A method for extracting mannose based on konjac flour

Abstract

The application discloses a kind of based on konjak powder's mannose extraction method, its extraction system includes: konjak powder pretreatment, preparation extraction solvent, separation and filtration, chromatographic separation, mannose purification, crystallization and drying and finished product detection preservation, the preparation extraction solvent includes konjak powder dissolution, enzymatic extraction, the crystallization and drying include mannose crystallization, crystalline separation and crystalline drying.The application can effectively reduce the starch impurities in enzymatic extraction of mannose by the method, thereby effectively improve the extraction quality of mannose, by separation and filtration, chromatographic separation and mannose purification step, can effectively remove the impurities in solution, by chromatographic technique is separated, to purify the mannose therein, by reverse phase high performance liquid chromatography column to the separated mannose is purified, to obtain high-purity mannose, so as to effectively improve the extraction quality of mannose.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mannose extraction from konjac powder, in particular to a method for extracting mannose from konjac powder. BACKGROUND

[0002] Mannose is a six-carbon straight-chain alcohol with high compatibility with human metabolism, and is usually used as a sweetener, stabilizer or flavoring agent. It is an important carbohydrate in many organisms and can be extracted from various plant sources and microorganisms. Konjac powder is a powder obtained by grinding and processing konjac tubers. The main component of konjac plants is glucan, including mannoglucan and hemicellulose. Mannose is a kind of mannoglucan, so it can be extracted from konjac powder.

[0003] According to Chinese Patent Application No. 202410198319.3, a method for extracting high-polymerization degree glucomannan dietary fiber from enzymatic konjac powder is disclosed, which comprises enzyme hydrolysis control, heating and holding, filtration and nanofiltration. By using the enzyme hydrolysis method on konjac powder, the enzyme hydrolysis process is strictly controlled. When the sugar content of the enzyme hydrolysis liquid is ≥6Brix or the sugar content does not change continuously for two times, sodium hydroxide is quickly added to deacetylate and terminate the reaction. At the same time, the glucomannan that has not been deacetylated forms gel particles under alkaline conditions, which can significantly improve the product transmittance and reduce the product viscosity. By using the enzyme hydrolysis method, the chemical residues are less, the high-polymerization degree dietary fiber can be obtained, the functionality of konjac extract is improved, and after processing, high-polymerization degree glucomannan dietary fiber with a polymerization degree greater than 12 is obtained, which has no sticky feeling after water dissolution and good transmittance.

[0004] The prior art effectively solves the problem of affecting food taste and properties due to the stickiness of glucomannan after water is added. It has the advantages of no sticky feeling after water dissolution and good transmittance. However, the use of enzyme hydrolysis for extraction results in a large amount of starch impurities in the extracted mannose, thereby reducing the extraction quality of mannose.

[0005] Therefore, a method for extracting mannose from konjac powder is provided. SUMMARY

[0006] The present application aims to provide a method for extracting mannose from konjac powder, which has the advantages of improving the extraction quality of mannose and reducing the starch impurities in mannose, and solves the problem of reducing the extraction quality of mannose due to a large amount of starch impurities in mannose during enzyme hydrolysis extraction.

[0007] To achieve the above object, the present application provides the following technical solutions: A konjac flour-based mannose extraction method, its extraction system comprises: konjac flour pretreatment, preparation of extraction solvent, separation and filtration, chromatographic separation, mannose purification, crystallization and drying, and finished product detection and preservation, the preparation of extraction solvent comprises konjac flour dissolution, enzymatic extraction, the crystallization and drying comprises mannose crystallization, crystal separation and crystal drying;

[0008] Its extraction method comprises the following steps:

[0009] A, first, the konjac flour is pretreated, high-quality konjac flour is selected as the raw material, the konjac flour is dried by a drying machine, and after drying, the konjac flour is screened by a screening machine to ensure that it is dry and free of impurities;

[0010] B, then, the extraction solvent is prepared, the selected konjac flour raw material is mixed with water in a certain proportion, is fully stirred until uniform, and is formed into a paste, an appropriate amount of beta-mannanase is added to the konjac flour paste, the mannose is decomposed, and the mannose is released;

