A process for the production of glucose from corn using dry milling

Abstract

The present application belongs to the technical field of glucose preparation, and particularly relates to a process for producing glucose by using corn dry method. The process for producing glucose by using corn dry method provided by the present application comprises the steps of corn kernel pretreatment, freezing treatment, high-pressure steam explosion treatment, liquefaction, saccharification, refining and the like. The process for producing glucose by using corn dry method provided by the present application combines freezing and thawing, high-pressure steam explosion and multi-stage enzymolysis and the like process conditions for regulation and control, effectively improves the liquefaction efficiency, enhances the saccharification effect and speeds up the saccharification reaction speed, so that high-purity glucose with stable quality is quickly obtained, which meets the current standard and specification requirements. Moreover, the process can shorten the time required for liquefaction and saccharification, effectively reduce energy consumption and lower the overall production cost, and a more efficient conversion process ensures that more starch is converted into glucose, improves the raw material use efficiency, and maximizes the reduction of resource waste.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of glucose preparation, and particularly relates to a process for producing glucose by using corn dry method. BACKGROUND

[0002] Glucose, as one of the most widely existing and essential monosaccharides in nature, plays a crucial role in living organisms. It is the main source of cellular energy metabolism and is involved in various 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. Meanwhile, glucose is also an important industrial raw material, widely used in the fields of food, pharmaceutical, fermentation industry, etc.

[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, rich in starch, so it has become the main raw material source for glucose production. According to the different processing methods, the extraction of corn starch can be divided into two main processes: dry method and wet method. The traditional wet method production process refers to the corn raw material being soaked in warm water, and after coarse and fine grinding, the embryo, fiber and protein are separated to obtain high-purity starch products. However, in this process, in order to achieve effective pretreatment, a large amount of water resources is consumed. For example, in the corn wet countercurrent soaking process, corn usually needs to be soaked for a long time to soften the tissue structure, making it easier for subsequent mechanical separation. This process not only causes significant waste of water resources, but also produces wastewater containing high concentrations of organic matter, such as yellow slurry and other by-products, which can cause great pressure on the environment if not properly treated.

[0004] Compared with the wet method, the dry method process has obvious advantages in energy consumption and water consumption, as it does not require the use of a large amount of water for pretreatment. However, due to the characteristics of corn starch, i.e. the viscosity increases significantly when heated, resulting in reduced flowability. This can make it difficult to uniformly mix the material during liquefaction, which in turn affects the efficiency of enzyme action, possibly leading to insufficient liquefaction, reducing the efficiency of liquefaction, and increasing the likelihood 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 produced glucose may be reduced.

[0005] Therefore, how to improve the liquefaction and saccharification efficiency in the process of corn dry method for preparing glucose, so as to improve the purity of the prepared glucose, has very important research significance. SUMMARY

[0006] In order to solve the problems in the prior art, the present application aims to provide a process for producing glucose by dry method using corn.

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

[0008] S1, removing impurities in corn kernels, then adjusting moisture, and then carrying out peeling and degerming treatment to obtain degermed corn kernels;

[0009] S2, carrying out freezing treatment on the degermed corn kernels obtained in step S1, grinding into corn flour after thawing;

[0010] S3, preparing corn slurry by adding water to the corn flour obtained in step S2, stirring uniformly after adding an additive, soaking, and then carrying out high-pressure steam explosion treatment;

[0011] S4, cooling the corn slurry after high-pressure steam explosion treatment in step S3, adjusting pH, adding high-temperature alpha-amylase for primary enzymatic hydrolysis treatment, then heating and keeping for a period of time, cooling, adding medium-temperature alpha-amylase for secondary enzymatic hydrolysis treatment, to obtain liquefied liquid;

[0012] S5, warming the liquefied liquid obtained in step S4, adjusting pH, then adding composite enzyme for ultrasonic enzymatic hydrolysis, to obtain saccharified liquid;

[0013] S6, carrying out filtration, decolorization, ion exchange and concentration on the saccharified liquid obtained in step S5, to obtain glucose liquid.

[0014] Further, after removing impurities in step S1, the moisture of the corn kernels is adjusted to 15-18%, and then the corn kernels can be subjected to peeling and degerming treatment by using conventional process.

[0015] Further, the peeling treatment in step S1 can use a conventional corn peeling machine, and the corn kernels after removing impurities are fed into the peeling machine, and the friction force between the corn kernels is used to remove the seed coat by using a high-speed rotating friction wheel or cylinder.

[0016] Further, the degerming treatment in step S1 can use a conventional corn degerming machine, and the corn kernels after peeling are fed into the degerming machine, and the endosperm is separated from the endosperm by using mechanical extrusion or impact.

