Processing method of high-pressure double-heat-source baked soybeans

Abstract

The invention discloses a processing method of high-pressure double-heat-source baked soybeans. The processing method comprises the following steps: S1, preheating a reaction kettle: preheating the reaction kettle through a heating coil assembly; s2, preheating the materials: putting the soybeans into a reaction kettle, and heating the soybeans to 80-95 DEG C within 10-40 minutes; s3, heating and pressurizing: continuously supplying heat by a heating coil assembly, introducing steam into the reaction kettle to be in direct contact with the soybeans, heating the soybeans to 100-140 DEG C, keeping the temperature for 10-50 minutes, and increasing the pressure in the reaction kettle to 0.2-0.7 Mpa; s4, pressure relief: extracting steam in the reaction kettle through a high-pressure fan; s5, performing negative-pressure bursting and dehydration: vacuumizing the reaction kettle through a high-pressure fan, and expanding and bursting the soybeans; and S6, cold-drying and packaging. The method disclosed by the invention has the advantages that urease activity, glycinin and beta-conglycinin in the soybeans can be quickly destroyed at 100-140 DEG C, the protein solubility is improved, and the Maillard reaction is inhibited.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural biological products, in particular to a processing method for high-pressure dual-heat-source roasted soybeans. Background Art

[0002] Soybean is one of the main crops. The soy protein in soybean is the most abundant protein in nature. The amino acid composition of soybean is similar to that of essential amino acids for animals. It is also rich in calcium, phosphorus, iron, oligosaccharides and various vitamins. It is known as "growing gold". Therefore, soybeans are matured and crushed on the market to make animal feed.

[0003] Currently, commercially available methods for roasting soybeans include preheating, pressurized heating, negative pressure extraction, pressure relief, and pulverization and packaging. The heating process ripens the soybeans, destroying most anti-nutrients. Negative pressure extraction then causes the soybeans to burst, improving their nutritional properties. Currently, soybeans are ripened using indirect heating. For example, in a method for preparing anti-nutrient-reduced roasted soybeans (Application Publication No. CN117179134A), a heat transfer oil pipe is provided in an expansion tank, high-temperature heat transfer oil is poured into the pipe, and the soybeans in the expansion tank are heated and ripened. In a method for producing rumen-dried or roasted soybean feed (Application Publication No. CN115944021A), a jacket is provided on a spherical tank, high-temperature, high-pressure steam is introduced into the jacket, and the soybeans in the tank are heated and ripened.

[0004] When soybeans are indirectly heated, since soybeans are poor conductors, the internal and external heat is uneven, which not only requires a long time for heating and ripening, but also easily leads to the situation where the outside is ripe but the inside is too raw, or the inside is ripe but the outside is too burnt, resulting in unstable overall quality. When soybeans are ripe on the outside but raw on the inside, the protein solubility of soybeans is too high, which causes the biggest problem to be the excessive high anti-nutritional factors (urease, glycinin and β-conglycinin). The most harmful anti-nutritional factor to animals is the trypsin activity inhibitor, which changes the essential groups on the enzyme molecules, causing indigestion, diarrhea, and slow growth of animals. The most harmful anti-nutritional factor is β-conglycinin, followed by glycinin, which can induce allergic reactions in piglets and cause atrophy of the small intestinal villi, thereby reducing the animal's ability to absorb nutrients, and the large When soybeans are overripe, cooked inside and burnt outside, the protein solubility is too low, that is, the color is dark, and the amino acids and sugars undergo the Maillard reaction, making the amino acids unable to be absorbed and utilized. When the protein solubility is lower than 70%, the digestion and absorption rate of lysine is reduced. When the protein solubility is lower than 65%, the digestion and absorption rate of amino acids such as arginine, histidine, and tryptophan is reduced. Excessive heating will also reduce the metabolic energy value. Therefore, overripe soybeans reduce both the digestion and utilization rate of amino acids and their metabolic energy, while reducing the lysine content, which will lead to a waste of protein and energy. In layman's terms, animals eat but do not grow. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-pressure dual-heat source roasting soybean processing method that can quickly and evenly heat the inside and outside of soybeans by first indirect preheating and then direct steam heating, effectively reduce urease activity and antigens in soybeans, and improve the solubility of soybean protein.

[0006] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a processing method for roasting soybeans with high pressure and dual heat sources, comprising the following steps:

[0007] S1. Reactor preheating: Steam is introduced into the heating coil assembly of the reactor to preheat the reactor at a temperature of 40-90°C.

[0008] S2. Material preheating: After removing impurities, the soybeans are placed in a metering bin for metering. After metering, the soybeans are placed in a reactor, which rotates at a constant speed and heats the soybeans to 80-95°C within 10-40 minutes.

[0009] S3. Heating and pressurizing: Steam is continuously introduced into the heating coil assembly to provide heat. The reactor is kept rotating at a constant speed. The steam is introduced into the reactor into direct contact with the soybeans, heating the soybeans to 100-140° C. and maintaining this temperature for 10-50 minutes. The steam penetrates the soybeans and exists as free water in the soybean flesh and hulls, causing the soybeans to swell. The pressure in the reactor is then increased to 0.2-0.7 MPa.

[0010] S4, pressure relief: Steam is continuously introduced into the heating coil assembly to provide heat, while the reactor maintains a constant rotation speed. The introduction of steam into the reactor is stopped, and the pressure relief valve is opened. The steam in the reactor is discharged through the pressure relief valve to release the pressure to normal pressure, thereby cooling the soybeans in the reactor.

[0011] S5. Negative pressure bursting and dehydration: Steam is continuously introduced into the heating coil assembly for heating, maintaining the temperature in the reactor between 90 and 95°C. The reactor keeps rotating at a constant speed, and the reactor is vacuumed by a high-pressure blower to reduce the pressure in the reactor to -0.08 to -0.02 MPa. Under this negative pressure, the soybeans burst, and the condensed water in the reactor and the moisture in the soybeans will be released under this negative pressure. 60～95℃ It boils rapidly at a temperature of 10000℃ and turns into steam, which is then extracted by a high-pressure blower. During the explosion process, the reactor and soybeans are dehydrated and dried.