[0011] C, after the enzymatic reaction is completed, the solid residues in the solvent are removed by a centrifuge to obtain an aqueous solution containing mannose and glucose;

[0012] D, the sugar syrup obtained by filtration is separated by chromatographic technology to purify the mannose therein, and the mannose and glucose in the mixed sugar solution are further separated by ion exchange chromatography;

[0013] E, the separated mannose is purified by a reverse-phase high-performance liquid chromatography column to obtain high-purity mannose;

[0014] F, then, the purified mannose solution is slowly cooled to an appropriate temperature, as the temperature decreases, the solubility of the mannose decreases, thereby promoting the crystallization of the mannose, some crystallizing agent is added to the mannose solution during the crystallization process to promote the crystallization efficiency, the mannose crystals are separated from the solution by filtration, and then the separated mannose crystals are dried;

[0015] G, finally, the dried mannose crystals are subjected to finished product detection, and the qualified mannose is sealed and packaged.

[0016] Preferably, in step A, the drying temperature of the konjac flour raw material is controlled to be 50-80 DEG C, and the drying standard is that the moisture content of the konjac flour is less than 10%, and the moisture content can be determined by infrared drying method rapid detection technology.

[0017] Preferably, in step A, a 200-mesh screen is used for screening the konjac flour raw material, and the particle size of the screened konjac flour raw material is between 75 and 100 microns, and the particle size distribution can be detected and controlled by a laser particle size instrument.

[0018] Preferably, the ratio of the konjac flour raw material to water in step B is 1:10 to 1:20, the konjac flour is stirred by a blender during the pulping process, the stirring speed of the blender is controlled between 200 to 500 revolutions per minute, the PH is controlled between 5.5-6.5 during the enzymatic extraction in step B, and the PH regulator can be selected from phosphate buffer solution, acid regulator and alkaline regulator.

[0019] Preferably, the reaction temperature is controlled between 40℃ to 60℃ during the enzymatic extraction in step B, the enzyme structure will be destroyed when the temperature is higher than 60℃, and the reaction rate will be too slow when the temperature is lower than 40℃, the stirring speed of the blender is controlled at 200 revolutions per minute, and the addition amount of β-mannanase is 0.05%-0.5%.

[0020] Preferably, the crystallization agent in step F can be selected from ammonium sulfate and sodium acetate, the mannose solution is cooled to below room temperature in step F, and the drying temperature of the mannose crystal is controlled between 40℃ to 50℃ in step F.

[0021] Preferably, the detection items of the finished product of mannose in step G include mannose content, moisture content, ash content, PH value, appearance and color, crystal morphology, solubility, heavy metal lead and cadmium content, total bacterial colony count, Escherichia coli count and mold and yeast count, and the test methods in step G adopt high performance liquid chromatography, drying weight method, combustion residue method, PH meter measurement, visual inspection, microscope observation, water solubility test, atomic absorption spectrometry, culture medium counting method and membrane filtration method.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The present application can effectively reduce the starch impurities in the enzymatically extracted mannose, thereby effectively improving the extraction quality of mannose, and the impurities in the solution can be effectively removed through the separation and filtration, chromatographic separation and mannose purification steps, the mannose is purified through the chromatographic technology, the separated mannose is purified through the reverse phase high performance liquid chromatography column, and high-purity mannose is obtained, so that the extraction quality of mannose can be effectively improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure is a schematic diagram of the mannose extraction process of the present application. DETAILED DESCRIPTION

[0025] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0026] The present application provides a technical solution, a konjac flour-based mannose extraction method, its extraction system includes: konjac flour pretreatment, preparation of extraction solvent, separation and filtration, chromatographic separation, mannose purification, crystallization and drying and finished product detection and preservation, preparation of extraction solvent includes konjac flour dissolution, enzymatic extraction, crystallization and drying includes mannose crystallization, crystal separation and crystal drying;

[0027] The extraction method includes the following steps:

