Production process of soybean protein isolate with high soybean flavor

Abstract

The invention provides a production process of high-bean-flavor soybean protein isolate. The production process comprises the following steps: carrying out microwave treatment on high-temperature soybean meal; carrying out superfine grinding on the treated high-temperature soybean meal and low-temperature soybean meal; mixing the crushed high-temperature soybean meal and low-temperature soybean meal; mixing the mixed material with water, adjusting the pH value and the temperature, and carrying out a stirring reaction; after the reaction, carrying out centrifugal separation to obtain a primary solid phase and a primary liquid phase; mixing the obtained primary solid phase with water, adjusting the pH value and the temperature, and stirring; performing centrifugal separation to obtain a secondary solid phase and a secondary liquid phase; mixing the primary liquid phase and the secondary liquid phase, adjusting the pH value, and settling to obtain a protein suspension; carrying out centrifugal separation on the protein suspension to obtain acidic solid-phase protein slurry; and stirring the acidic solid-phase protein slurry with water, adjusting the pH value, and then carrying out sterilization and drying treatment. The soybean protein isolate with high bean flavor is prepared by the production process; the protein is good in stability and suitable for providing various nutritional and health-care proteins.

Description

Technical Field

[0001] The present invention relates to the technical field of soybean protein processing, and particularly relates to a production process of high soy - flavored soy protein isolate. Background Art

[0002] Plant - protein beverages are milk - like liquid beverages mainly made from plant kernels, pulp, etc. (such as soybeans, peanuts, almonds, walnuts, coconuts, and grains), and are processed with plant protein as the main body. In today's food market, plant - protein beverages are widely favored by consumers due to their rich nutritional components, such as low cholesterol content, rich in protein and amino acids, and appropriate amounts of unsaturated fatty acids. Among them, soy protein, as an important source of plant protein, is increasingly widely used in the fields of solid beverages, liquid beverages, and health products.

[0003] Currently, a common soy - protein production process (such as the preparation method published in CN200910266501.3) is as follows: Weigh 100 g of low - temperature soybean meal and dissolve it in 2 L of water. Adjust the pH of the solution to 8.0 with 30% food - grade sodium hydroxide, adjust the temperature to 50 °C, and after extraction for 30 minutes, centrifuge to obtain the liquid - phase soy milk; then adjust the soy milk to the isoelectric point pH 4.5 with 10% food - grade hydrochloric acid, stir at low speed for 10 minutes, and separate to obtain the solid - phase soy - protein curd; then adjust the pH of the solution to 5.0 with 30% food - grade sodium hydroxide, adjust the concentration to 10%, adjust the temperature of the feed liquid to 20 °C at normal pressure, and add 0.1% ethyl maltol and react for 4 hours; then adjust the temperature of the feed liquid to 80 °C at normal pressure, adjust the pH to 9.0 with 40% sodium hydroxide, adjust the concentration to 8%, add 0.2% soy - odor masking agent and react for 2 hours; then quickly cool down to 40 °C within 15 minutes, increase the pressure of the feed liquid to more than 40 MPa through high - pressure equipment, and introduce direct steam to raise the temperature of the feed liquid to 130 °C, maintain for 20 seconds, and then input it into a flash - evaporation deodorization device (negative pressure - 0.09 Mpa, maintain for 60 minutes, and the temperature of the feed liquid drops to 55 °C), and finally spray - dry the obtained protein solution to produce a powdered product.

[0004] However, this existing - technology solution has obvious defects. On the one hand, the ethyl maltol used as a food additive does not meet the usage standards of soy protein isolate and will bring non - soy - source odors, resulting in off - flavors; on the other hand, the type of soy - odor masking agent used is unknown and there is non - compliance, which seriously affects the quality and safety of soy protein isolate and limits its application in fields with high quality requirements. Summary of the Invention

[0005] The present invention provides a production process of high soy - flavored soy protein isolate to solve the defects in the existing technology.

