A method for producing a high-hardness full-bean filled tofu

Abstract

The present application relates to the technical field of whole bean filled bean curd, and particularly relates to a high-hardness whole bean filled bean curd production method, comprising the following steps: (1) first point slurry: the temperature of whole bean soybean milk is controlled at 50-55 DEG C, emulsified magnesium and glutamine transaminase are added into the whole bean soybean milk, and then the whole bean soybean milk is uniformly mixed to obtain first point slurry soybean milk; (2) second point slurry: the first point slurry soybean milk is heated to 63-68 DEG C, and then gypsum liquid is added into the first point slurry soybean milk, and then the first point slurry soybean milk is uniformly mixed to obtain second point slurry soybean milk; (3) filling and squatting brain: after the second point slurry soybean milk is filled, the temperature is controlled at 63-68 DEG C, and then the second point slurry soybean milk is statically solidified. In the production method, specific coagulants are used, and specific adding sequences and two-stage point slurry processes are used, so that the whole bean filled bean curd has both the hardness of old bean curd and the delicate and tender taste of tender bean curd.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of whole-bean filled tofu, and particularly relates to a high-hardness whole-bean filled tofu manufacturing method. BACKGROUND

[0002] The raw material of tofu is beans such as yellow beans, green beans, white beans and peas. The beans are shelled and washed, soaked in water for a proper time, and then ground into raw bean milk by adding a certain proportion of water. After processing, the protein content of the soybeans is not reduced, and the digestion and absorption rate is improved. At the same time, tofu is delicious and appetizing, and is loved by consumers at home and abroad.

[0003] However, at present, the production of tofu is mostly based on traditional production processes, which are complicated, time-consuming, and have a low yield. Most of the tofu on the market is made by processes such as soaking beans and grinding pulp. During the grinding process, a large amount of bean dregs is generated, and many nutritional components in the soybeans are lost with the yellow pulp water and bean dregs, resulting in low utilization of raw materials and low economic benefits. The bean dregs contain rich calcium and dietary fiber, and are usually used as feed or discarded as waste, causing resource waste and environmental pollution.

[0004] Whole-bean filled tofu is a product made by soaking, grinding, heating, cooling or not cooling, mixing with a coagulant, and then injecting into a container for sealing and heating to solidify. The product does not discard yellow pulp water and bean dregs during the manufacturing process, and can retain more nutritional components in the soybeans to improve the nutritional value of the tofu. However, filled tofu is usually soft and difficult to achieve the hardness and taste of old tofu. After the general raw pulp is cooked, the secondary bonds of the protein molecules are broken, the spatial structure of the protein is changed, the molecules become easy to approach, and the three-dimensional network structure is easily formed under the action of the coagulant, resulting in solidification. However, the presence of internal cellulose in whole-bean tofu makes it difficult for the protein to approach, which is not conducive to the solidification of the tofu, further increasing the difficulty of improving the hardness of whole-bean filled tofu. When the existing tofu coagulant and solidification process are used to make whole-bean filled tofu, the product hardness is not comparable to that of old tofu. SUMMARY

[0005] In order to solve the technical problem that whole-bean filled tofu is difficult to achieve a hardness comparable to that of old tofu, the present application provides a high-hardness whole-bean filled tofu manufacturing method. The specific coagulant is used in the manufacturing method, and the specific addition sequence and two-stage point pulp process are used, so that the whole-bean filled tofu has a hardness comparable to that of old tofu and a delicate and tender taste of soft tofu.

[0006] The specific technical scheme of the present application is as follows:

[0007] A high-hardness whole-bean filled tofu manufacturing method comprises the following steps:

[0008] (1) Primary point slurry: the whole soybean milk is controlled at a temperature of 50-55℃, and emulsified magnesium and glutamine transaminase are added thereto under stirring to obtain primary point slurry soybean milk;

[0009] (2) Secondary point slurry: the primary point slurry soybean milk is heated to 63-68℃, and then gypsum solution is added thereto to obtain secondary point slurry soybean milk;

[0010] (3) Filling and squatting brain: after the secondary point slurry soybean milk is filled, the temperature is controlled at 63-68℃, and the soybean milk is allowed to stand and solidify.

