Maltose syrup special for bean powder processing and preparation method thereof

Abstract

The application relates to the technical field of agricultural and sideline food processing, and discloses a maltose syrup special for bean powder processing and a preparation method thereof, which is prepared from starch as raw material through a specific enzymolysis process, and the key feature is that the physicochemical indexes are as follows: DE value is 50-55, maltose content is greater than or equal to 50%, glucose is less than or equal to 4%, and the light transmittance is greater than or equal to 95%. The preparation method of the maltose syrup mainly comprises the steps of slurry mixing and liquefaction, enzymolysis and saccharification, refining and purification, vacuum concentration and standardization treatment. The application also provides the application of the syrup in the whole process of bean powder production, ensures the system uniformity and processing stability of the bean powder base material in the batching stage, guarantees the pure sensory quality of the product, and comprehensively improves the brewing performance, appearance form and shelf life stability of the bean powder.

Description

Technical Field

[0001] This invention relates to the field of agricultural and sideline food processing technology, specifically to a special maltose syrup for soybean flour processing and its preparation method. Background Technology

[0002] The agricultural and sideline food processing industry is a comprehensive industry that uses agricultural, forestry, animal husbandry and fishery products as raw materials and engages in production activities such as grain milling, feed processing, vegetable oil and sugar processing, slaughtering and meat processing, and aquatic product processing. It covers three major areas: primary processing, deep processing and agricultural product circulation services.

[0003] Currently, due to the poor compatibility between conventional syrup components used in soybean flour production and the soybean protein system, it is impossible to ensure that the syrup and soybean milk are stably combined at a suitable temperature during the ingredient mixing stage. When syrup components cause protein flocculation and uneven distribution, it will result in a rough product texture and uncoordinated flavor release, and the processing stability of soybean flour base cannot be guaranteed. At the same time, in the subsequent heat treatment stages of homogenization, concentration and drying, it is impossible to ensure that the syrup maintains its own physicochemical stability under specific temperature, pressure and vacuum conditions, which will cause non-enzymatic browning or decomposition of the syrup, resulting in darker product color and deteriorated flavor. Furthermore, it is impossible to control the rheological properties abnormally during the processing in real time.

[0004] Therefore, a special maltose syrup for soybean flour processing and its preparation method are proposed to solve the above problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a special maltose syrup for soybean flour processing and its preparation method, which solves the problems mentioned in the background art, such as the inability to ensure stable combination of syrup and soybean milk at a suitable temperature during the ingredient mixing stage, and the inability to ensure that the syrup maintains its physicochemical stability under specific temperature, pressure and vacuum conditions.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a special maltose syrup for soybean flour processing and its preparation method, the preparation method comprising the following steps: Step 1: Slurry liquefaction. Select starch as raw material, add water to prepare starch milk and then liquefy it. Step 2: Enzymatic hydrolysis and saccharification. The liquefied liquid is mixed with a saccharifying enzyme compound preparation and enzymatically hydrolyzed under specific conditions to obtain a saccharified liquid. Step 3: Refining and purification. The saccharified solution is sequentially filtered, decolorized, and subjected to ion exchange treatment to obtain a refined sugar solution. Step 4: Vacuum concentration, the refined sugar solution is concentrated under specific vacuum and temperature conditions to obtain the special maltose syrup for soybean flour processing; Step 5: Standardization process: The maltose syrup concentrate is tested and adjusted by batch mixing to ensure that the final product meets the preset physicochemical indicators, thus obtaining the special maltose syrup for soybean flour processing. In step two, the indicators for controlling the saccharified solution at the end of enzymatic hydrolysis are: DE value 50-55, maltose content greater than or equal to 50%, glucose content less than or equal to 4%, and light transmittance greater than or equal to 95%.

[0007] Preferably, in step one, the slurry liquefaction includes the following steps: Starch raw materials are mixed with water under stirring conditions to prepare a starch milk with a mass concentration of 30%-40%. The pH value of the starch milk is adjusted to 5.5-6.2 with acid or alkali. A thermoresistant α-amylase is added at a rate of 100-200 units per gram of dry starch. The temperature is then raised to 85℃-95℃ and maintained for 10-30 minutes to complete the liquefaction process and obtain a liquefied liquid.

