A high-nutrient, high-calcium multi-element soybean flour and its preparation method

Abstract

This invention discloses a high-nutrient, high-calcium, multi-element soybean flour and its preparation method in the field of soybean flour processing technology. The flour comprises the following components: modified compound fermented soybean flour, compound modified starch, sweet potato leaf extract, oat flour, nut powder, fruit juice powder, calcium carbonate, soybean lecithin, and seasonings. This invention proposes a method of improving the nutrient content and absorption of soybean flour by mixing compound soybean milk with activated probiotics through hydrolysis, enzymatic hydrolysis, and β-cyclodextrin glycosylation modification. The addition of compound modified starch obtained through β-amylase hydrolysis, hexose oxidase oxidation, and the addition of konjac glucomannan and L-arginine improves the stability and extends the shelf life of the soybean flour. The addition of sweet potato leaf extract and oat flour further enhances the nutritional value of the soybean flour while helping to eliminate free radicals in the body and enhance immune, antioxidant, anti-inflammatory, and hypoglycemic functions.

Description

Technical Field

[0001] This invention belongs to the field of soybean flour processing technology, specifically referring to a high-nutrition, high-calcium multi-element soybean flour and its preparation method. Background Technology

[0002] With the consumption of animal-based foods such as milk and meat approaching saturation, and with health and environmental protection becoming increasingly important, the development of plant-based foods is unstoppable. In particular, the market for plant-based milk and plant-based meat is booming, indicating that plant-based multi-element soy powder has enormous development potential. Soybeans are an important plant protein resource, with a protein content as high as 30-40%, a fat content of 15-20%, and a carbohydrate content of 20-30%. In addition, they are rich in minerals, vitamins, dietary fiber, and various bioactive substances, making them an important source of nutrition for humans. Because soybeans are high in protein and cholesterol-free, they are widely used as ingredients in various nutritional foods or directly processed into high-protein nutritional foods.

[0003] In recent years, consumers have increasingly higher demands for the flavor, texture, quality, solubility, stability, and nutritional value of soy flour. However, existing products mainly suffer from the following problems in terms of processing and quality: soy flour comes in a wide variety of types and is expensive, but its nutritional value is low and its absorption after consumption is poor; soy flour has low solubility, poor dispersibility, and poor stability. Summary of the Invention

[0004] To address the above issues and overcome the shortcomings of existing technologies, this invention provides a high-nutrition, high-calcium multi-element soy flour and its preparation method. To solve the problems of low nutritional value, poor absorption after consumption, poor solubility and dispersibility, and poor antioxidant and blood sugar-lowering functions of soy flour, this invention proposes a method of improving the nutrient content and absorption of soy flour by mixing it with activated probiotics after hydrolysis of compound soy milk by papain, enzymatic hydrolysis by transglutaminase, and β-cyclodextrin glycosylation modification. The addition of a composite modified starch obtained through β-amylase hydrolysis, hexose oxidase oxidation, and the addition of konjac glucomannan and L-arginine improves the stability of soy flour during freezing, thawing, and heating, reduces its dryness, and extends its shelf life. The addition of sweet potato leaf extract and oat flour further enhances the nutritional value of the soy flour while helping to eliminate free radicals in the body and enhance immune, antioxidant, anti-inflammatory, and blood sugar-lowering functions.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The present invention proposes a high-nutrition, high-calcium multi-element soybean powder, which comprises the following components in parts by weight: 60-80 parts of modified compound fermented soybean powder, 20-40 parts of compound modified starch, 5-10 parts of sweet potato leaf extract, 3-5 parts of oat flour, 15-20 parts of nut powder, 10-15 parts of fruit juice powder, 3-5 parts of calcium carbonate, 1-2 parts of soybean lecithin, and 2-3 parts of seasoning;

[0006] Preferably, the nut powder includes at least one of white sesame powder, black sesame powder, almond powder, walnut powder, cashew powder, peanut powder, and pine nut powder;

[0007] Nut powder: Rich in high-quality protein, which helps maintain healthy muscle tissue; rich in unsaturated fatty acids, which helps maintain cardiovascular health and brain function; rich in dietary fiber, which helps promote digestive health and regulate blood sugar and cholesterol levels; rich in vitamins such as vitamin E, B vitamins, and vitamin K, which help maintain normal bodily functions, enhance the immune system, and promote cell repair; rich in minerals such as magnesium, iron, zinc, potassium, and calcium, which help promote bone health, nerve conduction, and blood circulation.

[0008] Preferably, the fruit juice powder includes at least one of strawberry juice powder, lemon juice powder, blueberry juice powder, blackcurrant juice powder, grape juice powder, and orange juice powder;

[0009] Fruit juice powder: Rich in antioxidants such as flavonoids and polyphenols, it helps combat free radical damage and protects cells from oxidative stress. Fruit juice powder has the natural aroma and sweetness of fruit, which can enhance the texture and flavor of food when added to soy powder, making it more delicious. At the same time, the natural pigments in fruit juice powder can give soy powder a richer color, increasing its visual appeal. Fruits contain natural preservatives such as citric acid and malic acid, and adding fruit juice powder to soy powder can act as a preservative, extending the shelf life of soy powder.