[0011] The process of soybean milk solidification to form tofu involves complex physical and chemical changes. In the two-stage point slurry process of the present application:

[0012] 1) At the time of primary point slurry, the temperature is controlled at 50-55℃, and glutamine transaminase plays a role, which catalyzes the acyl transfer reaction of glutamine to cause covalent cross-linking between proteins (or polypeptides), so as to make the molecular chains of proteins (or polypeptides) close to each other, promote the subsequent solidification reaction involving emulsified magnesium and gypsum, and be beneficial to the formation of a more compact gel structure. Gypsum has not been added at this time, and emulsified magnesium does not participate in the reaction at 50-55℃, so that the reflow network gel structure of soybean milk will not be affected due to the participation of gypsum and emulsified magnesium in the solidification reaction, which can make the prepared tofu have higher hardness.

[0013] 2) From the late primary point slurry to the early secondary point slurry, emulsified magnesium begins to slowly release Mg 2+ At the time of secondary point slurry, heating to 63-68℃, emulsified magnesium continues to slowly release Mg 2+ , and Mg 2+ begins to participate in the solidification reaction, and instantaneously mixes with gypsum after the addition of gypsum. In this process, since emulsified magnesium releases Mg 2+ at a slow speed, it can be fully dispersed in the soybean milk under stirring, and the speed of the solidification reaction is slowed down, which is beneficial to the formation of a compact gel structure. In addition, gypsum can endow tofu with better hardness, and also make it have better water retention capacity and elasticity, so that the tofu has a delicate and tender taste, but its solubility is poor and it is easy to precipitate to the bottom. In the present application, since Mg 2+ initially plays a role in solidification to make the soybean milk moderately thick, it can prevent the precipitation of gypsum, so that it can be instantaneously positioned in the soybean milk after being poured into the soybean milk, and then be better positioned and dispersed in the soybean milk to play a solidification role.

[0014] 3) Although emulsified magnesium participates in the coagulation reaction at the secondary point slurry, the present application adds it at the primary point slurry instead of the secondary point slurry, so that it can be fully dispersed into the soybean milk by using the stirring condition at the primary point slurry. If stirring is performed at the secondary point slurry, it is difficult for the gypsum to be positioned in the soybean milk instantaneously, and precipitation is prone to occur, so the emulsified magnesium is not added at the secondary point slurry.

[0015] After combining the above theoretical analysis and a large number of experiments, the present application team found that the use of emulsified magnesium, glutamine transaminase and gypsum as coagulants, combined with a specific addition sequence and a two-stage point slurry process, can effectively improve the hardness of the full-bean filled tofu. Without adding edible colloid, the full-bean filled tofu can have a hardness comparable to that of old tofu, and at the same time, the water can be locked inside the tofu, making the full-bean filled tofu have a delicate and tender taste similar to that of soft tofu.

[0016] Preferably, the mass ratio of the emulsified magnesium, glutamine transaminase and gypsum is 1:0.4-0.6:1.0-1.5.

[0017] In the emulsified magnesium, glutamine transaminase and gypsum, when the amount of glutamine transaminase is too small, the covalent cross-linking formed at the primary point slurry is less, and it is difficult to effectively promote the subsequent coagulation reaction involving emulsified magnesium and gypsum. When the amount of emulsified magnesium is too small, the slow coagulation effect is poor, and it is difficult to use its preliminary coagulation effect to fix the gypsum. When the amount of gypsum is too small, the water retention capacity of the tofu is poor, and the hardness is low. Based on this, the mass ratio of emulsified magnesium, glutamine transaminase and gypsum is controlled at 1:0.4-0.6:1.0-1.5, so that the full-bean filled tofu has a higher hardness.

[0018] Preferably, step (1) is performed under a micro-vacuum state, and the vacuum pressure is -0.05 to -0.07 MPa.

[0019] Preferably, in step (1), the process of adding emulsified magnesium and glutamine transaminase adopts an intermittent stirring point slurry method, and the stirring speed is 2500-3500 r / min.

[0020] Preferably, in step (1), the preparation method of the full-bean soybean milk includes the following steps:

[0021] (1.1) Peeling and coarse grinding: peel the soybeans, mix with water, and perform wet crushing to obtain raw slurry;

[0022] (1.2) High-pressure jet milling and boiling: perform high-pressure jet milling on the raw slurry, and then cook it thoroughly to obtain full-bean soybean milk.

[0023] Through the two processes of wet crushing and high-pressure jet milling, the full-bean filled tofu can have a more delicate taste. Through boiling, the beany smell can be removed.

[0024] Preferably, in step (1.1), the concentration of the raw slurry is 10-12 °Bé.

[0025] Preferably, in step (1), the mass ratio between the emulsified magnesium and the soybeans used to prepare the full-bean soybean slurry is 2.5-10:100.

[0026] Preferably, in step (1.2), the pressure of the high-pressure jet mill is 100-120 MPa.

