Preparation method of leisure whole bean tough dried tofu and mobile water bath heat preservation and solidification device for its processing

Abstract

The invention relates to the field of bean products, and provides a method for preparing leisure whole bean tough dried bean curd and a mobile water bath heat preservation and solidification device for processing the same. The preparation method comprises the following steps: 1) mixing peeled soybeans and water to obtain a coarsely ground paste, then ultrafinely grinding to obtain a finely ground paste, and then high-pressure homogenizing to obtain whole bean milk; 2) boiling the whole bean milk and cooling it to 60-70°C, adding a compound coagulant to emulsify and paste to obtain bean curd, and the bean curd is heat-insulated and solidified at 50-60°C; the compound coagulant includes emulsified magnesium, calcium sulfate and TG enzyme; 3) the solidified bean curd is pressed to obtain dried bean curd. No bean dregs are produced in the production process, the soybean utilization rate is high, the product has good water retention, a tough and elastic taste, a delicate texture, a unique flavor and stable quality. The device comprises a conveying chain, a paste-spraying machine is provided at the input end of the conveying chain, an automatic flipping device is provided at the output end, and a sandwich water bath is provided on the conveying chain, and the temperature of the sandwich water bath is controlled by a temperature control system.

Description

Technical Field

[0001] The invention relates to the field of bean products, in particular to a method for preparing leisure whole bean tough dried bean curd and a mobile water bath heat preservation and coagulation device for its processing. Background Art

[0002] With the development of tourism, as a leisure snack, leisure dried bean curd products have been loved by people. The leisure dried bean curd sold on the market now is mainly produced by traditional technology. Soybeans are soaked, ground, centrifuged and de-slaged. The soybean milk after removing the dregs is then processed by brain coagulation, flower breaking, cloth wrapping, pressing and other processes to make dried bean curd blanks, and then stewed and seasoned, vacuum packed, and high-temperature sterilized to make leisure dried bean curd. For example, patent CN108740065A discloses a method for preparing leisure dried bean curd, which is prepared by raw material selection, bean soaking, grinding and other processes, and then prepared by alkali stringing, stewing and mixing to prepare leisure dried bean curd; the invention performs alkali stringing treatment on the bean embryo, which can increase the toughness of the dried bean curd, remove the fishy smell of the dried bean curd, and make the dried bean curd easier to taste during the stewing process; the prepared dried bean curd has a smooth surface, no hard skin layer, clear layers and no adhesion, will not break after folding, and has good toughness, and will not leak oil, harden and agglomerate after long-term storage.

[0003] New dry or wet ultrafine grinding machines, ultrahigh pressure homogenizers, high pressure jet mills and other technologies can ultrafinely grind bean dregs and add them to bean products together with soy milk to achieve the production of whole bean products. Whole bean milk contains more dietary fiber and sugars, so traditional coagulation technologies such as magnesium chloride, calcium sulfate, and gluconolactone cannot achieve a good coagulation effect. Therefore, an ideal solution is needed. Summary of the invention

[0004] The invention provides a method for preparing leisure whole bean tough dried tofu and a mobile water bath heat preservation and coagulation device for processing the same. Whole bean milk is prepared through a step-by-step refining process, and a compound coagulant is used to perform heat preservation, emulsification and coagulation on the whole bean milk to obtain whole bean tough dried tofu with fine texture, good water retention, tough and elastic taste and high yield.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: The method for preparing the leisure whole bean tough dried tofu comprises the following steps: 1) mixing dehulled soybeans and water to obtain a coarse grind paste, then ultrafine grinding to obtain a fine grind paste, and then high-pressure homogenization to obtain whole soybean milk; 2) boiling whole soybean milk, cooling it to 60-70° C., adding a compound coagulant to emulsify the milk to obtain bean curd, and keeping the bean curd warm at 50-60° C. for coagulation; the compound coagulant includes emulsified magnesium, calcium sulfate and TG enzyme; 3) The solidified bean curd is pressed into dried bean curd.

[0006] Preferably, the dehulled soybeans are soybeans with a dehulling rate of ≥ 90%. The soybeans are selected to be large, uniform, full, free of mold and impurities.

[0007] As a preferred embodiment, the mass ratio of dehulled soybeans to water is 1:4-7; the particle size D of the coarsely ground paste is 90 The particle size D of the finely ground paste is 200-250 μm. 90 The particle size is 150-180 μm, the concentration of whole bean milk is 11-14%, and the particle size D 90 As a further preferred embodiment, the particle size D of the coarsely ground paste is 50-60 μm. 90 The particle size D of the finely ground paste is 250 μm. 90 The particle size is 180 μm, the concentration of whole bean milk is 11-14%, and the particle size D 90 is 60μm.

