Medicated food bean curd prepared from sour slurry and preparation method of medicated food bean curd

Abstract

The invention relates to the technical field of bean products, and discloses medicated tofu curded by sour slurry and a preparation method thereof. The medicated food bean curd is prepared by using black beans, water and medicated food components (including Chinese wolfberry fruit powder, red date powder, astragalus membranaceus powder, angelica sinensis powder and cistanche deserticola powder) in a specific proportion as raw materials and using purely-fermented sour slurry as a coagulator. The preparation method mainly comprises the steps of raw material pretreatment, cooked pulp preparation, pulp boiling and fusion, sour pulp curdling, compression molding and the like. The invention aims to solve the technical problems that in the prior art, a chemical coagulator is used, so that the bean curd is rough in texture and heavy in beany flavor, medicated food components are non-uniformly dispersed, and active components are easy to lose. According to the medicated food bean curd and the preparation method thereof disclosed by the invention, the sour slurry preparation and the slurry cooking process are combined, and the raw material ratio is optimized, so that the prepared medicated food bean curd is fine and smooth in texture, good in elasticity, mellow in flavor, free of beany flavor, uniform in medicated food component distribution and high in functional component retention rate, and is mainly used as a food with nutrition and health-care functions. Derivative varieties such as cold bean curds and high-protein bean curds can be prepared through modular adjustment.

Description

Technical Field

[0001] This invention relates to the field of tofu, and particularly to medicinal tofu made with sour curd and its preparation method. Background Technology

[0002] Tofu, a traditional soybean product, is widely present in East Asian culinary culture. Its preparation typically involves soaking, grinding, and boiling soybeans, followed by the addition of a coagulant. With increasing consumer demand for healthy foods, medicinal tofu has emerged. This type of tofu incorporates traditional Chinese medicinal herbs to impart specific health benefits, such as replenishing qi and blood and enhancing immunity. Current medicinal tofu preparation methods largely rely on conventional tofu-making processes, involving the selection of coagulants and the methods of adding medicinal components, aiming to combine nutrition and functionality.

[0003] In existing technologies, the preparation of medicinal tofu often employs chemical coagulants (such as gypsum and glucono-delta-lactone) for coagulation. For example, a typical existing technical solution involves using black beans as the base material, adding medicinal powders such as goji berries and red dates, and using gypsum as the coagulant to coagulate the tofu. Specifically, this solution includes: soaking black beans, grinding them into a paste, boiling the paste, adding the medicinal components, then using a gypsum aqueous solution to coagulate the paste at high temperature, allowing it to stand, and then pressing it into shape. While this solution can achieve the basic preparation of medicinal tofu, due to the characteristics of chemical coagulants, the coagulation process easily leads to hardening of the tofu texture, insufficient elasticity, and a noticeable beany taste. Furthermore, the medicinal components are prone to precipitation or uneven distribution during coagulation due to incompatibility in the coagulation reaction, affecting the fusion of components and the stability of efficacy.

[0004] The inventors of this application have discovered the following technical problems with the above-mentioned technology: the existing medicinal tofu preparation uses chemical coagulants, which results in a coarse texture and a strong beany taste in the tofu. Furthermore, the medicinal components are prone to precipitation or loss during the coagulation process, leading to a reduction in product quality and functional consistency. Summary of the Invention

[0005] This invention provides a medicinal tofu prepared with acid coagulation and its preparation method. The technical problem to be solved is that the existing preparation of medicinal tofu uses chemical coagulants, which results in a rough texture and a strong beany taste. In addition, the medicinal components are prone to precipitation or loss during the coagulation process, which reduces the consistency of product quality and function.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows:

[0007] The medicinal tofu made with fermented sour whey contains black beans, water, and medicinal ingredients, and is produced by using pure-culture fermented sour whey as a coagulant. The medicinal ingredients, based on 1 kg of black beans, consist of the following components:

[0008] 10-30g of goji berry powder;

[0009] 20-50g of red date powder;

[0010] Astragalus powder 5-10g;

[0011] 5-10g of Angelica sinensis powder;

[0012] 5-10g of Cistanche deserticola powder;

[0013] 25g of magnesium chloride;

[0014] 125g of water.

[0015] Furthermore, the black beans are non-GMO selenium-enriched black beans with a protein content between 42% and 45% and a fat content between 18% and 22%.