[0008] Preferably, the starch raw material is at least one of corn starch, tapioca starch or waxy corn starch, and the activity unit of the heat-resistant α-amylase is 20000 U / mL.

[0009] Preferably, in step two, the enzymatic hydrolysis and saccharification includes the following steps: The liquefied liquid is cooled to 55℃-60℃, the pH is adjusted to 5.0-5.8, and a saccharifying enzyme compound preparation consisting of fungal amylase and β-amylase is added. The amount of fungal amylase added is controlled to be 0.5-1.5 units per gram of dry starch, and the amount of β-amylase added is 5-15 units per gram of dry starch. The saccharification reaction is carried out under stirring conditions for 20-40 hours, during which the temperature is maintained at 55℃-60℃.

[0010] Preferably, the fungal amylase has an enzyme activity unit of 10000 U / g, and the β-amylase has an enzyme activity unit of 2000 U / g. During the saccharification reaction, the DE value is measured every 8-12 hours. When the DE value reaches 50-55, the temperature of the liquid is raised to 85℃-95℃ and maintained for 10-30 minutes to inactivate the enzyme and terminate the saccharification reaction.

[0011] Preferably, in step three, the purification process includes the following steps: Filtration: The saccharified liquid after enzyme inactivation is first coarsely filtered through a 100-200 mesh sieve to remove insoluble impurities, and then finely filtered through a plate and frame filter or membrane filtration equipment to obtain a clear sugar solution. Decolorization: Pump the clarified sugar solution into a decolorization tank, heat it to 70℃-80℃, add powdered activated carbon accounting for 0.5%-2.0% of the dry matter weight of the sugar solution, stir and decolorize for 20-40 minutes, and then filter it through a filter press to remove the activated carbon to obtain the decolorized sugar solution; Ion exchange: The decolorized sugar solution is passed sequentially through a strong acid cation exchange resin column and a weak base anion exchange resin column, with the flow rate controlled at 1 to 3 times the volume of the resin column per hour to remove inorganic ions and colored substances from the sugar solution, thereby obtaining the refined sugar solution, the conductivity of which is less than or equal to 50 μS / cm.

[0012] Preferably, in the decolorization step, the activated carbon is added in two stages. The first addition is 70% of the total addition. After decolorization for 20 minutes, the mixture is filtered, and the remaining 30% of activated carbon is added to the filtrate for a second decolorization of 20 minutes.

[0013] Preferably, in step four, vacuum concentration is carried out in a vacuum evaporator, with the vacuum degree of the evaporator controlled at -0.08MPa to -0.09MPa and the evaporation temperature at 60℃-65℃, concentrating the refined sugar solution to a solid content of 75%-85%, thereby obtaining the maltose syrup for soybean flour processing.

[0014] Preferably, in step five, the standardization process includes the following specific steps: Samples of the concentrated maltose syrup were taken and tested for their DE value, maltose content, and glucose content. Different batches of concentrated maltose syrup with preset physicochemical indicators were mixed, or other batches of syrup or specific components that met the indicator requirements were added to batches that did not meet the standards for adjustment, until the DE value of the mixed maltose syrup was stable between 50 and 55, the maltose content was greater than or equal to 50%, and the glucose content was less than or equal to 4%. This completed product standardization and yielded the soybean flour processing-specific maltose syrup with uniform composition and performance.

[0015] Preferably, the malt syrup has the following physicochemical properties: The DE value is 50-55, the maltose content is greater than or equal to 50%, the glucose content is less than or equal to 4%, the light transmittance is greater than or equal to 95%, and the maltose syrup is configured to the following process conditions suitable for soybean flour production: ingredient temperature 50℃-60℃, homogenization temperature 60℃-65℃, pressure 15MPa-25MPa, concentration temperature 60℃-65℃, and vacuum degree -0.08MPa to -0.09MPa.

[0016] Compared with the prior art, the present invention provides a special maltose syrup for soybean flour processing and its preparation method, which has the following beneficial effects: 1. In this invention, by controlling the physicochemical properties of the special maltose syrup for soybean flour processing within a specific range, especially by limiting the combination of a low glucose content with a specific maltose content and DE value, the maltose syrup can avoid excessive interaction between sugars and soybean protein under heating conditions when mixed with soybean milk. This solves the problem of protein flocculation and uneven distribution caused by conventional syrups, ensuring the uniformity and processing stability of the soybean flour base material during the ingredient preparation stage, and laying a good foundation for subsequent processes.