[0006] The present invention provides a production process for high soybean flavor soy protein isolate, comprising the following steps:

[0007] 1) Microwave treatment of high-temperature soybean meal: The high-temperature soybean meal is cooked through a microwave dryer;

[0008] 2) Crushing: The high-temperature soybean meal treated in step 1) is ultra-finely crushed to 80 - 100 mesh; meanwhile, the low-temperature soybean meal is crushed to 80 - 100 mesh;

[0009] 3) Mixing: The crushed high-temperature soybean meal and low-temperature soybean meal are mixed in a ratio of 1:5 - 1:10;

[0010] 4) Leaching: The mixed material in step 3) is mixed with water in a weight ratio of 1:8 - 10, the pH value and temperature are adjusted, and stirring reaction is carried out;

[0011] 5) Centrifugal separation: The extract in step 4) is centrifugally separated to obtain a primary solid phase and a primary liquid phase;

[0012] 6) The primary solid phase obtained in step 5) is mixed with water in a mass ratio of 1:3 - 5, the pH value and temperature are adjusted, stirring is carried out, and then it is pulverized and transported to a storage tank by a multi-stage homogenizing pump, and stored for 15 - 30 min waiting for separation;

[0013] 7) The liquid phase in step 6) is centrifugally separated to obtain a secondary solid phase and a secondary liquid phase;

[0014] 8) The primary liquid phase in step 5) and the secondary liquid phase in step 7) are mixed, the pH value is adjusted, and sedimentation is carried out to obtain a protein suspension;

[0015] 9) The protein suspension in step 8) is centrifugally separated to obtain an acidic solid-phase protein slurry;

[0016] 10) Neutralization: The acidic solid-phase protein slurry is stirred with 3 - 5 times the weight of water, and the pH value is adjusted to 6.5 - 7.5 using food-grade alkali;

[0017] 11) Sterilization: The liquid phase obtained in step 10) is sterilized at 130 - 135 °C for 5 - 9 seconds; after sterilization, flash degassing is carried out;

[0018] 12) Drying: The liquid material after flash degassing is spray-dried.

[0019] According to the production process for high soybean flavor soy protein isolate provided by the present invention, in step 1), the thickness of the high-temperature soybean meal during microwave treatment is 1 - 1.5 cm, the microwave treatment time is 8 - 10 min, and the temperature of the soybean meal is 120 - 140 °C.

[0020] According to a production process of high soybean flavor soy protein isolate provided by the present invention, in step 2), the high-temperature soybean meal and the low-temperature soybean meal are pulverized by a jet mill.

[0021] According to a production process of high soybean flavor soy protein isolate provided by the present invention, in step 3), the mixing equipment for the high-temperature soybean meal and the low-temperature soybean meal is a ribbon mixer.

[0022] According to a production process of high soybean flavor soy protein isolate provided by the present invention, in step 4), the pH value is adjusted to 7.5 - 7.8 with a food-grade alkali, the temperature is 50 - 55 °C, and the stirring reaction is carried out for 20 - 60 min.

[0023] According to a production process of high soybean flavor soy protein isolate provided by the present invention, in step 6), the pH value is adjusted to 8.5 - 10.0 with a food-grade alkali, the water temperature is 40 - 50 °C, and the stirring is carried out for 15 min.

[0024] According to a production process of high soybean flavor soy protein isolate provided by the present invention, in step 8), the pH value is adjusted to 4.5 - 4.8 with a food-grade acid.

[0025] According to a production process of high soybean flavor soy protein isolate provided by the present invention, the high-temperature soybean meal promotes the Maillard reaction through microwave treatment to generate soybean flavor substances. After the high-temperature soybean meal and the low-temperature soybean meal are mixed, the low-temperature soybean meal adsorbs the volatile soybean flavor organic compounds volatilized from the high-temperature soybean meal. The low-temperature soybean meal has a high protein yield, masks the fishy smell by absorbing the volatile soybean flavor organic compounds volatilized from the high-temperature soybean meal, and at the same time mixes with the high-temperature soybean meal to ensure the protein yield.