[0017] In step S1, by removing impurities, it is ensured that no foreign contaminants are introduced in the subsequent processing process, and the purity of the product is ensured. Adjusting the moisture to 15-18% helps to maintain the optimal state of the raw material, and avoids affecting the peeling and degerming effect due to too high or too low humidity.

[0018] Further, the degerminated corn kernels in step S2 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 inside remains hard.

[0019] Further, the degerminated corn kernels after thawing in step S2 are crushed to a particle size of 40 to 60 mesh.

[0020] In step S2, the process of low-temperature freezing and thawing can form ice crystals in the internal water of the corn kernels, destroy the cell wall structure, and make the starch particles more easily released, which helps to improve the enzyme hydrolysis efficiency in the subsequent steps.

[0021] Further, the amount of the additive added in step S3 is 1.5 to 2.2% of the weight of the corn powder obtained in step S2, and the additive is composed of 2-hydroxybutanedioic acid, polyvinyl alcohol, and calcium lignosulfonate in a weight ratio of 1 to 2:3 to 5:1, preferably 1.2:4:1; and the additive is soaked for 1 to 2 hours after being added.

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

[0023] Further, the dry matter content of the corn slurry in step S3 is 30 to 40%.

[0024] Further, the pressure in the high-pressure steam explosion process in step S3 is 1.4 to 1.6 MPa, the temperature is 130 to 160°C, and the treatment time is 100 to 140 seconds.

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

[0026] Further, in step S4, after the first enzyme hydrolysis, the temperature is heated to 130 to 140°C, and the temperature is maintained for 8 to 10 minutes, and then the temperature is cooled to 50 to 60°C for the second enzyme hydrolysis.

[0027] Further, in step S4, the high-temperature alpha-amylase is Bacillus licheniformis alpha-amylase, and the amount of addition is 25 to 35 U / g of corn powder, preferably 30 U / g; and the medium-temperature alpha-amylase is Aspergillus oryzae alpha-amylase, and the amount of addition is 30 to 45 U / g of corn powder, preferably 40 U / g.

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

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

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

[0031] In step S3, the corn flour is treated by high-pressure steam explosion, which can realize rapid heating and expansion under high temperature and high pressure in a short time, destroy the crystal structure of the starch granules, and thus make the structure of the starch granules loose. This change in structure increases the exposed area of the starch molecules, improves the contact opportunity between the enzymes and the starch molecules in the subsequent enzymatic hydrolysis process, and enables the enzymes to more effectively cut the starch chains to convert them into glucose or other short-chain sugars, which can significantly improve the subsequent enzymatic hydrolysis effect, reduce the time and energy consumption of the enzymatic hydrolysis, and improve the glucose yield. However, during the high-pressure steam explosion process, the distribution of the material may not be uniform, resulting in that part of the material cannot be fully exposed to the high-temperature and high-pressure steam, while another part of the material may be over-processed. Therefore, the application adds the aid composed of 2-hydroxybutanedioic acid, polyvinyl alcohol and calcium lignosulfonate to the corn slurry before the steam explosion treatment, which plays a key role in the subsequent enzymatic hydrolysis process and promotes the degradation and swelling of the starch in the corn slurry, so that the corn slurry can maintain good fluidity in the high-temperature and high-pressure environment, prevent the starch granules from caking and settling, and ensure the uniform distribution of the starch granules in the high-temperature and high-pressure environment, thereby improving the hydrolysis efficiency and reducing the risk of equipment blockage.

[0032] Then in step S4, the corn slurry is enzymatically hydrolyzed in stages by selecting the enzyme preparation and controlling the enzymatic hydrolysis conditions, which fully utilizes the optimal working environment of the two enzymes, avoids the risk of deactivation of a single enzyme species exposed to adverse conditions for a long time, and enables the liquefaction to be more complete. Through the steam explosion and enzymatic liquefaction processes in steps S3 and S4, the starch molecules are hydrolyzed to the size of dextrin and oligosaccharides, the number of substrate molecules increases, the number of terminal groups increases, and the opportunity for saccharifying enzyme action increases, which is conducive to the subsequent saccharification reaction. Moreover, the reaction degree of liquefaction can be effectively improved, and the generation of by-products can be reduced, which helps to improve the purity of glucose and simplify the subsequent separation and purification steps.