[0017] 2. In this invention, the specific composition and thermal stability design of the special maltose syrup for soybean flour processing enable it to adapt to the process conditions of key heat treatment steps in soybean flour production. In the presence of this maltose syrup, the liquid system can maintain stable rheological properties under specific temperature, pressure and vacuum conditions, inhibiting the non-enzymatic browning reaction of sugars at high temperatures. This solves the technical defects of easy color deepening and flavor deterioration of products during processing, and ensures the pure sensory quality of the product.

[0018] 3. In this invention, by synergistically optimizing the composition and functional characteristics of the special maltose syrup for soybean flour processing, it can play a role in increasing the glass transition temperature of the liquid and regulating the viscosity of the material in the final spray drying stage. This improves the microstructure of soybean flour products at the molecular level and synergistically solves the common problems of poor solubility, easy clumping, poor flowability and short shelf life of traditional soybean flour products. It comprehensively improves the reconstitution performance, appearance and shelf stability of soybean flour. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1: A special maltose syrup for soybean flour processing and its preparation method, the preparation method includes the following steps: Step 1: Slurry liquefaction. Select starch as raw material, add water to prepare starch milk and then liquefy it. Step 2: Enzymatic hydrolysis and saccharification. The liquefied liquid is mixed with a saccharifying enzyme compound preparation and enzymatically hydrolyzed under specific conditions to obtain a saccharified liquid. Step 3: Refining and purification. The saccharified solution is sequentially filtered, decolorized, and subjected to ion exchange treatment to obtain a refined sugar solution. Step 4: Vacuum concentration. The refined sugar solution is concentrated under specific vacuum and temperature conditions to obtain maltose syrup for soybean flour processing. Step 5: Standardization process: The maltose syrup concentrate is tested and adjusted by batch mixing to ensure that the final product meets the preset physicochemical indicators, thus producing a special maltose syrup for soybean flour processing. In step two, the indicators for controlling the saccharified liquid at the end of enzymatic hydrolysis are: DE value 50, maltose content greater than or equal to 50%, glucose content less than or equal to 4%, and light transmittance greater than or equal to 95%.

[0021] Step one, slurry liquefaction, includes the following steps: Starch raw materials and water are mixed under stirring conditions to prepare a starch milk with a mass concentration of 30%. The pH value of the starch milk is adjusted to 5.5 with acid or alkali. Heat-resistant α-amylase is added at a rate of 100 units per gram of dry starch. The temperature is then raised to 85°C and kept at that temperature for 10 minutes to complete the liquefaction process and obtain a liquefied liquid.

[0022] The starch raw material is corn starch, and the enzyme activity unit of the heat-resistant α-amylase is 20000 U / mL.

[0023] Step two, enzymatic hydrolysis and saccharification, includes the following steps: The liquefied liquid was cooled to 55°C, the pH was adjusted to 5.0, and a saccharifying enzyme compound preparation consisting of fungal amylase and β-amylase was added. The amount of fungal amylase added was controlled to be 0.5 units per gram of dry starch, and the amount of β-amylase added was 5 units per gram of dry starch. The saccharification reaction was carried out for 20 hours under stirring conditions, and the temperature was kept at 55°C during the process.

[0024] The activity units of fungal amylase are 10000 U / g, and the activity units of β-amylase are 2000 U / g. During the saccharification reaction, the DE value is measured every 8 hours. When the DE value reaches 50, the temperature of the liquid is raised to 85℃ and maintained for 10 minutes to inactivate the enzyme and terminate the saccharification reaction.

[0025] Step three, purification, includes the following steps: Filtration: The saccharified liquid after enzyme inactivation is first coarsely filtered through a 100-mesh sieve to remove insoluble impurities, and then finely filtered through a plate and frame filter or membrane filtration equipment to obtain a clear sugar solution. Decolorization: Pump the clarified sugar solution into a decolorization tank, heat it to 70°C, add powdered activated carbon accounting for 0.5% of the dry matter weight of the sugar solution, stir and decolorize for 20 minutes, then filter it through a filter press to remove the activated carbon, and obtain the decolorized sugar solution; Ion exchange: The decolorized sugar solution is passed sequentially through a strong acid cation exchange resin column and a weak base anion exchange resin column, with the flow rate controlled at 1 times the resin column volume per hour, to remove inorganic ions and colored substances from the sugar solution, resulting in a refined sugar solution with a conductivity of less than or equal to 50 μS / cm.