[0026] The production process of a high soybean - flavor soy protein isolate provided by the present invention realizes rapid, uniform and continuous production through microwave treatment, precisely controls the Maillard reaction between proteins and carbohydrates in high - temperature soybean meal, precisely controls the Maillard reaction products, and avoids over - reaction and insufficient reaction. It controls the flavor and color. By utilizing the advantage that microwave can heat the whole body, the Maillard reaction occurs in the whole high - temperature soybean meal, ensuring a high Maillard reaction rate and high Maillard reaction products, and avoiding the uneven Maillard reaction from outside to inside caused by other heat treatment technologies, which results in over - reaction on the outside, insufficient reaction inside, and difficult control of the Maillard reaction. By using the heat conduction mode from outside to inside of microwave heating, the target Maillard reaction products are obtained on the surface layer of the soybean meal, greatly reducing the utilization rate of high - temperature soybean meal. Microwave treatment absorbs microwave energy simultaneously inside and outside as a whole, realizes synchronous Maillard reaction, and improves the utilization rate of soybean meal; through mixing, high - temperature soybean meal and low - temperature soybean meal utilize the adsorption ability of proteins in the low - temperature soybean meal powder to adsorb the volatile organic compounds with soybean flavor volatilized from high - temperature soybean meal, thereby improving the protein yield in low - temperature soybean meal. High - temperature soybean meal provides soybean flavor, and after being absorbed by the proteins in low - temperature soybean meal, protein yield is provided through production and separation. The yield of high - temperature soybean meal is very low, while the yield of low - temperature soybean meal is high. Therefore, the mixing of high - temperature soybean meal and low - temperature soybean meal ensures soybean flavor while providing sufficient protein yield. This production process can produce soy protein isolate with high soybean flavor; the soybean flavor is rich. It has good stability and is suitable for providing various protein for nutritional and health care. Moreover, it can improve the color of the protein, increase the change in the yellow - red color system of the protein, and enhance visual attraction. Detailed Description of the Invention

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and presented here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the provided embodiments of the present invention is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

[0029] It should be noted that: similar reference numerals and letters denote similar items in the following figures. Therefore, once an item is defined, it does not need to be further defined and explained in the subsequent figures. In addition, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0030] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "inside", "outside", "upper", etc. is the orientation or positional relationship, or the orientation or positional relationship in which the invention product is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present invention.

[0031] The present invention provides a production process for high soy - flavored soy protein isolate, which includes the following steps:

[0032] 1) Microwave treatment of high - temperature soybean meal: The high - temperature soybean meal is cooked through a microwave dryer.

[0033] 2) Crushing: The high - temperature soybean meal processed in step 1) is ultra - finely crushed to 80 - 100 meshes; at the same time, the low - temperature soybean meal is crushed to 80 - 100 meshes.

[0034] 3) Mixing: The crushed high - temperature soybean meal and low - temperature soybean meal are mixed in a ratio of 1:5 - 1:10.

[0035] 4) Leaching: The mixed materials in step 3) are mixed with water in a weight ratio of 1:8 - 10, and the pH value and temperature are adjusted for stirring reaction.

[0036] 5) Centrifugal separation: The extract in step 4) is centrifugally separated to obtain a primary solid phase and a primary liquid phase.

[0037] 6) The primary solid phase obtained in step 5) is mixed with water in a mass ratio of 1:3 - 5, the pH value and temperature are adjusted, and stirring is carried out. Subsequently, it is crushed and transported to a storage tank using a multi - stage homogenizing pump and stored for 15 - 30 minutes for separation.

[0038] 7) The liquid phase in step 6) is centrifugally separated to obtain a secondary solid phase and a secondary liquid phase.

[0039] 8) The primary liquid phase in step 5) and the secondary liquid phase in step 7) are mixed, the pH value is adjusted, and sedimentation is carried out to obtain a protein suspension.

[0040] 9) The protein suspension in step 8) is centrifugally separated to obtain an acidic solid - phase protein slurry.

[0041] 10) Neutralization: The acidic solid - phase protein slurry is stirred with 3 - 5 times its weight of water, and the pH value is adjusted to 6.5 - 7.5 using food - grade alkali.

[0042] 11) Sterilization: The liquid phase obtained in step 10) is sterilized at 130 - 135 °C for 5 - 9 seconds; after sterilization, flash degassing is carried out.

[0043] 12) Drying: The liquid material after flash evaporation and degassing is spray-dried.

[0044] To further optimize the above technical solution, in step 1), the thickness of the high-temperature soybean meal during microwave treatment is 1 - 1.5 cm, the microwave treatment time is 8 - 10 min, and the temperature of the soybean meal is 120 - 140 °C.

[0045] To further optimize the above technical solution, in step 2), the high-temperature soybean meal and the low-temperature soybean meal are pulverized using a pneumatic pulverization device.

[0046] To further optimize the above technical solution, in step 3), the mixing device for the high-temperature soybean meal and the low-temperature soybean meal is a ribbon mixer.