[0008] Preferably, the pressure of high-pressure homogenization is 80-100 bar.

[0009] Preferably, the pulp is cooked by direct steam injection, and the conditions are: steam pressure 0.15-0.2MPa, pulp temperature 100-103°C maintained for 3-4 minutes.

[0010] Preferably, cooling is performed by means of a plate heat exchanger.

[0011] Preferably, the pulping is performed using an online continuous pulping machine with a rotation speed of 4000-6000 rpm.

[0012] Preferably, the mass ratio of whole bean milk to the compound coagulant is 100:1-2.

[0013] Preferably, the mass proportions of the components of the compound coagulant are: 50-60 parts of magnesium emulsifier, 15-20 parts of calcium sulfate, and 10-15 parts of TG enzyme.

[0014] Preferably, the compound coagulant further contains seasonings, and the weight percentage of the seasonings is 5-12 parts. More preferably, the seasonings are composed of: 2-4 parts of edible salt, 2-5 parts of spices, and 1-3 parts of monosodium glutamate.

[0015] Preferably, the heat preservation and solidification time is 20-30 minutes.

[0016] Preferably, the temperature for heat preservation and solidification is 55-57°C.

[0017] Preferably, the pressing time is 50-70 minutes, and hydraulic pressure is used to press the dried tofu into a thickness of 1.2-1.5 cm.

[0018] Preferably, the dried tofu is cut into a cuboid of 6-6.5 cm in length and 2-2.2 cm in width.

[0019] Preferably, the dried tofu is cut into pieces, seasoned and mixed with ingredients, vacuum-packed, sterilized at high temperature, cooled, and packed into boxes for storage.

[0020] The present invention also provides a mobile water bath heat preservation and solidification device for processing leisure whole bean curd, comprising a conveyor chain, a pulping machine is provided at the input end of the conveyor chain, an automatic plate turning device is provided at the output end, and a sandwich water bath is provided on the conveyor chain, and the temperature of the sandwich water bath is controlled at 55-65° C. by a temperature control system. The water bath temperature needs to be slightly higher than the coagulation temperature of the bean curd to keep the bean curd at 50-60° C.

[0021] The dosing machine uses a compound coagulant to emulsify the whole bean milk to obtain the soymilk, which is then placed in a coagulation box and transported to the automatic flipping device along a conveyor chain. The soymilk is solidified during the transportation process. A sandwich water bath is provided on the conveyor chain to keep the soymilk warm throughout the process. The sandwich water bath is equipped with a steam pipe, and the temperature of the sandwich water bath is controlled at 55-65°C through a temperature control system. The temperature control system includes a thermometer, a gas valve, and a pressure gauge.

[0022] Preferably, an automatic plate stacking device and a press are sequentially arranged behind the automatic plate turning device; the automatic plate turning device pours the soybean curd in the solidification box onto a pressing plate covered with a wrapping cloth, and then evenly wraps the solidified soybean curd with the wrapping cloth at four corners; the automatic plate stacking device stacks 10-15 of the above-obtained pressing plates into a pile, and feeds them into the press for pressing together.

[0023] Therefore, the beneficial effects of the present invention are: (1) Whole bean soy milk is produced by grinding the soybeans step by step. No dregs are produced during the production process, which fully utilizes the raw materials and reduces the cost of processing dregs.

[0024] (2) Whole bean soy milk contains a lot of dietary fiber and polysaccharides. Ordinary coagulation technology and processes cannot achieve complete gelation. The produced dried tofu has a loose structure, soft surface, is fragile, and has no shape. This technology uses a compound coagulant and TG enzyme technology to produce whole bean tough dried tofu with delicate and tender texture, no pores, strong gelation, and good water retention.

[0025] (3) TG enzyme can work under the temperature condition of 5-60℃, and has high activity in the temperature range of 42-57℃. If the bean curd is not kept warm after slurrying, the temperature of the bean curd will drop quickly, which will seriously affect the gel between proteins. In order to take into account the reaction of TG enzyme and the subsequent pressing of dried bean curd, the temperature of the bean curd is kept at 55-57℃. The present invention adopts water bath insulation technology to keep the TG enzyme in the optimal reaction temperature during the slurrying process after slurrying, so as to make the gel between proteins more complete.

[0026] (4) After the tofu brain is solidified, it is not broken into pieces and directly put into the brain, so that the tofu tissue can maintain its original solidified state after being pulped.