[0026] In the decolorization step, activated carbon is added in two stages. The first addition is 70% of the total amount added. After decolorization for 20 minutes, the mixture is filtered, and the remaining 30% of activated carbon is added to the filtrate for a second decolorization of 20 minutes.

[0027] In step four, vacuum concentration is carried out in a vacuum evaporator. The vacuum degree of the evaporator is controlled at -0.08MPa and the evaporation temperature is 60℃. The refined sugar solution is concentrated to a solid content of 75%, which yields maltose syrup for soybean flour processing.

[0028] Step five, the standardization process includes the following specific steps: Samples of the concentrated maltose syrup were taken and tested for their DE value, maltose content, and glucose content. Different batches of concentrated maltose syrup with preset physicochemical indicators were mixed, or other batches of syrup or specific components that met the indicator requirements were added to batches that did not meet the standards for adjustment, until the DE value of the mixed maltose syrup was 50, the maltose content was greater than or equal to 50%, and the glucose content was less than or equal to 4%, thus completing product standardization and obtaining a soybean flour processing-specific maltose syrup with uniform composition and performance.

[0029] Malt syrup has the following physicochemical properties: The DE value is 50, the maltose content is greater than or equal to 50%, the glucose content is less than or equal to 4%, the light transmittance is greater than or equal to 95%, and the maltose syrup is configured to be suitable for the following process conditions for soybean flour production: ingredient temperature 50℃, homogenization temperature 60℃, pressure 15MPa, concentration temperature 60℃, and vacuum degree -0.08MPa.

[0030] Example 2: A special maltose syrup for soybean flour processing and its preparation method, the preparation method includes the following steps: Step 1: Slurry liquefaction. Select starch as raw material, add water to prepare starch milk and then liquefy it. Step 2: Enzymatic hydrolysis and saccharification. The liquefied liquid is mixed with a saccharifying enzyme compound preparation and enzymatically hydrolyzed under specific conditions to obtain a saccharified liquid. Step 3: Refining and purification. The saccharified solution is sequentially filtered, decolorized, and subjected to ion exchange treatment to obtain a refined sugar solution. Step 4: Vacuum concentration. The refined sugar solution is concentrated under specific vacuum and temperature conditions to obtain maltose syrup for soybean flour processing. Step 5: Standardization process: The maltose syrup concentrate is tested and adjusted by batch mixing to ensure that the final product meets the preset physicochemical indicators, thus producing a special maltose syrup for soybean flour processing. In step two, the indicators for controlling the saccharified liquid at the end of enzymatic hydrolysis are: DE value 52.5, maltose content greater than or equal to 50%, glucose content less than or equal to 4%, and light transmittance greater than or equal to 95%.

[0031] Step one, slurry liquefaction, includes the following steps: Starch raw materials and water are mixed under stirring conditions to prepare a starch milk with a mass concentration of 35%. The pH value of the starch milk is adjusted to 5.85 with acid or alkali. Heat-resistant α-amylase is added at a rate of 150 units per gram of dry starch. The temperature is then raised to 90°C and kept at that temperature for 20 minutes to complete the liquefaction process and obtain a liquefied liquid.

[0032] The starch raw materials are corn starch and cassava starch, and the enzyme activity unit of the heat-resistant α-amylase is 20000 U / mL.

[0033] Step two, enzymatic hydrolysis and saccharification, includes the following steps: The liquefied liquid was cooled to 57.5℃, the pH was adjusted to 5.4, and a saccharifying enzyme compound preparation consisting of fungal amylase and β-amylase was added. The amount of fungal amylase added was controlled at 1.0 unit per gram of dry starch, and the amount of β-amylase added was 10 units per gram of dry starch. The saccharification reaction was carried out under stirring conditions for 30 hours, during which the temperature was maintained at 57.5℃.

[0034] The activity units of fungal amylase are 10000 U / g, and the activity units of β-amylase are 2000 U / g. During the saccharification reaction, the DE value is measured every 10 hours. When the DE value reaches 52.5, the temperature of the liquid is raised to 90℃ and maintained for 20 minutes to inactivate the enzyme and terminate the saccharification reaction.