[0012] S6. Cold-dry packaging: After dehydration, re-pressurize and close the pressure relief valve at the same time. Discharge the burst and dry soybeans from the reactor and place them in a cold-drying box for dry cooling. After dry cooling, place them in a storage bin for storage. When needed, take them out and place them in a grinder to grind them into powder and then bag them.

[0013] Furthermore, in the aforementioned high-pressure dual-heat source roasting soybean processing method, when processing low-moisture soybeans with a moisture content of less than 13%, in S2, the low-moisture soybeans need to be preheated to 90-100°C within 20-40 minutes, including 20 minutes and 90°C; when processing high-moisture soybeans with a moisture content of 14%, in S2, the high-moisture soybeans need to be preheated to 85-90°C within 10-20 minutes, excluding 20 minutes and 90°C.

[0014] Furthermore, in the aforementioned high-pressure dual-heat source roasting soybean processing method, in S2, the steam pressure in the heating coil assembly is 0.2~0.7Mpa, when preheating low-moisture soybeans, the steam pressure in the heating coil assembly is 0.4~0.7Mpa, including 0.4Mpa, and when preheating high-moisture soybeans, the steam pressure in the heating coil assembly is 0.2~0.4Mpa, excluding 0.4Mpa.

[0015] Furthermore, in the aforementioned high-pressure dual-heat source roasted soybean processing method, in which, in S3, when steam heating and pressurizing low-moisture soybeans, the pressure in the reactor needs to be controlled at 0.4~0.7Mpa, including 0.4Mpa; when steam heating and pressurizing high-moisture soybeans, the pressure in the reactor needs to be controlled at 0.2~0.4Mpa, excluding 0.4Mpa.

[0016] Furthermore, in the aforementioned high-pressure dual-heat-source roasting soybean processing method, the rotation speed of the reactor in S2, S3, S4 and S5 is 1 to 2 revolutions / min.

[0017] Furthermore, the aforementioned high-pressure dual-heat source roasting soybean processing method, wherein the reactor is rotatably arranged between two platforms, rollers are arranged on the two platforms, and swivels are arranged on the two rollers. The two rotation centers on the reactor are respectively connected to the two rollers, and a feed port and a discharge port are arranged on the reactor. A reflux pipe is arranged in the reactor, and a heating coil assembly is arranged on the reflux pipe. An air inlet pipe extending into the reactor and connected to the heating coil assembly is connected to a swivel, and the air inlet pipe is connected to a steam generator. An air baffle is fully welded in the reactor, and the air baffle is connected to the reflux pipe and blocks the outlet of the air inlet pipe. At the air end, an air inlet is provided on the air baffle plate, the air inlet end on the heating coil assembly is connected to the air inlet on the air baffle plate, a water outlet is provided on the air baffle plate, the water outlet end on the return pipe is connected to the water outlet on the air baffle plate, a drain pipe is coaxially arranged in the air inlet pipe, the port of the drain pipe is located below all the air inlets, the drain pipe is connected to the pumping equipment, and a connecting pipe is connected to another swivel, one end of the connecting pipe extends into the reactor, and a three-way valve is provided on the other end of the connecting pipe, one end of the three-way valve is connected to the external condenser and the high-pressure fan in sequence, a pressure relief valve is provided on this end, and the other end of the three-way valve is connected to the steam generator.

[0018] Furthermore, the aforementioned high-pressure dual-heat source roasting soybean processing method, wherein the heating coil assembly includes: three spiral tubes with the same diameter, the three spiral tubes are spirally wound around the same axis and fixed on the return pipe, and the air outlet ends of the three spiral tubes are connected to the return pipe, the pitch of each spiral tube is 1.5 to 2 times the diameter of the spiral tube, the gap between the three spiral tubes is 4 to 5 times the diameter of the spiral tube, and three air inlets are provided on the air baffle plate, and the air inlet ends of the three spiral tubes are respectively connected to the three air inlets on the air baffle plate.

[0019] Furthermore, in the aforementioned high-pressure dual-heat-source roasting soybean processing method, the rotation center of the reactor is set at the left and right ends of the reactor, and the reactor is turned over between the two bases in a rolling manner.

[0020] Furthermore, in the aforementioned high-pressure dual-heat-source roasting soybean processing method, a thermocouple is provided on the reactor.

[0021] The advantages of the present invention are that: the dual heat source heating method of using superheated steam to directly contact and conduct heat with soybeans and the heating coil assembly to perform auxiliary heating can make the soybeans heat quickly and evenly, and can quickly destroy the urease activity, soybean globulin and β-conglycinin in soybeans at 100-140°C, and can even basically remove the urease activity at 140°C or below, and reduce the soybean globulin and β-conglycinin to 16.7±2mg / g and 4.9±2mg / g respectively, thereby reducing allergenicity; when steam is used to directly heat and pressurize soybeans, the steam enters the soybeans to cause the soybeans to swell, and then during negative pressure bursting, the soybeans can burst in the expanded state, making the internal structure of the soybeans loose, making the soybeans softer and having a better taste; under the hydration action of steam, it is not easy to produce excessive Maillard reaction, the damage to essential amino acids is small, and the protein solubility is improved; during the negative pressure bursting and dehydration process, the pressure in the reactor is controlled at -0.08～- 0.02 Mpa, which can avoid excessive protein oxidation or the formation of β-folded structure, make the protein solubility of soybean higher and the emulsification of oil stronger, thereby maintaining a higher digestibility and edible taste, and can also maintain the stability of soybean, which is conducive to storage and transportation; when the negative pressure is pumped, steam is passed into the heating coil assembly to continuously supply heat, and the condensed water in the reactor and the moisture in the soybean will quickly evaporate into steam under negative pressure and high temperature, and then be extracted by the high-pressure fan, which plays a role in rapid dehydration and drying when the soybean is subjected to negative pressure explosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a reactor used in the processing method of high-pressure dual-heat source roasted soybeans described in the present invention.

