Sleep-aiding and blood pressure-lowering soybean dregs-based 3D-printed plant-based steak and preparation method thereof

Abstract

The application discloses a sleep-aiding and blood pressure-lowering bean dregs-based 3D printing plant meatloaf and a preparation method thereof, and belongs to the technical field of high-value modification of grain and oil by-products and processing of functional plant-based meat products. The raw material of the plant meatloaf is composed of solid-phase powder and liquid-phase medium. The solid-phase powder comprises enzyme-bacteria coupling modified bean dregs base, soybean protein isolate and konjac glucomannan. The liquid-phase medium is edible vegetable oil and sterile water. The overall water content of the printing slurry is controlled to be 55% to 60%. The modified bean dregs base is prepared through two-step segmented enzyme hydrolysis coupling micro-oxygen dynamic fermentation. The active ingredients of gamma-aminobutyric acid and blood pressure-lowering peptides are enriched. The intact dietary fiber skeleton is retained. The plant meatloaf 3D printing ink has the characteristics of shear thinning and self-setting when standing. In combination with 0° unidirectional layer-by-layer scanning biomimetic printing and low-temperature gradient air drying solidification process, the fiber is arranged in a directional and ordered manner.

Description

Technical Field

[0001] This invention relates to the fields of high-value modification of grain and oil by-products, processing of functional plant-based meat products, and 3D printing of food, specifically to a soybean residue-based 3D printed plant-based meat steak that improves sleep and helps lower blood pressure, and its preparation method. Background Technology

[0002] Soybean residue, a major byproduct of soybean processing, is rich in dietary fiber, plant protein, and free amino acids, making it a low-cost natural raw material for preparing plant-based meat products. Gamma-aminobutyric acid (GABA) and blood pressure-lowering peptides are two important functional components; GABA improves sleep, while GABA helps lower blood pressure by inhibiting angiotensin-converting enzyme (ACE) activity. Utilizing bio-modification technology to process soybean residue and selectively enrich these active ingredients is a key approach to developing functional plant-based meat products. However, existing soybean residue-based plant-based meat processing technologies have the following shortcomings: In terms of bio-modification, single fermentation processes can only achieve surface substance transformation, resulting in low efficiency in enriching active ingredients; while single enzymatic hydrolysis or simultaneous combined enzymatic hydrolysis processes can release protein precursors, they easily cause excessive hydrolysis and damage to the dietary fiber in soybean residue, leading to a loss of fibrous skeletal support, a loose texture, and an inability to simultaneously achieve the release of active ingredients and the preservation of the fiber structure. Regarding 3D printing adaptability, existing soybean residue-based printing slurries are not optimized for the rheological properties of high-fiber systems. The slurry viscosity and thixotropy are unstable, easily leading to problems such as filament breakage, collapse, and poor interlayer adhesion during printing. Furthermore, in conventional disordered scanning printing modes, the fiber arrangement is chaotic, resulting in products with low biomimicry of meat texture and a rough mouthfeel. In terms of curing processes, traditional high-temperature curing methods easily cause the loss of heat-sensitive active ingredients such as GABA, while also leading to product hardening and reduced chewiness. Summary of the Invention

[0003] The purpose of this invention is to provide a 3D-printed plant-based meat steak with soybean residue as a sleep aid and blood pressure lowering agent, and its preparation method, in order to solve the technical problems existing in the prior art, such as the contradiction between the enrichment of active ingredients and the preservation of the fiber skeleton during the processing of soybean residue-based plant-based meat, the unstable rheological properties of 3D printing slurry leading to filament breakage and collapse and poor interlayer adhesion, the disordered fiber arrangement leading to low biomimicry of meat texture, and the loss of heat-sensitive active ingredients and hardening of product texture caused by high-temperature curing.

[0004] To achieve the above objectives, the present invention discloses the following technical solution: a okara-based 3D printed plant-based steak with sleep-aiding and auxiliary blood pressure lowering effects, the raw materials of which are composed of solid-phase powder and liquid-phase medium; in terms of mass percentage, the solid-phase powder comprises 89.0%~93.0% enzyme-microorganism coupled modified okara matrix, 6.0%~10.0% soy protein isolate, and 0.8%~1.5% konjac glucomannan, and the sum of the percentages of all solid-phase components is 100%; the liquid-phase medium is edible vegetable oil and sterile water, the addition amount of the edible vegetable oil is 2.0%~4.0% of the total mass of the solid-phase powder, and the overall moisture content of the printing slurry is controlled at 55%~60%; the modified okara matrix is prepared by two-step segmented enzymatic hydrolysis coupled with micro-oxygen dynamic fermentation, which synergistically enriches the active ingredients of γ-aminobutyric acid and antihypertensive peptides, and retains the complete dietary fiber skeleton synchronously.

