Process for producing glucose by using corn dry method

Abstract

The invention belongs to the technical field of glucose preparation, and particularly relates to a process for producing glucose by using a corn dry method. The invention provides a process for producing glucose by using a corn dry method. The process comprises the steps of corn kernel pretreatment, freezing treatment, high-pressure steam explosion treatment, liquefaction, saccharification, refining and the like. According to the process for producing the glucose by using the corn dry method, regulation and control are carried out in combination with process conditions such as freezing and unfreezing, high-pressure steam explosion and multi-stage enzymolysis, so that the liquefaction efficiency is effectively improved, the saccharification effect is enhanced, and the saccharification reaction speed is accelerated, and therefore, the high-purity glucose with stable quality is rapidly obtained and meets the current standard and specification requirements. And the process can shorten the time required by liquefaction and saccharification, can effectively reduce the energy consumption and reduce the overall production cost, ensures that more starch is converted into glucose through a more efficient conversion process, improves the use efficiency of raw materials, and furthest reduces the resource waste.

Description

Technical Field

[0001] The invention belongs to the technical field of glucose preparation, and in particular relates to a process for producing glucose by using corn dry method. Background Art

[0002] Glucose, as one of the most widely present and vital monosaccharides in nature, plays a key role in organisms. It is the main source of cellular energy metabolism and is involved in a variety of physiological processes. For example, in the human body, glucose is not only an important fuel for the brain and nervous system, but also plays an important role in maintaining liver function and promoting detoxification. At the same time, due to its easy absorption and utilization by the body, glucose is also widely used in the medical field, such as for the treatment of hypoglycemia and as part of intravenous nutrition. At the same time, glucose is also an important industrial raw material, widely used in food, pharmaceutical, fermentation industry and other fields.

[0003] Traditional glucose production methods mainly rely on the hydrolysis of starch, and corn is one of the most important food crops in the world. It is rich in starch and has become the main source of raw materials for glucose production. According to different processing methods, the extraction of corn starch can be divided into two main processes: dry and wet. The traditional wet production process refers to the soaking of corn raw materials in warm water, and the separation of embryos, fibers and proteins after coarse and fine grinding, and finally obtaining high-purity starch products. However, in this process, a large amount of water resources are required to achieve effective pretreatment. For example, in the corn wet countercurrent soaking process, corn is usually soaked for a long time to soften the tissue structure to facilitate subsequent mechanical separation. This process not only causes significant waste of water resources, but also contains high concentrations of organic matter in the wastewater generated in the later treatment, such as by-products such as yellow pulp water. If these wastewaters are not properly treated, they will bring great pressure to the environment.

[0004] Compared with the wet process, the dry process has obvious advantages in energy consumption and water consumption because it does not require the use of large amounts of water for pretreatment. However, due to the characteristics of corn starch, the viscosity increases significantly when heated, resulting in reduced fluidity. This may make it difficult to mix the materials evenly during the liquefaction process, which in turn affects the efficiency of the enzyme, may lead to insufficient liquefaction, reduce the efficiency of liquefaction, and increase the possibility of producing by-products. In addition, if the liquefaction is not thorough enough, the subsequent saccharification step will also be affected, and the purity of the glucose produced in the end may be reduced.

[0005] Therefore, how to improve the liquefaction and saccharification efficiency in the process of preparing glucose from corn by dry method, so as to improve the purity of the produced glucose, is of great research significance. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the object of the present invention is to provide a process for producing glucose by using corn dry process. The technical solution of the present invention is:

[0007] A process for producing glucose by dry method using corn comprises the following steps:

[0008] S1. After removing impurities from corn kernels, adjusting the moisture, and then performing a dehulling and degerming process to obtain degermed corn kernels;

[0009] S2, freezing the degermed corn kernels obtained in step S1, and grinding them into corn flour after thawing;

[0010] S3, adding water to the corn flour obtained in step S2 to prepare corn steep liquor, adding an auxiliary agent, stirring evenly, soaking, and then performing high-pressure steam explosion treatment;

[0011] S4, cooling the corn syrup after the high-pressure steam explosion treatment in step S3, adjusting the pH, adding high-temperature α-amylase for primary enzymolysis treatment, and then heating and keeping the temperature for a period of time, cooling, adding medium-temperature α-amylase for secondary enzymolysis treatment, and obtaining a liquefied liquid;

[0012] S5, heating the liquefied liquid obtained in step S4, adjusting the pH, and then adding a composite enzyme for ultrasonic enzymolysis to obtain a saccharified liquid;

[0013] S6. Filter, decolorize, ion exchange, and concentrate the saccharified liquid obtained in step S5 to obtain glucose liquid.