[0023] Figure 2 yes Figure 1 Schematic diagram of the structure of the heating coil assembly. DETAILED DESCRIPTION

[0024] The processing method of high-pressure dual-heat source roasted soybeans of the present invention comprises the following steps:

[0025] S1, preheating the reactor 1: passing steam into the heating coil assembly 3 of the reactor 1 to preheat the reactor 1, the preheating temperature being 40-90°C;

[0026] S2. Material preheating: After removing impurities from the soybeans, place them in a metering bin for metering. After metering, place the soybeans into the reactor 1 through the feed port 11. The reactor 1 rotates at a constant speed of 1 to 2 revolutions per minute. Since the temperature in the reactor 1 decreases during material addition, the soybeans need to be preheated to 80 to 95° C. within 10 to 40 minutes using the steam in the heating coil assembly 3.

[0027] S3, heating and pressurizing: the reactor 1 keeps rotating at a constant speed, and steam is continuously introduced into the heating coil assembly 3 to continue heating. At the same time, the steam is directly passed into the reactor 1 through the connecting pipe 52 to directly contact the soybeans. The steam penetrates into the soybeans and exists in the soybean flesh and soybean skin in the form of free water. A portion of the free water combines with macromolecules such as protein and starch in the soybeans through hydrogen bonds, causing the soybean volume to expand. Another portion of the free water enters the soybean cells to further expand the soybean volume. The soybeans are heated to 100-140° C. and maintained for 10-50 minutes, and the pressure in the reactor 1 is increased to 0.2-0.7 MPa. Heating and pressurizing in a closed environment can effectively reduce the urease activity in the soybeans, and most of the heat-stable antigens β-conglycinin and glycinin are directly destroyed, the antigens are significantly reduced, and the protein solubility is moderate. At this time, the soybeans are heated to a moderate temperature, heated evenly, matured to a moderate degree, and have a rich aroma.

[0028] S4, pressure relief: Steam is continuously introduced into the heating coil assembly 3 to continuously supply heat, while the reactor 1 maintains a constant rotation speed. The introduction of steam into the reactor is stopped, and the pressure relief valve is opened. The steam in the reactor 1 is forced under pressure through the connecting pipe 52 and the pressure relief valve into the condenser for condensation. As the pressure in the reactor 1 decreases, the remaining steam in the reactor 1 no longer flows into the condenser, and a portion of the remaining steam in the reactor 1 condenses into water, resulting in a large amount of moisture in the reactor 1 and the soybeans.

[0029] S5, negative pressure burst and dehydration: Steam is continuously introduced into the heating coil assembly 3 to continuously supply heat, and the temperature in the reactor is maintained between 90 and 95 ° C. The reactor 1 keeps rotating at a constant speed, and the high-pressure blower is turned on to pump negative pressure into the reactor 1. During the negative pressure pumping process, the uncondensed steam in the reactor 1 will be pumped into the condenser, and the pressure in the reactor 1 will gradually decrease. The boiling point of the condensed water in the reactor 1 and the water in the soybeans will gradually decrease under the negative pressure environment. When the pressure in the reactor 1 is reduced to -0.08~-0.02Mpa When the negative pressure is applied, the condensed water in the reactor 1 and the water in the soybeans will 60～95℃The moisture in the soybean skin will quickly evaporate into steam at a temperature of 1000 nm. The moisture in the soybean skin will quickly evaporate into steam and be drawn away, resulting in a rapid loss of moisture in the soybean skin. The rate of moisture loss in the soybean skin is much higher than the rate of moisture loss in the soybean flesh. After the moisture in the soybean skin is quickly lost, the soybean skin will shrink rapidly, while the volume of the soybean flesh will hardly change. Therefore, the soybean skin will rupture first. When the soybean skin ruptures, the moisture in the soybean flesh will quickly evaporate into steam under high temperature and low pressure. The moisture in the soybean flesh will destroy the soybean cell structure during rapid evaporation, causing the cell wall to rupture, thereby causing the soybean to burst and the internal structure of the soybean to become loose. The condensed water in the reactor 1 and the moisture in the soybeans will be quickly boiled and converted into steam under a high temperature and low pressure environment, which can keep the soybeans and the reactor 1 dry.

[0030] S6. Cold-dry packaging: After dehydration is completed, the positive pressure is restored, and the popped and dried soybeans are discharged from the reactor 1 and placed in a cold-drying box for dry cooling. After dry cooling, they are placed in a storage bin for storage. When needed, they are taken out and placed in a grinder to be crushed into powder and then bagged.

[0031] In S1, the reactor 1 is preheated to 40-90°C. Since there is no interference from other materials in the reactor 1 at this time, the internal temperature distribution in the reactor 1 can be made more uniform, and the heating efficiency of the soybeans can be improved when the soybeans enter the reactor 1.

[0032] In S2, preheating soybeans to 80-95°C within 10-40 minutes can make the soybeans in an over-raw state of being ripe on the outside and raw on the inside, which facilitates the steam in S3 to penetrate into the interior of the soybeans. American soybeans and Brazilian soybeans are often used on the market to be processed into soybean feed. The moisture content of American soybeans is low, less than 13%, and they have high hardness, a relatively compact structure, and full grains, while the moisture content of Brazilian soybeans is high, at 14%, with relatively low hardness, a relatively loose structure, and small grains. The moisture content requirements of American soybeans and Brazilian soybeans are both restricted in accordance with the new standards implemented by China on December 1, 2023. From the perspective of protecting food, reducing the moisture content of soybeans to 13% is conducive to storage and is not easy to mold. The reason why the moisture content requirements for Brazilian soybeans are relatively loose is because Brazil's storage conditions and equipment performance are not sufficient to support high requirements. Therefore, China's moisture content requirements for Brazilian soybeans are slightly looser than those for American soybeans.

