses a preparation method of carboxymethyl curdlan polysaccharide-based colloidal aqueous solution containing nano silver particles in the technical field of biomedicine. The method is implemented by the following technical scheme that: the method comprises the following steps of: mixing aqueous solution of silver nitrate and aqueous solution of carboxymethyl curdlan, wherein the concentration of the silver nitrate is 0.001 to 0.01mol / L, and the concentration of the carboxymethyl curdlan is 0.001 to 0.1g / mL; and performing ultraviolet irradiation to obtain nano silver-containing colloidal aqueous solution with different particle diameter and particle diameter distribution. The process of the method is simple; the raw materials involved in the reaction are environment-friendly and pollution-free, have biocompatibility, and do not need post treatment; and by changing the concentration of the silver nitrate, the concentration of the carboxymethyl curdlan, the molecularweight and the illumination time, the particle diameter and the particle diameter distribution of the nano silver particles are adjusted and controlled, namely the size is adjustable.

The invention discloses a plant starch-chitosan composite packaging film and a preparation method thereof, and relates to the technical field of packaging films. The plant starch-chitosan composite packaging film comprises raw materials in parts by mass as follows: 90-100 parts of plant starch, 50-60 parts of chitosan, 25-30 parts of rhizoma coptidis, 20-25 parts of rosemary, 15-20 parts of konjak powder, 15-18 parts of sodium alginate, 12-15 parts of polyvinyl alcohol, 12-15 parts of epoxidized soybean oil, 10-12 parts of low-methoxy pectin, 8-10 parts of calcium citrate, 8-10 parts of curdlan, 6-9 parts of edible gelatine, 5-8 parts of genipin, 4-6 parts of polyglycerol fatty acid ester, 3-5 parts of edible essence and 1,000-2,000 parts of water. According to the plant starch-chitosan composite packaging film and the preparation method thereof, the plant starch and the chitosan are taken as main raw materials, and the production cost is reduced; various coalescing agents with edible safety and an extracting solution of a Chinese herbal medicine rhizoma coptidis and rosemary are added, so that the prepared packaging film has better physical and mechanical property, barrier property and anti-oxidation function and can be used for packaging various kinds of food.

The invention discloses an edible protein / polysaccharide composite membrane and a preparation method and application thereof.The composite membrane is prepared through the method that a Curdlan solution, a carboxymethyl chitosan solution and plasticizer glycerinum are added into a protein solution including one of soybean protein, casein and whey protein, the pH value of the mixed liquid is adjusted to be 5-8; ultrasonic degassing is conducted, MTG is added, and membrane-forming liquid is acquired; the membrane-forming liquid is poured into a polyfluortetraethylene plate, a reaction is conducted for 30-60 minutes at the temperature of 55-65 DEG C, sizing and sterilization are conducted, 4-DEG C cooling is conducted for 10-20 minutes, drying is conducted under the conditions that RH is 30-50% and the temperature ranges from 20 DEG C to 30 DEG C, and then membrane uncovering is conducted.The heat stability of the membrane is improved by adding Curdlan into the common edible protein solution, chitosan is added so that the membrane can have the antibacterial performance, microorganism source transglutaminase is added to catalyze the protein and cross linking between the protein and chitosan, and the chemical performance of the membrane is improved.

A propolis food product that contains propolis active ingredients with improved bio-absorbability and is readily ingested. The propolis food products containing propolis extracts are gelled by gelatinizers. The gelantinizers are materials such as shiitake extracts, curdlan, agarics extracts and further including sulfated saccharides, .beta.-glucans, carrageenan, locust bean gum, xanthan gum, or agar. The propolis food products are prepared by water or alcohol extraction. Furthermore, the steps involve preparing a gelantinizer solution by adding a gelatinizer to water and adding propolis extracts thereto so that the amount of the propolis extracts in the food product is from 2 to 25 w / w %, a gel composition is then formed by admixing the solution in order to uniformly disperse the propolis extracts.

The invention discloses a medium-high temperature resistant biological profile modifying / water plugging agent for oilfield exploitation. The medium-high temperature resistant biological profile modifying / water plugging agent consists of a microbial polysaccharide base profile modifying agent and delay gel, wherein the microbial polysaccharide base profile modifying agent is a microbial polysaccharide curdlan compound hydrogen bond binding force accelerant or microbial polysaccharide curdlan and a coagulant aid; the delay gel is one or more of polyhydric alcohol, high-molecular polymer hydrolysis polyacrylamide and gluconate. The invention further discloses a preparation method for the biological profile modifying / water plugging agent. The profile modifying / water plugging agent disclosed by the invention can be used for keeping the mobility of the system at a medium-high temperature (65-90 DEG C); moreover, the viscosity is increased slowly, so that the needs of smoothly conveying the profile modifying / water plugging agent to a special underground depth part are met.