[0014] Furthermore, after removing impurities in step S1, the moisture content of the corn kernels is adjusted to 15-18%, and then the corn kernels can be dehulled and degermed using conventional processes.

[0015] Furthermore, the peeling process in step S1 can be performed using a conventional corn peeling machine, where the corn kernels after impurities are removed are fed into the peeling machine, and the friction between the corn kernels caused by the high-speed rotating friction wheel or roller is used to remove the seed coat.

[0016] Furthermore, the degermination process in step S1 may be performed using a conventional corn degerminator, wherein the dehulled corn kernels are fed into the degerminator, and the germ is separated from the endosperm by mechanical squeezing or impact.

[0017] In step S1, impurities are removed to ensure that no foreign contaminants are introduced during subsequent processing, thereby ensuring the purity of the product. Adjusting the moisture content to 15-18% helps maintain the best state of the raw materials and avoids the effects of peeling and degerming being affected by excessive or low humidity.

[0018] Furthermore, in step S2, the degermed corn kernels are frozen at -40 to -30°C for 10 to 12 hours, and then thawed at room temperature for 2 to 3 hours until the surface is slightly wet but the interior remains hard.

[0019] Furthermore, in the step S2, the thawed degermed corn kernels are crushed to a particle size of 40 to 60 meshes.

[0020] In step S2, through the low-temperature freezing and thawing process, the water inside the corn kernels can form ice crystals, destroying the cell wall structure, making it easier to release starch granules, which helps to improve the enzymatic hydrolysis efficiency in subsequent steps.

[0021] Furthermore, the amount of the additive added in step S3 is 1.5-2.2% of the weight of the corn flour obtained in step S2, and the additive is composed of 2-hydroxysuccinic acid, polyvinyl alcohol and calcium lignin sulfonate in a weight ratio of 1-2:3-5:1, preferably 1.2:4:1; soaking is carried out for 1-2 hours after adding the additive.

[0022] Furthermore, the polyvinyl alcohol is polyvinyl alcohol 1788.

[0023] Furthermore, the dry matter content of the corn steep liquor in step S3 is 30-40%.

[0024] Furthermore, the pressure during the high-pressure steam explosion in step S3 is 1.4-1.6 MPa, the temperature is 130-160° C., and the processing time is 100-140 s.

[0025] Furthermore, in step S4, the corn steep liquor after the high-pressure steam explosion treatment is cooled to 85-95° C., and the pH value is adjusted to 6.0-7.0.

[0026] Furthermore, in step S4, after the primary enzymolysis, the mixture is heated to 130-140° C., kept warm for 8-10 minutes, and then cooled to 50-60° C. for secondary enzymolysis.

[0027] Furthermore, the high-temperature α-amylase in step S4 is Bacillus licheniformis α-amylase, and its addition amount is 25-35U / g corn flour, preferably 30U / g; the medium-temperature α-amylase is Aspergillus oryzae α-amylase, and its addition amount is 30-45U / g corn flour, preferably 40U / g.

[0028] Furthermore, in step S4, the enzymatic hydrolysis time of the first enzymatic hydrolysis is 60 to 80 minutes, and the enzymatic hydrolysis time of the second enzymatic hydrolysis is 50 to 60 minutes.

[0029] Furthermore, the saccharifying enzyme in step S5 is a combination of glucoamylase and pullulanase; the addition amount of the glucoamylase is 60-70U / g corn flour, preferably 65U / g; the addition amount of the pullulanase is 20-30U / g corn flour, preferably 25U / g.