[0035] Step three, purification, includes the following steps: Filtration: The saccharified liquid after enzyme inactivation is first coarsely filtered through a 150-mesh sieve to remove insoluble impurities, and then finely filtered through a plate and frame filter or membrane filtration equipment to obtain a clear sugar solution. Decolorization: Pump the clarified sugar solution into a decolorization tank, heat it to 75°C, add powdered activated carbon accounting for 1.25% of the dry matter weight of the sugar solution, stir and decolorize for 30 minutes, then filter it through a filter press to remove the activated carbon, and obtain the decolorized sugar solution. Ion exchange: The decolorized sugar solution is passed sequentially through a strong acid cation exchange resin column and a weak base anion exchange resin column, with the flow rate controlled at twice the volume of the resin column per hour, to remove inorganic ions and colored substances from the sugar solution, resulting in a refined sugar solution with a conductivity of less than or equal to 50 μS / cm.

[0036] In the decolorization step, activated carbon is added in two stages. The first addition is 70% of the total amount added. After decolorization for 20 minutes, the mixture is filtered, and the remaining 30% of activated carbon is added to the filtrate for a second decolorization of 20 minutes.

[0037] In step four, vacuum concentration is carried out in a vacuum evaporator. The vacuum degree of the evaporator is controlled at -0.085MPa and the evaporation temperature is 62.5℃. The refined sugar solution is concentrated to a solid content of 80%, which yields maltose syrup for soybean flour processing.

[0038] Step five, the standardization process includes the following specific steps: Samples of the concentrated maltose syrup were taken and tested for their DE value, maltose content, and glucose content. Different batches of concentrated maltose syrup with preset physicochemical indicators were mixed, or other batches of syrup or specific components that met the indicator requirements were added to batches that did not meet the standards for adjustment, until the DE value of the mixed maltose syrup was 52.5, the maltose content was greater than or equal to 50%, and the glucose content was less than or equal to 4%. This completed product standardization and yielded a soybean flour processing-specific maltose syrup with uniform composition and performance.

[0039] Malt syrup has the following physicochemical properties: The DE value is 52.5, the maltose content is greater than or equal to 50%, the glucose content is less than or equal to 4%, the light transmittance is greater than or equal to 95%, and the maltose syrup is configured to meet the following process conditions suitable for soybean flour production: ingredient temperature 55℃, homogenization temperature 62.5℃, pressure 20MPa, concentration temperature 62.5℃, and vacuum degree -0.085MPa.

[0040] Example 3: A special maltose syrup for soybean flour processing and its preparation method, the preparation method includes the following steps: Step 1: Slurry liquefaction. Select starch as raw material, add water to prepare starch milk and then liquefy it. Step 2: Enzymatic hydrolysis and saccharification. The liquefied liquid is mixed with a saccharifying enzyme compound preparation and enzymatically hydrolyzed under specific conditions to obtain a saccharified liquid. Step 3: Refining and purification. The saccharified solution is sequentially filtered, decolorized, and subjected to ion exchange treatment to obtain a refined sugar solution. Step 4: Vacuum concentration. The refined sugar solution is concentrated under specific vacuum and temperature conditions to obtain maltose syrup for soybean flour processing. Step 5: Standardization process: The maltose syrup concentrate is tested and adjusted by batch mixing to ensure that the final product meets the preset physicochemical indicators, thus producing a special maltose syrup for soybean flour processing. In step two, the indicators for controlling the saccharified liquid at the end of enzymatic hydrolysis are: DE value 55, maltose content greater than or equal to 50%, glucose content less than or equal to 4%, and light transmittance greater than or equal to 95%.

[0041] Step one, slurry liquefaction, includes the following steps: Starch raw materials and water are mixed under stirring conditions to prepare a starch milk with a mass concentration of 40%. The pH value of the starch milk is adjusted to 6.2 with acid or alkali. Thermoresistant α-amylase is added at a rate of 200 units per gram of dry starch. The temperature is then raised to 95°C and kept at that temperature for 30 minutes to complete the liquefaction process and obtain a liquefied liquid.

[0042] The starch raw materials are corn starch, cassava starch, and waxy corn starch. The activity unit of the heat-resistant α-amylase is 20000 U / mL.