[0027] Preferably, in step (1.1), the dehulling rate of the soybeans after dehulling is 50-60%.

[0028] Preferably, in step (2), the mass ratio between the gypsum and water in the gypsum solution is 1:8-12.

[0029] Preferably, in step (3), the standing coagulation time is 20-30 min.

[0030] Preferably, after step (2), pasteurization is performed, and the specific process includes the following steps: water bath at 85-90 °C for 40-45 min, cooling in water at 15-30 °C for 50-70 min, and then cooling in water at no more than 10 °C to a center temperature of no more than 10 °C.

[0031] Compared with the prior art, the present application has the following advantages:

[0032] (1) The present application uses emulsified magnesium, glutamine transaminase, and gypsum as coagulants, and cooperates with a specific addition order and a two-stage slurry-pointing process, so that the full-bean filled tofu has both the hardness comparable to that of old tofu and the delicate and tender taste of soft tofu.

[0033] (2) The present application controls the mass ratio of emulsified magnesium, glutamine transaminase, and gypsum in the range of 1:0.4-0.6:1.0-1.5, so that the full-bean filled tofu has higher hardness. DETAILED DESCRIPTION

[0034] The present application will be further described below in conjunction with examples.

[0035] Overall example

[0036] A method for making high-hardness full-bean filled tofu includes the following steps:

[0037] (1) First slurry-pointing: the full-bean soybean slurry is controlled at a temperature of 50-55 °C, emulsified magnesium and glutamine transaminase are added thereto, and mixed to obtain a first slurry-pointed soybean slurry;

[0038] (2) Secondary point slurry: the primary point slurry soy milk is heated to 63-68°C, then the gypsum solution is added and mixed to obtain the secondary point slurry soy milk;

[0039] (3) Filling and squatting brain: after the secondary point slurry soy milk is filled, the temperature is controlled at 63-68°C, and it is left to stand for 20-30 min.

[0040] As a specific embodiment, in step (1), the preparation method of the whole-bean soy milk comprises the following steps:

[0041] (1.1) Peeling and rough grinding: the soybeans are peeled, the peeling rate is 50-60%, then mixed with water and wet-pulverized to obtain raw slurry with a concentration of 10-12°Bé;

[0042] (1.2) High-pressure jet milling and burning slurry: the raw slurry is high-pressure jet milled at a pressure of 100-120 MPa, then cooked to obtain whole-bean soy milk.

[0043] As a specific embodiment, the mass ratio of the emulsified magnesium, glutamine transaminase and gypsum is 1:0.4-0.6:1.0-1.5.

[0044] As a specific embodiment, step (1) is carried out under micro-vacuum, and the vacuum pressure is -0.05 to -0.07 MPa.

[0045] As a specific embodiment, in step (1), the process of adding emulsified magnesium and glutamine transaminase adopts the intermittent stirring point slurry method, and the stirring speed is 2500-3500 r / min.

[0046] As a specific embodiment, in step (1), the mass ratio of the emulsified magnesium to the soybeans used to prepare the whole-bean soy milk is 2.5-10:100.

[0047] As a specific embodiment, in step (2), in the gypsum solution, the mass ratio of gypsum to water is 1:8-12.

[0048] As a specific embodiment, in step (3), the standing time for coagulation is 20-30 min.

[0049] As a specific embodiment, after step (2), pasteurization is carried out, and the specific process comprises the following steps: water bath at 85-90°C for 40-45 min, then cooling in water at 15-30°C for 50-70 min, and then cooling in water at no more than 10°C to a center temperature of no more than 10°C.

[0050] Example 1

[0051] A whole-bean filled tofu is prepared by the following steps:

[0052] (1) Selecting material: Selecting soybean with large, uniform, full, no mildew, no impurities as raw material. According to weight parts, soybean 100 parts, emulsified magnesium 5 parts, glutamine transaminase (TG enzyme) 2.5 parts and gypsum powder 5 parts are weighed.

[0053] (2) Soybean peeling: Using low temperature baking peeling process, the bean skin on the surface of soybean is removed, and the peeled soybean with a peeling rate of 54% is obtained.

[0054] (3) Rough grinding: Adding normal temperature water to the peeled soybean, rough grinding is carried out by wet grinding machine, and 10°Bé raw slurry is obtained.

[0055] (4) High pressure jet: The raw slurry enters the high pressure jet mill, and the jet is carried out at 100 MPa, and the superfine whole soybean raw slurry is obtained.

[0056] (5) Burning slurry: The superfine whole soybean raw slurry is punched into the steam cooking tank and fully cooked, and the cooked slurry is obtained.