[0030] Furthermore, in step S5, the temperature is raised to 55-63° C., preferably 58° C., and the pH is adjusted to 5.0-5.5; in step S5, the ultrasonic frequency is 20-30 kHz, and the enzymatic hydrolysis time is 7-10 h.

[0031] In step S3, corn flour is treated by high-pressure steam explosion, which can achieve rapid heating and expansion under high temperature and high pressure conditions in a short time, destroy the crystalline structure of starch granules, and make the structure of starch granules loose. This structural change increases the exposure area of ​​starch molecules, increases the contact opportunity between enzymes and starch molecules in the subsequent enzymolysis process, enables the enzyme to more effectively cut starch chains and convert them into glucose or other short-chain sugars, can significantly improve the subsequent enzymolysis effect, reduce the time and energy consumption of enzymolysis, and increase the yield of glucose. During the high-pressure steam explosion process, the distribution of materials may be uneven, resulting in some materials not being fully exposed to high-temperature and high-pressure steam, while other materials may be over-processed. Therefore, before the steam explosion treatment, the present invention adds an auxiliary agent consisting of 2-hydroxysuccinic acid, polyvinyl alcohol and calcium lignin sulfonate to soak the corn slurry when preparing the corn slurry. These auxiliary agents play a key role in the high-pressure steam explosion and the subsequent enzymatic hydrolysis process, and can promote the degradation and swelling of starch in the corn slurry, so that the corn slurry can maintain good fluidity in a high-temperature and high-pressure environment, prevent starch particles from agglomerating and settling, etc., ensure that the starch particles are evenly distributed in the high-temperature and high-pressure environment, improve the hydrolysis efficiency, and reduce the risk of equipment blockage.

[0032] Then in step S4, by selecting the enzyme preparation and controlling the enzymolysis conditions, the corn pulp is enzymolyzed in stages, making full use of the optimal working environment of the two enzymes, avoiding the risk of inactivation of a single enzyme species under long-term exposure to adverse conditions, and making liquefaction more sufficient. Through the steam explosion and enzymolysis liquefaction process in steps S3 and S4, the starch molecules are hydrolyzed to the size of dextrin and oligosaccharide ranges, the number of substrate molecules increases, the number of terminal groups increases, and the opportunity for saccharifying enzymes to act increases, which is conducive to subsequent saccharification reactions. And it can effectively improve the reaction degree of liquefaction and reduce the generation of by-products, which helps to improve the purity of glucose and simplify the subsequent separation and purification steps.

[0033] Furthermore, in step S6, the saccharified liquid is subjected to refining steps such as filtering, decolorizing, ion exchanging and concentrating. The saccharified liquid can be processed by conventional technical means in the prior art according to the needs of the product. For example, in the present invention, a plate and frame filter press can be used to filter the saccharified liquid to remove impurities and insoluble substances; then activated carbon is added for decolorization and the activated carbon is filtered out; finally, an ion exchange resin is used to remove inorganic salts and organic impurities in the saccharified liquid, and the saccharified liquid is concentrated to a solid content of 70-80%.

[0034] In step S6, glucoamylase and pullulanase are used for combined enzymolysis, assisted by ultrasonic treatment. The cavitation effect generated by ultrasound promotes the contact between the enzyme and the substrate, accelerates the reaction rate, and helps disperse the material to reduce the problem of excessive local concentration. This combination not only improves the saccharification efficiency, but also ensures that as much starch as possible is converted into glucose monomers, further improving the yield of the final product.

[0035] Furthermore, the temperature during the ion exchange process is 45-55° C., and the ion exchange resin is passed in the order of strongly acidic cations-weakly basic anions-strongly acidic cations-weakly basic anions.