The invention discloses a polysaccharide-base gel composite film, and a preparation method and application thereof. The preparation method comprises the following steps: adding a Curdlan solution, a sodium carboxymethyl cellulose solution and glycerol into any one or two of an edible polysaccharide-sodium alginate solution and a carrageenin solution, and regulating the pH value of the mixed solution to 4-8 to obtain a film forming solution; carrying out ultrasonic degassing, and pouring into a teflon plate; setting, carrying out sterilization treatment, cooling at 4 DEG C for 10-20 minutes, and carrying out drying and film peeling under certain conditions; and after the film is peeled, immersing the film in any one or two of a KCl solution and a NaOH solution for 5-20 minutes, and naturally airing. Common polysaccharide substances in food are used as the matrix, the glycerol is used as the plasticizer, and the Curdlan and sodium carboxymethyl cellulose are added to prepare the composite film. The composite film has the advantages of favorable mechanical properties, favorable water tightness and favorable heat stability, and is green, environment-friendly and edible.

The invention discloses edible composite cling film, and a preparation method and application thereof. The composite film is prepared by the following steps: adding a polyvinyl alcohol solution, a chitosan solution, a phenolic acid substance and a plasticizer in an edible polysaccharide Curdlan suspension, adjusting the pH value of the mixed solution to 3-5, carrying out ultrasonic degassing to obtain a film-forming liquid, pouring the film-forming liquid into a polytetrafluoroethylene plate, carrying out heat preservation for carrying out a reaction for 8-10 minutes at a temperature of 90-120DEG C, carrying out sizing, carrying out sterilization treatment, carrying out ultraviolet irradiation treatment for 5-10 minutes, carrying out hot-air circulating drying treatment at a temperature of 90-120 DEG C for 30-60 minutes, and carrying out cooling at a temperature of 4 DEG C to obtain the edible composite cling film. The edible composite film provided by the invention has the advantagesof high tensile strength and high extensibility, has excellent integrity, tensile strength and extensibility after being stewed in boiling water for 1 hour, and can effectively prolong the shelf lifeof fruits, vegetables and the meat products.

The invention discloses a polysaccharide-based silver nano-particle preparing method and relates to the technical field of preparation of silver nano-particles. Prepared oxidized curdlan with the carboxyl group content 2.07-4.87mmol / g and a silver nitrate solution are mixed in an isopyknic mode to form a mixed solution, the mixed solution reacts under the magnetic stirring at the constant temperature of 70-100 DEG C for 0.5-2h and then is cooled to be at the room temperature, filtered, centrifuged, dispersed, dialyzed and freeze-dried to prepare polysaccharide-based silver nano-particles, and spherical silver nano-particles controllable in particle diameter can be obtained by controlling the concentration of the oxidized curdlan, the carboxyl group content and the silver nitrate concentration. Therefore, the polysaccharide-based silver nano-particle preparing method is environment-friendly, simple and easy to operate and enables the silver nano-particles to be controllable in particle diameter, evenly dispersed and good in stability, and continuous large-scale production can be achieved.

The invention provides a carboxymethyl curdlan gum physical hydrogel and a preparation method thereof, belonging to the technical field of high polymer material; the mass percent of the carboxymethyl curdlan gum physical hydrogel is 3-20% while the balance is water. The preparation method comprises the following steps: preparing carboxymethyl curdlan gum aqueous solution; regulating pH value and performing freeze-thaw treatment; compared with the prior art, the invention adopts the freeze-thaw treatment to prepare carboxymethyl curdlan gum physical hydrogel; the preparation method is easy and convenient and the strength of the hydrogel can be enhanced through increasing freeze-thaw circling times, reducing freeze temperature, prolonging freeze time and the like; no chemical cross-linking agent or organic solvent with poison and side effect to organism is introduced in the hydrogel preparation process with freeze-thaw treatment. The carboxymethyl curdlan gum has immunity activity and anti-tumor activity, so the physical hydrogel has potential application in biomedical sciences, such as being taken as sustained and control drug carrier, and has more advantages compared with other hydrophilic gums.