[0057] (6) Soybean milk cooling: The cooked slurry is cooled to 55℃.

[0058] (7) First point slurry: Under the condition of micro vacuum state (vacuum pressure is-0.06 MPa), the temperature of the cooked slurry is maintained at 50-55℃, the intermittent 3000r / min stirring point slurry method is adopted, the emulsified magnesium and TG enzyme are added, and the mixed slurry is obtained.

[0059] (8) Second point slurry and filling: The mixed slurry enters the pipeline and is rapidly heated to 65℃, the gypsum liquid (prepared by mixing gypsum powder and water with a mass ratio of 1:10) is poured into the mixed slurry after the pipeline discharge port, and filling is carried out, the pipeline length is 0.5m, and the mixed slurry flow rate is 1.5t / h.

[0060] (9) Squat brain: After filling and sealing the box, it is placed in the heating frame at 65℃ for 20min.

[0061] (10) Pasteurization: 88℃ water bath for 40min, normal temperature water cooling for 1h, 10℃ ice water cooling to the center temperature of 10℃.

[0062] Example 2

[0063] A whole soybean filling tofu is prepared by the following steps:

[0064] (1) Selecting material: Selecting soybean with large, uniform, full, no mildew, no impurities as raw material. According to weight parts, soybean 100 parts, emulsified magnesium 2.5 parts, TG enzyme 1.5 parts and gypsum powder 3.75 parts are weighed.

[0065] (2) Soybean peeling: A low-temperature baking peeling process is used to remove the soybean skin from the surface of the soybean, obtaining peeled beans with a peeling rate of 54%.

[0066] (3) Coarse grinding: Add room temperature water to the dehulled beans and coarsely grind them using a wet mill to obtain a raw pulp with a Bé of 10°.

[0067] (4) High-pressure jet mill: The raw soybean pulp enters the high-pressure jet mill and is jetted at 110 MPa to obtain ultra-fine whole soybean pulp.

[0068] (5) Cooking: Put the ultra-fine whole soybean pulp into the steam cooking tank and cook it thoroughly to remove the beany smell and obtain cooked pulp.

[0069] (6) Soy milk cooling: Cool the cooked soy milk to 55°C.

[0070] (7) Primary slurrying: Under a slightly vacuum state (vacuum pressure of -0.06 MPa), the cooked slurry temperature is maintained at 50-55°C, and an intermittent stirring slurrying method of 2500 r / min is used to add emulsified magnesium and TG enzyme to obtain a mixed slurry.

[0071] (8) Secondary slurry filling: The mixed slurry enters the pipeline and is quickly heated to 68°C. The gypsum liquid (made of gypsum powder and water with a mass ratio of 1:8) is poured into the mixed slurry at the pipeline discharge port and then filled. The pipeline length is 0.5m and the mixed slurry flow rate is 1.5t / h.

[0072] (9) Squatting brain: After filling and sealing the box, let it stand in a 65℃ heat preservation heating box for 20 minutes.

[0073] (10) Pasteurization: 88℃ water bath for 40 min, cooling in room temperature water for 1 h, cooling in 10℃ ice water until the core temperature is 10℃.

[0074] Example 3

[0075] A whole soybean stuffed tofu is prepared by the following steps:

[0076] (1) Material selection: Use soybeans that are large, uniform, plump, free of mold and impurities as raw materials. Weigh 100 parts of soybeans, 10 parts of magnesium emulsifier, 4 parts of TG enzyme, and 12 parts of gypsum powder by weight.

[0077] (2) Soybean peeling: A low-temperature baking peeling process is used to remove the soybean skin from the surface of the soybean, obtaining peeled beans with a peeling rate of 54%.

[0078] (3) Coarse grinding: Add room temperature water to the dehulled beans and coarsely grind them using a wet mill to obtain a raw pulp with a Bé of 12°.

[0079] (4) High pressure jet flow: the raw slurry enters a high pressure jet flow mill, and a jet flow is generated at 120 MPa to obtain superfine whole soybean raw slurry.

[0080] (5) Burned slurry: the superfine whole soybean raw slurry is punched into a steam slurry cooking tank to be fully cooked, and the soybean smell is removed to obtain cooked slurry.

[0081] (6) Soybean slurry cooling: the cooked slurry is cooled to 55°C.

[0082] (7) First time point slurry: under the condition of micro-extraction vacuum (vacuum pressure is -0.06 MPa), the temperature of the cooked slurry is maintained at 50-55°C, the intermittent 3500 r / min stirring point slurry mode is adopted, emulsified magnesium and TG enzyme are added, and mixed slurry is obtained.