[0033] When preheating American soybeans, they need to be preheated to 85-95°C, including 85°C, to heat the American soybeans to an over-cooked state with the outside ripe and the inside raw. During the heating process, the steam pressure in the heating coil assembly 3 needs to be controlled between 0.4 and 0.7 MPa, including 0.4 MPa, so as to improve the heating efficiency and heat the American soybeans to 85-95°C within 20-40 minutes, including 20 minutes and 85°C. When preheating Brazilian soybeans, the soybeans need to be heated to 80-85°C, not including 85°C, to heat the Brazilian soybeans to an over-cooked state with the outside ripe and the inside raw. In the raw state, during the heating process, the steam pressure in the heating coil assembly 3 needs to be controlled between 0.2 and 0.4 MPa, excluding 0.4 MPa, to ensure the heating efficiency, so that the Brazilian soybeans are heated to 80-85°C within 10-20 minutes, excluding 20 minutes and 85°C; regardless of whether it is American soybeans or Brazilian soybeans, after being heated to the over-raw state of being cooked on the outside and raw on the inside, since the reactor 1 is always in a state of uniform rotation, the soybeans are in uninterrupted contact with the heating coil assembly 3, and the soybeans will not be in contact with the heating coil assembly 3 for a long time, resulting in the outer surface being burnt yellow.

[0034] In S3, the soybeans are directly contact-heated with steam. The high penetrability of steam can penetrate deep into the interior of the soybeans. The tiny water droplets in the steam can penetrate into the internal tissue of the soybeans. The fiber structure in the soybeans absorbs water and softens. The inside and outside of the soybeans are surrounded by steam and can be heated evenly and efficiently. Moreover, since the steam can penetrate deep into the interior of the soybeans and heat the inside and outside of the soybeans at the same time, the inside and outside of the soybeans can be synchronously heated to 100-140°C within 10 minutes to mature them. At this temperature, the protein and other heat-sensitive nutrients in the soybeans are not easily destroyed, and the nutritional value of the soybeans can be better preserved. In a high-humidity environment, the secondary bonds of the protein are broken to a large extent and denatured sufficiently, which in turn promotes the inactivation of urease and trypsin inhibitors in the soybeans, thereby losing the ability to inhibit trypsin. When processing American soybeans, steam is introduced into the reactor 1 to increase the pressure in the reactor 1 to 0.4-0.7Mpa, so that the inside and outside of the American soybeans can be heated to 100-140°C within 10 minutes. When processing Brazilian soybeans, steam is introduced into the reactor 1 to increase the pressure in the reactor 1 to 0.2-0.4Mpa, so that the inside and outside of the Brazilian soybeans can be heated to 100-140°C within 10 minutes. Different pressures are selected when heating American soybeans and Brazilian soybeans because American soybeans have a higher hardness and steam needs to penetrate the American soybeans at a higher pressure environment to soften the fibers in the American soybeans. Brazilian soybeans have a lower hardness and steam can penetrate the Brazilian soybeans at a lower pressure environment to quickly soften the fibers inside the Brazilian soybeans.

[0035] In the process of roasting soybeans, as the temperature rises, the Maillard reaction will be intensified, especially when the temperature reaches above 150°C, the Maillard reaction is intense. At the same time, water is also a catalyst that promotes the Maillard reaction. When the water activity is between 0.6 and 0.7, the Maillard reaction is most intense. In a preparation method of reduced-resistance roasted soybeans with application publication number: CN117179134A, the soybeans are heated by indirect heating with heat-conducting oil to prevent the soybeans from contacting with water to inhibit the Maillard reaction. However, in this method, the soybeans need to be heated to 160°C. The temperature is relatively high, ranging from 240°C to 240°C, which cannot inhibit the Maillard reaction and easily aggravates the Maillard reaction. In a production method of rumen-dried or roasted soybean feed with application publication number: CN115944021A, soybeans are soaked in a zinc salt solution and then indirectly heated with steam. Although the soybeans are heated at a temperature of 110-130°C, the activity of water in the zinc salt solution at this temperature is between 0.5 and 0.8, which also easily promotes the Maillard reaction and makes the soybean product dark yellow. A darker color indicates that the protein solubility is too low.

[0036] Research has found that when the water activity is too high or too low, the Maillard reaction will be inhibited. When soybeans are directly heated and pressurized with steam, the water activity in the steam is significantly increased. Under hydration, this high-moisture environment not only reduces the concentration of the reactants, but also reduces the effective collisions between the reactants, making it difficult for the Maillard reaction to proceed. In addition, the highly active water will adsorb on the polar groups of the protein macromolecules to form a hydration layer, so that the free amino groups on lysine form hydrogen bonds with the polar water molecules, which can provide short-term protection for the amino groups and avoid direct Maillard reaction with carbonyl compounds, thereby reducing the effectiveness of lysine. Moreover, when directly heating soybeans with steam, it is only necessary to control the heating temperature at 100-140°C to ripen the inside and outside of the soybeans together, so that the soybeans are heated at a lower temperature to prevent excessive Maillard reaction.

[0037] In S5, during the popping process of soybeans, the fishy substances are destroyed and a strong aroma is produced, which can significantly improve animal appetite. In addition, this type of product can be ultra-finely crushed and can be widely used in aquatic feed and suckling pig feed, with a wider range of applications. Since the expansion coefficient of soybean oil is small, the oil in the soybeans is wrapped by protein and other substances, and the oil will not be oxidized, thereby improving the utilization rate of the oil, and the oil will not penetrate to the outside. The product has good fluidity and is non-sticky, which can improve the mixing uniformity when subsequently used in feed.