[0047] To further optimize the above technical solution, in step 4), the pH value is adjusted to 7.5 - 7.8 using a food-grade alkali, the temperature is 50 - 55 °C, and the stirring reaction is carried out for 20 - 60 min.

[0048] To further optimize the above technical solution, in step 6), the pH value is adjusted to 8.5 - 10.0 using a food-grade alkali, the water temperature is 40 - 50 °C, and the stirring is carried out for 15 min.

[0049] To further optimize the above technical solution, in step 8), the pH value is adjusted to 4.5 - 4.8 using a food-grade acid.

[0050] To further optimize the above technical solution, the high-temperature soybean meal promotes the Maillard reaction through microwave treatment to generate soy flavor substances. After the high-temperature soybean meal and the low-temperature soybean meal are mixed, the low-temperature soybean meal adsorbs the soy flavor volatile organic compounds volatilized from the high-temperature soybean meal. The low-temperature soybean meal has a high protein yield, removes the beany flavor by absorbing the soy flavor volatile organic compounds volatilized from the high-temperature soybean meal, and at the same time mixes with the high-temperature soybean meal to ensure the protein yield.

[0051] To introduce more clearly and in detail a production process of high soy flavor soybean protein isolate provided by the embodiments of the present invention, the following will be described in combination with specific embodiments.

[0052] Example 1

[0053] 1. Microwave treatment of high-temperature soybean meal: The high-temperature soybean meal is cooked through a microwave dryer. The thickness of the high-temperature soybean meal during microwave treatment is 1 cm, the microwave treatment time is 8 min, and the temperature of the soybean meal is 120 °C.

[0054] 2. Pulverization: The treated high-temperature soybean meal is super-finely pulverized to 80 mesh. The low-temperature soybean meal is pulverized to 80 mesh.

[0055] 3. Mixing: The high-temperature soybean meal and the low-temperature soybean meal are mixed in a ratio of 1:5.

[0056] 4. Extraction: Mix the materials mixed in Step 3 with water at a weight ratio of 1:8. Adjust the pH value to 7.5 using food-grade alkali, keep the temperature at 50°C, and stir and react for 20 minutes.

[0057] 5. Centrifugal separation: Centrifugally separate the extract in Step 4 to obtain primary solid phase and primary liquid phase.

[0058] 6. Mix the solid phase obtained in Step 5 with water at a mass ratio of 1:3. Add food-grade alkali to adjust the pH value to 8.5, keep the water temperature at 40°C, stir for 15 minutes, then use a multi-stage homogenizing pump to crush and convey it to a storage tank, and store for 15 minutes waiting for separation.

[0059] 7. Centrifugally separate the liquid phase in Step 6 to obtain secondary solid phase and secondary liquid phase.

[0060] 8. After mixing the primary liquid phase in Step 5 and the secondary liquid phase in Step 7, add food-grade acid to adjust the pH value to 4.5, and carry out sedimentation to obtain a protein suspension.

[0061] 9. Centrifugally separate the protein suspension in Step 8 to obtain an acidic solid-phase protein slurry.

[0062] 10. Neutralization: Stir the acidic solid-phase protein slurry with 3 times its weight of water, and adjust the pH value to 6.5 using food-grade alkali.

[0063] 11. Sterilization: Sterilize the liquid phase obtained in Step 10 at 130°C for 5 seconds; after sterilization, carry out flash evaporation and degassing.

[0064] 12. Drying: Spray-dry the liquid material after flash evaporation and degassing.

[0065] Result: The score of soybean flavor is 8.1, the score of soybean fishy smell is 7.9, and the score of color is 8.9.

[0066] Example 2

[0067] 1. Microwave treatment of high-temperature soybean meal: Cure the high-temperature soybean meal through a microwave dryer. The thickness of the high-temperature soybean meal for microwave treatment is 1.5 cm, the microwave treatment time is 10 minutes, and the temperature of the soybean meal is 140°C.

[0068] 2. Crushing: Ultra-finely crush the treated high-temperature soybean meal to 100 mesh. Crush the low-temperature soybean meal to 100 mesh.

[0069] 3. Mixing: Mix high-temperature soybean meal and low-temperature soybean meal at a ratio of 1:10.

[0070] 4. Extraction: Mix the materials mixed in Step 3 with water at a weight ratio of 10. Adjust the pH value to 7.8 using food-grade alkali, keep the temperature at 55°C, and stir and react for 60 minutes.