[0027] (5) When making soy milk, some flavor substances are added to the soy milk to make the product more evenly flavored and reduce the braising process. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is the front view of the mobile water bath insulation coagulation device.

[0029] Figure 2 It is a top view of the mobile water bath insulation and coagulation device.

[0030] In the figure, 1. slurry barrel, 2. slurry dosing machine, 3. solidification box, 4. bracket, 5. conveyor chain, 6. sandwich water bath, 61. cover, 7. steam pipe, 8. air valve, 9. pressure gauge, 10. thermometer, 11. automatic flip device. DETAILED DESCRIPTION

[0031] The technical solution of the present invention is further described below through specific embodiments.

[0032] In the present invention, unless otherwise specified, the raw materials and equipment used can be purchased from the market or are commonly used in the art. The methods in the embodiments, unless otherwise specified, are all conventional methods in the art. Unless otherwise specified, parts are all weight parts, temperatures are expressed in ° C or at ambient temperature, and pressures are atmospheric pressure or near atmospheric pressure. There are many variations and combinations of reaction conditions (such as component concentrations, desired solvents, solvent mixtures, temperatures, pressures, and other reaction ranges) and conditions that can be used to optimize the purity and yield of the product obtained by the method, and only reasonable routine experiments will be required to optimize such method conditions.

[0033] Example Dried tofu is a food made mainly from soybeans. It originated in China and has a history of more than 2,100 years. It is deeply loved by the Chinese people and the people of the world. Dried tofu is rich in nutrition, high in protein, low in fat, and contains iron, calcium, phosphorus, magnesium and other trace elements necessary for the human body. It is known as "plant meat". Dried tofu is a tonic and heat-clearing health food. Regular consumption can replenish qi, clear heat and moisten dryness, promote the production of body fluids and quench thirst, and clean the stomach. Modern medicine has confirmed that in addition to increasing nutrition, helping digestion, and increasing appetite, dried tofu is also very beneficial to the growth and development of teeth and bones; dried tofu does not contain cholesterol and is a medicinal food for patients with hypertension, hyperlipidemia, hypercholesterolemia, arteriosclerosis, and coronary heart disease. It is also a good food therapy for children, the sick and the elderly to supplement nutrition.

[0034] With the development of food processing technology, various new soybean pulping equipment has emerged continuously, providing guarantee for the development of soy products. New dry or wet ultrafine pulping machines, ultra-high pressure homogenizers, high-pressure jet mills and other technologies can ultrafinely grind the bean dregs that the original pulping technology cannot achieve, and add them to soy products together with soy milk to realize the production of whole bean products. The product has a soft and elastic taste, fine texture, high moisture content, good water retention, natural bean flavor, and after being marinated and seasoned, it can be made into a unique and leisure-friendly tough dried tofu.

[0035] With the development of food biotechnology, the application of emulsified coagulant technology, compound coagulation technology, and TG enzyme in soy products, through the study of the characteristics of each coagulant, the mechanism of action of the pulp coagulation process, whole bean milk contains more dietary fiber and carbohydrates, and the traditional coagulation technology of magnesium chloride, calcium sulfate, gluconolactone, etc. cannot achieve a good coagulation effect. The present invention forms a leisure whole bean tough dried tofu prepared by water bath insulation coagulation process and its device by studying new ultrafine pulping technology and modern advanced emulsified coagulation technology and whole bean milk insulation coagulation technology. In the traditional process of dried bean curd, magnesium chloride is purchased as a coagulant, which has a fast coagulation speed and poor water retention of the obtained dried bean curd. The moisture content of the leisure dried bean curd is relatively low, generally controlled at 45-50%, and the taste is rough and fragile. Therefore, breaking the brain after the slurry is applied is convenient for squeezing out the yellow slurry water. The present invention adopts a compound emulsified coagulant technology with a synergistic effect of multiple coagulants. The protein gelling property and water retention property are good after coagulation. In order to improve the yield of dried bean curd and its delicate and organized structure, a non-breaking process is adopted, that is, the brain is directly added without breaking the brain after the solidification of the bean curd, which overcomes the problem that the traditional dried bean curd needs to be broken after the slurry is solidified and then wrapped with cloth and pressed, resulting in the production of dried bean curd with less delicate tissue, more pores, poor water retention, rough taste and the like.

[0036] 1. A method for preparing leisure whole bean tough dried tofu The following steps are involved: 1. Material selection: Choose soybeans that are large, uniform, plump, free of mold and impurities as raw materials.

[0037] 2. Peeling: The soybeans are fed into an automatic continuous peeling machine to obtain peeled beans with a peeling rate of ≥ 90%.