[0033] Further, in step S6, the saccharification liquid is subjected to filtration, decolorization, ion exchange, and concentration, etc. The conventional technical means in the prior art can be used for processing according to the needs of the product. For example, in the present application, a plate and frame filter press can be used to filter the saccharification liquid to remove impurities and insoluble substances; then activated carbon is added for decolorization, and the activated carbon is filtered out; finally, ion exchange resin is used to remove inorganic salts and organic impurities in the saccharification liquid, and the saccharification liquid is concentrated to 70-80% solid content.

[0034] In step S6, a combination of glucoamylase and pullulanase is used for enzymatic hydrolysis, and ultrasonic treatment is assisted. The cavitation effect of ultrasonic waves promotes the contact between the enzyme and the substrate, accelerates the reaction rate, and helps to disperse the material, reducing 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] Further, the temperature in the ion exchange process is 45-55℃, and the ion exchange resin is passed in the order of strong acid cation-weak base anion-strong acid cation-weak base anion.

[0036] Compared with the prior art, the process for producing glucose from corn provided by the present application has the following advantages:

[0037] The process for producing glucose from corn provided by the present application combines the regulation of process conditions such as freezing and thawing, high-pressure steam explosion, and multi-stage enzymatic hydrolysis, effectively improving the liquefaction efficiency, enhancing the saccharification effect, and accelerating the saccharification reaction speed, thereby quickly obtaining high-purity glucose with stable quality that meets the current standards and specifications. The process can shorten the time required for liquefaction and saccharification, thereby effectively reducing energy consumption and overall production costs. The more efficient conversion process ensures that more starch is converted into glucose, improves the efficiency of raw material use, and maximizes resource waste reduction. DETAILED DESCRIPTION

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

[0039] In the following examples and comparative examples, the reagents not specifically mentioned are conventional reagents, which can be purchased from conventional reagent production and sales companies. The methods used are conventional technical methods, and some raw material production companies are as follows:

[0040] Bacillus licheniformis alpha-amylase, CAS# 9000-85-5, Catalog# A299001; glucoamylase, CAS# 9032-08-0, Catalog# A107823; pullulanase, CAS# 9075-68-7, Catalog# P299007, all purchased from Shanghai Aladdin Biochem Technology Co., Ltd;

[0041] Aspergillus oryzae alpha-amylase, CAS# 9001-19-8, Catalog# J01412; beta-amylase, CAS# 9000-91-3, Catalog# M62206, both purchased from Shanghai Miry Biochemical Technology Co., Ltd;

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

[0043] 2-hydroxybutanedioic acid, CAS# 97-67-6; calcium lignosulfonate, CAS# 8061-52-7;

[0044] Povidone K-30, CAS# 9003-39-8, Catalog# S30268, purchased from Shanghai Yuan Ye Biological Technology Co., Ltd.

[0045] Example 1

[0046] A process for producing glucose from corn by dry method, comprising the following steps:

[0047] S1, remove the impurities in the corn kernels, adjust the moisture content to 15%, and then use the conventional process to remove the skin and embryo of the corn kernels to obtain the de-embryo corn kernels;

[0048] S2, freeze the de-embryo corn kernels obtained in step S1 at -30℃ for 12h, then thaw at room temperature for 2h, when the surface is slightly wet but the inside still maintains the hardness, crush to a particle size of 40 mesh to obtain corn powder;

[0049] S3, prepare corn slurry by adding water to the corn powder obtained in step S2, adjust the slurry to a dry matter content of 30%, then add 1.5% by weight of the corn powder of an additive composed of 2-hydroxybutanedioic acid, polyvinyl alcohol and calcium lignosulfonate in a weight ratio of 1:5:1, stir uniformly, soak for 1h, and then perform high-pressure steam explosion treatment under the conditions of a pressure of 1.4MPa and a temperature of 130℃ for a treatment time of 140s;

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

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

[0052] S6, filtering the saccharified liquid obtained in step S5 using a plate-and-frame filter press to remove impurities and insoluble substances, then adding activated carbon for decolorization and filtering out the activated carbon, and finally removing inorganic salts and organic impurities in the saccharified liquid using ion exchange resin, concentrating the saccharified liquid to a solid content of 70% through the ion exchange resin at a temperature of 45℃ in the order of strong acid cation-weak base anion-strong acid cation-weak base anion, to obtain a glucose liquid.