[0071] 5. Centrifugal separation: The extract in step 4 is subjected to centrifugal separation to obtain a primary solid phase and a primary liquid phase.

[0072] 6. Mix the solid phase obtained in step 5 with water in a mass ratio of 1:5, add food-grade alkali to adjust the pH value to 10.0, the water temperature is 50 °C, stir for 15 min, then use a multi-stage homogenizing pump to crush and transport it to a storage tank, and store for 30 min for separation.

[0073] 7. Centrifuge the liquid phase in step 6 to obtain a secondary solid phase and a secondary liquid phase.

[0074] 8. Mix the primary liquid phase in step 5 and the secondary liquid phase in step 7, then add food-grade acid to adjust the pH value to 4.8, and perform sedimentation to obtain a protein suspension;

[0075] 9. Centrifuge the protein suspension in step 8 to obtain an acidic solid-phase protein slurry.

[0076] 10. Neutralization: Stir the acidic solid-phase protein slurry with 5 times its weight of water, and use food-grade alkali to adjust the pH value to 7.5.

[0077] 11. Sterilization: Sterilize the liquid phase obtained in step 10 at 130 - 135 °C for 9 seconds; after sterilization, perform flash evaporation and degassing; 12. Drying: Spray-dry the liquid material after flash evaporation and degassing.

[0078] Result: The score for soybean flavor is 8.8, the score for soybean odor is 8.7, and the score for color is 9.0.

[0079] Example 3

[0080] 1. Microwave treatment of high-temperature soybean meal: Cure the high-temperature soybean meal through a microwave dryer. The thickness of the high-temperature soybean meal during microwave treatment is 1.3 cm, the microwave treatment time is 9 min, and the temperature of the soybean meal is 130 °C.

[0081] 2. Crushing: The treated high-temperature soybean meal is ultra-finely crushed to 90 mesh. The low-temperature soybean meal is crushed to 90 mesh.

[0082] 3. Mixing: Mix high-temperature soybean meal and low-temperature soybean meal in a ratio of 1:7.

[0083] 4. Leaching: Mix the mixed material in step 3 with water in a weight ratio of 1:9, use food-grade alkali to adjust the pH value to 7.7, the temperature is 50 - 55 °C, and stir and react for 40 min.

[0084] 5. Centrifugal separation: The extract in step 4 is subjected to centrifugal separation to obtain a primary solid phase and a primary liquid phase.

[0085] 6. Mix the solid phase obtained in step 5 with water at a mass ratio of 1:3.5, add food-grade alkali to adjust the pH value to 9.0, keep the water temperature at 45 °C, stir for 15 min, then use a multi-stage homogenizing pump to crush and transport it to a storage tank, and store for 20 min for separation.

[0086] 7. Centrifuge the liquid phase in step 6 to obtain a secondary solid phase and a secondary liquid phase.

[0087] 8. Mix the primary liquid phase in step 5 and the secondary liquid phase in step 7, then add food-grade acid to adjust the pH value to 4.6 and perform sedimentation to obtain a protein suspension.

[0088] 9. Centrifuge the protein suspension in step 8 to obtain an acidic solid-phase protein slurry.

[0089] 10. Neutralization: Stir the acidic solid-phase protein slurry with 3.5 times its weight of water, and use food-grade alkali to adjust the pH value to 7.0.

[0090] 11. Sterilization: Sterilize the liquid phase obtained in step 10 at 133 °C for 6 seconds; perform flash evaporation and degassing after sterilization.

[0091] 12. Drying: Spray-dry the liquid material after flash evaporation and degassing.

[0092] Result: The score for the bean flavor is 8.3, the score for the bean odor is 8.5, and the score for the color is 8.4.

[0093] Comparative Example 1

[0094] a) Extraction: Mix the raw material of low-temperature defatted soybean meal with water at a weight ratio of 1:10, keep the water temperature at 50 °C, stir for 45 min, and then wait for separation.

[0095] b) Centrifugal separation: Centrifuge the extract in step a) to obtain primary soybean dregs and primary soybean milk. After washing the primary soybean dregs, obtain secondary soybean dregs and secondary soybean milk, and mix the primary soybean milk and the secondary soybean milk.