[0005] The okara protein is wrapped by a dense fiber network. First, the alkaline protease is used to directionally cleave the wrapped soy protein, so as to maximally retain functional polypeptides and active precursors, and ensure the sleep-aiding and auxiliary blood pressure lowering effects of subsequent fermentation; then, cellulase is used to mildly loosen the fiber structure, precisely regulate the rheological properties of the printing ink, and preserve the integrity of the fiber skeleton at the same time.

[0006] Preferably, the viscosity of the konjac glucomannan is ≥20000 mPa·s; the purity of the soy protein isolate is ≥90%; the edible vegetable oil is sunflower seed oil or refined soybean oil.

[0007] Preferably, the 3D printing ink has exclusive rheological properties: at 10 s -1 shear rate, the apparent viscosity is 800~1500 mPa·s, the storage modulus G'=200~500 Pa, the loss modulus G"<G', and the thixotropic recovery rate is ≥85%, which endows the ink with shear thinning and static self-shaping characteristics.

[0008] The present invention provides a preparation method of the okara-based 3D printed plant-based steak with sleep-aiding and auxiliary blood pressure lowering functions, comprising the following steps:

[0009] S1. The okara is subjected to impurity removal, rinsing with normal-temperature clear water for 3 to 5 times, and low-temperature drying at 40°C until the moisture content is 10%±0.5%, followed by low-temperature crushing and sieving to obtain 80~100 mesh particles, so as to prepare pretreated okara;

[0010] S2. Prepare a suspension by mixing pretreated soybean residue and water at a material-to-liquid ratio of 1:9, sterilize at 90℃ for 10 min, and then cool. Employ a two-step segmented enzymatic hydrolysis process: first, add 0.8% alkaline protease (by weight of total suspension) at pH 8.0–8.5 and 45–50℃, and hydrolyze for 1.0 h; then adjust the pH to 4.5–5.0 and the temperature to 50–55℃, and add 0.4% cellulase for 0.5 h of enzymatic hydrolysis; after hydrolysis, adjust the system pH to 5.8–6.2, and inoculate with 2.0% viable bacteria (≥1×10⁻⁶). 9 CFU / mL Lactobacillus brevis fermentation broth was fermented at 30℃ for 7 h. Active ingredients were enriched by intermittent microaerobic aeration at 5~8 mL / min and aeration for 1 min every 30 min. After fermentation, the active ingredients were inactivated at 85℃ for 5 min and filtered through 100 mesh to obtain modified soybean residue base material.

[0011] S3. Modified soybean residue, soy protein isolate, and konjac glucomannan are compounded and pre-dispersed evenly in proportion. Based on the total mass of solid powder, 2.0%~4.0% edible vegetable oil is added, and water is added to adjust the moisture content of the slurry to 55%~60%. Homogenize at 80~120 r / min for 3~5 min, and degas under vacuum at -0.05 MPa for 5 min to prepare 3D printing ink. Soy protein isolate acts as a filler and binder in the aqueous system. Its globular protein partially unfolds under shearing and interweaves with the soybean residue fiber network. Edible vegetable oil (sunflower seed oil / soybean oil) is embedded in the network pores in the form of tiny droplets, playing a lubricating and plasticizing role. The two work together to make up for the defects of the loose matrix of pure soybean residue, giving the product an elasticity and juiciness similar to real meat.

[0012] S4. Under a constant temperature of 28℃ and a base plate temperature of 25℃, plant-based meat steak blanks were prepared by printing with a nozzle with an inner diameter of 1.2 mm, a printing speed of 32~38 mm / s, a layer thickness of 0.25 mm, a 100% fill rate, and a 0° unidirectional layer-by-layer scanning mode.

[0013] S5. Place the plant-based meat steak blank in a windless, constant temperature and humidity environment at 30℃ and 40%~50% relative humidity, and allow it to be gradually air-dried and cured for 25 minutes to obtain the finished 3D printed plant-based meat steak.