The invention discloses a polysaccharide / alcohol soluble protein composite membrane and a preparation method of the polysaccharide / alcohol soluble protein composite membrane. According to the polysaccharide / alcohol soluble protein composite membrane and the preparation method of the polysaccharide / alcohol soluble protein composite membrane, polysaccharide (including curdlan or curdlan / konjac glucomannan mixed polysaccharide) and alcohol soluble protein (including wheat alcohol soluble protein or corn alcohol soluble protein) are taken as raw materials, a plasticizer and an emulgator are taken as auxiliary elements, tape casting and drying are conducted after blending modification is conducted according to a physical method, and then the polysaccharide / alcohol soluble protein composite membrane is obtained. The raw materials of the composite membrane are natural renewable resources and are abundant and easy to obtain. The polysaccharide / alcohol soluble protein composite membrane prepared with the method is flat and smooth, has excellent mechanical property and barrier property and is high in water vapor permeability, oxygen permeability and light transmittance, capable of being degraded naturally and rapidly and free of poison and pollution. The polysaccharide / alcohol soluble protein composite membrane can be used as a food packaging film or a sustained-release material for food or drugs.

The invention provides a surimi product and a preparation method thereof. The surimi product comprises: 4-20 parts by weight of composite starch, 0-22 parts by weight of emulsified pulp, 0.8-4 parts by weight of composite protein, 0.05-0.5 parts by weight of compound phosphate and 0-0.5 parts by weight of curdlan. The method for making surimi products includes: adding 0.05-0.5 parts by weight of compound phosphate, 0-22 parts of emulsified pulp, 4-20 parts of compound starch, 0.8-4 parts of compound protein and Curdlan gum with a weight part of 0-0.5 is chopped and mixed evenly to form a surimi product. The surimi product and the preparation method provided by the invention improve the elasticity of the surimi product and reduce the production cost.

A pasty dental alginate impression material composition having features that fluidity of a mixture is changeable by changing mixing ratio of both pastes, sufficient working time can be kept, and liquid separation in abase material paste does not occur during storage, comprises the base material paste composed mainly of 1-20 wt. % alginate and water, and a setting material paste composed mainly of 10-60 wt. % calcium sulfate and a liquid component unreactive with the calcium sulfate, wherein the base material paste does not contain a filler substantially, but contains 0.01-5 wt. % carbonate of sodium or potassium as a retarder and 0.01-15 wt. % one or more polysaccharides such as carrageenan, pullulan, curdlan, xanthan gum, pectin, konjak glucomannan, and locust bean gum, and the setting material paste contain 0.01-10 wt. % phosphate of sodium or potassium as a retarder, and 0.5-30 wt. % polybutene.

The invention discloses a method for preparing curdlan gel granules and a product thereof. The method comprises the following steps of: a, preparing curdlan dispersion liquid; b, adding aqueous alkali into the curdlan dispersion liquid to obtain curdlan solution; c, dripping the curdlan solution into acidic forming liquid to obtain low gel granules; and d, heating the low gel granules to the temperature of over 80 DEG C to obtain high gel granules. The product of the curdlan gel granules prepared by the method has a spherical shape or a water-drop shape.

The invention belongs to microbial fermentation, and particularly discloses Rhizobium radiobacter and a method for producing curdian fermentation liquor by using the strain. The method for producing the curdian fermentation liquor by using the strain comprises the following steps of: inoculating seed liquid which contains Rhizobium radiobacter CGMCC No.5031 serving as the strain after amplification culture into culture solution of a fermentation tank according to the inoculation amount of between 5 and 10 mass percent, wherein the fermentation culture solution contains a carbon source, an essential nitrogen source and nutrient substances; regulating the pH value of the fermentation culture solution, and performing ventilation fermentation; and supplementing a carbon source, a nitrogen source, nutrient substances and water in the fermentation process, and performing ventilation fermentation for not less than 90 hours to obtain fermentation liquid containing curdian. By the method, the defect that the content of solid matter in the curdian fermentation liquor is low in the prior art is overcome; and the method has the advantages that: the carbon source in the fermentation liquor can be better utilized by the strain, the transformation rate is high in the fermentation process, the content of the solid matter in the fermentation liquor is high, the production cost is greatly reduced and the like.