[0096] c) Acid precipitation: Adjust the pH value of the mixture of primary soybean milk and secondary soybean milk to 4.8 for sedimentation; precipitate at the isoelectric point to recover the protein.

[0097] d) Centrifugal separation: Centrifuge the acid precipitation liquid in step c) to obtain an acidic solid-phase protein slurry.

[0098] e) Neutralization: Dilute the acidic solid-phase protein slurry with 2 times its weight of water and homogenize it. The homogenization pressure is 50 MPA. Continuously neutralize the diluted acidic protein liquid and the diluted food-grade alkali through a static mixer to adjust the pH to 7.2; the Brix is 12.5.

[0099] f) Sterilization: Perform high-temperature short-time sterilization on the protein slurry at a sterilization temperature of 149°C for 8 seconds; the sterilization effect reaches process sterilization;

[0100] g) Vacuum degassing: After sterilization, perform vacuum degassing, and control the vacuum degree to 70 kPa; remove the soybean odor through vacuum degassing,

[0101] h) Spray drying: Produce protein powder through spray drying;

[0102] Results: The score for soybean flavor is 2.1, the score for soybean odor is 4.2, and the score for color is 2.2.

[0103] The evaluation methods for the above Examples 1-3 and Comparative Example 1 are as follows:

[0104] Flavor: Weigh 10 grams of protein powder and place it in an 8-ounce clean glass jar, cover the lid, and the members of the test group tap the glass jar three times to vibrate the product, causing the protein powder to slightly rise in the jar, then open the lid and sniff carefully three times to score.

[0105] Color: Weigh 5.00 g of protein powder and 100 ml of distilled water at 50°C, put the protein powder into the distilled water and stir evenly, observe in a black box illuminated by 15 LED lights, and score.

[0106] The sensory panel consists of 9 people with SGS sensory evaluation qualifications. The reference for soybean flavor substances is cooked Italian white bean powder, and the reference for soybean odor substances is raw soybean powder. After evaluation, remove the highest and lowest values and calculate the average value for analysis. The evaluation form is shown in Table 2

[0107] Table 1 Sensory Evaluation Form

[0108]

[0109] It can be seen that compared with Comparative Example 1, in Examples 1-3 of the present application, by subjecting high-temperature soybean meal to microwave cooking treatment and mixing it with low-temperature soybean meal, soybean flavor substances are effectively generated and retained, while soybean odor substances and anti-nutritional factors are destroyed, increasing the soybean flavor score from 2.1 to above 8.1 and the soybean odor score from 4.2 to above 7.9; adopting a multi-stage extraction, precise pH adjustment (alkaline conditions promote protein dissolution, acidic conditions for precise acid precipitation) and fine solid-liquid separation process reduces the residue of impurities such as fibers and polyphenols. Combining mild high-temperature short-time sterilization and flash degassing avoids excessive protein denaturation and color browning, increasing the color score from 2.2 to above 8.4, and significantly optimizing the overall sensory quality (soybean flavor, soybean odor, color).