[0016] Furthermore, the water is weakly alkaline with a pH of 6.8-7.2, rich in metasilicic acid, and has small molecular clusters with a molecular cluster diameter of less than 2 nanometers.

[0017] Furthermore, some or all of the water was replaced by a decoction of Polygonum multiflorum and American ginseng to prepare cold tofu.

[0018] Furthermore, shrimp or bacon pieces are added and evenly mixed into the tofu pudding to prepare high-protein medicinal tofu.

[0019] The preparation method of the medicinal tofu mentioned above includes the following steps:

[0020] S1. Raw material pretreatment: Soak black beans in an automatic temperature control system for 5-6 hours;

[0021] S2. Preparation of cooked soy milk: Soaked black beans are mixed with water and ground into a paste. The resulting soy paste is first heated and cooked, and then the paste and residue are separated to obtain cooked soy milk.

[0022] S3. Boiling and Blending: Boil the cooked soy milk and add the medicinal ingredients, stirring and mixing evenly;

[0023] S4. Sour coagulation: Cool the mixed soy milk to 80±2℃, pour in magnesium chloride water (25g magnesium chloride dissolved in 125g water), keep warm and let stand for 15-20 minutes to form tofu curd;

[0024] S5. Pressing and shaping: Pour the tofu curd into a mold and press for 1-2 hours to shape it into the medicinal tofu.

[0025] Furthermore, in step S1, some or all of the water is replaced by the decoction of Polygonum multiflorum and American ginseng, and after pressing and molding in step S5, a steaming and refrigeration process of more than 2 hours is added to prepare cold tofu.

[0026] Furthermore, in step S5, shrimp meat or bacon bits are evenly mixed into the tofu pudding, and then pressed into shape to prepare high-protein medicinal tofu.

[0027] The beneficial effects of this invention are as follows:

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. Significantly improved the texture and flavor of tofu, enhancing product quality.

[0030] Compared to existing technologies that use chemical coagulants such as gypsum, this invention uses pure fermented sourdough as a coagulant. The organic acids and probiotic metabolites in the sourdough can undergo a gentler and more uniform cross-linking reaction with soybean protein. This distinctive technical feature results in a finer and denser tofu gel network structure. The direct technical effect is that the tofu prepared by this invention has a more elastic and soft texture, a silky smooth mouthfeel, and effectively eliminates the beany taste often associated with chemical coagulant production, presenting a rich and pure soybean aroma.

[0031] 2. Improved the integration of medicinal food components and the stability of functional ingredients.

[0032] Unlike existing technologies that simply mix medicinal powders before and after coagulation, which can easily lead to sedimentation and uneven distribution, this invention adds the medicinal components to boiled soy milk and stirs them thoroughly during the "boiling and blending" step. This step utilizes the convection and diffusion of the high-temperature liquid to fully disperse and initially gelatinize the medicinal powders, forming a more stable system with the soy milk protein. This difference avoids the rapid sedimentation of medicinal components during subsequent coagulation. Its beneficial effect is that it ensures the uniform distribution of medicinal components in the finished tofu and a higher retention rate of active ingredients (such as wolfberry polysaccharides and astragaloside A), thereby guaranteeing the consistency and effectiveness of the product's function.

[0033] 3. Through the synergistic selection of raw materials, the nutritional value and sensory characteristics of the product have been further optimized.

[0034] Existing technologies have relatively broad requirements for raw materials (such as black beans and water quality). This invention differs from existing technologies by explicitly limiting the use to high-protein, selenium-rich non-GMO black beans and weakly alkaline small-molecule cluster water. This distinguishing technical feature, combined with the aforementioned process, produces a synergistic effect: the superior black beans provide a higher protein extraction rate and natural selenium; the small-molecule cluster water, due to its strong penetrability, helps to more fully dissolve the effective components during the soaking and grinding stages. The technical effect is reflected in a significant increase in the core nutritional indicators of the finished tofu, such as protein and selenium content, and a bright, uniform, and natural color, achieving simultaneous optimization of nutritional and sensory quality.

[0035] 4. It has expanded the diversity of product functions while maintaining the stability of core processes.

[0036] Compared to the limitations of existing technologies with their singular solutions, this invention, through modular design, allows for the creation of products with diverse functional properties by replacing some of the water used in specific medicinal decoctions (such as for preparing cold tofu) or by incorporating functional ingredients after coagulation (such as for preparing high-protein tofu), while maintaining the core process unchanged. This distinctive technical feature allows for the diversified expansion of product functions without significantly increasing process complexity, meeting different market demands and demonstrating the invention's high adaptability and scalability. Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention.