[0083] (8) Second time point slurry and filling: the mixed slurry enters the pipeline and is rapidly heated to 63°C, the gypsum liquid (prepared by mixing gypsum powder and water at a mass ratio of 1:12) is flushed into the mixed slurry at the pipeline discharge port, the pipeline length is 0.5 m, and the flow rate of the mixed slurry is 1.5 t / h.

[0084] (9) Squat brain: after filling and sealing the box, it is placed in a heating frame at 65°C for 20 min.

[0085] (10) Pasteurization: 88°C water bath for 40 min, normal temperature water cooling for 1 h, and 10°C ice water cooling to a center temperature of 10°C.

[0086] Example 4

[0087] A whole soybean filled bean curd is prepared by the following steps:

[0088] (1) Material selection: soybeans with large, uniform, full, no mildew, no impurities are selected as raw materials. According to weight parts, 100 parts of soybeans, 1.5 parts of emulsified magnesium, 3.7 parts of TG enzyme and 7.3 parts of gypsum powder are weighed.

[0089] (2) Soybean peeling: low-temperature baking peeling process is adopted to remove the hull of the soybeans, and peeled beans with a peeling rate of 54% are obtained.

[0090] (3) Rough grinding: add normal temperature water to the peeled beans, and rough grinding is carried out by a wet pulverizer to obtain 10°Bé raw slurry.

[0091] (4) High pressure jet flow: the raw slurry enters a high pressure jet flow mill, and a jet flow is generated at 100 MPa to obtain superfine whole soybean raw slurry.

[0092] (5) Burned slurry: the superfine whole soybean raw slurry is punched into a steam slurry cooking tank to be fully cooked, and the soybean smell is removed to obtain cooked slurry.

[0093] (6) Soybean slurry cooling: the cooked slurry is cooled to 55°C.

[0094] (7) Primary pulp mixing: under the condition of micro-vacuum (vacuum pressure is -0.06 MPa), the temperature of cooked pulp is maintained at 50-55°C, the emulsified magnesium and TG enzyme are added by the way of intermittent 3000 r / min stirring pulp mixing, and the mixed slurry is obtained.

[0095] (8) Secondary pulp mixing and filling: the mixed slurry is rapidly heated to 65°C in the pipeline, the gypsum liquid (prepared by gypsum powder and water with a mass ratio of 1:10) is poured into the mixed slurry after being discharged from the pipeline outlet, the length of the pipeline is 0.5 m, and the flow rate of the mixed slurry is 1.5 t / h.

[0096] (9) Squat brain: after filling and sealing the box, the mixed slurry is placed in a heating frame at 65°C for 20 min.

[0097] (10) Pasteurization: 88°C water bath for 40 min, normal temperature water cooling for 1 h, and 10°C ice water cooling until the center temperature is 10°C.

[0098] Example 5

[0099] A full-bean filled tofu is prepared by the following steps:

[0100] (1) Material selection: yellow beans with large, uniform, full, no mildew, no impurities are selected as raw materials. According to weight parts, 100 parts of yellow beans, 5.8 parts of emulsified magnesium, 0.9 parts of TG enzyme and 5.8 parts of gypsum powder are weighed.

[0101] (2) Soybean peeling: low-temperature baking peeling process is used to remove the hull of yellow beans, and peeled beans with a peeling rate of 54% are obtained.

[0102] (3) Rough grinding: normal temperature water is added to the peeled beans, and rough grinding is carried out by a wet pulverizer to obtain 10°Bé raw pulp.

[0103] (4) High-pressure jet flow: the raw pulp enters the high-pressure jet flow mill, and the jet flow is obtained at 100 MPa to obtain superfine full-bean raw pulp.

[0104] (5) Pulp burning: the superfine full-bean raw pulp is punched into a steam cooking tank to cook thoroughly, and the cooked pulp is obtained.

[0105] (6) Soybean milk cooling: the cooked pulp is cooled to 55°C.

[0106] (7) Primary pulp mixing: under the condition of micro-vacuum (vacuum pressure is -0.06 MPa), the temperature of cooked pulp is maintained at 50-55°C, the emulsified magnesium and TG enzyme are added by the way of intermittent 3000 r / min stirring pulp mixing, and the mixed slurry is obtained.

[0107] (8) Secondary point slurry and filling: the mixed slurry is rapidly heated to 65°C in the pipeline, and the gypsum liquid (prepared by mixing gypsum powder and water in a mass ratio of 1:10) is poured into the mixed slurry at the discharge port of the pipeline to fill, the length of the pipeline is 0.5 m, and the flow rate of the mixed slurry is 1.5 t / h.