The invention discloses a milk beverage stabilizing agent, an acid milk beverage using the same and a preparation method in the technical field of food. The milk beverage stabilizing agent comprises the following components in percentage by mass: 50%-70% of carboxymethyl curdlan, 10%-30% of Arabic gum, 10%-20% of propylene glycol alginate and 5%-10% of guar gum. The acid milk beverage comprises the following components in percentage by mass: 1%-8% of whole milk powder or defatted milk powder, 0.2%-1% of stabilizing agent, 10%-20% of white granulated sugar and the balance of water. The preparation method for the acid milk beverage comprises the following steps: taking 35 to 55 DEG C water, adding the white granulated sugar and the stabilizing agent into the water in turn, and stirring the mixture till the white granulated sugar and the stabilizing agent are dissolved to obtain solution A; taking the 35 to 55 DEG C water, adding the whole milk powder or the defatted milk powder into the water, and stirring the mixture till the whole milk powder or the defatted milk powder is dissolved to obtain solution B; and mixing the solution A and the solution B, cooling the solution to between 15 and 25 DEG C, adjusting pH to 4 by using citric acid solution, and heating, homogenizing and pasteurizing the solution to obtain the acid milk beverage. Because the carboxymethyl curdlan and the Arabic gum are introduced into the stabilizing agent, the stabilizing agent has good emulsifying effect and acid resistance, and can effectively improve the stability of a product.

The invention relates to dumpling wrapper, solves the technical problems that wrapper of existing quick-frozen dumplings is easy to crack during cold storage, and the existing quick-frozen dumplings are easy to break, and provides quick-frozen anti-cracking dumpling wrapper. The quick-frozen anti-cracking dumpling wrapper is made by mixing flour, potato modified starch and quality improver, adding water to make dough and pressing the dough. The quick-frozen anti-cracking dumpling wrapper is characterized in that based on 100 parts of flour, 5-15 parts of the potato modified starch is added, 1.5-2 parts of the quality improver is added, 40-55 parts of the water is added, the quality improver is made by mixing composite phosphate, curdlan and ascorbic acid according to a portion of 2:3:1. Shelf life of dumplings made of the quick-frozen anti-cracking dumpling wrapper can be prolonged effectively, quality of the dumplings can be improved, and return rate can be reduced.

The invention relates to a gel film with curdlan quaternary ammonium salt and polyvinyl alcohol and application of the gel film in the antibacterial aspect. The curdlan quaternary ammonium salt and the polyvinyl alcohol are used as film-forming materials for the gel film. The polyvinyl alcohol is emulsified and hydrophobically modified by the aid of grease substances, and packaging materials comprise components including the 0.02-0.10g / mL H2O polyvinyl alcohol, 0.002-0.020 g / mL H2O total surfactants, the 0.005-0.02 g / mL H2O grease substances and 0.005-0.02 g / mL H2O plasticizers, the components are subjected to reaction, composite emulsification, freezing, thawing and cross-linking in aqueous solution to obtain the packaging materials, and a weight ratio of the curdlan quaternary ammonium salt to the polyvinyl alcohol is 4:1-1:4. Mixed emulsion is subjected to repeated freezing, thawing and cross-linking at the temperatures of -10--40 DEG C after being poured into a container, standing still and being de-foamed, and then is dried at the temperatures of 30-40 DEG C by means of air blowing so as to obtain the gel film. The gel film with the curdlan quaternary ammonium salt and the polyvinyl alcohol and the application have the advantages that the gel film has uniform microstructures and broad-spectrum antibacterial and sterilization performance and is excellent in mechanical property, and antibacterial effects can be realized by the gel film for Escherichia coli, staphylococcus, staphylococcus aureus and mildew; the gel film can be degraded, and the antibacterial effects can be realized by the gel film.

The invention relates to an exopolysaccharide generated by pseudomonas, a culture method and application. The pseudomonas sp. QL212 is preserved in common microbe center of China Committee for Culture Collection of Microorganisms on September 12, 2014, at the address of Institute of Microbiology of Chinese Academy of Sciences, No.3, Yard No. 1, West Beichen Road, Chaoyang District, Beijing, and having the preservation number of CGMCC NO.9651. The curdlan synthesized by the pseudomonas sp. QL212 serves as the exopolysaccharide; through fermentation condition optimization, the yield of curdlan is up to 5.94 g / L which is higher than the production peak of the already known pseudomonas curdlan.