[0038] This invention relates to a method for preparing medicinal tofu using fermented whey as a coagulant. The core of this method lies in using pure fermented whey as a coagulant, combined with a specific ratio of medicinal ingredients (such as wolfberry powder, jujube powder, astragalus powder, angelica powder, and cistanche powder), and employing the "Six Must-Haves for Good Tofu" standard (pure water, non-fermented beans, fully fermented whey, fermented with acid, rich aroma, and perfect color) to optimize raw materials and processes, thus producing tofu that possesses nutritional and medicinal benefits as well as excellent sensory qualities. Furthermore, this invention achieves precise addition and process control of medicinal ingredients through mechanized and modular design, making it suitable for large-scale production.

[0039] These "six musts" specifically include:

[0040] 1. Water must be pure: Pure, slightly alkaline (pH 6.8-7.2), small-molecule cluster water rich in metasilicic acid must be used. This type of water has strong penetrating power, which helps improve the quality of tofu and its associated health benefits.

[0041] 2. Doubifei: Strictly select high-quality soybeans that are non-GMO, high in protein (42%-45%), and have a suitable fat content (18%-22%). Emphasis is placed on the naturalness and high nutritional value of the raw materials.

[0042] 3. The soy pulp must be fully cooked: The "fully cooked soy pulp process" must be used (i.e., heating the soy paste first, then separating the soy pulp). This process can effectively reduce the beany taste, enhance the soy aroma, and form a stable emulsion system, resulting in a smoother texture and better microbial control.

[0043] 4. **Use of pure fermented sour liquid as a coagulant:** Tofu must be made using pure fermented sour liquid as a coagulant, and the use of chemical coagulants (such as gypsum or glucono delta-lactone) is strictly prohibited. This traditional method ensures that the tofu has a more resilient and elastic texture and incorporates beneficial components such as probiotics.

[0044] 5. **Fragrant and Pure:** Finished tofu must have a rich, pure soybean aroma, free of any off-odors. This directly reflects the combination of high-quality raw materials and traditional craftsmanship.

[0045] 6. Color must be correct: Finished tofu must be milky white or slightly yellow, with a bright, uniform, and natural color. This reflects the freshness of the tofu and the complete preservation of its nutrients.

[0046] Example 1: Preparation of basic medicinal tofu

[0047] This embodiment describes in detail the preparation process of basic medicinal tofu, with raw materials and process parameters strictly following the "Six Must-Haves Good Tofu" standard.

[0048] Raw material preparation:

[0049] Black beans: Non-GMO selenium-enriched black beans are selected, with a protein content of 43% (between 42% and 45%) and a fat content of 20% (between 18% and 22%). The black beans are from the "Heinong 48" variety produced in Heilongjiang Province, and the selenium content is tested to be 0.15 mg / kg.

[0050] Water: Weakly alkaline small-molecule cluster water is used, with a pH of 7.0 (between 6.8 and 7.2), rich in metasilicic acid (content of 25 mg / L), and the molecular cluster diameter is less than 2 nanometers. The water source is purified water that has undergone reverse osmosis and ionization treatment, meeting international healthy water standards.

[0051] Medicinal diet ingredients (based on 1 kg of black beans):

[0052] Goji berry powder: 20g (range 10-30g)

[0053] Red date powder: 35g (range 20-50g)

[0054] Astragalus powder: 7g (range 5-10g)

[0055] Angelica sinensis powder: 7g (range 5-10g)

[0056] Cistanche deserticola powder: 7g (range 5-10g)

[0057] Coagulant: 25g of magnesium chloride is dissolved in 125g of water to form an aqueous solution of magnesium chloride.

[0058] Other: The amount of water used for grinding is 7 kg (7:1 ratio with black beans).

[0059] Preparation steps:

[0060] S1. Raw material pretreatment:

[0061] Soak 1 kg of selenium-enriched black beans in an automatic temperature-controlled soaking system for 5.5 hours (range 5-6 hours). Maintain the water temperature at 25°C, and use a water level sensor to ensure the water level is 10 cm above the bean surface. After soaking, the black beans absorb approximately 120% of the water, resulting in plump beans that are easy to grind into a paste.