[0014] Preferably, in step S3, the optimal process parameters for the compounding of modified soybean residue, soy protein isolate, and konjac glucomannan are as follows: 91.0% modified soybean residue, 7.5% soy protein isolate, and 1.5% konjac glucomannan in the solid powder; 3.0% edible vegetable oil by weight of the solid powder; 58% moisture content in the slurry; homogenization at 100 r / min for 4 min; and 10 s for the resulting ink. -1 At the shear rate, the apparent viscosity is 1100 mPa·s, the storage modulus G'=350 Pa, and the thixotropic recovery rate is 92%.

[0015] Konjac glucomannan (KGM) is a high-molecular-weight non-gelling polysaccharide that forms a dense hydrogen-bonded network with water molecules at specific concentrations. During the 3D printing extrusion process, mechanical shear forces disrupt this hydrogen-bonded network, causing a sudden decrease in viscosity, i.e., shear thinning, which enables smooth filament extrusion. After extrusion, the shear force disappears, and the hydrogen-bonded network rapidly reorganizes, restoring high viscosity, i.e., it self-shapes upon standing, thus supporting the weight of the upper structure and solving the problems of collapse and filament breakage.

[0016] Preferably, the optimal printing speed in step S4 is 35 mm / s.

[0017] Preferably, the temperature of the low-temperature pulverization in step S1 is 10~20℃.

[0018] Preferably, the two-step segmented enzymatic hydrolysis process in step S2 is as follows: first, adjust the system pH to 8.2 and temperature to 48℃, add 0.8% alkaline protease and hydrolyze for 1.0 h; then adjust the pH to 4.8 and temperature to 52℃, add 0.4% cellulase and hydrolyze for 0.5 h; the microaerobic intermittent aeration mode is 6 mL / min microaerobic intermittent aeration, aerating for 1 min every 30 min.

[0019] Under microaerobic intermittent dynamic aeration conditions, the metabolic pathway of *Lactobacillus brevis* shifts towards the glutamate decarboxylase (GAD) system. The microaerobic environment satisfies the oxygen demand for the early proliferation of lactic acid bacteria and induces efficient expression of GAD enzymes. GAD enzymes catalyze the decarboxylation of glutamate in the system to generate GABA. Simultaneously, the lactic acid produced during fermentation lowers the pH of the system, further activating GAD enzyme activity and achieving targeted and efficient enrichment of GABA.

[0020] Preferably, the relative humidity during gradient air drying in step S5 is 45%. GABA and antihypertensive peptides are both heat-sensitive substances; traditional high-temperature baking can lead to thermal degradation or loss through Maillard reactions. Low-temperature gradient air drying (i.e., gradually decreasing temperature / humidity) avoids premature surface crusting that could block internal moisture during moisture removal. Simultaneously, slow moisture evaporation allows sufficient time for protein and polysaccharide networks to rearrange and cross-link via hydrogen bonds, effectively eliminating residual internal stress during printing, preventing interlayer cracking, achieving stable curing, and maintaining chewiness.

[0021] The present invention also discloses the use of the above-mentioned soybean residue-based 3D printed plant-based meat steak in the preparation of functional dietary foods or plant-based meat products.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. This invention constructs a two-step segmented enzyme hydrolysis pre-process and microbial post-process fermentation enzyme-bacterial coupling modification technology, which breaks through the technical limitations of traditional simultaneous enzyme hydrolysis, single enzyme hydrolysis or single-strain fermentation. It is adapted to the optimal reaction system of alkaline protease, cellulase and Lactobacillus brevis respectively, significantly improving enzyme activity utilization and strain metabolic efficiency. While fully degrading macromolecular proteins to release polypeptide active precursors and loosening the dense fiber structure, it completely preserves the dietary fiber skeleton of soybean residue, solving the industry problem of mutual exclusion between activity enrichment and fiber preservation.

[0024] 2. This invention adopts a micro-aerobic dynamic intermittent aeration fermentation process, which precisely controls the dissolved oxygen environment of fermentation with a micro-aerobic intermittent aeration of 5~8 mL / min and an aeration of 1 min every 30 min. This adapts to the specific metabolic pattern of Lactobacillus brevis, greatly increases the enrichment of γ-aminobutyric acid and antihypertensive peptides, significantly improves the ACE inhibition rate, and endows the product with stable auxiliary functions of lowering blood pressure and improving sleep.