[0038] In this step, when the American soybeans are subjected to negative pressure bursting, because the American soybeans are relatively hard, have a relatively compact structure, and have full grains, it is generally necessary to use -0.08～-0.05Mpa of negative pressure is used to perform negative pressure bursting on American soybeans, while Brazilian soybeans have relatively low hardness, relatively loose structure, and small grains. -0.065~-0.02Mpa The negative pressure of Brazilian soybeans can be used to perform vacuum bursting. When the U.S. soybeans and Brazilian soybeans are subjected to vacuum bursting, there is an overlapping area of ​​the bursting negative pressure range of -0.065 to -0.05Mpa. When conducting experimental data statistics, there are microstructural differences between soybean individuals of the same variety, such as seed coat thickness, cell arrangement, etc. Some high-hardness U.S. soybeans may burst at -0.05Mpa due to local defects such as micro-damage to the seed coat, while some low-hardness Brazilian soybeans may need to burst at -0.065Mpa due to their relatively dense structure. These individual differences will cause the bursting negative pressure range of the two soybeans to overlap in the range of -0.065 to -0.05Mpa, forming a "transition zone" for common bursting; secondly, in actual production, the setting of negative pressure parameters often includes a certain degree of safety redundancy, and the use of negative pressure parameters for U.S. soybeans with higher hardness is not recommended. -0.08～-0.05 The wide range of negative pressures (MPa) covers two extreme cases: for example, the hardest soybeans require -0.08 MPa to burst, while some only need -0.05 MPa to burst. For Brazilian soybeans with lower hardness, a wide range of -0.065 to -0.02 MPa is used, also covering two extreme cases: for example, the hardest soybeans require -0.065 MPa to burst, while some only need -0.03 MPa to burst. This overlapping negative pressure range of -0.065 to -0.05 MPa serves as a "universal parameter," balancing the processing efficiency of both types of soybeans and reducing the costs associated with frequent equipment adjustments. Depending on the soybean type, controlling the negative pressure between -0.08 and -0.02 MPa can prevent excessive protein oxidation or the formation of β-pleated structures, resulting in higher protein solubility and stronger oil emulsification, thereby maintaining a high digestibility and taste. It also maintains soybean stability, facilitating storage and transportation.

[0039] In this embodiment, Figure 1 、 Figure 2As shown, the reactor 1 is rotatably arranged between two platforms 2, and rollers are horizontally arranged on the two platforms 2. The rotation centers of the left and right ends of the reactor 1 are respectively connected to the two rollers, and the reactor is flipped between the two platforms 2 in a rolling manner. A swivel 5 is provided on the two rollers. A feed port 11 and a discharge port are provided on the reactor 1. The discharge port is not shown in the figure. A reflux pipe 12 is provided in the reactor 1, and a heating coil assembly 3 is provided on the reflux pipe 12. An air inlet pipe 13 extending into the reactor 1 and connected to the heating coil assembly 3 is connected to one swivel 5. The air inlet pipe 11 is provided with a heating coil assembly 3. 3 is connected to the steam generator, so that the reactor 1 will not affect the air intake of the heating coil assembly 3 when it is turned over. An air baffle 14 is fully welded in the reactor 1. The air baffle 14 is connected to the return pipe 12 and blocks the outlet end of the air inlet pipe 13. The heating coil assembly 3 includes: three spiral tubes 31 with the same diameter, the three spiral tubes 31 are spirally wound around the same axis and fixed on the return pipe 12, and the outlet ends of the three spiral tubes 31 are all connected to the return pipe 12, the pitch of each spiral tube 31 is 1.5 to 2 times the diameter of the spiral tube 31, and the gap between the three spiral tubes 31 is the spiral diameter. The diameter of the spiral tube 31 is 4 to 5 times. This arrangement allows the soybeans in the reactor 1 to fall smoothly. Three air inlets are provided on the air baffle 14. The air inlet ends of the three spiral tubes 31 are respectively connected to the three air inlets on the air baffle 14. A water outlet is provided on the air baffle 14. The water outlet end on the reflux pipe 12 is connected to the water outlet on the air baffle 14. A drain pipe 131 is coaxially provided in the air inlet pipe 13. The port of the drain pipe is located below all the air inlets. The drain pipe 131 is connected to the pumping equipment. High-temperature steam enters the air baffle 14 and the air inlet pipe 13 from the air inlet pipe 13. The high-temperature steam enters the cavity between the air inlet ends and then enters the three spiral tubes 31 through the air inlet for heating. When the high-temperature steam enters the return pipe 12 from the spiral tube 31, part of the steam will condense, and the condensed water will be stored in the cavity between the air baffle 14 and the air inlet end of the air inlet pipe 13. When the liquid level is above the port of the drain pipe 131, the drain pipe 131 is water-sealed, and the high-temperature steam cannot be discharged from the drain pipe 131. The pumping equipment extracts the water in the cavity through the drain pipe 131 to prevent too much water from entering the spiral tube 31 and affecting the heating effect of the heating coil assembly 3.After the soybeans enter the reactor 1, the reactor 1 rotates, allowing the soybeans to roll and contact with the heating coil assembly 3. In S1 and S2, high-temperature steam is introduced into the heating coil assembly 3 through the steam generator to heat the reactor 1 and the soybeans. A thermocouple 4 is provided on the reactor 1. The temperatures in S1, S2 and S3 are based on the temperature displayed by the thermocouple 4. A connecting pipe 52 is connected to the rotary pass 5 at the rotation center of the other end of the reactor 1. One end of the connecting pipe 52 extends into the reactor 1. A three-way valve 51 is provided at the other end of the connecting pipe 52. One end of the three-way valve 51 is connected to an external condenser and a high-pressure blower in sequence. A pressure relief valve is provided on this end, which is not shown in the figure. The other end of the three-way valve 51 is connected to the steam generator. In S3, the three-way valve 51 is switched to the steam generator pipeline, and the steam generator passes high-temperature steam into the reactor 1 through the rotary pass 5 and the connecting pipe 52 to pressurize and heat the soybeans in the reactor 1. When pressure relief and negative pressure extraction are performed, the three-way valve 51 is switched to the pressure relief valve pipeline, and the pressure relief valve is opened. During the pressure relief process in S4, the steam in the reactor 1 directly enters the condenser through the pressure relief valve for condensation. During the negative pressure extraction process in S5, the pressure relief valve is not closed, and the reactor 1 is evacuated by the high-pressure fan. The residual hot air in the reactor 1 enters the condenser through the connecting pipe 52 for condensation.