[0062] S2. Preparation of cooked pulp:

[0063] Soaked black beans were mixed with 7 kg of small-molecule cluster water and ground in batches using a high-efficiency grinder (3000 rpm) to obtain a soybean paste. The soybean paste was then heated and matured: it was heated to 95°C using a steam-jacketed kettle and kept at that temperature for 5 minutes to inactivate lipoxygenase and anti-nutritional factors. After maturation, the paste was separated from the residue using a centrifugal filter (200 mesh) to obtain cooked soy milk. The protein extraction rate was measured to be 86.5%, higher than the 80% of ordinary processes.

[0064] S3. Boiling and blending:

[0065] Transfer the cooked soy milk to the intelligent soy milk cooker, bring it to a boil, and maintain a simmer for 3 minutes. Then, automatically add the medicinal ingredients (20g goji berry powder, 35g red date powder, 7g astragalus powder, 7g angelica powder, and 7g cistanche powder), and mix thoroughly at 150 rpm to ensure complete dispersion and blending of the powders. During the cooking process, the soy milk temperature is maintained at 100°C to further sterilize and promote the release of the medicinal components.

[0066] S4. Preparation of acid slurry:

[0067] Cool the mixed soy milk to 80°C (±2°C fluctuation allowed), then pour in a pre-prepared magnesium chloride aqueous solution (25g magnesium chloride dissolved in 125g water). The curdling process is carried out in a temperature-controlled system, maintaining the temperature and allowing it to stand for 18 minutes (range 15-20 minutes) to form tofu curds. The tofu curds have a delicate texture, good elasticity, and no beany smell.

[0068] S5. Compression molding:

[0069] Pour the tofu curd into a mold lined with cotton cloth and press it using a hydraulic molding machine at 0.2 MPa pressure for 1.5 hours (range 1-2 hours). After shaping, you will obtain medicinal tofu. The finished tofu weighs approximately 2.8 kg, with a yield of 70% (based on the dry weight of black beans).

[0070] Finished product characteristics:

[0071] Sensory quality: The tofu is milky white with a slight yellow tinge, and has a bright and uniform color (the color must be correct); it has a rich and mellow bean aroma and no off-flavors (the aroma must be mellow); it has a full and silky texture and moderate elasticity.

[0072] Nutritional composition: Testing revealed a protein content of 12.5g / 100g, a fat content of 6.8g / 100g, and a selenium content of 0.05mg / 100g. The retention rate of medicinal ingredients such as wolfberry polysaccharides and astragaloside A exceeded 90%.

[0073] Microbiological safety: Total bacterial count <500 CFU / g, far below the national standard (≤100,000 CFU / g), shelf life up to 7 days (refrigerated).

[0074] This embodiment demonstrates the complete preparation process of basic medicinal tofu, highlighting the synergistic effect of raw material selection and process control, achieving high nutritional value, safety, and medicinal properties.

[0075] Example 2: Preparation of Cold Tofu

[0076] This embodiment, based on claims 4 and 7, describes a variant scheme for preparing cold tofu by replacing part of the water with a decoction of Polygonum multiflorum and American ginseng.

[0077] Raw material preparation:

[0078] Black beans, medicinal ingredients, and coagulant: Same as in Example 1.

[0079] Water substitution: Use the decoction of Polygonum multiflorum and American ginseng to replace 30% of the grinding water (i.e., 2.1 kg decoction + 4.9 kg small molecule cluster water).

[0080] Preparation of decoction: Take 15g of Polygonum multiflorum and 10g of American ginseng, add 500mL of water, decoct for 1 hour, filter to obtain decoction, and cool to room temperature for later use.

[0081] Preparation steps:

[0082] Steps S1-S3 are the same as in Example 1, except that in S1, the water used for soaking and grinding is the above-mentioned mixed water (decoction + small molecule cluster water).

[0083] S4. Preparation of acid slurry: Same as in Example 1.

[0084] S5. Compression molding and post-processing:

[0085] After pressing the tofu pudding into shape (same as in Example 1), add steaming and refrigeration steps:

[0086] Steaming: Place the shaped tofu in a steamer and steam at 100°C for 20 minutes to fix its shape and enhance its medicinal effects.

[0087] Refrigeration: Transfer to the refrigeration unit and refrigerate at 4°C for at least 2 hours, until the tofu is completely set. Chilled tofu has a firmer texture and is suitable for slicing and cold dishes.