[0036] Compared with the prior art, the process for producing glucose by dry method using corn provided by the present invention has the following advantages:

[0037] The present invention provides a process for producing glucose by dry corn, which is combined with the regulation of freezing and thawing, high-pressure steam explosion and multi-stage enzymatic hydrolysis, to effectively improve the liquefaction efficiency, enhance the saccharification effect, and accelerate the saccharification reaction speed, thereby quickly obtaining high-purity glucose with stable quality, which meets the requirements of current standards and specifications. In addition, the process can shorten the time required for liquefaction and saccharification, thereby effectively reducing energy consumption and overall production costs. A more efficient conversion process ensures that more starch is converted into glucose, improves the efficiency of raw material use, and minimizes resource waste. DETAILED DESCRIPTION

[0038] The present invention is further illustrated below through the description of specific implementation methods, but this is not a limitation of the present invention. Those skilled in the art can make various modifications or improvements based on the basic idea of ​​the present invention, but as long as they do not deviate from the basic idea of ​​the present invention, they are all within the protection scope of the present invention.

[0039] In the following examples and comparative examples, reagents not otherwise specified are conventional reagents and can be purchased from conventional reagent production and sales companies. The methods used, unless otherwise specified, are all existing technologies. Information such as some raw material manufacturers is as follows:

[0040] Bacillus licheniformis α-amylase, CAS number: 9000-85-5, product number: A299001; glucoamylase, CAS number: 9032-08-0, product number: A107823; pullulanase, CAS number: 9075-68-7, product number: P299007, were all purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0041] Aspergillus oryzae α-amylase, CAS No.: 9001-19-8, Catalog No.: J01412; β-amylase, CAS No.: 9000-91-3, Catalog No.: M62206, were purchased from Shanghai Myrrel Biochemical Technology Co., Ltd.;

[0042] Polyvinyl alcohol 1788, CAS number: 25213-24-5, product number: JS1392, purchased from Hubei Jusheng Technology Co., Ltd.;

[0043] 2-Hydroxybutanediol, CAS No.: 97-67-6; Calcium lignin sulfonate, CAS No.: 8061-52-7;

[0044] Povidone K-30, CAS No.: 9003-39-8, Part No.: S30268, was purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0045] Example 1

[0046] A process for producing glucose by dry method using corn comprises the following steps:

[0047] S1. removing impurities from corn kernels, adjusting the moisture content of the corn kernels to 15%, and then performing dehulling and degerming treatment on the corn kernels using a conventional process to obtain degermed corn kernels;

[0048] S2, freezing the degermed corn kernels obtained in step S1 at -30°C for 12 hours, and then thawing them at room temperature for 2 hours, until the surface is slightly wet but the inside still retains hardness, and then crushing them to a particle size of 40 meshes to obtain corn flour;

[0049] S3, adding water to the corn flour obtained in step S2 to prepare corn slurry, adjusting the slurry to a dry matter content of 30%, then adding 1.5% of the weight of the corn flour and an additive composed of 2-hydroxysuccinic acid, polyvinyl alcohol and calcium lignin sulfonate in a weight ratio of 1:5:1, stirring evenly, soaking for 1 hour, and then performing high-pressure steam explosion treatment under the conditions of a pressure of 1.4 MPa and a temperature of 130° C. for a treatment time of 140 seconds;

[0050] S4, cooling the corn steep liquor after the high-pressure steam explosion treatment in step S3 to 85°C, adjusting the pH to 6.0-6.5, then adding 25U / g of Bacillus licheniformis α-amylase for primary enzymolysis for 80min, then heating to 130°C, keeping the temperature for 10min, cooling to 50°C, and then adding 30U / g of Aspergillus oryzae α-amylase for secondary enzymolysis for 50min to obtain a liquefied liquid;

[0051] S5, heating the liquefied liquid obtained in step S4 to 55° C., adjusting the pH to 5.0-5.5, and then adding 60 U / g of glucoamylase and 20 U / g of pullulanase for enzymolysis under an ultrasonic frequency of 20 kHz for 10 h to obtain a saccharified liquid;

[0052] S6. The saccharified liquid obtained in step S5 is filtered by a plate and frame filter press to remove impurities and insoluble substances; then activated carbon is added for decolorization, and the activated carbon is filtered out; finally, an ion exchange resin is used to remove inorganic salts and organic impurities in the saccharified liquid, and the saccharified liquid is concentrated to 70% of solids by passing through the ion exchange resin at a temperature of 45° C. in the order of strong acid cation-weak base anion-strong acid cation-weak base anion, thereby obtaining a glucose solution.