The invention provides a solvent method for extracting and making curdlan, relating to the purification and extraction as well as production technique of curdlan products. The technical proposal is as follows: (1) an organic solvent such as alcohol and isopropanol is taken as a dehydrating agent to dehydrate the curdlan aqueous alkali, the gel phenomenon does not exist in the production process, thereby being easy to remove water, salinity and pigment; (2) after the curdlan and the organic solvent are mixed, the solid and liquid are separated by adopting the layered overflow way; (3) the organic solvent is applied for a plurality of times to extract the curdlan with a plurality of times of dehydration. The method adopts the organic solvent method to purify and extract as well as produce the curdlan, and has an extracting yield more than 90 percent; the product has high purity quotient and good quality; the production process can realize the serialization and the automation.

The invention discloses a preparation method of Curdlan oligomers. The method comprises the following steps of: fully dissolving Curdlan polysaccharide into a solvent to obtain a homogeneous solution; adding acid at a temperature in a range of 80-140 DEG C, wherein a final concentration of the acid in the solution is 0.1-10 M; reacting for 30-500 min; adding organic solvent sediments which are 3-5 times as much as the volume of reaction liquid and meanwhile, stirring and filtering to obtain a milky solid; washing the solid by the organic solvent 1-4 times to obtain the Curdlan oligomers with an average molecular weight of 340-4000 Da, which is measured by an efficient liquid phase detection after drying. The degradation efficiency of the preparation method reaches more than 85%. The Curdlan oligomers are oligomers formed by connecting glucose molecules through beta-(1->3) glucosidic bonds; the degree of polymerization (Degree of Polymerization, DP) of the Curdlan oligomers is 2-24; a molecular formula of the Curdlan oligomers is (C6H12O6)n, wherein n is equal to 2-24. The average molecular weight of the Curdlan oligomers is 340-4000 Da. The preparation method provided by the invention has a simple and controllable preparation process, short reaction time and good degradation efficiency, and is environmentally friendly and suitable for industrial production.

The invention relates to a preparation method of dried beancurd stick and dried beancurd stick prepared thereby. The preparation method comprises the following steps: 1) grinding peeled soybean into soybean milk; 2) carrying out homogenization treatment on the soybean milk and preparing the homogenized soybean milk; 3) adding a mildew preventive and a film-forming agent in the homogenized soybean and carrying out heating and milk boiling treatment; and 4) heating, uncovering bamboo and forming. The method adopts a water grinder for grinding and high-pressure homogenization, and improves the dissolution rate of protein, thus improving the yield of the dried beancurd stick; film-forming agent Curdlan is added in the homogenized soybean milk so as to accelerate the film forming speed; and mildew preventive calcium propionate is added to effectively restrain the growth of the mould, and prolong the shelf life of the dried beancurd stick. The invention has the advantages of low cost, simple and easy technique and larger application and promotion values.

The invention belongs to post-extraction of microbial polysaccharide, and in particular relates to a post-extraction method of curdlan. The method comprises the following process steps: fermentation broth enzyme treatment, membrane treatment, first dissolution, sedimentation and filtration, secondary dissolution, sedimentation and filtration, drying and the like. By using the method of the invention, the technical defects in the prior art that high production cost is high because of the adoption of alcohol extraction and large potential safety hazard exists in the production process are solved. The post-extraction method of the invention can be used for effectively removing thallus and impurities and has the advantages of rapid extraction schedule, small influence on material quality, safe production and low cost.

The invention relates to a cholesteryl-carboxymethyl Curdlan nanometer particle and a preparing method. Cholesterol and carboxymethyl Curdlan are used as raw materials. The carboxyl of the carboxymethyl Curdlan is activated by 1-(3-dimethylaminopropyl)-3-ethylcarbodimide hydrochloride (EDC.HCl) and N-hydroxysuccinimide (NHS) firstly, and then reacts with the cholesterol to be synthesized. The mole proportion of the carboxymethyl Curdlan to the cholesterol to EDC to NHS is 1:(0.2-5):1:5. The prepared amphipathic polymer is beneficial to preparing nanometer particles and entrapping hydrophobic drugs. The invention has the advantages of simple preparing method, good reproducibility, high drug entrapping efficiency and easy industrial production, the drug entrapping particle can greatly prolong the action time of the drugs in human bodies, obviously change the distribution of the drugs in different organs, and achieve the functions on reducing toxic or side effect, prolong the circulation time in the human bodies and enhances the biological availability of the drugs.