[0088] Finished product characteristics:

[0089] Sensory quality: The tofu is slightly darker in color (due to the Polygonum multiflorum component), appearing as a light brown, but still shiny and uniform; it has a faint medicinal aroma in its bean flavor and a refreshing taste.

[0090] Medicinal effects: The addition of Polygonum multiflorum and American ginseng enhances the effects of tonifying the liver and kidneys, replenishing qi and nourishing yin, making it suitable for consumption in summer or as a medicinal diet.

[0091] Shelf life: Extended to 10 days under refrigeration.

[0092] This embodiment demonstrates the feasibility of diversifying the functions of tofu through water substitution and subsequent processing, showcasing the modular design advantages of the invention.

[0093] Example 3: Preparation of High-Protein Medicinal Tofu

[0094] This embodiment, based on claims 5 and 8, describes a high-protein variant with added shrimp meat pieces, suitable for populations requiring additional protein intake.

[0095] Raw material preparation:

[0096] Black beans, medicinal ingredients, coagulant, water: same as in Example 1.

[0097] High-protein additive: 50g of shrimp meat chunks (must be odorless and pre-treated). The shrimp meat chunks should be approximately 3mm x 3mm in size and steamed before use.

[0098] Preparation steps:

[0099] Steps S1-S4 are the same as in Example 1.

[0100] S5. Compression molding:

[0101] After the tofu pudding has formed, evenly mix the shrimp pieces into it, then pour it into a mold and press it into shape (pressure 0.25 MPa, time 1 hour). The shrimp pieces must be evenly distributed to avoid affecting the tofu's structure.

[0102] Finished product characteristics:

[0103] Sensory quality: Evenly distributed shrimp meat particles are visible in the tofu, with a slightly yellow color and red spots; the taste is richer, and the protein content is increased to 15.2g / 100g.

[0104] Nutritional Enhancement: Shrimp meat provides high-quality animal protein and minerals, which, in synergy with medicinal ingredients, enhance immunity and kidney tonification.

[0105] Application scenarios: Suitable as a fitness food or nutritional supplement for the elderly.

[0106] This embodiment demonstrates the invention's ability to meet specific market demands by adding functional ingredients while maintaining the basic principles of medicinal cuisine.

[0107] Comparative Example 1: No acid slurry was used for coagulation (gypsum was used as the coagulant).

[0108] This comparative example aims to compare the differences between acid slurry preparation and traditional coagulants, highlighting the importance of "acid slurry preparation before coagulation".

[0109] Raw material preparation:

[0110] Black beans, water, and medicinal ingredients: Same as in Example 1.

[0111] Coagulant: 30g of edible gypsum (calcium sulfate) dissolved in 150g of water, replacing magnesium chloride.

[0112] Preparation steps:

[0113] Similar to Example 1, only the gypsum aqueous solution was used in the S4 grouting step, with a grouting temperature of 85°C and a standing time of 20 minutes.

[0114] Finished product characteristics:

[0115] Tofu has a firm texture, lacks elasticity, and has a rough mouthfeel.

[0116] It has a strong beany smell (due to high hexanal content) and insufficient bean aroma.

[0117] The medicinal ingredients were not well integrated, and some ingredients precipitated during the curdling process.

[0118] Microbial control is generally adequate, with a total bacterial count of approximately 2000 CFU / g.

[0119] The comparison shows that sour syrup curdling is superior to gypsum curdling in terms of texture, flavor, and safety.

[0120] Comparative Example 2: No medicinal ingredients added

[0121] This comparative study aims to verify the effect of adding medicinal herbs to tofu on enhancing its nutritional value and efficacy.

[0122] Raw material preparation:

[0123] Black beans, water, coagulant: same as in Example 1.

[0124] No medicinal ingredients are added.

[0125] Preparation steps:

[0126] It is exactly the same as Example 1.

[0127] Finished product characteristics:

[0128] The tofu is of good basic quality, but lacks medicinal properties.

[0129] Nutritional analysis showed that the content of active substances (such as soy isoflavones and polysaccharides) was low, and there were no wolfberry, astragalus and other ingredients.

[0130] In sensory evaluation, the flavor is simple and lacks the complex aroma characteristic of medicinal cuisine.