[0053] Example 2

[0054] A process for producing glucose by dry method using corn comprises the following steps:

[0055] S1. removing impurities from corn kernels, adjusting the moisture content of the corn kernels to 17%, and then performing dehulling and degerming treatment on the corn kernels using a conventional process to obtain degermed corn kernels;

[0056] S2, freezing the degermed corn kernels obtained in step S1 at -35°C for 11 hours, and then thawing them at room temperature for 2.5 hours, until the surface is slightly wet but the inside still retains hardness, and then crushing them into a particle size of 50 meshes to obtain corn flour;

[0057] S3, adding water to the corn flour obtained in step S2 to prepare corn slurry, adjusting the slurry to a dry matter content of 34%, then adding 1.7% of the weight of the corn flour and an additive consisting of 2-hydroxysuccinic acid, polyvinyl alcohol 1788 and calcium lignin sulfonate in a weight ratio of 1.2:4:1, stirring evenly, soaking for 1.5 hours, and then performing high-pressure steam explosion treatment under the conditions of a pressure of 1.5 MPa and a temperature of 150° C. for a treatment time of 120 seconds;

[0058] S4, cooling the corn steep liquor after the high-pressure steam explosion treatment in step S3 to 90° C., adjusting the pH to 6.0-6.5, then adding 30 U / g of Bacillus licheniformis α-amylase for primary enzymolysis for 70 min, then heating to 135° C., keeping the temperature for 9 min, cooling to 55° C., then adding 40 U / g of Aspergillus oryzae α-amylase for secondary enzymolysis for 55 min, and obtaining a liquefied liquid;

[0059] S5, heating the liquefied liquid obtained in step S4 to 58° C., adjusting the pH to 5.0-5.5, and then adding 65 U / g of glucoamylase and 25 U / g of pullulanase for enzymolysis at an ultrasonic frequency of 25 kHz for 8 h to obtain a saccharified liquid;

[0060] S6. The saccharified liquid obtained in step S5 is filtered by a plate and frame filter press to remove impurities and insoluble substances; then activated carbon is added for decolorization, and the activated carbon is filtered out; finally, an ion exchange resin is used to remove inorganic salts and organic impurities in the saccharified liquid, and the saccharified liquid is concentrated to 75% of solids by passing through the ion exchange resin at a temperature of 50° C. in the order of strong acid cation-weak base anion-strong acid cation-weak base anion, thereby obtaining a glucose solution.

[0061] Example 3

[0062] A process for producing glucose by dry method using corn comprises the following steps:

[0063] S1. removing impurities from corn kernels, adjusting the moisture content of the corn kernels to 18%, and then performing dehulling and degerming treatment on the corn kernels using a conventional process to obtain degermed corn kernels;

[0064] S2, freezing the degermed corn kernels obtained in step S1 at -40°C for 10 hours, and then thawing them at room temperature for 3 hours, until the surface is slightly wet but the inside still retains hardness, and then crushing them into a particle size of 60 meshes to obtain corn flour;

[0065] S3, adding water to the corn flour obtained in step S2 to prepare corn slurry, adjusting the slurry to a dry matter content of 40%, then adding 2.2% of the weight of the corn flour and an additive consisting of 2-hydroxysuccinic acid, polyvinyl alcohol and calcium lignin sulfonate in a weight ratio of 2:3:1, stirring evenly, soaking for 2 hours, and then performing high-pressure steam explosion treatment under the conditions of a pressure of 1.6 MPa and a temperature of 160° C. for 100 seconds;

[0066] S4, cooling the corn steep liquor after the high-pressure steam explosion treatment in step S3 to 95° C., adjusting the pH to 6.5-7.0, then adding 35 U / g of Bacillus licheniformis α-amylase for primary enzymolysis for 60 min, then heating to 140° C., keeping the temperature for 8 min, cooling to 60° C., then adding 45 U / g of Aspergillus oryzae α-amylase for secondary enzymolysis for 60 min, and obtaining a liquefied liquid;

[0067] S5, heating the liquefied liquid obtained in step S4 to 63° C., adjusting the pH to 5.0-5.5, and then adding 70 U / g of glucoamylase and 30 U / g of pullulanase for enzymolysis at an ultrasonic frequency of 30 kHz for 7 h to obtain a saccharified liquid;