[0038] 3. Refining: Refining is performed according to the ratio of dehulled soybeans to water of 1:4-7 to obtain a particle size D 90 It is a coarsely ground paste of 200-250μm.

[0039] 4. Wet ultrafine grinding: The above-obtained paste is further ultrafinely ground to obtain a particle size D 90 It is a finely ground paste of 150-180μm.

[0040] 5. High-pressure homogenization: The paste obtained above is homogenized under high pressure, with a homogenizer pressure of 80-100 Bar to obtain a particle size of 11-14% and a particle size of D 90 Whole bean milk with a particle size of 50-60 μm.

[0041] 6. Boiling: The whole bean milk obtained above is boiled by steam direct injection, with a steam pressure of 0.15-0.2MPa and a slurry temperature of 100-103℃ for 3-4 minutes. The whole bean milk is cooled to 60-70℃ by a plate heat exchanger and put into a storage tank for standby use. Since the whole bean milk contains more dietary fiber and other polysaccharides and is relatively viscous, steam direct injection boiling is not easy to coke and the boiling is more uniform.

[0042] 7. Pulping: The temperature of whole bean milk is controlled at 50-60℃, and high-speed emulsification and pulping are performed by an online continuous pulping machine. The speed of the pulping machine is 4000-6000 rpm, and the whole bean milk and the compound coagulant are mixed in a mass ratio of 100:1.0-2.0. The mass fractions of each component of the compound coagulant used for pulping are: 50-60 parts of emulsified magnesium, 15-20 parts of calcium sulfate, 10-15 parts of TG enzyme, and 5-12 parts of seasoning; as a further preferred embodiment, the composition of the seasoning is: 2-4 parts of edible salt, 2-5 parts of spices, and 1-3 parts of monosodium glutamate. Spices include chili powder, garlic powder, scallion powder, cumin powder, ginger powder, black pepper powder, cinnamon powder, red pepper powder, white pepper powder, etc.

[0043] Emulsified magnesium is a slow-release coagulant. Magnesium chloride is embedded in oil through oil emulsification. When it acts, magnesium chloride is slowly released to combine with protein molecules in soybean milk to produce a coagulation. Without embedded magnesium chloride, the point slurry solidification speed is fast, and the product has poor water retention. Therefore, the present invention uses emulsified magnesium coagulant. The solidification speed of calcium sulfate is relatively slow, and it can better retain moisture. After solidification, the texture is fine and the structure is tight. TG enzyme (glutamine aminotransferase) can catalyze protein polypeptides to occur intramolecular and intermolecular covalent cross-linking, thereby improving the structure and function of protein, improving the water retention and gel ability of protein, and then improving the flavor, taste, texture and appearance of dried bean curd.

[0044] Since whole bean milk is not processed by removing the bean dregs, it contains more dietary fiber and other polysaccharides, which will affect the coagulation effect. The present invention requires the use of a compound calcium sulfate as a coagulant, which causes a faster coagulation speed. The dried bean curd has more pores and the texture is not delicate, so a slow-release emulsified magnesium is required to achieve complete coagulation.

[0045] The seasoning is used for seasoning. When adding part of the flavoring substances to the soy milk, the product is more evenly flavored and the braising process is reduced. The seasoning will have a certain effect on coagulation, but the present invention controls the amount of addition so that it does not affect coagulation.

[0046] 8. Heat preservation and coagulation. The tofu obtained by emulsification and slurrying is put into a coagulation box for water bath heat preservation and coagulation. The box is kept warm while moving to achieve continuous production. The heat preservation temperature is 50-60°C (more preferably 55-57°C) for 20-30 minutes. Slurrying and coagulation are carried out simultaneously. The slurrying and coagulation are carried out at the same time. The slurrying needs to be kept for a certain time so that the coagulant and protein molecules can be fully combined to form a gel. Therefore, step 8 is a coagulation stabilization process.

[0047] 9. Turn over: Pour the fully solidified bean curd from the solidification box into the pressing plate. When turning over, press the upper and lower plates evenly to ensure that the solidified bean curd is not damaged. The bean curd on the pressing plate is wrapped in cloth and sent into the press for pressing and molding.

[0048] 10. Pressing: The total time is 50-70 minutes, and the hydraulic segmented pressing method in the prior art is used. The pressed dried bean curd is taken out from the press, and the wrapping cloth is removed. The thickness of the pressed dried bean curd is about 1.2-1.5 cm.