[0025] 3. This invention uses natural soy protein isolate and konjac glucomannan as functional matrices to construct a 3D printing ink rheology system without the addition of exogenous starch, synthetic binders, or artificial fillers. By precisely controlling the slurry moisture content, homogenization speed, and vacuum degassing parameters through graded control, the ink achieves a 10-second... -1 With exclusive rheological properties of apparent viscosity of 800~1500 mPa·s, storage modulus G'=200~500 Pa, and thixotropic recovery rate ≥85% at shear rate, the printing process is characterized by continuous filament output without filament breakage or collapse, high molding qualification rate, and good process repeatability.

[0026] 4. This invention achieves the orderly arrangement of soybean residue fibers along the printing direction by combining 0° unidirectional layer-by-layer scanning directional biomimetic printing with 30° low temperature gradient air drying and curing process. This highly mimics the layered texture and chewy feel of natural animal muscle, while avoiding the loss of heat-sensitive active ingredients and product hardening caused by high temperature curing. It simultaneously achieves excellent taste, high biomimeticity and stable physiological activity.

[0027] 5. This invention uses inexpensive industrial soybean residue as the core raw material to replace high-cost refined protein raw materials, realizing the green and high-value recycling of grain and oil by-products. The entire set of process parameters is precise and controllable, with excellent repeatability, and can be adapted to flexible and large-scale industrial production, effectively reducing production costs. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating the preparation process of soybean residue-based 3D printed plant-based meat steaks.

[0029] Figure 2 This is a comparative schematic diagram showing the GABA content in the plant-based meat cutlets prepared in Examples 1-3 and Comparative Examples 1-4.

[0030] Figure 3This is a schematic diagram comparing the polypeptide content in the plant-based meat cutlets prepared in Examples 1-3 and Comparative Examples 1-4.

[0031] Figure 4 This is a schematic diagram comparing the ACE inhibition rates of plant-based meat cutlets prepared in Examples 1-3 and Comparative Examples 1-4. Detailed Implementation

[0032] The present invention will be further described in detail below with reference to the embodiments. Unless otherwise specified, all raw materials used in the following embodiments are commercially available products. Fresh wet soybean residue was obtained from a soybean product processing enterprise; alkaline protease was purchased from Novozymes; cellulase was purchased from DSM; and *Lactobacillus brevis* fermentation broth was purchased from the China Industrial Microbial Culture Collection Center. Soybean protein isolate purity ≥90%, konjac glucomannan viscosity ≥20000 mPa·s, and edible vegetable oil was sunflower seed oil or refined soybean oil. γ-aminobutyric acid (GABA) content was determined by high-performance liquid chromatography (HPLC) according to GB / T 30987-2020. Peptide content was determined by the Folin-Ciocalteu colorimetric method according to GB 5009.5-2016. ACE inhibition rate was determined by in vitro ultraviolet spectrophotometry. Intact fiber retention rate was determined by 100-mesh wet sieving. Fiber order was determined using a stereomicroscope combined with Image-Pro Plus image analysis software. Texture properties were determined using a TA-XT2i texture analyzer. The sensory evaluation was conducted by 10 professional food sensory evaluators using a 100-point scoring system.

[0033] Example 1

[0034] This embodiment provides a soybean residue-based 3D-printed plant-based meat steak that aids sleep and helps lower blood pressure. The specific preparation steps are as follows:

[0035] S1: Select fresh wet soybean residue, remove impurities mechanically, rinse 4 times with room temperature water to remove residual slurry and soluble impurities; spread the material with a thickness of ≤2 cm, dry at a constant temperature of 40℃ for 6 h, and control the moisture content of soybean residue to 10%±0.3%; after low-temperature and low-speed crushing (crushing temperature 10~20℃), sieve to 80~100 mesh particles to obtain pretreated soybean residue.