[0040] Soybeans (U.S. soybeans were used in this example) were divided into 6 groups, each weighing approximately 9 tons. The 6 groups of soybeans were then placed in 6 reactors 1 for preheating at the same time and temperature. Steam was then introduced at the same pressure for heating. The steam heating temperatures in the 6 reactors 1 were 90° C., 100° C., 110° C., 120° C., 130° C., and 140° C., respectively. Samples were taken for testing every 10 minutes, and the same sample was tested multiple times independently. The following data were obtained:

[0041] Table 1: Physical and chemical data of urease activity at different temperature ranges and time periods Effect of dual heat source rapid explosion roasting process on urease activity in soybeans (mg / g·min)

[0042]

[0043] As can be seen from Table 1, through direct steam heating, urease activity will decrease with the extension of heating time or the increase of heating temperature. Heating soybeans to 90℃ and maintaining it for 50 minutes by direct steam heating can only slightly reduce the urease activity in soybeans, which is far higher than the national standard of 0.4 mg / g·min. When soybeans are heated to 100℃ and maintained for 40 minutes, the urease activity in soybeans gradually decreases to below 0.1 mg / g·min. Maintaining it at this temperature for 50 minutes can basically eliminate the urease activity in soybeans. When soybeans are heated to 110℃ and maintained for 30 minutes, the urease activity in soybeans gradually decreases to below 0.1 mg / g·min. Maintaining it for 40 minutes or more can basically eliminate the urease activity in soybeans. When soybeans are heated to 120℃ and maintained for 20 minutes, the urease activity in soybeans gradually decreases to the point of being basically eliminated. When soybeans are heated to 130℃ and maintained for 20 minutes, the urease activity in soybeans gradually decreases to the point of being basically eliminated. When soybeans are heated to 140℃ and maintained for 10 minutes, the urease activity in soybeans gradually decreases to the point of being basically eliminated. The Maillard reaction of soybeans will only be intensified in an environment of 150°C, and the high water activity in steam will further limit the Maillard reaction. Therefore, limiting the heating temperature of soybeans to a maximum of 140°C can not only effectively remove the urease activity in soybeans, but also effectively limit the excessive Maillard reaction.

[0044] Table 2: Physicochemical data of protein solubility at different temperature ranges and time periods Effect of dual heat source rapid explosion baking process on soybean protein solubility (%)

[0045]

[0046] As can be seen from Table 2, through direct steam heating, the solubility of soybean protein will decrease with the extension of heating time or the increase of heating temperature. Among them, when soybeans are heated to 90℃ and maintained for 50min, the solubility of soybean protein in soybeans is always higher than 80%; when soybeans are heated to 100℃ and maintained for 40min, the solubility of soybean protein in soybeans is always higher than 80%, and when maintained at this temperature for 50min, the solubility of soybean protein in soybeans is slightly lower than 80% and much higher than 75%; when soybeans are heated to 110℃ and maintained for 30min, the solubility of soybean protein in soybeans is higher than 75%, and when maintained at this temperature for 40min~50min, the solubility of soybean protein in soybeans is higher than 70% and lower than 75%; when soybeans are heated to 120℃ and maintained for 20min, the solubility of soybean protein in soybeans is higher than 80%. The solubility of soybean protein is higher than 75%. If the temperature is maintained for 30 minutes, the solubility of soybean protein in soybean is higher than 70% and lower than 75%. If the temperature is continued to be maintained for 40 minutes to 50 minutes, the solubility of soybean protein in soybean is lower than 70%; when soybeans are heated to 130 and maintained for 10 minutes, the solubility of soybean protein in soybeans is higher than 75%. If the temperature is maintained for 20 minutes, the solubility of soybean protein in soybeans is higher than 70% and lower than 75%. If the temperature is continued to be maintained for 30 minutes or more, the solubility of soybean protein in soybeans is lower than 70%; when soybeans are heated to 140℃ and maintained for 10 minutes, the solubility of soybean protein in soybeans is higher than 75%. If the temperature is maintained for 20 minutes or more, the solubility of soybean protein in soybeans is lower than 70%. If only the solubility of soybean protein is considered, the shorter the heating time, the better. However, the inactivation law of urease activity is similar to the high-temperature dissolution law of soybean protein solubility: under the same heating time, the higher the temperature, the lower the urease activity and the lower the solubility of soybean protein. Under the same heating temperature, the longer the time, the lower the urease activity and the lower the solubility of soybean protein. Therefore, it is necessary to combine urease activity and soybean protein solubility to select the appropriate heating time and heating temperature.

[0047] From Table 2 combined with Table 1, it can be seen that when soybeans are heated to 90°C, although the solubility of soybean protein is high, the urease activity in soybeans is high, which will affect the animal's absorption of soybean nutrients, so the scheme of heating to 90°C is not feasible; when soybeans are heated to 100°C and maintained for 40min~50min, it can ensure that the urease activity is lower than 0.1mg / g·min and the solubility of soybean protein is higher than 75%. In particular, when the temperature is maintained for 50min, the urease activity in soybeans is basically removed, and the solubility of soybean protein is 79.2%, which is just slightly lower than 80%; when soybeans are heated to 110°C and maintained for 30min, it can ensure that the urease activity is lower than 0.1mg / g·min and the solubility of soybean protein is higher than 75%. When the temperature is continued to be maintained for 40min~50min, the urease activity in soybeans is basically removed, and the solubility of soybean protein is higher than 70%; 120℃ and maintained for 20min, which can ensure that the urease activity is lower than 0.1mg / g·min and the solubility of soybean protein is higher than 75%. When maintained at this temperature for 30min, the urease activity is basically removed, and the solubility of soybean protein is higher than 70%; soybeans are heated to 130℃ and maintained for 10min, the urease activity is 0.1mg / g·min, and the solubility of soybean protein is higher than 75%. When maintained at this temperature for 20min, the urease activity is basically removed, and the solubility of soybean protein is higher than 70%. When maintained at this temperature for 30min or more, although the urease activity is basically removed, the solubility of soybean protein is lower than 70%; soybeans are heated to 140℃ and maintained for 10min, the urease activity is lower than 0.1mg / g·min, and the solubility of soybean protein is higher than 75%. When maintained at this temperature for 20min, although the urease activity is basically removed, the solubility of soybean protein is lower than 70%. By combining Table 1 and Table 2, the most appropriate heating time and temperature can be selected to roast soybeans according to customer requirements. For example, if the customer requires a protein solubility higher than 75% and a urease activity lower than 0.1 mg / g·min, multiple heating options are available: maintaining the temperature at 100°C for 40 to 50 minutes, maintaining the temperature at 110°C for 30 minutes, or maintaining the temperature at 120°C for 20 minutes. The optimal roasting method can then be selected based on the time cost of roasting the soybeans and the steam cost generated.