[0053] Example 2

[0054] A process for producing glucose from corn using a dry method, comprising the following steps:

[0055] S1, removing impurities from corn kernels, adjusting the moisture content to 17%, then peeling and degerming 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℃ for 11 h, then thawing at room temperature for 2.5 h, and when the surface is slightly wet but the inside remains hard, crushing to a particle size of 50 mesh, to obtain corn powder;

[0057] S3, preparing corn slurry by adding water to the corn powder obtained in step S2, adjusting the slurry to a dry matter content of 34%, then adding 1.7% by weight of an additive composed of 2-hydroxybutanedioic acid, polyvinyl alcohol 1788, and calcium lignosulfonate in a weight ratio of 1.2:4:1, stirring uniformly, soaking for 1.5 h, then performing high-pressure steam explosion treatment under the condition of a pressure of 1.5 MPa and a temperature of 150℃ for a treatment time of 120 s;

[0058] S4, cooling the corn slurry after the high-pressure steam explosion treatment in step S3 to 90℃, adjusting the pH to 6.0-6.5, then adding 30 U / g of Bacillus licheniformis alpha-amylase for a first enzymatic treatment for 70 min, then heating to 135℃, maintaining for 9 min, cooling to 55℃, then adding 40 U / g of Aspergillus oryzae alpha-amylase for a second enzymatic treatment for 55 min, to obtain a liquefied liquid;

[0059] S5, warming the liquefied liquid obtained in step S4 to 58℃, adjusting the pH to 5.0-5.5, then adding 65 U / g of glucoamylase and 25 U / g of pullulanase for enzymatic treatment under the condition of an ultrasonic frequency of 25 kHz for 8 h, to obtain a saccharified liquid;

[0060] S6, filtering the saccharified liquid obtained in step S5 using a plate-and-frame filter press to remove impurities and insoluble substances, then adding activated carbon for decolorization and filtering out the activated carbon, and finally removing inorganic salts and organic impurities in the saccharified liquid using ion exchange resin, concentrating the saccharified liquid to a solid content of 75% through the ion exchange resin at a temperature of 50℃ in the order of strong acid cation-weak base anion-strong acid cation-weak base anion, to obtain a glucose liquid.

[0061] Example 3

[0062] A process for producing glucose from corn using a dry method, comprising the following steps:

[0063] S1, removing impurities from corn kernels, adjusting the moisture content to 18%, then peeling and degerming 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℃ for 10 h, then thawing at room temperature for 3 h, and when the surface is slightly wet but the inside remains hard, crushing to a particle size of 60 mesh, to obtain corn powder;

[0065] S3, preparing corn slurry by adding water to the corn powder obtained in step S2, adjusting the slurry to a dry matter content of 40%, then adding 2.2% by weight of an additive composed of 2-hydroxybutanedioic acid, polyvinyl alcohol, and calcium lignosulfonate in a weight ratio of 2:3:1, stirring uniformly, soaking for 2 h, then performing high-pressure steam explosion treatment under the conditions of a pressure of 1.6 MPa and a temperature of 160℃ for a treatment time of 100 s;

[0066] S4, the corn slurry after the high-pressure steam explosion treatment in step S3 is cooled to 95℃, the pH is adjusted to 6.5-7.0, then 35 U / g of Bacillus licheniformis alpha-amylase is added for a first enzymatic treatment for 60 min, then heated to 140℃, kept for 8 min, cooled to 60℃, then 45 U / g of Aspergillus oryzae alpha-amylase is added for a second enzymatic treatment for 60 min, to obtain a liquefied liquid;

[0067] S5, the liquefied liquid obtained in step S4 is heated to 63℃, the pH is adjusted to 5.0-5.5, then 70 U / g of glucoamylase and 30 U / g of pullulanase are added for enzymatic treatment under the condition of 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 decolorized by activated carbon, and the activated carbon is filtered out, finally the inorganic salts and organic impurities in the saccharified liquid are removed by ion exchange resin, at a temperature of 55℃, in the order of strong acid cation-weak base anion-strong acid cation-weak base anion, the saccharified liquid is concentrated to a solid content of 80%, to obtain a glucose liquid.

[0069] Comparative Example 1

[0070] Compared with Example 2, the difference is that the degerminated corn kernels in step S2 are not subjected to freezing treatment, but are directly crushed to a particle size of 50 mesh, and other components and operation 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 aid in step S3 is replaced by povidone K30, i.e. the aid is composed of 2-hydroxybutanedioic acid, povidone K30 and calcium lignosulfonate in a weight ratio of 1.2:4:1, and other components and operation processes are the same as those in Example 2.

[0073] Comparative Example 3

[0074] Compared with Example 2, the difference is that the calcium lignosulfonate is not added in the aid in step S3, but the amount of polyvinyl alcohol 1788 is correspondingly increased, i.e. the aid is composed of 2-hydroxybutanedioic acid and polyvinyl alcohol 1788 in a weight ratio of 1.2:5, and other components and operation processes are the same as those in Example 2.