[0036] S2: Mix pretreated soybean residue with water at a material-to-liquid ratio of 1:9, stir at a constant speed for 30 min to prepare a uniform suspension, sterilize in a 90℃ water bath for 10 min, and then allow to cool naturally to room temperature; employ a two-step segmented enzymatic hydrolysis process: first, adjust the system pH to 8.2 and temperature to 48℃, add 0.8% alkaline protease for 1.0 h to degrade macromolecular proteins and generate polypeptide active precursors; then adjust the pH to 4.8 and temperature to 52℃, add 0.4% cellulase for 0.5 h to loosen the dense fiber structure; finally, adjust the system pH to 6.0, and inoculate with 2% Lactobacillus brevis fermentation broth (viable count ≥1×10⁻⁶). 9The active ingredients were enriched by fermenting at a constant temperature of 30℃ for 7 h using a micro-aerobic intermittent aeration mode of 6 mL / min (aeration for 1 min every 30 min); after fermentation, the active ingredients were inactivated by water bath at 85℃ for 5 min and filtered through a 100-mesh sterile filter to obtain the modified soybean residue base material.

[0037] S3: A dry-mix pre-dispersed mixture of 91.0% modified soybean residue base, 7.5% soy protein isolate (purity ≥90%), and 1.5% konjac glucomannan (viscosity ≥20000 mPa·s) was prepared by mass ratio. Based on the total solid mass, 3.0% sunflower seed oil was added and mixed thoroughly. Water was added to adjust the slurry moisture content to 58%. The mixture was homogenized at 100 r / min for 4 min, followed by vacuum degassing at -0.05 MPa for 5 min to prepare the printing ink. The resulting ink was tested for 10 s... -1 At the shear rate, the apparent viscosity is 1100 mPa·s, the storage modulus G'=350 Pa, the thixotropic recovery rate is 92%, and the rheological properties are excellent and stable.

[0038] S4: In a constant temperature and dust-free environment of 28℃ and a base plate of 25℃, a 1.2 mm inner diameter nozzle is used, with a printing speed of 35 mm / s, a layer thickness of 0.25 mm, a 100% fill rate, and 0° unidirectional layer-by-layer scanning printing to prepare plant-based meat steak blanks.

[0039] S5: Place the printed blank in a constant temperature and humidity environment with 30℃ and 45% relative humidity and no wind for 25 minutes to air dry, and the finished soybean residue-based plant meat steak is obtained.

[0040] Example 2

[0041] This embodiment provides a soybean residue-based 3D-printed plant-based meat steak that improves sleep and helps lower blood pressure. The preparation method is basically the same as that in Example 1, except that: in step S3, the solid phase powder ratio is 93.0% modified soybean residue base, 6.2% soy protein isolate, and 0.8% konjac glucomannan (total solid phase 100%); based on the total solid phase mass, the amount of edible vegetable oil added is 2.0%, and the moisture content of the slurry is controlled at 60%; the remaining process parameters and operation steps are consistent with those in Example 1.

[0042] Example 3

[0043] This embodiment provides a soybean residue-based plant-based meat steak with sleep-improving and blood pressure-lowering functions. Its preparation method is basically the same as that of Example 1, except that: the solid phase powder ratio is 89.0% modified soybean residue base, 10.0% soy protein isolate, and 1.0% konjac glucomannan; based on the total mass of the solid phase, the amount of edible vegetable oil added is 4.0%, the water content of the slurry is 55%, and the remaining process parameters and operation steps remain unchanged.

[0044] Comparative Example 1

[0045] This comparative example is used to verify the core role of compound enzymatic hydrolysis in the release of active precursors. The preparation process is the same as in Example 1, the only difference being that the gradient double enzymatic hydrolysis modification step is omitted. After pretreatment of soybean residue, it is directly mixed with liquid and sterilized, and then inoculated with an equal amount of Lactobacillus brevis for single fermentation modification. The subsequent ink rheology control, 3D printing, and low-temperature shaping processes are exactly the same as in Example 1.

[0046] Comparative Example 2

[0047] This comparative example provides a modified soybean residue-based 3D printed plant-based meat steak. The preparation process is basically the same as that of Example 1, except that after completing the gradient double enzymatic hydrolysis modification, the microaerobic intermittent dynamic aeration fermentation enrichment step is omitted, and only the enzymatic hydrolysis modification step is retained. The subsequent process parameters are the same as those of Example 1.

[0048] Comparative Example 3

[0049] This comparative example provides a modified soybean residue-based 3D printed plant-based meat steak. The preparation process is basically the same as that of Example 1, except that a "high-dose, long-term excessive complex enzymatic hydrolysis process" is adopted: the pH of the system is uniformly adjusted to 7.0 and the temperature to 50°C, and double the amount of alkaline protease and cellulase (each at 0.8% of the suspension mass) are added. Enzymatic hydrolysis is carried out continuously for 3.0 h, resulting in excessive breakage of the soybean residue fiber structure. After enzymatic hydrolysis, the same micro-aerobic fermentation, pulping, printing and constant temperature curing process are carried out.