[0068] S6. The saccharified liquid obtained in step S5 is filtered by a plate and frame filter press to remove impurities and insoluble substances; then activated carbon is added for decolorization, and the activated carbon is filtered out; finally, an ion exchange resin is used to remove inorganic salts and organic impurities in the saccharified liquid, and the saccharified liquid is concentrated to 80% of solids by passing through the ion exchange resin at a temperature of 55° C. in the order of strong acid cation-weak base anion-strong acid cation-weak base anion, thereby obtaining a glucose solution.

[0069] Comparative Example 1

[0070] Compared with Example 2, the difference is that in step S2, the degermed corn kernels are not frozen, but directly crushed to a particle size of 50 meshes. Other components and operating processes are the same as those in Example 2.

[0071] Comparative Example 2

[0072] Compared with Example 2, the difference is that the polyvinyl alcohol 1788 in the auxiliary agent of step S3 is replaced by povidone K30, that is, the auxiliary agent is composed of 2-hydroxysuccinic acid, povidone K30 and calcium lignin sulfonate in a weight ratio of 1.2:4:1, and the other components and operating process are the same as those in Example 2.

[0073] Comparative Example 3

[0074] Compared with Example 2, the difference is that calcium lignin sulfonate is not added to the auxiliary agent in step S3, but the amount of polyvinyl alcohol 1788 is increased accordingly, that is, the auxiliary agent is composed of 2-hydroxysuccinic acid and polyvinyl alcohol 1788 in a weight ratio of 1.2:5, and other components and operating processes are the same as those in Example 2.

[0075] Comparative Example 4

[0076] Compared with Example 2, the difference is that high-pressure steam explosion treatment is not performed in step S3, and the enzymatic hydrolysis time in step S4 is increased. That is, the specific steps of step S3 and step S4 are as follows:

[0077] S3, adding water to the corn flour obtained in step S2 to prepare corn slurry, adjusting the slurry to a dry matter content of 34%, then adding 1.7% of the weight of the corn flour and an additive consisting of 2-hydroxysuccinic acid, polyvinyl alcohol 1788 and calcium lignin sulfonate in a weight ratio of 1.2:4:1, stirring evenly, and soaking for 1.5 hours;

[0078] S4. Heat the corn slurry to 90°C, adjust the pH to 6.0-6.5, then add 30U / g of Bacillus licheniformis α-amylase for primary enzymatic hydrolysis for 1.5h, then heat to 135°C, keep warm for 9min, cool to 55°C, then add 40U / g of Aspergillus oryzae α-amylase for secondary enzymatic hydrolysis for 2h to obtain a liquefied liquid.

[0079] The other components and operation process are the same as those in Example 2.

[0080] Comparative Example 5

[0081] Compared with Example 2, the difference is that the Aspergillus oryzae α-amylase in step S3 is replaced by β-amylase, that is, the specific steps of step S4 are:

[0082] S4, the corn steep liquor after high pressure steam explosion treatment in step S3 was cooled to 90°C, the pH was adjusted to 6.0-6.5, and then 30U / g of Bacillus licheniformis α-amylase was added for primary enzymolysis for 70min, and then heated to 135°C, kept warm for 9min, cooled to 55°C, the pH was adjusted to 4.5-5.0, and 40U / g of β-amylase was added for secondary enzymolysis for 55min to obtain a liquefied liquid. Other components and operation processes are the same as those in Example 2.

[0083] Test Example 1: Quality Test of Glucose Prepared by the Present Invention

[0084] The DE value (%) (glucose equivalent value) and glucose purity (%) of the glucose solutions prepared in Examples 1 to 3 of the present invention and Comparative Examples 1 to 5 were tested respectively. The test results are shown in Table 1.