The invention relates to the technical field of food processing, in particular to composite gel and a cereal suspension beverage and preparation methods thereof. The composite gel is prepared from curdlan, gellan gum, sodium carboxymethyl cellulose and water. The gellan gum, the sodium carboxymethyl cellulose and the curdlan are used in a matched way; then, the obvious cooperative and synergistic effects can be achieved; the water preservation performance of the gel can be obviously improved. The cereal suspension beverage product provided by the invention belongs to a particle suspension cereal beverage processed by using husked mungbean, oat, coix seeds, white granulated sugar, fruit juice, curdlan, gellan gum, sodium carboxymethyl cellulose, pigments and food flavoring through a scientific and reasonable processing process. The product has the advantages that nutrition and health are realized; the mouthfeel is fresh and cool; the stability is high; the mungbean grains in the product have mild color; the curdlan particles have high elasticity; the beverage is suitable for common people to drink.

The invention discloses an incision beta-1,3-glucanase coding gene from cellulosimicrobium cellulans, as well as enzyme, a preparation method and application of the incision beta-1,3-glucanase coding gene. The incision beta-1,3-glucanase coding gene is cloned to an escherichia coli expression vector through a technical method of gene engineering, so that an escherichia coli recombination strain capable of realizing heterologous expression of the enzyme can be obtained; incision beta-1,3-glucanase prepared through the heterologous expression of the strain can directly and efficiently degrade solid Curdlan. The invention further provides an antibiological inoculant, which is the incision beta-1,3-glucanase, for preventing and treating animal and plant diseases; the antibiological inoculant belongs to the field of biological prevention and treatment, and is expected to be novel biological pesticide. The incision beta-1,3-glucanase provided by the invention can be widely applied to the field of agriculture, food, feed additives, medicines, glucooligosaccharides preparation and the like.

A preparation method of thermally irreversible gel protective film of bird's nest and its application in the processing of fruity bird's nest beverage. After mixing the hot solutions in equal proportions (or using curdlan, sodium alginate and other thermally irreversible gels as raw materials), put the stewed and drained bird's nest into soaking for 15-30 minutes, remove and cool (cool at room temperature, dry with cold wind) , ice water bath, etc.) to form a heat irreversible gel protective film; the weight composition of the fruity bird's nest drink is: bird's nest 0.3%~1.5%, fruit juice 3%~15%, sweetener 3%~8%, acidity regulator 0.005%~0.2%, thickener 0.09%~0.15%, essence 0.1%~0.3%. The present invention applies the thermally irreversible gel to the processing of the bird's nest beverage, which not only helps to maintain the appearance and taste of the bird's nest, but also has good flavor and color, is sweet and sour, and is suitable for all ages.

The invention relates to a gel coated fruit berry and a preparation method of the gel coated fruit berry. Curdlan is mainly used to coat fresh-cut fruit berries; as irreversible gel generated by curdlan through heating has high resistance to various food processing conditions, the gel coated fruit berry can be directly mixed with other food raw materials to be processed, the process steps can be greatly simplified and the production cost is reduced; besides, the curdlan gel has mouthfeel similar to that of the fresh-cut fruit berry, and thus curdlan suspension liquid prepared from fruit juice also has flavor similar to that of the fresh-cut fruit berry; common food gum is added between the curdlan gel and the fresh-cut fruit berry and can fill gaps between the curdlan gel and the fresh-cut fruit berry, so that the curdlan gel and the fresh-cut fruit berry can be combined well; the fresh-cut fruit berry can be stable in a curdlan gel shell, and the quality of the product is improved.

The invention discloses a method for purifying curdlan by use of a membrane separation process. The method comprises the steps of dissolving curdlan fermentation broth or a crude curdlan product in an alkaline solution; by means of the principle that curdlan molecules completely stretched in an aqueous solution can pass through a microfiltration membrane with an aperture higher than 10 nm and microbial bacteria and insoluble impurities can not pass through the microfiltration membrane and the advantage that a ceramic microfiltration membrane is resistant to acid and alkali, separating and removing the microbial bacteria and insoluble impurities in curdlan aqueous alkali by filtering through the ceramic microfiltration membrane, collecting to obtain clear curdlan aqueous alkali with relatively low concentration, adding acid in the clear curdlan aqueous alkali for neutralization to separate out the curdlan in the form of neutralization gel, filtering and concentrating by using an ultrafiltration membrane to obtain the curdlan neutralization gel, adding water to wash and desalt, and finally dewatering and drying through an organic solvent to obtain a high-quality curdlan product. The dry purity of the product exceeds 95%, the gel strength is increased to 1000-1200 g / cm<2>, and the performance is stable.