[0050] Comparative Example 4

[0051] This comparative example provides a conventional soybean residue-based 3D printed plant-based meat steak. The preparation process is basically the same as that of Example 1. The difference is that unmodified refined soybean residue is used as the core raw material, combined with 8% soy protein isolate and 5% gluten powder as exogenous auxiliary materials. The finished product is prepared by traditional extensive slurry preparation, disordered scanning printing and high temperature curing process, simulating the mainstream processing technology in the industry.

[0052] Product performance testing methods

[0053] All samples tested in this invention were tested using national / industry standard methods. Each sample group was prepared in triplicate, and each group was tested in triplicate. The average value was taken. The specific testing methods are as follows:

[0054] (1) Detection of γ-aminobutyric acid (GABA) content (high performance liquid chromatography): According to GB / T 30987-2020 "Determination of free amino acids in plants", accurately weigh 2.0 g of sample, add 10 mL of 5% trichloroacetic acid solution, extract by ultrasonication in ice water bath for 30 min, centrifuge at 8000 r / min for 15 min, and take the supernatant to filter through a 0.22 μm organic filter membrane; use o-phthalaldehyde pre-column derivatization method, C18 reverse phase column (4.6 mm × 250 mm, 5 μm), mobile phase is acetonitrile-0.1 mol / L sodium acetate buffer (volume ratio 40:60), flow rate 1.0 mL / min, detection wavelength 338 nm, column temperature 30℃, injection volume 20 μL; use external standard method to draw standard curve, and quantitatively calculate the GABA content in the sample, unit mg / 100 g.

[0055] (2) Detection of polypeptide content (Folin-Ciocalteu colorimetric method): According to GB 5009.5-2016 "National Food Safety Standard - Determination of Protein in Food", weigh 1.0 g of sample powder, add 10 mL of 10% trichloroacetic acid solution, let stand for 30 min to precipitate, centrifuge at 10000 r / min for 10 min to remove macromolecular proteins, and take the supernatant as the polypeptide test solution; use bovine serum albumin as standard to prepare gradient standard solutions, add Folin-Ciocalteu reagent to develop color in the dark for 20 min, measure the absorbance at a wavelength of 760 nm, plot the standard curve, and calculate the polypeptide content in the sample, in mg / 100g.

[0056] (3) ACE inhibition rate detection (in vitro ultraviolet spectrophotometry): Prepare 0.1 U / mL ACE enzyme solution, 5 mmol / L muscarinyl-histyl-leucine (HHL) substrate solution, and 0.1 mol / L borax buffer (pH 8.3); add buffer, sample test solution, and HHL substrate in sequence, preheat in a water bath at 37℃ for 10 min, add angiotensin-converting enzyme (ACE) solution and react for 30 min, and add 1.0 mol / L hydrochloric acid to terminate the reaction; use blank group and control group as references, and measure absorbance at a wavelength of 228 nm.

[0057] Calculate the ACE inhibition rate using the formula:

[0058]

[0059] (4) Detection of intact fiber retention rate: Weigh 5.0 g of dried sample, add 50 mL of sterile pure water, soak at room temperature for 30 min, wet sieve using a 100 mesh standard sieve, collect the intact fiber components on the sieve, dry at low temperature and weigh, calculate the percentage of intact fiber mass to the total mass of the sample, which is the intact fiber retention rate.

[0060] (5) Fiber orderliness detection: The finished product sample is sliced ​​and sampled. Five different areas are photographed under a stereo microscope at 100x magnification. The number of fibers in the same direction and the total number of fibers in the field of view are counted by Image-Pro Plus image analysis software. The proportion of fibers in the same direction is calculated, which is the fiber orderliness.

[0061] (6) Texture characteristics test: The TA-XT2i texture analyzer was used with a P / 36R cylindrical probe. The finished sample was cut into regular blocks of 10 mm × 10 mm × 5 mm. Test parameters: pre-test speed 2 mm / s, test speed 1 mm / s, post-test speed 2 mm / s, compression deformation 40%, interval between two compressions 5s, trigger force 5g. Each group of samples was tested 8 times, and the core texture parameters of sample elasticity and chewiness were recorded.