[0108] (9) Sinking brain: after filling and sealing the box, it is placed in a heating frame at 65°C for 20 min.

[0109] (10) Pasteurization: water bath at 88°C for 40 min, cooling in normal temperature water for 1 h, and cooling in ice water to a center temperature of 10°C.

[0110] Example 6

[0111] A full-bean filled tofu is prepared by the following steps:

[0112] (1) Material selection: yellow beans with large, uniform, full, no mildew, and no impurities are selected as raw materials. According to weight parts, 100 parts of yellow beans, 7.3 parts of emulsified magnesium, 3.7 parts of TG enzyme, and 1.5 parts of gypsum powder are weighed.

[0113] (2) Soybean peeling: low-temperature baking peeling process is used to remove the hull of the yellow beans, and peeled beans with a peeling rate of 54% are obtained.

[0114] (3) Rough grinding: add normal temperature water to the peeled beans, and rough grinding is carried out by a wet pulverizer to obtain 10°Bé raw slurry.

[0115] (4) High-pressure jet flow: the raw slurry enters the high-pressure jet flow mill, and the jet flow is carried out at 100 MPa to obtain superfine full-bean raw slurry.

[0116] (5) Slurry burning: the superfine full-bean raw slurry is punched into a steam cooking tank to cook thoroughly, and the cooked slurry is obtained by removing the bean smell.

[0117] (6) Soybean milk cooling: cool the cooked slurry to 55°C.

[0118] (7) First point slurry: under the condition of micro-vacuum (vacuum pressure is -0.06 MPa), maintain the temperature of the cooked slurry at 50-55°C, and add emulsified magnesium and TG enzyme by intermittent 3000 r / min stirring point slurry method to obtain mixed slurry.

[0119] (8) Secondary point slurry and filling: the mixed slurry is rapidly heated to 65°C in the pipeline, and the gypsum liquid (prepared by mixing gypsum powder and water in a mass ratio of 1:10) is poured into the mixed slurry at the discharge port of the pipeline to fill, the length of the pipeline is 0.5 m, and the flow rate of the mixed slurry is 1.5 t / h.

[0120] (9) Sinking brain: after filling and sealing the box, it is placed in a heating frame at 65°C for 20 min.

[0121] (10) Pasteurization: 88°C water bath for 40 min, normal temperature water cooling for 1 h, 10°C ice water cooling to the center temperature of 10°C.

[0122] Comparative Example 1

[0123] A full-bean filled tofu was prepared by the following steps:

[0124] (1) Material selection: large, uniform, full, no moldy, no impurities yellow soybean as raw material. According to the weight part, 100 parts of yellow soybean, 5 parts of emulsified magnesium, 2.5 parts of TG enzyme and 5 parts of gypsum powder were weighed.

[0125] (2) Soybean peeling: low temperature baking peeling process was used to remove the hull of the yellow soybean, and the peeling rate of the peeled bean was 54%.

[0126] (3) Rough grinding: normal temperature water was added to the peeled bean, and rough grinding was carried out by wet grinding machine to obtain 10°Bé raw slurry.

[0127] (4) High pressure jet: the raw slurry entered the high pressure jet mill, and the jet was carried out at 100 MPa to obtain superfine full-bean raw slurry.

[0128] (5) Slurry burning: the superfine full-bean raw slurry was punched into the steam cooking tank to cook thoroughly, and the cooked slurry was obtained.

[0129] (6) Soybean milk cooling: the cooked slurry was cooled to 55°C.

[0130] (7) Point slurry: under the condition of micro-extraction vacuum (vacuum pressure-0.06 MPa), the temperature of the cooked slurry was maintained at 50-55°C, and the intermittent 3000r / min stirring point slurry method was used to add emulsified magnesium, TG enzyme and gypsum liquid (prepared by mixing gypsum powder and water with a mass ratio of 1:10), and the mixed slurry was obtained.

[0131] (8) Filling: the mixed slurry was quickly heated to 65°C in the pipeline, and then filled after passing through the pipeline. The length of the pipeline was m, and the flow rate of the mixed slurry was m / s.

[0132] (9) Squat brain: after filling and sealing the box, it was placed in the heating frame at 65°C for 20 min.

[0133] (10) Pasteurization: 88°C water bath for 40 min, normal temperature water cooling for 1 h, 10°C ice water cooling to the center temperature of 10°C.