[0049] 11. Cut into pieces: Cut into rectangles of 6.0-6.5cm long and 2.0-2.2cm wide, and cool them for later use.

[0050] 12. Seasoning and mixing: According to the flavor of the product, mix it into products with different flavors such as five-spice flavor, spicy flavor, barbecue flavor, etc.

[0051] 13. Vacuum packaging: Put each small piece into a bag and seal it with a fully automatic vacuum packaging machine to make small package products.

[0052] 14. High temperature sterilization: maximum temperature 115℃, 15 minutes.

[0053] 15. Cool down.

[0054] 16. Packing and storage: The dried tofu is packed and sent to the normal temperature warehouse.

[0055] 2. A mobile water bath heat preservation and solidification device for processing whole bean and tough dried tofu It includes a conveyor chain, a pulping machine is provided at the input end of the conveyor chain, an automatic plate turning device is provided at the output end, and a sandwich water bath is provided on the conveyor chain. The temperature of the sandwich water bath is controlled at 55-65°C by a temperature control system. The pulping machine uses a compound coagulant to emulsify and pulp the whole bean milk to obtain soybean curd. The soybean curd is placed in a coagulation box and transported to the automatic plate turning device along the conveyor chain. The soybean curd is solidified during the transportation process. A sandwich water bath is provided on the conveyor chain to keep the soybean curd warm throughout the process. The sandwich water bath is equipped with a steam pipe, and the temperature of the sandwich water bath is controlled at 55-65°C by a temperature control system. The temperature control system includes a thermometer, a gas valve and a pressure gauge.

[0056] An automatic plate stacking device and a press are arranged in sequence behind the automatic plate turning device; the automatic plate turning device pours the bean curd in the solidification box onto a pressing plate covered with a wrapping cloth, and then evenly wraps the solidified bean curd with the wrapping cloth at four corners; the automatic plate stacking device stacks 10-15 of the above-obtained pressing plates into a pile, and sends them together into the press for pressing.

[0057] The whole bean dried tofu of the present invention is preferably made of soybean raw material, and is processed through the processes of selection, peeling, coarse and fine grinding, ultrafine grinding, high-pressure homogenization, steam direct injection pulping, cooling, online automatic emulsification and pulping, water bath insulation solidification, pressing, etc. The process has a high degree of automation, the product is hygienic and safe, no bean dregs are produced in the production process, the soybean utilization rate is high, the product has good water retention, a tough and elastic taste, a delicate texture, a unique flavor, and stable quality.

[0058] Example 1 A method for preparing leisure whole bean tough dried tofu, the steps are as follows: 1. Material selection: Choose soybeans that are large, uniform, plump, free of mold and impurities as raw materials.

[0059] 2. Peeling: The soybeans are fed into an automatic continuous peeling machine to obtain peeled beans with a peeling rate of ≥ 90%.

[0060] 3. Grinding: Grind the dehulled soybeans and water in a ratio of 1:5 to obtain a particle size of D 90 It is a coarsely ground paste of 250 μm.

[0061] 4. Wet ultrafine grinding: The above-obtained paste is further ultrafinely ground to obtain a particle size D 90 It is a finely ground paste of 180 μm.

[0062] 5. High-pressure homogenization: The obtained paste is homogenized under high pressure at a homogenizer pressure of 90 Bar to obtain a particle size of 14% and a particle size of D 90 The whole bean soy milk is 60μm.

[0063] 6. Boiling: The whole bean milk obtained above is boiled by steam direct injection with a steam pressure of 0.15 MPa and a slurry temperature of 103°C for 3 minutes; the whole bean milk is cooled to 70°C by a plate heat exchanger and placed in a storage tank for standby use.

[0064] 7. Pulping: The temperature of whole bean milk is controlled at 70℃, and high-speed emulsification and pulping are performed by an online continuous pulping machine. The speed of the pulping machine is 5000 rpm, and the whole bean milk and the compound coagulant are mixed in a mass ratio of 100:1.0. The mass parts of each component of the compound coagulant are: 50 parts of emulsified magnesium, 15 parts of calcium sulfate, 10 parts of TG enzyme, 2 parts of edible salt, 2 parts of spices (chili powder purchased from Hongfang Biotechnology (Kunshan) Co., Ltd.), and 1 part of monosodium glutamate.

[0065] 8. Heat preservation and solidification: the soybeans obtained by emulsification and slurrying are put into a solidification box for heat preservation and solidification in a water bath. The heat preservation is carried out while moving to realize continuous production. The heat preservation temperature is 57°C and the time is 20 minutes.