[0043] Step two, enzymatic hydrolysis and saccharification, includes the following steps: The liquefied liquid was cooled to 60°C, the pH was adjusted to 5.8, and a saccharifying enzyme compound preparation consisting of fungal amylase and β-amylase was added. The amount of fungal amylase added was controlled at 1.5 units per gram of dry starch, and the amount of β-amylase added was 15 units per gram of dry starch. The saccharification reaction was carried out under stirring conditions for 40 hours, during which the temperature was maintained at 60°C.

[0044] The activity units of fungal amylase are 10000 U / g, and the activity units of β-amylase are 2000 U / g. During the saccharification reaction, the DE value is measured every 12 hours. When the DE value reaches 55, the temperature of the liquid is raised to 95℃ and maintained for 30 minutes to inactivate the enzyme and terminate the saccharification reaction.

[0045] Step three, purification, includes the following steps: Filtration: The saccharified liquid after enzyme inactivation is first coarsely filtered through a 200-mesh sieve to remove insoluble impurities, and then finely filtered through a plate and frame filter or membrane filtration equipment to obtain a clear sugar solution. Decolorization: Pump the clarified sugar solution into a decolorization tank, heat it to 80°C, add powdered activated carbon accounting for 2.0% of the dry matter weight of the sugar solution, stir and decolorize for 40 minutes, then filter it through a filter press to remove the activated carbon, and obtain the decolorized sugar solution; Ion exchange: The decolorized sugar solution is passed sequentially through a strong acid cation exchange resin column and a weak base anion exchange resin column, with the flow rate controlled at 3 times the resin column volume per hour, to remove inorganic ions and colored substances from the sugar solution, resulting in a refined sugar solution with a conductivity of less than or equal to 50 μS / cm.

[0046] In the decolorization step, activated carbon is added in two stages. The first addition is 70% of the total amount added. After decolorization for 20 minutes, the mixture is filtered, and the remaining 30% of activated carbon is added to the filtrate for a second decolorization of 20 minutes.

[0047] In step four, vacuum concentration is carried out in a vacuum evaporator. The vacuum degree of the evaporator is controlled at -0.09MPa and the evaporation temperature is 65℃. The refined sugar solution is concentrated to a solid content of 85%, which yields maltose syrup for soybean flour processing.

[0048] Step five, the standardization process includes the following specific steps: Samples of the concentrated maltose syrup were taken and tested for their DE value, maltose content, and glucose content. Different batches of concentrated maltose syrup with preset physicochemical indicators were mixed, or other batches of syrup or specific components that met the indicator requirements were added to batches that did not meet the standards for adjustment, until the DE value of the mixed maltose syrup stabilized at 55, the maltose content was greater than or equal to 50%, and the glucose content was less than or equal to 4%. This completed product standardization and yielded a soybean flour processing-specific maltose syrup with uniform composition and performance.

[0049] Malt syrup has the following physicochemical properties: The DE value is 55, the maltose content is greater than or equal to 50%, the glucose content is less than or equal to 4%, the light transmittance is greater than or equal to 95%, and the maltose syrup is configured to be suitable for the following process conditions for soybean flour production: ingredient temperature 60℃, homogenization temperature 65℃, pressure 25MPa, concentration temperature 65℃, and vacuum degree -0.09MPa.

[0050] Comparative Example 1: The difference between this comparative example and Example 1 is that the glucose content was not controlled during the enzymatic hydrolysis saccharification process in the preparation of malt syrup in this comparative example, and the glucose content of the resulting malt syrup was greater than 10%, with a DE value of 60. Comparative Example 2: The difference between this comparative example and Example 2 is that in the preparation of malt syrup in this comparative example, only fungal amylase was used in the enzymatic hydrolysis and saccharification stage, and no β-amylase was added. The maltose content of the obtained malt syrup was 30%, and the DE value was 48. Comparative Example 3 differs from Example 3 in that the ion exchange treatment step is omitted in the purification process of this comparative example. Comparative Example 4 differs from Example 3 in that the preparation process of this comparative example does not include standardized processing steps, resulting in significant batch-to-batch variations in the composition of the malt syrup product.