[0131] The comparison shows that the addition of medicinal ingredients significantly enhances the functionality and market value of tofu.

[0132] Comparative Example 3: Using ordinary water and non-preferred black beans

[0133] This comparative example aims to verify the necessity of the "pure water" and "non-pure beans" standards.

[0134] Raw material preparation:

[0135] Black beans: Made from ordinary genetically modified soybeans (38% protein content), not selenium-enriched varieties.

[0136] Water: Tap water (pH 7.5, high hardness, non-small molecule cluster water) is used.

[0137] Medicinal food ingredients and coagulant: Same as in Example 1.

[0138] Preparation steps:

[0139] Same as Example 1.

[0140] Finished product characteristics:

[0141] The tofu is dull in color and uneven in appearance.

[0142] It has a rough texture and a strong beany taste.

[0143] The protein extraction rate is only 78%, and the nutritional content is low.

[0144] The shelf life is shortened, and the total bacterial count is approximately 5000 CFU / g.

[0145] The comparison highlights the crucial role of selecting superior raw materials in quality control.

[0146] Experimental Example: Evaluation of Tofu Quality and Efficacy

[0147] To verify the advantages of the present invention, we conducted systematic tests on the tofu prepared in Examples 1-3 and Comparative Examples 1-3, including physical properties, nutritional components, sensory evaluation and in vitro efficacy experiments.

[0148] 1. Physical property testing:

[0149] Texture analysis: The hardness, elasticity, and viscosity of tofu were determined using a texture analyzer. The results are shown in Table 1.

[0150] Color measurement: Use a colorimeter to measure L*, a*, and b* values ​​to evaluate color uniformity.

[0151] Table 1: Results of tofu texture test (n=3)

[0152] sample Hardness (N) Elasticity (mm) Viscosity (mJ) Example 1 12.5 8.2 1.2 Example 2 13.1 7.8 1.4 Example 3 14.0 7.5 1.6 Comparative Example 1 18.5 5.0 2.5 Comparative Example 2 12.8 8.0 1.3 Comparative Example 3 15.2 6.5 2.0

[0153] Analysis: The tofu produced in Examples 1-3 had moderate hardness and elasticity, low viscosity, and a better texture. Comparative Example 1 (made with gypsum) had excessive hardness and poor elasticity; Comparative Example 3 (made with ordinary raw materials) had uneven texture.

[0154] 2. Nutritional composition analysis:

[0155] Protein, fat, and selenium content: determined according to national standard methods.

[0156] Active ingredients: Lycium barbarum polysaccharides, astragaloside A, and soy isoflavones were determined by HPLC. The results are shown in Table 2.

[0157] Table 2: Nutritional and Active Ingredient Content (per 100g)

[0158] sample Protein (g) Fat (g) Selenium (μg) Lycium barbarum polysaccharides (mg) Astragaloside A (mg) Example 1 12.5 6.8 50 15.2 0.8 Example 2 12.3 6.5 48 14.8 0.7 Example 3 15.2 7.2 52 15.0 0.8 Comparative Example 1 11.8 6.5 45 10.5 0.5 Comparative Example 2 10.5 5.8 40 Not detected Not detected Comparative Example 3 9.8 5.2 10 12.1 0.6

[0159] Analysis: The nutritional and active ingredients in Examples 1-3 were significantly higher than those in the comparative example, especially the addition of medicinal ingredients which brought about functional enhancement.

[0160] 3. Sensory evaluation:

[0161] Ten trained panelists were invited to rate the color, aroma, texture, and overall acceptability of the tofu (1-10 points). The results are shown in Table 3.

[0162] Table 3: Sensory Evaluation Scores (Average Score)

[0163] sample Color aroma taste Overall acceptance Example 1 9.0 9.2 9.1 9.1 Example 2 8.5 8.8 8.7 8.7 Example 3 8.8 8.9 9.0 8.9 Comparative Example 1 7.0 6.5 6.0 6.5 Comparative Example 2 8.5 7.8 8.0 8.1 Comparative Example 3 6.5 6.0 6.5 6.3

[0164] Analysis: Examples 1-3 scored highly in all sensory aspects, while Comparative Examples 1 and 3 scored lower due to defects in raw materials and processes.

[0165] 4. In vitro efficacy experiments:

[0166] Antioxidant activity: IC50 value was determined using the DPPH free radical scavenging assay.