[0085] Table 1

[0086] Group Glucose purity (%) DE value (%) Example 1 96.45 98.21 Example 2 97.03 98.47 Example 3 96.79 98.16 Comparative Example 1 92.04 92.98 Comparative Example 2 93.32 94.69 Comparative Example 3 95.13 95.72 Comparative Example 4 83.63 85.25 Comparative Example 5 90.16 93.44

[0087] As shown in Table 1, the processes of Examples 1 to 3 of the present invention can obtain high-purity glucose under the condition of greatly shortening the liquefaction and saccharification time. When some conditions in the process of the present invention are changed in Comparative Examples 1 to 5, the purity and DE value of the obtained glucose are reduced to varying degrees, indicating that the steps of the process for producing glucose by dry corn provided by the present invention complement each other, and the synergistic effect between the steps makes the entire production process smoother and more efficient, and also improves the quality and yield of the final product.

[0088] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A process for producing glucose using a corn dry process, characterized in that: The steps include: S1. After removing impurities from corn kernels, adjusting the moisture, and then performing a dehulling and degerming process to obtain degermed corn kernels; S2, freezing the degermed corn kernels obtained in step S1, and grinding them into corn flour after thawing; S3, adding water to the corn flour obtained in step S2 to prepare corn steep liquor, adding an auxiliary agent, stirring evenly, soaking, and then performing high-pressure steam explosion treatment; S4, cooling the corn syrup after the high-pressure steam explosion treatment in step S3, adjusting the pH, adding high-temperature α-amylase for primary enzymolysis treatment, and then heating and keeping the temperature for a period of time, cooling, adding medium-temperature α-amylase for secondary enzymolysis treatment, and obtaining a liquefied liquid; S5, heating the liquefied liquid obtained in step S4, adjusting the pH, and then adding a composite enzyme for ultrasonic enzymolysis to obtain a saccharified liquid; S6. Filter, decolorize, ion exchange, and concentrate the saccharified liquid obtained in step S5 to obtain glucose liquid.

2. The process for producing glucose by dry method using corn according to claim 1, characterized in that: In step S2, the degermed corn kernels are frozen at -40 to -30°C for 10 to 12 hours, and then thawed at room temperature for 2 to 3 hours.

3. The process for producing glucose by dry method using corn according to claim 1, characterized in that: In the step S2, the thawed degermed corn kernels are crushed to a particle size of 40 to 60 meshes.

4. The process for producing glucose by dry method using corn according to claim 1, characterized in that: The amount of the additive added in step S3 is 1.5-2.2% of the weight of the corn flour obtained in step S2, and the additive is composed of 2-hydroxysuccinic acid, polyvinyl alcohol and calcium lignin sulfonate in a weight ratio of 1-2:3-5:

1.

5. The process for producing glucose by dry method using corn according to claim 1, characterized in that: The pressure during the high-pressure steam explosion in step S3 is 1.4-1.6 MPa, the temperature is 130-160° C., and the processing time is 100-140 seconds.

6. The process for producing glucose by dry method using corn according to claim 1, characterized in that: In step S4, the corn steep liquor after high pressure steam explosion is cooled to 85-95° C., and the pH value is adjusted to 6.0-7.

0.

7. The process for producing glucose by dry method using corn according to claim 1, characterized in that: In the step S4, after the primary enzymolysis, the mixture is heated to 130-140° C., kept warm for 8-10 minutes, and then cooled to 50-60° C. for secondary enzymolysis.

8. The process for producing glucose by dry method using corn according to claim 1, characterized in that: The high-temperature α-amylase in step S4 is Bacillus licheniformis α-amylase, and its addition amount is 25-35 U / g corn flour; the medium-temperature α-amylase is Aspergillus oryzae α-amylase, and its addition amount is 30-45 U / g corn flour.

9. The process for producing glucose by dry method using corn according to claim 1, characterized in that: The saccharifying enzyme in step S5 is a combination of glucoamylase and pullulanase; the addition amount of the glucoamylase is 60-70 U / g corn flour; the addition amount of the pullulanase is 20-30 U / g corn flour.

10. The process for producing glucose by dry method using corn according to claim 1, characterized in that: In the step S5, the temperature is raised to 55-63° C., and the pH is adjusted to 5.0-5.5; in the step S5, the ultrasonic frequency is 20-30 kHz, and the enzymatic hydrolysis time is 7-10 h.