[0048] Table 3: Physicochemical data of antigens (i.e. glycinin and β-conglycinin) at different temperatures and time periods

[0049] Effect of dual-heat source rapid explosion roasting process on glycinin / β-conglycinin (mg / g)

[0050]

[0051]

[0052] As shown in Table 3, direct steam heating rapidly decreases the glycinin and β-conglycinin content in soybeans with increasing heating time or temperature. When soybeans are heated in Reactor 1, a minimum of 20 minutes of reaction time is required for significant and irreversible denaturation of glycinin and β-conglycinin, allowing for effective detection. When soybeans were heated to 100°C and maintained at this temperature for 20-50 minutes, the glycinin content decreased from 118.1 mg / g to 71.6 mg / g, and the β-conglycinin content decreased from 105.6 mg / g to 60.7 mg / g; when soybeans were heated to 110°C and maintained at this temperature for 20-50 minutes, the glycinin content decreased from 70.5 mg / g to 17.2 mg / g, and the β-conglycinin content decreased from 55.4 mg / g to 8.3 mg / g; when soybeans were heated to 120°C and maintained at this temperature for 20-50 minutes, the glycinin content decreased from 58.2 mg / g to

[0053] 8.6 mg / g, while the β-conglycinin content decreased from 40.6 mg / g to 3.4 mg / g; soybeans were heated to 130 ° C and maintained at this temperature for 20 to 50 minutes, and the glycinin content decreased from 28.6 mg / g to

[0054] When soybeans were heated to 140°C and maintained at this temperature for 20 to 50 minutes, the glycinin content decreased from 23.4 mg / g to 3.6 mg / g, while the β-conglycinin content decreased from 15.6 mg / g to 1.2 mg / g.

[0055] From Table 1, Table 2 and Table 3, it can be seen that heating soybeans to 100℃ and maintaining it for 40min-50min can not only control the urease activity below 0.1mg / g·min and the protein solubility above 75%, but also ensure that the glycinin content and β-conglycinin content are controlled at 71.6-85.6mg / g and 60.7-77.2mg / g respectively; heating soybeans to 110℃ and maintaining it for 30min can not only control the urease activity at 0.1mg / g·min The protein solubility is higher than 75%, and the glycinin content and β-conglycinin content are controlled at 40.2 mg / g and 20.4 mg / g respectively. When the temperature is maintained for 40-50 minutes, the protein solubility is higher than 70% and lower than 75%, and the glycinin content and β-conglycinin content are controlled at 17.2-25.6 mg / g and 8.3-10.7 mg / g respectively. Heating soybeans to 120°C and maintaining for 20 minutes can not only reduce the urease activity, but also reduce the protein solubility. The solubility of soybeans was controlled below 0.1 mg / g·min, the solubility of protein was higher than 75%, and the content of glycinin and β-conglycinin was controlled at 58.2 mg / g and 40.6 mg / g respectively. When the temperature was maintained for 30 min, the solubility of protein was higher than 70% and lower than 75%, and the content of glycinin and β-conglycinin was controlled at 20.1 mg / g and 10.2 mg / g respectively. Heating soybeans to 130°C and maintaining it for 20 min not only can urease be removed, but also the solubility of soybeans was controlled below 0.1 mg / g·min, the solubility of protein was higher than 75%, and the content of glycinin and β-conglycinin was controlled at 58.2 mg / g and 40.6 mg / g respectively. The activity is controlled below 0.1 mg / g·min, the protein solubility is higher than 70% and lower than 75%, and the glycinin content and β-conglycinin content are controlled at 15.5 mg / g and 6.2 mg / g, respectively; when soybeans are heated to 140°C and maintained for 20 minutes, although the urease activity is controlled below 0.1 mg / g·min, the glycinin content and β-conglycinin content are controlled at 23.4 mg / g and 15.6 mg / g, respectively, the protein solubility is lower than 70%.