[0028] A, first, pretreat the konjac flour, select high-quality konjac flour as raw material, dry the konjac flour through the dryer, and screen the konjac flour after drying through the screening machine to ensure that it is dry and free of impurities;

[0029] B, then prepare the extraction solvent, mix the selected konjac flour raw material with water in a certain proportion, stir thoroughly until uniform, and add an appropriate amount of β-mannanase to the konjac flour paste to decompose mannans and release mannose;

[0030] C, after the enzymatic reaction is completed, remove the solid residues in the solvent by centrifuge to obtain an aqueous solution containing mannose and glucose;

[0031] D, the filtered syrup is separated by chromatographic technology to purify the mannose therein, and the mannose and glucose in the mixed sugar solution are further separated by ion exchange chromatography;

[0032] E, the separated mannose is purified by reverse-phase high-performance liquid chromatography column to obtain high-purity mannose;

[0033] F, then slowly cool the purified mannose solution to an appropriate temperature, as the temperature decreases, the solubility of mannose decreases, thereby promoting the crystallization of mannose, some crystallizing agents are added to the mannose solution during the crystallization process to promote the crystallization efficiency, the mannose crystals are separated from the solution by filtration, and then the separated mannose crystals are dried;

[0034] G, finally, the dried mannose crystals are subjected to finished product detection, and the qualified mannose is sealed and packaged.

[0035] Embodiment two:

[0036] In embodiment one, plus the following process:

[0037] The konjac flour raw material drying temperature in step A is controlled at 50-80℃, and the drying standard is that the moisture content of the konjac flour is <10%, which can be determined by infrared drying method rapid detection technology.

[0038] The extraction method includes the following steps:

[0039] A. First, the konjac flour is pretreated, and high-quality konjac flour is selected as the raw material. The konjac flour is dried by a drying machine, and then sieved by a sieving machine to ensure that it is dry and free of impurities. The konjac flour raw material drying temperature is controlled at 50-80℃, and the moisture content is determined by infrared drying method rapid detection technology. The moisture content of the konjac flour is <10%, which can be sieved and processed. The konjac flour raw material is sieved with a 200-mesh screen, and the particle size distribution is detected and controlled by a laser particle size analyzer. The particle size of the sieved konjac flour raw material is between 75μm and 100μm, which can be processed in the next step;

[0040] B. Then prepare the extraction solvent. Mix the selected konjac flour raw material with water in a certain proportion, stir well until uniform, and form a paste. Add an appropriate amount of β-mannanase to the konjac flour paste to decompose mannans and release mannose. The ratio of konjac flour raw material to water is 1:10 to 1:20. Stir with a blender to prevent the konjac flour from clumping. The blender speed is controlled at 200-500 rpm. The reaction temperature during enzyme hydrolysis is controlled at 40-60℃, the blender speed is controlled at 200 rpm, the pH is controlled at 5.5-6.5, and the addition amount of β-mannanase is 0.05%-0.5%;

[0041] C. After the enzyme hydrolysis reaction is completed, remove the solid residues in the solvent by centrifuge to obtain an aqueous solution containing mannose and glucose;

[0042] D. The filtered sugar syrup is separated by chromatography to purify the mannose therein. The mannose and glucose in the mixed sugar solution are further separated by ion exchange chromatography;

[0043] E. The separated mannose is purified by reverse-phase high-performance liquid chromatography column to obtain high-purity mannose;

[0044] F, then the purified mannose solution is slowly cooled to the appropriate temperature, the mannose solution is cooled to below room temperature, as the temperature decreases, the solubility of mannose decreases, thereby promoting the crystallization of mannose, some crystallization agent is added to the mannose solution during the crystallization process to promote the crystallization efficiency, the mannose crystals are separated from the solution by filtration, and then the separated mannose crystals are dried, ammonium sulfate and sodium acetate are selected as the crystallization agent during the crystallization process, and the drying temperature of the mannose crystals is controlled between 40-50℃;

[0045] G, finally, the dried mannose crystals are tested for finished product, and the tested mannose is sealed and packaged.