[0134] Comparative Example 2

[0135] A full-bean filled tofu was prepared by the following steps:

[0136] (1) Material selection: Select yellow soybeans with large, uniform, full, no mildew, no impurities as raw materials. According to weight parts, take 100 parts of yellow soybeans, 5 parts of emulsified magnesium, 2.5 parts of TG enzyme and 5 parts of gypsum powder.

[0137] (2) Soybean peeling: Adopt low-temperature baking peeling process to remove the hull of the yellow soybeans, and get peeled beans with a peeling rate of 54%.

[0138] (3) Rough grinding: Add normal temperature water to the peeled beans, and rough grind through a wet grinder to get raw slurry of 10°Bé.

[0139] (4) High-pressure jet flow: The raw slurry enters the high-pressure jet flow mill, and jet flows at 100 MPa to get superfine whole bean raw slurry.

[0140] (5) Slurry boiling: The superfine whole bean raw slurry is punched into a steam boiling tank for full boiling to remove the bean smell and get cooked slurry.

[0141] (6) Soybean milk cooling: Cool the cooked slurry to 55℃.

[0142] (7) First time slurry adding: Under the condition of micro vacuum state (vacuum pressure is -0.06 MPa), maintain the temperature of the cooked slurry at 50-55℃, and add TG enzyme by using intermittent 3000r / min stirring slurry adding mode to obtain mixed slurry.

[0143] (8) Second time slurry adding and filling: The mixed slurry enters the pipeline for rapid heating to 65℃, and the emulsified magnesium and gypsum liquid (prepared by mixing gypsum powder and water with a mass ratio of 1:10) are poured into the mixed slurry after the pipeline discharge port, and then filling is carried out. The pipeline length is 0.5m, and the flow rate of the mixed slurry is 1.5t / h.

[0144] (9) Brain squatting: After filling and sealing, place in a heating frame at 65℃ for 20min.

[0145] (10) Pasteurization: 88℃ water bath for 40min, normal temperature water cooling for 1h, and 10℃ ice water cooling to 10℃ center temperature.

[0146] Test Example 1: Sensory index

[0147] The whole bean filled tofu prepared in each example and comparative example is subjected to sensory evaluation, and the results are shown in Table 1.

[0148] Table 1 Sensory evaluation index and results of whole bean filled tofu

[0149]

[0150]

[0151] Test Example 2: Physicochemical index

[0152] The full-bean filled tofu prepared in each example and comparative example was subjected to detection of nutritional component content and hardness, and the results are shown in Table 2.

[0153] Table 2: Physicochemical test indexes and results

[0154]

[0155]

[0156] 1 : Comparative Example 2 cannot be detected for hardness due to no molding.

[0157] From Table 1 and Table 2, it can be seen that:

[0158] (1) The full-bean filled tofu of Examples 1-3 has a relatively high hardness, close to that of old tofu (hardness of about 350-400 g), and has suitable chewiness and relatively high water retention. It is shown that by using the method of the present application, the full-bean filled tofu can have both the hardness of old tofu and the delicate and smooth taste of soft tofu.

[0159] (2) Compared with adding the gypsum liquid at the second time of pulping (Example 1), adding the gypsum liquid at the first time of pulping (Comparative Example 1) will result in poor coagulation effect, and the full-bean filled tofu obtained has loose structure, poor hardness, water retention and chewiness. This is because: if the gypsum liquid is added at the first time of pulping, on the one hand, the gypsum will participate in the coagulation reaction in advance, which will affect the re-flowing network gel structure of the soy milk, and on the other hand, the gypsum cannot be fully positioned and dispersed in the soy milk, which will affect its coagulation effect.

[0160] (3) Adding the emulsified magnesium at the second time of pulping (Comparative Example 2) will result in that the full-bean filled tofu cannot be molded. This is because: at the second time of pulping, no stirring is performed in order to enable the gypsum to be positioned well in the soy milk instantaneously, and if the emulsified magnesium is filled into the soy milk together with the gypsum liquid at the second time of pulping, the emulsified magnesium cannot be fully dispersed in the soy milk, resulting in too poor coagulation effect.

[0161] (4) Compared with Example 4, the full-bean filled tofu of Example 1 is better molded, and has relatively high hardness, chewiness and water retention, which shows that under the condition that the total amount of emulsified magnesium, glutamine transaminase and gypsum is fixed, too small amount of emulsified magnesium will result in too small hardness, chewiness and water retention of the full-bean filled tofu prepared. This is because: at the second time of pulping, the emulsified magnesium is slowly released and participates in the coagulation reaction, and its initial coagulation effect can make the soy milk moderately thick, thereby preventing the gypsum from precipitating, so that the gypsum can be positioned well in the soy milk instantaneously after being filled into the soy milk, and then be positioned and dispersed in the soy milk to play a coagulation role, and thus when the amount of emulsified magnesium is too small, it will be difficult to use its initial coagulation effect to fix the gypsum.