[0062] (7) Sensory evaluation test: Ten professional food sensory evaluation personnel were formed, and a 100-point scoring standard was adopted. The evaluation was based on five dimensions: texture regularity, meat chewiness, biomimicry realism, aroma purity, and mouth softness. Each item was worth 20 points, and the total score was 100 points. Rinse your mouth with water before scoring, and evaluate individual samples at 15-minute intervals to avoid taste interference. The average score was taken as the sensory evaluation result.

[0063] Product performance results analysis

[0064] All samples from the embodiments and comparative examples were subjected to standardized testing. The testing indicators included intact fiber retention rate, fiber orderliness, textural properties, sensory evaluation score and printing success rate, γ-aminobutyric acid (GABA) content, peptide content, and ACE inhibition rate. Three samples were prepared for each group, and each group was tested three times in parallel. The average value was taken. Specific test results are shown in Table 1 and Appendix. Figures 2-4 As shown.

[0065] Table 1 Comparison of texture, sensory properties, and printing performance of plant-based meat patties in each experimental group

[0066] Example 1 95.82±1.26 94.22±3.56 85.51±1.14 33.28±0.84 94.21±1.07 98.51±0.87 Example 2 96.13±1.05 90.45±1.62 82.82±1.27 31.53±1.21 93.53±1.24 94.23±1.09 Example 3 95.23±1.29 92.51±2.03 80.20±1.52 29.65±1.02 91.65±1.43 90.62±1.24 Comparative Example 1 86.45±2.16 62.34±2.52 71.42±1.81 18.28±0.96 78.36±1.92 82.35±2.15 Comparative Example 2 42.37±3.52 45.81±3.27 62.66±2.33 20.63±0.75 70.51±2.25 75.13±2.52 Comparative Example 3 40.12±3.23 42.17±3.57 50.51±2.45 11.58±0.72 62.34±2.28 51.50±2.81 Comparative Example 4 95.36±2.82 82.60±2.25 75.37±1.68 22.65±1.25 89.92±1.79 90.29±1.57

[0067] From Table 1 and Figures 2-4 The test data show that the products of each embodiment of the present invention are significantly superior to the comparative examples in terms of functional activity, fiber integrity, printing stability, texture, and taste. Example 1 exhibits the best overall performance, achieving a comprehensive breakthrough in efficient enrichment of active ingredients, intact fiber structure, stable printing, and high biomimetic meat texture. Examples 2 and 3 show slight performance fluctuations, demonstrating that the formulation and process of the present invention have a reasonable adjustable range, suitable for flexible industrial production. The significant performance deficiencies of the comparative examples fully verify the advantages of the integrated technology system of the present invention, which includes gradient moderate enzyme-bacterial modification, micro-oxygen targeted enrichment, hierarchical rheological regulation, and directional biomimetic curing.

[0068] The above description is merely a preferred embodiment of the present invention. The present invention is not limited to the above-described embodiments. Any embodiment that achieves the technical effects of the present invention by the same or equivalent means should fall within the protection scope of the present invention. Within the protection scope of the present invention, various modifications and variations can be made to the technical solutions and / or implementation methods.

Claims

1. A 3D-printed plant-based meat steak made from soybean residue that aids sleep and helps lower blood pressure, characterized in that... The raw materials consist of solid-phase powder and liquid-phase medium. The solid-phase powder, by mass percentage, includes 89.0%~93.0% enzyme-bacterial coupled modified soybean residue substrate, 6.0%~10.0% soy protein isolate, and 0.8%~1.5% konjac glucomannan, with the total percentage of each solid-phase component being 100%. The liquid-phase medium is edible vegetable oil and sterile water, with the amount of edible vegetable oil added being 2.0%~4.0% of the total mass of the solid-phase powder. The overall moisture content of the printing slurry is controlled at 55%~60%. The modified soybean residue substrate is prepared through a two-step segmented enzymatic hydrolysis coupled with micro-aerobic dynamic fermentation, synergistically enriching γ-aminobutyric acid and antihypertensive peptide active ingredients while simultaneously retaining the complete dietary fiber skeleton.

2. The soybean residue-based 3D printed plant-based meat steak according to claim 1, characterized in that, The konjac glucomannan has a viscosity ≥20000 mPa·s; the soy protein isolate has a purity ≥90%; and the edible vegetable oil is sunflower seed oil or refined soybean oil.