[0075] Comparative Example 4

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

[0077] S3, the corn powder obtained in step S2 is prepared into corn slurry by adding water to obtain a dry matter content of 34%, and then 1.7% of the corn powder by weight of an additive composed of 2-hydroxybutanedioic acid, polyvinyl alcohol 1788 and calcium lignosulfonate in a weight ratio of 1.2:4:1 is added, stirred uniformly, and soaked for 1.5 h;

[0078] S4, the corn slurry is heated to 90℃, the pH is adjusted to 6.0-6.5, then 30 U / g of Bacillus licheniformis alpha-amylase is added for primary enzymatic hydrolysis for 1.5 h, then heated to 135℃, kept for 9 min, cooled to 55℃, then 40 U / g of Aspergillus oryzae alpha-amylase is added for secondary enzymatic hydrolysis for 2 h, to obtain a liquefied liquid.

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

[0080] Comparative Example 5

[0081] Compared with Example 2, the difference is that the Aspergillus oryzae alpha-amylase in step S3 is replaced by beta-amylase, i.e., the specific step S4 is:

[0082] S4, the corn slurry after high-pressure steam explosion treatment in step S3 is cooled to 90℃, the pH is adjusted to 6.0-6.5, then 30 U / g of Bacillus licheniformis alpha-amylase is added for primary enzymatic hydrolysis for 70 min, then heated to 135℃, kept for 9 min, cooled to 55℃, the pH is adjusted to 4.5-5.0, then 40 U / g of beta-amylase is added for secondary enzymatic hydrolysis for 55 min, to obtain a liquefied liquid. The other components and operation processes are the same as those in Example 2.

[0083] Test Example 1, quality detection of glucose prepared by the present application

[0084] The DE value (%) (glucose equivalent value) and glucose purity (%) of the glucose liquid prepared by Example 1-3 and Comparative Example 1-5 of the present application are detected respectively, and 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 process of Example 1-3 of the present application can obtain high-purity glucose under the condition of greatly shortened liquefaction and saccharification time. When part of the conditions in the process of Comparative Example 1-5 are changed, the purity and DE value of the prepared glucose all decrease to different degrees, indicating that the steps of the process for producing glucose from corn provided by the present application complement each other, the synergistic effect between the steps makes the whole production process more smooth and 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 invention. Any person skilled in the art can 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 those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A process for producing glucose using a dry corn process, characterized in that, Includes the following steps: S1. After removing impurities from the corn kernels, adjust the moisture content, and then perform dehulling and degerming to obtain degermed corn kernels. S2. Freeze the degermed corn kernels obtained in step S1, and grind them into corn flour after thawing. S3. The corn flour obtained in step S2 is mixed with water to prepare corn slurry, the additives are added, the mixture is stirred evenly and soaked, and then high-pressure steam explosion treatment is carried out. S4. Cool down the corn liquor after the high-pressure steam explosion treatment in step S3, adjust the pH, add high-temperature α-amylase for a first enzymatic hydrolysis treatment, then heat and keep warm for a period of time, cool down, add medium-temperature α-amylase for a second enzymatic hydrolysis treatment, and obtain liquefied liquid. S5. Heat the liquefied liquid obtained in step S4, adjust the pH, and then add a compound enzyme for ultrasonic enzymatic hydrolysis to obtain a saccharified liquid; S6. Filter, decolorize, ion exchange, and concentrate the saccharified liquid obtained in step S5 to obtain a glucose solution. The auxiliary agent in step S3 is composed of 2-hydroxysuccinic acid, polyvinyl alcohol and calcium lignosulfonate in a weight ratio of 1~2:3~5:

1. The pressure during the high-pressure steam explosion process in step S3 is 1.4~1.6 MPa, the temperature is 130~160℃, and the processing time is 100~140 s; 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.

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

4. The process for producing glucose using the dry method of corn according to claim 1, characterized in that, The amount of additive added in step S3 is 1.5 to 2.2% of the weight of the corn flour obtained in step S2.

5. The process for producing glucose using the dry method from corn according to claim 1, characterized in that, In step S4, the corn syrup treated with high-pressure steam explosion is cooled to 85~95℃ and the pH is adjusted to 6.0~7.

0.

6. The process for producing glucose using the dry method from corn according to claim 1, characterized in that, In step S4, after the first enzymatic hydrolysis, the temperature is heated to 130-140°C and kept at that temperature for 8-10 minutes, then cooled to 50-60°C for a second enzymatic hydrolysis.

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

8. The process for producing glucose using the dry method from corn according to claim 1, characterized in that, In step S5, the temperature is raised to 55-63℃ 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.