[0110] Therefore, the production process of a high soy - bean - flavor soy protein isolate provided by the present invention realizes rapid, uniform and continuous production through microwave treatment, precisely controls the Maillard reaction between proteins and carbohydrates in high - temperature soybean meal, precisely controls the Maillard reaction products, and avoids over - reaction and insufficient reaction. It controls the flavor and color. By taking advantage of the overall heating ability of microwaves, the Maillard reaction occurs in the whole high - temperature soybean meal, ensuring a high Maillard reaction rate and high Maillard reaction products, and avoiding the uneven Maillard reaction from the outside to the inside caused by other heat - treatment technologies, which may result in over - reaction on the outside, insufficient reaction on the inside, and difficulty in controlling the Maillard reaction. Using the heat - conduction method from the outside to the inside of microwave heating, the target Maillard reaction products are obtained on the surface layer of the soybean meal, greatly reducing the utilization rate of high - temperature soybean meal. Microwave treatment enables the whole soybean meal to absorb microwave energy simultaneously both inside and outside, realizing synchronous Maillard reaction and improving the utilization rate of soybean meal; through mixing, the high - temperature soybean meal and low - temperature soybean meal utilize the adsorption ability of proteins in the low - temperature soybean meal powder to adsorb the volatile organic compounds with soy - bean flavor volatilized from the high - temperature soybean meal, thereby improving the protein yield in the low - temperature soybean meal. The high - temperature soybean meal provides soy - bean flavor, and after being absorbed by the proteins in the low - temperature soybean meal, the protein yield is provided through production separation. The yield of high - temperature soybean meal is very low, while the yield of low - temperature soybean meal is high. Therefore, the mixture of high - temperature soybean meal and low - temperature soybean meal ensures soy - bean flavor while providing sufficient protein yield. This production process can produce soy protein isolate with high soy - bean flavor; the soy - bean flavor is rich. It has good stability and is suitable for providing various protein products for nutrition and health care. Moreover, it can improve the color of the protein, increase the change in the yellow - red color system of the protein, and enhance the visual attraction.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A production process of high soybean flavor soy protein isolate, characterized in that, The following steps are involved: 1) Microwave treatment of high-temperature soybean meal: The high-temperature soybean meal is matured by a microwave dryer; 2) Crushing: The high-temperature soybean meal treated in step 1) is ultra-finely crushed to 80-100 mesh; and the low-temperature soybean meal is crushed to 80-100 mesh; 3) Mixing: Mix the crushed high-temperature soybean meal and low-temperature soybean meal in a ratio of 1:5-1:10; 4) Extraction: Mix the mixed material in step 3) with water in a weight ratio of 1:8-10, adjust the pH value and temperature, and stir to react; 5) Centrifugal separation: centrifuge the extract in step 4) to obtain a solid phase and a liquid phase; 6) Mixing the primary solid phase obtained in step 5) with water in a mass ratio of 1:3-5, adjusting the pH value and temperature, stirring, and then crushing and transporting to a storage tank using a multi-stage homogenizing pump, storing for 15-30 minutes and waiting for separation; 7) The liquid phase in step 6) is centrifuged to obtain a secondary solid phase and a secondary liquid phase; 8) mixing the primary liquid phase in step 5) and the secondary liquid phase in step 7), adjusting the pH value, and performing sedimentation to obtain a protein suspension; 9) centrifuging the protein suspension in step 8) to obtain an acidic solid phase protein slurry; 10) Neutralization: Stir the acidic solid protein slurry with 3-5 times the weight of water, and adjust the pH value to 6.5-7.5 using food grade alkali; 11) Sterilization: sterilize the liquid phase obtained in step 10) at 130-135° C. for 5-9 seconds; and flash degasify after sterilization; 12) Drying: The degassed liquid is spray dried.

2. The production process of a high soybean flavor soy protein isolate according to claim 1, characterized in that, In the step 1), the soybean meal is subjected to microwave treatment at a thickness of 1-1.5 cm, the microwave treatment time is 8-10 min, and the soybean meal temperature is 120-140° C.

3. The production process of a high soybean flavor soy protein isolate according to claim 1, characterized in that, The high-temperature soybean meal and the low-temperature soybean meal in step 2) are pulverized by air flow pulverizing equipment.

4. The production process of a high soybean flavor soy protein isolate according to claim 1, characterized in that, The mixing equipment for the high-temperature soybean meal and the low-temperature soybean meal in step 3) is a ribbon mixer.

5. The production process of a high soybean flavor soy protein isolate according to claim 1, characterized in that, In the step 4), the pH value is adjusted to 7.5-7.8 using food grade alkali, the temperature is 50-55° C., and the reaction is stirred for 20-60 minutes.

6. The production process of a high soybean flavor soy protein isolate according to claim 1, characterized in that, In step 6), a food-grade alkali is used to adjust the pH value to 8.5-10.0, the water temperature is 40-50° C., and stirring is performed for 15 minutes.

7. The production process of a high soybean flavor soy protein isolate according to claim 1, characterized in that, In step 8), food grade acid is used to adjust the pH value to 4.5-4.

8.

8. The production process of a high soybean flavor soy protein isolate according to any one of claims 1-7, characterized in that, The high-temperature soybean meal is treated with microwaves to promote carbonylamine reaction to generate bean-flavored substances. After the high-temperature soybean meal is mixed with the low-temperature soybean meal, the low-temperature soybean meal absorbs the volatile organic matter with bean flavor volatilized from the high-temperature soybean meal. The low-temperature soybean meal has a high protein yield, and the bean smell is masked by absorbing the volatile organic matter with bean flavor volatilized from the high-temperature soybean meal. At the same time, the protein yield is ensured by mixing with the high-temperature soybean meal.

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