[0046] Example three:

[0047] In example two, the following process is added:

[0048] In step A, the konjac powder raw material is screened with a 200 mesh screen, and the particle size of the screened konjac powder raw material is between 75-100 μm, which can be detected and controlled by a laser particle size analyzer.

[0049] The extraction method includes the following steps:

[0050] A, first, the konjac powder is pretreated, and high-quality konjac powder is selected as the raw material, which is dried by a drying machine, and then screened by a screening machine to ensure that it is dry and free of impurities, the drying temperature of the konjac powder raw material is controlled between 50-80℃, the moisture content is determined by infrared drying method rapid detection technology, the moisture content of the konjac powder is less than 10%, which can be screened and processed, the konjac powder raw material is screened with a 200 mesh screen, and the particle size distribution is detected and controlled by a laser particle size analyzer, the particle size of the screened konjac powder raw material is between 75-100 μm, which can be processed in the next step;

[0051] B, then prepare the extraction solvent, mix the selected konjac powder raw material with water in a certain proportion, stir well until uniform, add an appropriate amount of β-mannanase to the konjac powder paste to decompose the mannans and release the mannose, the ratio of konjac powder raw material to water is 1:10 to 1:20, the konjac powder is prevented from clumping by stirring with a stirrer, the stirring speed is controlled between 200-500 rpm, the reaction temperature is controlled between 40-60℃ during the enzymatic hydrolysis, the stirring speed is controlled at 200 rpm during the reaction, the PH is controlled between 5.5-6.5, and the addition amount of β-mannanase is 0.05%-0.5%;

[0052] C, after the enzymatic hydrolysis reaction is completed, the solid residues in the solvent are removed by a centrifugal machine to obtain an aqueous solution containing mannose and glucose;

[0053] D, the filtered syrup is separated by chromatography to purify the mannose therein, and the mannose and glucose in the mixed sugar solution are further separated by ion exchange chromatography;

[0054] E, the separated mannose is purified by a reverse-phase high-performance liquid chromatography column to obtain high-purity mannose;

[0055] F, then the purified mannose solution is slowly cooled to an appropriate temperature, the mannose solution is cooled below room temperature, as the temperature decreases, the solubility of mannose decreases, thereby promoting the crystallization of mannose, some crystallizing agent is added to the mannose solution during the crystallization process to promote the crystallization efficiency, the mannose crystals are separated from the solution by filtration, and then the separated mannose crystals are dried, ammonium sulfate and sodium acetate are selected as the crystallizing agent during the crystallization process, and the drying temperature of the mannose crystals is controlled between 40°C and 50°C;

[0056] G, finally, the dried mannose crystals are tested for finished product, and the qualified mannose is sealed and packaged.

[0057] Example Four:

[0058] In Example Three, the following process is added:

[0059] The ratio of konjac flour to water in step B is 1:10 to 1:20, and the konjac flour is stirred by a stirrer during the pulping process, and the stirring speed is controlled between 200 and 500 revolutions per minute, and the PH value is controlled between 5.5 and 6.5 during the enzymatic extraction in step B, and the PH regulator can be selected from phosphate buffer solution, acid regulator and alkaline regulator.

[0060] The extraction method comprises the following steps:

[0061] A, first, the konjac flour is pretreated, and high-quality konjac flour is selected as the raw material, and the konjac flour is dried by a drying machine, and then sieved by a screening machine to ensure that it is dry and free of impurities, and the drying temperature of the konjac flour raw material is controlled between 50°C and 80°C, and the moisture content is determined by infrared drying method rapid detection technology, and the moisture content of the konjac flour is less than 10%, and the sieving process can be carried out, and the sieving of the konjac flour raw material is carried out with a 200-mesh screen, and the particle size distribution is detected and controlled by a laser particle size analyzer, and the particle size of the sieved konjac flour raw material is between 75μm and 100μm, and the next step can be carried out;