[0066] 9. Turn over: Pour the fully solidified bean curd from the solidification box into the pressing plate. When turning over, press the upper and lower plates evenly to ensure that the solidified bean curd is not damaged. The bean curd on the pressing plate is wrapped in cloth and sent into the press for pressing and molding.

[0067] 10. Pressing: The total time is 70 minutes, and the hydraulic segmented pressing method in the prior art is used. The pressed dried bean curd is taken out from the press, and the wrapping cloth is removed. The thickness of the pressed dried bean curd is about 1.2 cm.

[0068] 11. Cut into pieces: Cut into 6.0cm long and 2.0cm wide rectangles and cool them for later use.

[0069] 12. Seasoning and mixing: According to the flavor of the product, prepare it according to the formula to make a spicy product.

[0070] 13. Vacuum packaging: Put each small piece into a bag and seal it with a fully automatic vacuum packaging machine to make small package products.

[0071] 14. High temperature sterilization: maximum temperature 115℃, 15 minutes.

[0072] 15. Cool down.

[0073] 16. Packing and storage: The dried tofu is packed and sent to the normal temperature warehouse.

[0074] A mobile water bath heat preservation and solidification device suitable for the above-mentioned leisure whole bean tough dried tofu processing, such as Figure 1 and Figure 2 As shown. The device has a bracket 4, on which a conveying chain 5 is provided. In order to save space, the conveying chain 5 is U-shaped. The input end of the conveying chain 5 is provided with a pulping machine 2, and the output end is provided with an automatic flipping device 11, that is, the conveying chain 5 conveys the soybeans obtained after pulping by the pulping machine 2 to the automatic flipping device 11. A sandwich water bath 6 is provided on the conveying chain 5 to keep the soybeans warm throughout the process, and a cover 61 is provided above the sandwich water bath 6 to keep the soybeans warm.

[0075] Specifically: the whole bean milk prepared in the previous procedure is placed in a slurry barrel 1. The slurry dispenser 2 uses a compound coagulant to emulsify the whole bean milk to obtain soybean curd, which is placed in a coagulation box 3 and transported to the automatic flip device 11 along the conveyor chain 5. The soybean curd is solidified during the transportation process. A sandwich water bath 5 is provided on the conveyor chain 5 to keep the soybean curd warm throughout the process. The sandwich water bath 5 is equipped with a steam pipe 7. The steam pipe 7 is provided with a gas valve 8, a pressure gauge 9, a thermometer 10 and other devices to form a temperature control system (the specific implementation of temperature control is a prior art and is not described in detail in the present invention). The temperature of the sandwich water bath 6 is controlled at 62°C by the temperature control system.

[0076] An automatic plate stacking device and a press (not shown) are arranged in sequence behind the automatic plate turning device 11. The automatic plate turning device 11 pours the soybean curd in the solidification box onto the pressing plate covered with a wrapping cloth, and then wraps the solidified soybean curd evenly with the wrapping cloth at the four corners; the automatic plate stacking device stacks the 15 pressed plates obtained above into a pile and sends them together into the press for pressing.

[0077] Example 2 A method for preparing leisure whole bean tough dried tofu, the steps are as follows: 1. Material selection: Choose soybeans that are large, uniform, plump, free of mold and impurities as raw materials.

[0078] 2. Peeling: The soybeans are fed into an automatic continuous peeling machine to obtain peeled beans with a peeling rate of ≥ 90%.

[0079] 3. Grinding: Grind the dehulled soybeans and water in a ratio of 1:6 to obtain a particle size of D 90 The coarsely ground paste is 200 μm.

[0080] 4. Wet ultrafine grinding: The above-obtained paste is further ultrafinely ground to obtain a particle size D 90 It is a finely ground paste of 150μm.

[0081] 5. High-pressure homogenization: The obtained paste is homogenized under high pressure at a homogenizer pressure of 90 Bar to obtain a particle size of 11% and a particle size of D 90 The whole bean soy milk is 50μm.

[0082] 6. Boiling: The whole bean milk obtained above is boiled by steam direct injection with a steam pressure of 0.2 MPa and a slurry temperature of 100°C for 4 minutes; the whole bean milk is cooled to 60°C by a plate heat exchanger and placed in a storage tank for standby use.

[0083] 7. Pulping: The temperature of whole bean milk is controlled at 60°C, and high-speed emulsification and pulping are performed by an online continuous pulping machine at a speed of 4000 rpm. The whole bean milk and the compound coagulant are mixed in a mass ratio of 100:2.0. The mass parts of each component of the compound coagulant are: 60 parts of emulsified magnesium, 20 parts of calcium sulfate, 15 parts of TG enzyme, 4 parts of edible salt, 5 parts of spices (cumin powder purchased from Hongfang Biotechnology (Kunshan) Co., Ltd.), and 3 parts of monosodium glutamate.