[0056] During the lactation and juvenile stages, livestock have immature digestive systems and are fed with other supplementary feeds, so they require lower glycinin and β-conglycinin contents. Generally, the glycinin and β-conglycinin contents need to be controlled within 30 mg / g and 10 mg / g, respectively, to avoid affecting the health of the livestock's digestive system and reducing the livestock's ability to absorb nutrients in soybeans or other supplementary feeds. Due to the addition of other supplementary feeds, the protein solubility requirement needs to be controlled at above 70%, so the temperature can be selected at 110°C and maintained for 50 minutes. The urease activity is basically eliminated and the protein solubility is 70.1%. At the same time, the glycinin and β-conglycinin contents are 17.2 mg / g and 8.3 mg / g, respectively. This allows livestock in the lactation and juvenile stages to fully absorb nutrients without interfering with the digestive system. During adolescence and adulthood, livestock have mature digestive systems, so the protein solubility requirement is to be controlled at approximately 75%, the urease activity requirement is to be controlled at no higher than the national standard of 0.4 mg / g·min, and the antigen content (i.e., glycinin content and β-conglycinin content) is to be controlled below 100 mg / g. The desired soybeans can be obtained by selecting the appropriate heating temperature and heating time based on the combinations of Tables 1, 2, and 3.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A method for processing soybeans roasted with high pressure and dual heat sources, characterized in that: Here are the steps: S1. Reactor preheating: Steam is introduced into the heating coil assembly of the reactor to preheat the reactor at a temperature of 40-90°C. S2. Material preheating: After removing impurities, the soybeans are placed in a metering bin for metering. After metering, the soybeans are placed in a reactor, which rotates at a constant speed and heats the soybeans to 80-95°C within 10-40 minutes. S3. Heating and pressurizing: Steam is continuously introduced into the heating coil assembly to provide heat. The reactor is kept rotating at a constant speed. The steam is introduced into the reactor into direct contact with the soybeans, heating the soybeans to 100-140° C. and maintaining this temperature for 10-50 minutes. The steam penetrates the soybeans and exists as free water in the soybean flesh and hulls, causing the soybeans to swell. The pressure in the reactor is then increased to 0.2-0.7 MPa. S4, pressure relief: Steam is continuously introduced into the heating coil assembly to provide heat, while the reactor maintains a constant rotation speed. The introduction of steam into the reactor is stopped, and the pressure relief valve is opened. The steam in the reactor is discharged through the pressure relief valve to release the pressure to normal pressure, thereby cooling the soybeans in the reactor. S5. Negative pressure bursting and dehydration: Steam is continuously introduced into the heating coil assembly to provide heat, maintaining the temperature in the reactor between 90 and 95°C. The reactor rotates at a constant speed, and a high-pressure blower is used to evacuate the reactor, reducing the pressure in the reactor to -0.08 to -0.02 MPa. Under this negative pressure, the soybeans burst. The condensed water and moisture in the soybeans in the reactor rapidly boil at a temperature of 60 to 95°C under this negative pressure and convert into steam, which is then extracted by the high-pressure blower. During the bursting process, the reactor and the soybeans are dehydrated. S6. Cold-dry packaging: After dehydration, re-pressurize and close the pressure relief valve at the same time. Discharge the burst and dry soybeans from the reactor and place them in a cold-drying box for dry cooling. After dry cooling, place them in a storage bin for storage. When needed, take them out and place them in a grinder to grind them into powder and then bag them.

2. The method for processing high-pressure dual-heat-source roasted soybeans according to claim 1, characterized in that: When processing low-moisture soybeans with a moisture content of less than 13%, in S2, the low-moisture soybeans need to be preheated to 90-100°C within 20-40 minutes, including 20 minutes and 90°C; when processing high-moisture soybeans with a moisture content of 14%, in S2, the high-moisture soybeans need to be preheated to 85-90°C within 10-20 minutes, excluding 20 minutes and 90°C.

3. The method for processing high-pressure dual-heat-source roasted soybeans according to claim 2, characterized in that: In S2, the steam pressure in the heating coil assembly is 0.2~0.7Mpa. When preheating low-moisture soybeans, the steam pressure in the heating coil assembly is 0.4~0.7Mpa, including 0.4Mpa. When preheating high-moisture soybeans, the steam pressure in the heating coil assembly is 0.2~0.4Mpa, excluding 0.4Mpa.

4. The method for processing high-pressure dual-heat-source roasted soybeans according to claim 2, characterized in that: In S3, when steam heating and pressurizing low-moisture soybeans, the pressure in the reactor needs to be controlled at 0.4-0.7 MPa, including 0.4 MPa. When steam heating and pressurizing high-moisture soybeans, the pressure in the reactor needs to be controlled at 0.2-0.4 MPa, excluding 0.4 MPa.

5. The method for processing high-pressure dual-heat-source roasted soybeans according to claim 1, characterized in that: The rotation speed of the reactors in S2, S3, S4 and S5 is 1 to 2 revolutions / min.

6. The method for processing high-pressure dual-heat-source roasted soybeans according to any one of claims 1 to 5, characterized in that: The reactor is rotatably arranged between two platforms, rollers are arranged on the two platforms, and swivels are arranged on the two rollers. The two rotation centers on the reactor are respectively connected to the two rollers. A feed port and a discharge port are arranged on the reactor. A reflux pipe is arranged in the reactor, and a heating coil assembly is arranged on the reflux pipe. An air inlet pipe extending into the reactor and connected to the heating coil assembly is connected to a swivel. The air inlet pipe is connected to a steam generator. An air baffle is fully welded in the reactor. The air baffle is connected to the reflux pipe and blocks the air outlet end of the air inlet pipe. An air inlet is arranged on the air baffle. The air inlet end on the heating coil assembly is connected to the air inlet on the air baffle, the air baffle is provided with a water outlet, the water outlet end on the return pipe is connected to the water outlet on the air baffle, a drain pipe is coaxially arranged in the air inlet pipe, the port of the drain pipe is located below all the air inlets, the drain pipe is connected to the pumping equipment, and a connecting pipe is connected to another swivel, one end of the connecting pipe extends into the reactor, and a three-way valve is provided on the other end of the connecting pipe, one end of the three-way valve is connected to the external condenser and the high-pressure fan in sequence, and a pressure relief valve is provided on this end, and the other end of the three-way valve is connected to the steam generator.

7. The method for processing high-pressure dual-heat-source roasted soybeans according to claim 6, characterized in that: The heating coil assembly includes: three spiral tubes with the same diameter, the three spiral tubes are spirally wound around the same axis and fixed on the return pipe, and the air outlet ends of the three spiral tubes are connected to the return pipe, the pitch of each spiral tube is 1.5 to 2 times the diameter of the spiral tube, and the gap between the three spiral tubes is 4 to 5 times the diameter of the spiral tube. Three air inlets are provided on the air baffle, and the air inlet ends of the three spiral tubes are respectively connected to the three air inlets on the air baffle.

8. The method for processing high-pressure dual-heat-source roasted soybeans according to claim 6, characterized in that: The rotation center of the reactor is set at the left and right ends of the reactor, and the reactor is turned over between the two bases in a rolling manner.

9. The method for processing high-pressure dual-heat-source roasted soybeans according to claim 6, characterized in that: A thermocouple is provided on the reactor.

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