[0062] B, then prepare the extraction solvent, the selected konjac powder raw material and water mixed in a certain proportion, fully stirred to uniform, make it into a paste, add a appropriate amount of β-mannanase to the konjac powder paste, decompose the mannose, release the mannose, the ratio of konjac powder raw material and water is 1:10 to 1:20, through the blender to stir, to avoid the konjac powder appears agglomeration, blender speed control in 200 to 500 revolutions per minute, the reaction temperature is controlled between 40 to 60 DEG C in the process of enzymatic hydrolysis, the stirring speed is controlled at 200 rpm during the reaction, the PH is controlled in 5.5-6.5, the addition amount of β-mannanase is 0.05%-0.5%;

[0063] C, after the enzymatic reaction is completed, the solid residue in the solvent is removed by centrifuge, and the aqueous solution containing mannose and glucose is obtained;

[0064] D, the filtered syrup is separated by chromatography to purify the mannose therein, and the mannose and glucose in the mixed sugar solution are further separated by ion exchange chromatography;

[0065] E, the separated mannose is purified by reverse phase high performance liquid chromatography column to obtain high purity mannose;

[0066] F, then the purified mannose solution is slowly cooled to an appropriate temperature, the mannose solution is cooled to below room temperature, as the temperature decreases, the solubility of mannose decreases, thereby promoting the crystallization of mannose, some crystallizing agent is added to the mannose solution during the crystallization process to promote the crystallization efficiency, the mannose crystal is separated from the solution by filtration, then the separated mannose crystal is dried, ammonium sulfate and sodium acetate are selected as the crystallizing agent during the crystallization process, and the drying temperature of the mannose crystal is controlled between 40 DEG C and 50 DEG C;

[0067] G, finally, the dried mannose crystal is detected, and the qualified mannose is sealed and packaged.

[0068] Example five:

[0069] In example four, plus the following process:

[0070] The reaction temperature is controlled between 40 DEG C and 60 DEG C in step B of enzymatic extraction, the temperature higher than 60 DEG C will destroy the structure of the enzyme, and the temperature lower than 40 DEG C will lead to slow reaction rate, the stirring speed is controlled at 200 rpm during the reaction, and the addition amount of β-mannanase is 0.05%-0.5%.

[0071] The extraction method comprises the following steps:

[0072] A、Firstly, the konjac powder is pretreated, and konjac powder with good quality is selected as the raw material. The konjac powder is dried by a drying machine, and then screened by a screening machine to ensure that it is dry and free of impurities. The drying temperature of the konjac powder raw material is controlled at 50-80℃, and the moisture content is determined by infrared drying method rapid detection technology. The moisture content of the konjac powder is less than 10%, and the konjac powder raw material can be screened and processed. The 200 mesh screen is used for screening the konjac powder raw material, and the particle size distribution is detected and controlled by a laser particle size analyzer. The particle size of the screened konjac powder raw material is between 75-100μm, and the next step of processing can be carried out;

[0073] B、Then prepare the extraction solvent, mix the selected konjac powder raw material with water in a certain proportion, stir thoroughly until uniform, and form a paste. Add an appropriate amount of β-mannanase to the konjac powder paste to decompose mannans and release mannose. The ratio of konjac powder raw material to water is 1:10 to 1:20. Stir with a blender to prevent the konjac powder from clumping. The stirring speed is controlled at 200-500 rpm. The reaction temperature during enzyme hydrolysis is controlled at 40-60℃. The stirring speed is controlled at 200 rpm during the reaction. The PH is controlled at 5.5-6.5. The amount of β-mannanase added is 0.05%-0.5%;

[0074] C、After the enzyme hydrolysis reaction is completed, remove the solid residues in the solvent by centrifuge to obtain a water solution containing mannose and glucose;

[0075] D、The filtered sugar syrup is separated by chromatography to purify the mannose. The mannose and glucose in the mixed sugar solution are further separated by ion exchange chromatography;

[0076] E、The separated mannose is purified by reverse phase high performance liquid chromatography column to obtain high purity mannose;

[0077] F、Then slowly cool the purified mannose solution to an appropriate temperature. Cool the mannose solution to below room temperature. As the temperature decreases, the solubility of mannose decreases, which promotes the crystallization of mannose. Some crystallizing agents are added to the mannose solution during the crystallization process to improve the crystallization efficiency. The mannose crystals are separated from the solution by filtration, and then dried. Ammonium sulfate and sodium acetate are used as crystallizing agents during the crystallization process. The drying temperature of the mannose crystals is controlled at 40-50℃;

[0078] G、Finally, the dried mannose crystals are tested for finished product, and the tested mannose is sealed and packaged.