[0084] 8. Heat preservation and solidification: the soybeans obtained by emulsification and slurrying are put into a solidification box for heat preservation and solidification in a water bath. The heat preservation is carried out while moving to realize continuous production. The heat preservation temperature is 55°C and the time is 20 minutes.

[0085] 9. Turn over: Pour the fully solidified bean curd from the solidification box into the pressing plate. When turning over, press the upper and lower plates evenly to ensure that the solidified bean curd is not damaged. The bean curd on the pressing plate is wrapped in cloth and sent into the press for pressing and molding.

[0086] 10. Pressing: The total time is 50 minutes, and the hydraulic segmented pressing method in the prior art is used. The pressed dried bean curd is taken out from the press, and the wrapping cloth is removed. The thickness of the pressed dried bean curd is about 1.5 cm.

[0087] 11. Cut into pieces: Cut into 6.5cm long and 2.2cm wide rectangles, cool and set aside.

[0088] 12. Seasoning and mixing: According to the flavor of the product, prepare the product according to the formula to make five-spice flavors.

[0089] 13. Vacuum packaging: Put each small piece into a bag and seal it with a fully automatic vacuum packaging machine to make small package products.

[0090] 14. High temperature sterilization: maximum temperature 115℃, 15 minutes.

[0091] 15. Cool down.

[0092] 16. Packing and storage: The dried tofu is packed and sent to the normal temperature warehouse.

[0093] Example 3 The difference from Example 1 is that the coagulant in step 7 does not contain any seasoning.

[0094] Example 4 The difference from Example 1 is that the concentration of the whole bean milk prepared in step 5 is 16%, which is relatively high.

[0095] Example 5 The difference from Example 1 is that in step 7, the mass ratio of whole bean milk to the compound coagulant is 100:5, and the amount of the compound coagulant used is relatively large.

[0096] Example 6 The difference from Example 1 is that the amount of calcium sulfate in the coagulant in step 7 is 30 parts, which is too much.

[0097] Example 7 The difference from Example 1 is that the amount of TG enzyme used in the coagulant in step 7 is 20 parts, which is too much.

[0098] Comparative Example Comparative Example 1 The difference from Example 1 is that in step 3, the pulp is directly ground into 80 meshes, and there is no step 4.

[0099] Comparative Example 2 The difference from Example 1 is that the coagulant in step 7 is calcium sulfate.

[0100] Comparative Example 3 The difference from Example 1 is that the coagulant in step 7 is emulsified magnesium and calcium sulfate.

[0101] Comparative Example 4 The difference from Example 1 is that the coagulant in step 7 is calcium sulfate and TG enzyme.

[0102] Comparative Example 5 The difference from Example 1 is that the solidification process temperature in step 8 is 70° C., which is too high.

[0103] Test Results 1. Performance tests were performed on the dried tofu prepared in Examples 1 to 3.

[0104] 1. Sensory indicators project index Visual tasting results evaluate Color, aroma and taste Milky white, with bean fragrance, no sour taste Milky white, with bean fragrance, no sour taste qualified Morphological organization The structure is fine, tough and elastic, and the block shape is neat The structure is fine, tough and elastic, and the block shape is neat qualified Impurities No visible foreign matter No visible foreign matter qualified Label Meet GB7718 requirements conform to qualified 2. Physical and chemical indicators The leisure dried bean curd prepared by the present invention can have a moisture content of 55-60%, a protein content of ≥15.8g / 100g, and a dietary fiber content of ≥6.5g / 100g. The National Food Safety Standard-General Rules for Nutrition Labeling of Prepackaged Foods (GB 28050-2011) states that dietary fiber ≥6.0g / 100g can be called high dietary fiber. In addition, when making the slurry in Example 1 and Example 2, part of the flavor substances are added to the soy milk together, so that the product is more evenly flavored, and the braising process is reduced. Therefore, the leisure whole bean tough dried bean curd prepared by the present invention has the advantages of high yield, good toughness and elasticity, delicate tissue, water retention, even flavoring, unique taste and flavor, etc.