3. The soybean residue-based 3D printed plant-based meat steak according to claim 1, characterized in that, The 3D printing ink has exclusive rheological properties: at 10 s -1 shear rate, the apparent viscosity is 800~1500 mPa·s, the storage modulus G' is 200~500 Pa, the loss modulus G" is less than G', and the thixotropic recovery rate is ≥85%, which endows the ink with shear-thinning and static self-shaping characteristics.

4. A method for preparing soybean residue-based 3D-printed plant-based meat steaks as described in claim 1, characterized in that, Includes the following steps: S1. Soybean residue is cleaned of impurities, rinsed with room temperature water 3-5 times, dried at 40℃ to a moisture content of 10%±0.5%, pulverized at low temperature and sieved into 80-100 mesh particles to obtain pretreated soybean residue. S2. Prepare a suspension by mixing pretreated soybean residue and water at a material-to-liquid ratio of 1:9, sterilize at 90℃ for 10 min, and then cool. Employ a two-step segmented enzymatic hydrolysis process: first, add 0.8% alkaline protease (by weight of total suspension) at pH 8.0–8.5 and 45–50℃, and hydrolyze for 1.0 h; then adjust the pH to 4.5–5.0 and the temperature to 50–55℃, and add 0.4% cellulase for 0.5 h of enzymatic hydrolysis; after hydrolysis, adjust the system pH to 5.8–6.2, and inoculate with 2.0% viable bacteria (≥1×10⁻⁶). 9 CFU / mL Lactobacillus brevis fermentation broth was fermented at 30℃ for 7 hours. Active ingredients were enriched by intermittent microaerobic aeration at 5~8 mL / min and aeration for 1 min every 30 min. After fermentation, the broth was inactivated at 85℃ for 5 min and filtered through 100 mesh to obtain modified soybean residue base material. S3. Modified soybean residue, soy protein isolate and konjac glucomannan are compounded and pre-dispersed evenly in proportion. Based on the total mass of solid powder, 2.0%~4.0% edible vegetable oil is added, water is added to adjust the moisture content of the slurry to 55%~60%, homogenized at 80~120 r / min for 3~5 min, and degassed under vacuum at -0.05 MPa for 5 min to prepare 3D printing ink. S4. Under a constant temperature of 28℃ and a base plate temperature of 25℃, plant-based meat steak blanks were prepared by printing with a nozzle with an inner diameter of 1.2 mm, a printing speed of 32~38 mm / s, a layer thickness of 0.25 mm, a 100% fill rate, and a 0° unidirectional layer-by-layer scanning mode. S5. Place the plant-based meat steak blank in a windless, constant temperature and humidity environment at 30℃ and 40%~50% relative humidity, and allow it to be gradually air-dried and cured for 25 minutes to obtain the finished 3D printed plant-based meat steak.

5. The preparation method according to claim 4, characterized in that, In step S3, the optimal process parameters for the modified soybean residue, soy protein isolate, and konjac glucomannan compounded in the following proportions are: 91.0% modified soybean residue, 7.5% soy protein isolate, and 1.5% konjac glucomannan in the solid powder; 3.0% edible vegetable oil added; 58% slurry moisture content; homogenization at 100 r / min for 4 min; and the resulting ink is heated to 10 s. -1 At the shear rate, the apparent viscosity is 1100 mPa·s, the storage modulus G'=350 Pa, and the thixotropic recovery rate is 92%.

6. The preparation method according to claim 4, characterized in that, The optimal printing speed in step S4 is 35 mm / s.

7. The preparation method according to claim 4, characterized in that, The temperature of the low-temperature pulverization in step S1 is 10~20℃.

8. The preparation method according to claim 4, characterized in that, The two-step segmented enzymatic hydrolysis process in step S2 is as follows: first, adjust the pH of the system to 8.2 and the temperature to 48℃, add 0.8% alkaline protease and hydrolyze for 1.0 h; then adjust the pH to 4.8 and the temperature to 52℃, add 0.4% cellulase and hydrolyze for 0.5 h; the microaerobic intermittent aeration mode is 6 mL / min microaerobic intermittent aeration, aeration for 1 min every 30 min.

9. The preparation method according to claim 4, characterized in that, The relative humidity for gradient air drying curing in step S5 is 45%.

10. The use of the soybean residue-based 3D printed plant-based meat steak as described in claim 1 in the preparation of functional dietary foods or plant-based meat products.

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