[0167] Calcium absorption promotion rate: assessed using the Cac-2 cell model.

[0168] Microbial inhibition: Determine the diameter of the inhibition zone of tofu extract against common pathogenic bacteria (such as Escherichia coli).

[0169] The results are shown in Table 4.

[0170] Table 4: Results of in vitro efficacy tests

[0171] sample DPPHIC50 (mg / mL) Calcium absorption promotion rate (%) Diameter of the inhibition zone (mm) Example 1 0.85 35.2 12.5 Example 2 0.88 34.8 12.0 Example 3 0.82 35.5 13.0 Comparative Example 1 1.20 28.5 10.5 Comparative Example 2 1.50 25.0 9.0 Comparative Example 3 1.35 26.8 9.5

[0172] Analysis: Examples 1-3 showed significant antioxidant, calcium absorption-promoting, and antibacterial abilities, verifying the synergistic effects of medicinal cuisine and sour curd preparation.

[0173] Summary and Advantages Analysis

[0174] Through the comparison of the above embodiments and comparative examples, the advantages of the present invention are mainly reflected in:

[0175] 1. Enhanced Nutrition and Efficacy: The addition of medicinal ingredients upgrades tofu from an ordinary food to a functional food, with effects such as replenishing qi and blood and enhancing immunity.

[0176] 2. Process optimization: The combination of acid curdling and cooked soy milk process ensures the texture, flavor and safety of the tofu, meeting the "six must-haves" standard.

[0177] 3. Modular design: By offering variant options (such as cold tofu and high-protein tofu), we can meet diverse market demands.

[0178] 4. Mechanized control: Precise raw material ratios and process parameters ensure product consistency and scalability.

[0179] This invention not only inherits the traditional tofu-making process, but also provides a new direction for the modern health food industry through innovative integration.

[0180] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A medicinal tofu made with sour whey, characterized in that, The raw materials include black beans, water, and medicinal ingredients, and are prepared by using pure-culture fermented sourdough as a coagulant; wherein, based on 1 kg of black beans, the medicinal ingredients consist of the following components: 10-30g of goji berry powder; 20-50g of red date powder; Astragalus powder 5-10g; 5-10g of Angelica sinensis powder; 5-10g of Cistanche deserticola powder; 25g of magnesium chloride; 125g of water.

2. The medicinal tofu prepared with sour whey according to claim 1, characterized in that, The black beans mentioned are non-GMO selenium-enriched black beans with a protein content between 42% and 45% and a fat content between 18% and 22%.

3. The medicinal tofu prepared with sour whey according to claim 1, characterized in that, The water is weakly alkaline with a pH of 6.8-7.2, rich in metasilicic acid, and consists of small molecular clusters with a diameter of less than 2 nanometers.

4. The medicinal tofu prepared with acidic curdling according to claim 1, characterized in that, Some or all of the water was replaced by a decoction of Polygonum multiflorum and American ginseng.

5. The medicinal tofu prepared with sour whey according to claim 1, characterized in that, Add shrimp or bacon bits to prepare a high-protein medicinal tofu dish.

6. A method for preparing medicinal tofu as described in any one of claims 1-3, characterized in that, Includes the following steps: S1. Raw material pretreatment: Soak black beans in an automatic temperature control system for 5-6 hours; S2. Preparation of cooked soy milk: Soaked black beans are mixed with water and ground into a paste. The resulting soy paste is first heated and cooked, and then the paste and residue are separated to obtain cooked soy milk. S3. Boiling and Blending: Boil the cooked soy milk and add the medicinal ingredients, stirring and mixing evenly; S4. Sour coagulation: Cool the mixed soy milk to 80±2℃, pour in magnesium chloride water (25g magnesium chloride dissolved in 125g water), keep warm and let stand for 15-20 minutes to form tofu curd; S5. Pressing and shaping: Pour the tofu curd into a mold and press for 1-2 hours to shape it into the medicinal tofu.

7. The preparation method according to claim 6, characterized in that, In step S1, some or all of the water is replaced by a decoction of Polygonum multiflorum and American ginseng, and after pressing and molding in step S5, a steaming and refrigeration process of more than 2 hours is added to prepare cold tofu.

8. The preparation method according to claim 6, characterized in that, In step S5, shrimp meat or bacon bits are evenly mixed into the tofu pudding, and then pressed into shape to prepare high-protein medicinal tofu.