[0162] (5) Compared with example 5, the full-bean filling tofu of example 1 is relatively better in forming, and has higher hardness, chewiness and water retention, which indicates that when the total amount of emulsified magnesium, glutamine transaminase and gypsum is fixed, too little amount of glutamine transaminase will cause the hardness, chewiness and water retention of the prepared full-bean filling tofu to be too small. This is because: glutamine transaminase plays a role when the slurry is first spotted, causing covalent cross-linking between proteins (or polypeptides), which can make the molecular chains of proteins (or polypeptides) close to each other, promote the subsequent coagulation reaction involving emulsified magnesium and gypsum, and be conducive to forming a more compact gel structure, so when the amount of glutamine transaminase is too small, it will be difficult to effectively promote the subsequent coagulation reaction involving emulsified magnesium and gypsum.

[0163] (6) Compared with example 6, the full-bean filling tofu of example 1 has higher hardness, chewiness and water retention, which indicates that when the total amount of emulsified magnesium, glutamine transaminase and gypsum is fixed, too little amount of gypsum will cause the hardness, chewiness and water retention of the prepared full-bean filling tofu to be too small. This is because: when used alone, compared with emulsified magnesium and glutamine transaminase, gypsum can give the full-bean filling tofu higher water retention, chewiness and hardness, so when the amount of gypsum is too small, the hardness, chewiness and water retention of the tofu will be lower.

[0164] The raw materials and equipment used in the present application are all commonly used raw materials and equipment in the art unless otherwise specified; the methods used in the present application are all conventional methods in the art unless otherwise specified.

[0165] The above is only a preferred embodiment of the present application, and does not limit the present application in any way. Any simple modification, change and equivalent transformation of the above embodiment based on the technical essence of the present application still falls within the protection scope of the technical solution of the present application.

Claims

1. A method for preparing high-hardness whole bean-filled tofu, characterized in that: The following steps are involved: (1) Primary slurrying: controlling the temperature of whole soybean milk at 50-55°C, adding emulsified magnesium and transglutaminase thereto under stirring, and mixing to obtain primary slurry; the mass ratio of emulsified magnesium to soybeans used to prepare the whole soybean milk is 2.5-10:100; (2) Secondary slurrying: heat the primary slurrying soy milk to 63-68°C, then add gypsum liquid and mix well to obtain secondary slurrying soy milk; the mass ratio of emulsified magnesium, transglutaminase and gypsum is 1:0.4-0.6:1.0-1.5; in the gypsum liquid, the mass ratio of gypsum to water is 1:8-12; (3) Filling and simmering: After filling the secondary soy milk, control the temperature at 63~68℃ and let it stand for 20~30 minutes.

2. The production method according to claim 1, wherein: Step (1) is carried out under a slight vacuum state, with a vacuum pressure of -0.05 to -0.07 MPa.

3. The production method according to claim 1, wherein In step (1), the process of adding emulsified magnesium and transglutaminase adopts the method of intermittent stirring slurrying.

4. The production method according to claim 3, wherein: During the intermittent stirring and slurrying process, the stirring speed is 2500~3500r / min.

5. The production method according to claim 1, wherein: In step (1), the method for preparing whole soybean milk comprises the following steps: (1.1) Peeling and coarse grinding: After peeling the soybeans, mix them with water and perform wet grinding to obtain raw pulp; (1.2) High-pressure jet milling and slurry burning: The raw slurry is subjected to high-pressure jet milling and then boiled thoroughly to obtain whole bean soy milk.

6. The production method according to claim 5, characterized in that: In step (1.1), the concentration of the raw pulp is 10~12°Bé.

7. The production method according to claim 5, characterized in that: In step (1.1), the peeling rate of soybeans after peeling is 50~60%.

8. The production method according to claim 5, wherein: In step (1.2), the pressure of the high-pressure jet mill is 100-120 MPa.

9. The production method according to claim 1, wherein: After step (2), pasteurization is carried out, and the specific process includes the following steps: after being placed in a water bath at 85-90°C for 40-45 minutes, cooling in water at 15-30°C for 50-70 minutes, and then cooling in water at no higher than 10°C to a core temperature no higher than 10°C.

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