[0079] Example six:

[0080] In Example Five, the following procedure is added:

[0081] The crystallization agent in Step F can be ammonium sulfate and sodium acetate. The mannose solution in Step F is cooled to below room temperature. The drying temperature of the mannose crystals in Step F is controlled between 40°C and 50°C.

[0082] The extraction method includes the following steps:

[0083] A. First, the konjac powder is pretreated. High-quality konjac powder is selected as the raw material. The konjac powder is dried by a drying machine. After drying, the konjac powder is screened by a screening machine to ensure that it is dry and free of impurities. The drying temperature of the konjac powder raw material is controlled between 50°C and 80°C. The moisture content is determined by infrared drying method rapid detection technology. The moisture content of the konjac powder is <10%. The screened konjac powder raw material can be processed. The konjac powder raw material is screened with a 200-mesh screen. The particle size distribution is detected and controlled by a laser particle size analyzer. The particle size of the screened konjac powder raw material is between 75μm and 100μm. The screened konjac powder raw material can be processed in the next step.

[0084] B. Then, the extraction solvent is prepared. The selected konjac powder raw material is mixed with water in a certain proportion, stirred thoroughly until uniform, and formed into a paste. An appropriate amount of β-mannanase is added to the konjac powder paste to decompose the mannans and release the mannose. The ratio of konjac powder raw material to water is 1:10 to 1:20. The konjac powder is prevented from clumping by stirring with a stirrer. The stirring speed is controlled between 200 and 500 revolutions per minute. The reaction temperature during enzyme hydrolysis is controlled between 40°C and 60°C. The stirring speed during the reaction is controlled at 200 revolutions per minute. The pH is controlled between 5.5 and 6.5. The amount of β-mannanase added is 0.05% to 0.5%.

[0085] C. After the enzyme hydrolysis reaction is complete, the solid residues in the solvent are removed by a centrifuge to obtain a water solution containing mannose and glucose.

[0086] D. The filtered sugar syrup is separated by chromatography to purify the mannose. The mannose and glucose in the mixed sugar solution are further separated by ion exchange chromatography.

[0087] E. The separated mannose is purified by a reverse-phase high-performance liquid chromatography column to obtain high-purity mannose.

[0088] F, then the purified mannose solution is slowly cooled to the appropriate temperature, the mannose solution is cooled to below room temperature, as the temperature decreases, the solubility of mannose decreases, thereby promoting the crystallization of mannose, some crystallization agent is added to the mannose solution during the crystallization process to promote the crystallization efficiency, the mannose crystal is separated from the solution by filtration, and then the separated mannose crystal is dried, ammonium sulfate and sodium acetate are selected as the crystallization agent during the crystallization process, and the drying temperature of the mannose crystal is controlled between 40-50℃;

[0089] G, finally, the dried mannose crystal is subjected to product detection, and the qualified mannose is sealed and packaged.

[0090] Example seven:

[0091] In example six, the following process is added:

[0092] The product detection items of mannose in step G include mannose content, moisture content, ash content, PH value, appearance and color, crystal morphology, solubility, heavy metal lead and cadmium content, total bacterial colony count, escherichia coli and mold and yeast count, the test method in step G adopts high performance liquid chromatography, drying weight method, combustion residue method, PH meter measurement, visual inspection, microscope observation, water solubility test, atomic absorption spectrometry, culture medium counting method and membrane filtration method.