[0051] The performance of the maltose syrup for soybean flour processing and its preparation method in Examples 1-3 and Comparative Examples 1-4 was tested. The test items and test methods are as follows: Soy flour processing suitability test: Equal amounts of the test maltose syrup and standard soy milk were mixed at a specific temperature, and the uniformity, stability and whether protein flocculants were produced in the mixture were observed and recorded. Thermal processing stability test: Soy milk base containing the malt syrup to be tested was placed under specific temperature and vacuum conditions for simulated concentration treatment. Samples were taken before and after the treatment, and the color change of the product was measured using a colorimeter to evaluate the degree of Maillard reaction. Final product quality evaluation: The soybean powder made with the maltose syrup to be tested was spray-dried, and the flowability, solubility, color and state after reconstitution of the resulting soybean powder product were comprehensively evaluated in accordance with industry standard methods.

[0052] The test data of the special maltose syrup for soybean flour processing and its preparation method in Examples 1-3 and Comparative Examples 1-4 are recorded in the table below:

[0053] By comparing and analyzing the data in the table, it can be seen that the soybean flour processing-specific maltose syrup and its preparation method in Examples 1-3 have superior performance compared to the soybean flour processing-specific maltose syrup and its preparation method in Comparative Examples 1-4. This indicates that by controlling the physicochemical indicators of the soybean flour processing-specific maltose syrup within a specific range, especially by limiting the combination of a low glucose content with a specific maltose content and DE value, the maltose syrup can avoid excessive interaction between sugars and soybean protein under heating conditions when mixed with soy milk. This solves the problem of protein flocculation and uneven distribution that is easily caused by conventional syrups, ensuring the uniformity and processing stability of the soybean flour base material during the ingredient preparation stage, laying a good foundation for subsequent processes. The specific composition and thermal stability design of the soybean flour processing-specific maltose syrup further demonstrates this advantage. This allows the product to adapt to the critical heat treatment process conditions in soybean flour production. In the presence of this maltose syrup, the liquid system can maintain stable rheological properties under specific temperature, pressure, and vacuum conditions, inhibiting the non-enzymatic browning reaction of sugars at high temperatures. This solves the technical defects of easy color deepening and flavor deterioration in the product during processing, ensuring the pure sensory quality of the product. By synergistically optimizing the composition and functional characteristics of the soybean flour processing-specific maltose syrup, it can play a role in increasing the glass transition temperature of the liquid and regulating the viscosity of the material in the final spray drying stage. This improves the microstructure of soybean flour products at the molecular level and synergistically solves the common problems of poor solubility, easy clumping, poor flowability, and short shelf life of traditional soybean flour products, comprehensively improving the reconstitution performance, appearance, and shelf-life stability of soybean flour.

[0054] By comparing and analyzing the relevant data in the table, it can be seen that the maltose syrup for soybean flour processing and its preparation method of the present invention have superior comprehensive performance.

[0055] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a special maltose syrup for soybean flour processing, characterized in that, Includes the following steps: Step 1: Slurry liquefaction. Select starch as raw material, add water to make starch milk and then liquefy it. Step 2: Enzymatic hydrolysis and saccharification. The liquefied liquid is mixed with a saccharifying enzyme compound preparation and enzymatically hydrolyzed under specific conditions to obtain a saccharified liquid. Step 3: Refining and purification. The saccharified solution is sequentially filtered, decolorized, and subjected to ion exchange treatment to obtain a refined sugar solution. Step 4: Vacuum concentration, the refined sugar solution is concentrated under specific vacuum and temperature conditions to obtain the maltose syrup for soybean flour processing; Step 5: Standardization process: The maltose syrup concentrate is tested and adjusted by batch mixing to ensure that the final product meets the preset physicochemical indicators, thus obtaining the special maltose syrup for soybean flour processing. In step two, the indicators for controlling the saccharified solution at the end of enzymatic hydrolysis are: DE value 50-55, maltose content greater than or equal to 50%, glucose content less than or equal to 4%, and light transmittance greater than or equal to 95%.

2. The method for preparing a special maltose syrup for soybean flour processing according to claim 1, characterized in that, Step one, slurry liquefaction, includes the following steps: Starch raw materials are mixed with water under stirring conditions to prepare a starch milk with a mass concentration of 30%-40%. The pH value of the starch milk is adjusted to 5.5-6.2 with acid or alkali. A thermoresistant α-amylase is added at a rate of 100-200 units per gram of dry starch. The temperature is then raised to 85℃-95℃ and maintained for 10-30 minutes to complete the liquefaction process and obtain a liquefied liquid.