[0105] 2. Properties of the dried tofu prepared in each embodiment and comparative example Compared with Example 1: Comparative Example 1 directly grinds in one step, and although whole bean milk with the same particle size and fineness is obtained, the fineness of the obtained dried bean curd is not as good as that of Example 1. The concentration of whole bean milk in Example 4 is relatively high, and the water content of the obtained dried bean curd is relatively low, and the taste is relatively hard. When the concentration of whole bean milk is 11-14%, the protein and other components in the milk can better combine with the coagulant to form an ideal dried bean curd structure. Such a concentration can ensure that the dried bean curd is neither too loose nor too hard, and has a delicate taste and maintains a certain elasticity.

[0106] Comparative Example 2 uses only calcium sulfate as a coagulant, the coagulation speed is fast, the dried bean curd has many holes inside and the texture is not delicate, and a slow-release type of emulsified magnesium is needed to obtain dried bean curd with delicate texture. Comparative Example 3 uses only emulsified magnesium and calcium sulfate as coagulants, and does not use TG enzyme, and the toughness and elasticity of the dried bean curd are significantly reduced. The coagulant of Comparative Example 4 does not contain calcium sulfate, because emulsified magnesium is slowly released, the initial coagulation speed cannot keep up, and the effect of complete coagulation cannot be achieved. The insulation temperature of coagulation in Comparative Example 5 is too high, and the inactivation of TG enzyme cannot play a role. The obtained dried bean curd is not tough enough, too soft and brittle. The amount of the composite coagulant in Example 5 is too much, making the dried bean curd taste hard and not delicate enough. The amount of a certain component of the coagulant in Examples 6 and 7 is too much, which will also affect the coagulation process of the dried bean curd, and the resulting texture is not delicate enough.

[0107] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing leisure whole bean tough dried tofu, characterized in that: The following steps are involved: 1) Mixing dehulled soybeans and water to obtain a coarse grind paste, then ultrafine grinding to obtain a fine grind paste, and then high-pressure homogenization to obtain whole soybean milk; 2) After boiling the whole soybean milk, the milk is cooled to 60-70°C, and a compound coagulant is added to emulsify the milk to obtain the bean curd, which is then kept warm at 50-60°C for coagulation; the compound coagulant includes emulsified magnesium, calcium sulfate and TG enzyme; 3) The solidified tofu brain is pressed into dried tofu.

2. The method for preparing the leisure whole bean tough dried tofu according to claim 1, characterized in that: The mass ratio of dehulled soybeans to water is 1:4-7; the particle size of the coarsely ground paste is D 90 The particle size D of the finely ground paste is 200-250 μm. 90 The particle size is 150-180 μm, the concentration of whole bean milk is 11-14%, and the particle size D 90 50-60 μm.

3. The method for preparing the leisure whole bean tough dried tofu according to claim 1 or 2, characterized in that: The pulp is cooked by direct steam injection, and the conditions are: steam pressure 0.15-0.2 MPa, pulp temperature 100-103 ℃ maintained for 3-4 minutes.

4. The method for preparing the leisure whole bean tough dried tofu according to claim 1, characterized in that: The mass ratio of whole bean milk to the compound coagulant is 100:1-2.

5. The method for preparing the leisure whole bean tough dried tofu according to claim 1 or 4, characterized in that: The mass proportions of the components of the compound coagulant are: 50-60 parts of magnesium emulsifier, 15-20 parts of calcium sulfate, and 10-15 parts of TG enzyme.

6. The method for preparing the leisure whole bean tough dried tofu according to claim 5, characterized in that: The compound coagulant also contains seasoning, and the mass proportion of the seasoning is 5-12 parts.

7. The method for preparing the leisure whole bean tough dried tofu according to claim 1, characterized in that: The heat preservation and solidification time is 20-30 minutes.

8. The method for preparing the leisure whole bean tough dried tofu according to claim 1 or 7, characterized in that: The pressing time is 50-70 minutes, and hydraulic pressure is used to press the dried tofu into a thickness of 1.2-1.5 cm.

9. A mobile water bath heat preservation and coagulation device suitable for the method according to any one of claims 1 to 8, characterized in that: It includes a conveyor chain, a pulping machine is arranged at the input end of the conveyor chain, an automatic plate turning device is arranged at the output end, a sandwich water bath is arranged on the conveyor chain, and the temperature of the sandwich water bath is controlled by a temperature control system.

10. The mobile water bath heat preservation and coagulation device according to claim 9, characterized in that: An automatic plate stacking device and a press are arranged in sequence behind the automatic plate turning device; the automatic plate turning device pours the bean curd in the solidification box onto a pressing plate covered with a wrapping cloth, and then evenly wraps the solidified bean curd with the wrapping cloth at four corners; the automatic plate stacking device stacks 10-15 of the above-obtained pressing plates into a pile, and sends them together into the press for pressing.

Images