[0093] The extraction method includes the following steps:

[0094] A, first, the konjac powder is pretreated, and the konjac powder with good quality is selected as the raw material, the konjac powder is dried by the drying machine, and then the konjac powder is screened by the screening machine to ensure that it is dry and free of impurities, the drying temperature of the konjac powder raw material is controlled between 50-80℃, the moisture content is determined by infrared drying method rapid detection technology, the moisture content of the konjac powder is less than 10%, and the screening processing can be carried out, the 200 mesh screen is selected for the screening of the konjac powder raw material, the particle size distribution is detected and controlled by the laser particle size instrument, and the particle size of the screened konjac powder raw material is between 75-100μm, which can be processed in the next step;

[0095] B, then prepare the extraction solvent, the selected konjac powder raw material and water are mixed in a certain proportion, stirred thoroughly until uniform, to form a paste, add an appropriate amount of β-mannanase to the konjac powder paste, decompose mannans and release mannose, the ratio of konjac powder raw material to water is 1:10 to 1:20, stirring is carried out by a stirrer to prevent the konjac powder from caking, the stirring speed of the stirrer is controlled between 200 and 500 revolutions per minute, the reaction temperature during enzymolysis is controlled between 40 and 60 degrees Celsius, the stirring speed of the stirrer during the reaction is controlled at 200 revolutions per minute, the PH is controlled between 5.5 and 6.5, and the addition amount of β-mannanase is 0.05% to 0.5%;

[0096] C, after the enzymolysis reaction is completed, the solid residues in the solvent are removed by a centrifugal machine to obtain an aqueous solution containing mannose and glucose;

[0097] D, the sugar syrup obtained by filtration is separated by chromatography to purify the mannose therein, and the mannose and glucose in the mixed sugar solution are further separated by ion exchange chromatography;

[0098] E, the separated mannose is purified by a reverse-phase high-performance liquid chromatography column to obtain high-purity mannose;

[0099] F, then the purified mannose solution is slowly cooled to an appropriate temperature, the mannose solution is cooled to below room temperature, as the temperature decreases, the solubility of mannose decreases, thereby promoting the crystallization of mannose, some crystallizing agents are added to the mannose solution during the crystallization process to promote the crystallization efficiency, the mannose crystals are separated from the solution by filtration, then the separated mannose crystals are dried, ammonium sulfate and sodium acetate are selected as the crystallizing agents during the crystallization process, and the drying temperature of the mannose crystals is controlled between 40 and 50 degrees Celsius;

[0100] G, finally, the dried mannose crystals are tested for finished product, and the tested mannose that meets the requirements is sealed and packaged.

[0101] The quality of the mannose extracted from the konjac powder is detected according to the method in the above embodiment, and the detection results are shown in the following table:

[0102] Based on the quality detection report of the mannose extracted from the konjac powder

[0103] Test item Test method Test result Unit Mannose content High performance liquid chromatography 95.2％ ％ Moisture content Loss on drying method 2.1％ ％ Ash content Ignition residue method 0.05％ ％ PH value PH meter measurement 6.8 - Appearance and color Visual inspection White powder - Crystal form Microscopic observation Regular crystal, no impurities - Solubility Water solubility test Completely dissolved in water - Heavy metal content (lead) Atomic absorption spectrometry <0.1 ppm ppm Heavy metal content (cadmium) Atomic absorption spectrometry <0.05 ppm ppm Total bacterial count Culture medium counting method <100 cfu / g cfu / g Escherichia coli Membrane filtration method Not detected cfu / 100g Mold and yeast count Culture medium counting method <10 cfu / g cfu / g

[0104] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; it is not intended to exclude myriad other embodiments of the present application that other inventors can develop based on the same general inventive concepts embodied by the described embodiments. That is, although the present application is described in terms of particular embodiments and implementations, it is to be understood that the terminology used is for the purpose of descriptive clarity and that it should be taken in a descriptive sense and not a limiting sense.