3. The method for preparing a special maltose syrup for soybean flour processing according to claim 2, characterized in that, The starch raw material is at least one of corn starch, tapioca starch or waxy corn starch, and the activity unit of the heat-resistant α-amylase is 20000 U / mL.

4. The method for preparing a special maltose syrup for soybean flour processing according to claim 1, characterized in that, Step two, enzymatic hydrolysis and saccharification, includes the following steps: The liquefied liquid is cooled to 55℃-60℃, the pH is adjusted to 5.0-5.8, and a saccharifying enzyme compound preparation consisting of fungal amylase and β-amylase is added. The amount of fungal amylase added is controlled to be 0.5-1.5 units per gram of dry starch, and the amount of β-amylase added is 5-15 units per gram of dry starch. The saccharification reaction is carried out under stirring conditions for 20-40 hours, during which the temperature is maintained at 55℃-60℃.

5. The method for preparing a special maltose syrup for soybean flour processing according to claim 4, characterized in that, The fungal amylase has an enzyme activity unit of 10000 U / g, and the β-amylase has an enzyme activity unit of 2000 U / g. During the saccharification reaction, the DE value is measured every 8-12 hours. When the DE value reaches 50-55, the temperature of the liquid is raised to 85℃-95℃ and maintained for 10-30 minutes.

6. The method for preparing a special maltose syrup for soybean flour processing according to claim 1, characterized in that, Step three, purification, includes the following steps: Filtration: The saccharified liquid after enzyme inactivation is first coarsely filtered through a 100-200 mesh sieve to remove insoluble impurities, and then finely filtered through a plate and frame filter or membrane filtration equipment to obtain a clear sugar solution. Decolorization: Pump the clarified sugar solution into a decolorization tank, heat it to 70℃-80℃, add powdered activated carbon accounting for 0.5%-2.0% of the dry matter weight of the sugar solution, stir and decolorize for 20-40 minutes, and then filter it through a filter press to remove the activated carbon to obtain the decolorized sugar solution; Ion exchange: The decolorized sugar solution is passed sequentially through a strong acid cation exchange resin column and a weak base anion exchange resin column, with the flow rate controlled at 1 to 3 times the volume of the resin column per hour to remove inorganic ions and colored substances from the sugar solution, thereby obtaining the refined sugar solution, the conductivity of which is less than or equal to 50 μS / cm.

7. The method for preparing a special maltose syrup for soybean flour processing according to claim 6, characterized in that, In the decolorization step, activated carbon is added in two stages. The first addition is 70% of the total amount added. After decolorization for 20 minutes, the mixture is filtered, and the remaining 30% of activated carbon is added to the filtrate for a second decolorization of 20 minutes.

8. The method for preparing a special maltose syrup for soybean flour processing according to claim 1, characterized in that, In step four, vacuum concentration is carried out in a vacuum evaporator, with the vacuum degree of the evaporator controlled at -0.08MPa to -0.09MPa and the evaporation temperature at 60℃-65℃, concentrating the refined sugar solution to a solid content of 75%-85%, thus obtaining the special maltose syrup for soybean flour processing.

9. The method for preparing a special maltose syrup for soybean flour processing according to claim 1, characterized in that, Step five, the standardization process, includes the following specific steps: Samples of the concentrated maltose syrup were taken and tested for their DE value, maltose content, and glucose content. Different batches of concentrated maltose syrup with preset physicochemical indicators were mixed, or other batches of syrup or specific components that met the indicator requirements were added to batches that did not meet the standards for adjustment, until the DE value of the mixed maltose syrup was stable between 50 and 55, the maltose content was greater than or equal to 50%, and the glucose content was less than or equal to 4%. This completed product standardization and yielded the soybean flour processing-specific maltose syrup with uniform composition and performance.

10. A maltose syrup specifically for processing soybean flour, characterized in that, The malt syrup has the following physicochemical properties: The DE value is 50-55, the maltose content is greater than or equal to 50%, the glucose content is less than or equal to 4%, the light transmittance is greater than or equal to 95%, and the maltose syrup is configured to the following process conditions suitable for soybean flour production: ingredient temperature 50℃-60℃, homogenization temperature 60℃-65℃, pressure 15MPa-25MPa, concentration temperature 60℃-65℃, and vacuum degree -0.08MPa to -0.09MPa.

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