[0105] While the embodiments of the application have been shown and described herein, it is to be understood that the application is not limited to these embodiments. Rather, many modifications, changes, substitutions, and alterations can be made to the embodiments of the application without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

Claims

1. A method for extracting mannose based on konjac flour, characterized by: The extraction system comprises: konjac powder pretreatment, preparation of extraction solvent, separation and filtration, chromatographic separation, mannose purification, crystallization and drying, and product detection and preservation, the preparation of extraction solvent comprises konjac powder dissolution and enzymatic extraction, and the crystallization and drying comprises mannose crystallization, separation of crystalline body and drying of crystalline body. The extraction method comprises the following steps: A. First, the konjac powder is pretreated, high-quality konjac powder is selected as the raw material, the konjac powder is dried by a drying machine, and the dried konjac powder is screened by a screening machine to ensure that it is dry and free of impurities; B. Then, the extraction solvent is prepared, the selected konjac powder raw material is mixed with water in a certain proportion, is fully stirred until uniform, and is formed into a paste, and an appropriate amount of beta-mannanase is added to the konjac powder paste to decompose the mannans and release the mannose; C. After the enzymatic reaction is completed, the solid residues in the solvent are removed by a centrifugal machine to obtain an aqueous solution containing mannose and glucose; D. The filtered sugar syrup is separated by chromatographic technology to purify the mannose therein, and the mannose and glucose in the mixed sugar solution are further separated by ion exchange chromatography; E. The separated mannose is purified by a reverse-phase high-performance liquid chromatography column to obtain high-purity mannose; F. Then, the purified mannose solution is slowly cooled to an appropriate temperature, as the temperature decreases, the solubility of the mannose decreases, thereby promoting the crystallization of the mannose, some crystallizing agents are added to the mannose solution during the crystallization process to promote the crystallization efficiency, the mannose crystals are separated from the solution by filtration, and then the separated mannose crystals are dried; G. Finally, the dried mannose crystals are detected as a product, and the qualified mannose is sealed and packaged.

2. The method of claim 1, wherein the konjac flour-based extraction of mannose is characterized by: In the step A, the drying temperature of the konjac powder raw material is controlled at 50-80 DEG C, and the drying standard is that the water content of the konjac powder is less than 10%, and the water content can be determined by infrared drying method rapid detection technology.

3. The method for extracting mannose based on konjac flour according to claim 1, characterized in that: In the step A, a 200-mesh screen is used for screening the konjac powder raw material, and the particle size of the screened konjac powder raw material is 75-100 mu m, and the particle size distribution can be detected and controlled by a laser particle size instrument.

4. The method for extracting mannose based on konjac flour according to claim 1, characterized in that: In the step B, the ratio of the konjac powder raw material to water is 1:10-1:20, the konjac powder is stirred by a stirrer during the slurry preparation process, the stirring speed of the stirrer is controlled at 200-500 rpm, the PH value is controlled at 5.5-6.5 during the enzymatic extraction in the step B, and the PH regulator can be selected from phosphate buffer solution, acid regulator and alkaline regulator.

5. The method for extracting mannose based on konjac flour according to claim 1, characterized in that: In the step B, the reaction temperature during the enzymatic extraction is controlled at 40-60 DEG C, the enzyme structure is damaged when the temperature is higher than 60 DEG C, and the reaction rate is too slow when the temperature is lower than 40 DEG C, the stirring speed of the stirrer is controlled at 200 rpm during the reaction, and the addition amount of beta-mannanase is 0.05%-0.5%.

6. The method for extracting mannose based on konjac flour according to claim 1, characterized in that: In the step F, ammonium sulfate and sodium acetate can be selected as the crystallizing agent, the mannose solution is cooled to below room temperature in the step F, and the drying temperature of the mannose crystals is controlled at 40-50 DEG C in the step F.

7. The method for extracting mannose based on konjac flour according to claim 1, characterized in that: The mannose end product detection items in step G include mannose content, moisture content, ash content, pH value, appearance and color, crystal morphology, solubility, heavy metal lead and cadmium content, total bacterial colony count, Escherichia coli and mold and yeast count, and the test methods in step G adopt high performance liquid chromatography, drying weight loss method, combustion residue method, pH meter measurement, visual inspection, microscope observation, water solubility test, atomic absorption spectrometry, culture medium counting method and membrane filtration method.

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