[0010] Preferably, the seasoning includes at least one of erythritol, steviol glycosides, white sugar, and salt.

[0011] Soy lecithin contains unsaturated fatty acids such as linoleic acid and alpha-linolenic acid, which help lower bad cholesterol and maintain cardiovascular health.

[0012] Oat flour: Rich in low-GI (glycemic index) carbohydrates, adding oat flour to soy flour can lower the overall GI value of the product and help maintain stable blood sugar levels.

[0013] Preferably, the preparation method of the composite modified starch specifically includes the following steps:

[0014] ① Mix corn starch and potato starch to obtain composite starch, add β-amylase, disperse in 200 mL of 1 mol / L sodium phosphate buffer solution with pH 6.5, react at 50-60℃ for 12-18 h, add hexose oxidase, heat to 100℃, react for 2-4 h, cool to room temperature, centrifuge and filter at 1000 r / min for 10-15 min, wash the precipitate with deionized water, freeze dry to obtain pretreated composite modified starch;

[0015] ② Add the pretreated composite modified starch obtained in step ① to 300 mL of deionized water, stir at 300-500 r / min, add konjac glucomannan, heat to 60-65℃, and swell for 30-60 min to obtain the pretreated modified starch solution.

[0016] ③ Dissolve L-arginine in 50 mL of deionized water to obtain an L-arginine solution;

[0017] ④ Mix the pretreated modified starch solution obtained in step ② and the L-arginine solution obtained in step ③, heat treat in a water bath at 80-90℃ for 2-3 hours, cool to room temperature, centrifuge and filter at 500r / min for 20-30 minutes, wash the precipitate with deionized water, freeze dry to obtain composite modified starch.

[0018] Preferably, in step ①, based on the total starch content in the compound starch, the amount of β-amylase added is 0.1-0.5%, and the amount of hexose oxidase added is 0.3-0.5%.

[0019] Preferably, the mass ratio of the composite starch, konjac glucomannan, and L-arginine is 20-40:3-9:2-3.

[0020] Preferably, the preparation method of the sweet potato leaf extract specifically includes the following steps:

[0021] Sweet potato leaves were washed, dried, and pulverized. They were then extracted 2-3 times with a 50-70% (v / v) ethanol aqueous solution under a nitrogen atmosphere at 70-80℃ for 2-3 hours each time. After cooling to room temperature, the extract was filtered, concentrated under reduced pressure, and allowed to stand for flocculation. The extract was further purified by adsorption using a D101 macroporous adsorption resin column and a polyamide resin column, with a column diameter-to-height ratio of 1:(7-8). The resin column was washed with water until no sugar color was observed. The extract was then eluted with an 85% (v / v) ethanol aqueous solution at a flow rate of 3-5 mL / min. The eluent was concentrated under reduced pressure and spray-dried at an inlet air temperature of 160-180℃, an outlet air temperature of 80-90℃, and a flow rate of 15-20 mL / min to obtain the sweet potato leaf extract.

[0022] Sweet potato leaf extract: Rich in natural antioxidants such as chlorophyll, anthocyanins, vitamin C, flavonoids, and phenolic acids, it helps to eliminate free radicals in the body, reduce the damage of oxidative stress, and has a positive effect on anti-aging and cell protection. In addition, it also contains polysaccharides and dietary fiber, which on the one hand increase the viscosity and viscoelasticity of the soy flour, improving the texture and taste of the product, and on the other hand help control blood sugar fluctuations and stabilize blood sugar. Using ethanol aqueous solution reflux purification and resin column adsorption, nutrients such as cellulose and protein can be further separated to improve the purity and concentration of the target substances, aiming to enrich the beneficial components in the extract.

[0023] This invention also provides a method for preparing a high-nutrient, high-calcium, multi-element soybean flour, which specifically includes the following steps:

[0024] S1. Select clean, insect-free soybean raw materials, soak them in water at 30-40℃ for 10-12 hours, after soaking, take out the soybeans and put them into a grinder to grind them repeatedly to obtain soy milk, and then treat the soy milk with ultrasound to obtain soy slurry.

[0025] S2. Add papain to the soybean slurry obtained in S1, heat to 45-55℃, adjust the pH to 6.0-7.0, and keep warm for 3-5 hours to hydrolyze and obtain soybean protein hydrolysate.

[0026] S3. Add transglutaminase to the soybean protein hydrolysate obtained in step S2, heat to 50-60℃, adjust the pH to 5.0-7.0, incubate for 1-2 hours, place in a water bath at 80-100℃ and incubate for 20-30 minutes to inactivate the enzyme, and obtain soybean protein hydrolysate.

[0027] S4. Add β-cyclodextrin to the soybean protein hydrolysate obtained in step S3, stir and mix well, adjust the pH to 6.0-7.0, react at 60-80℃ for 2-3 hours, cool to room temperature, filter, separate the supernatant, concentrate under reduced pressure, and freeze dry to obtain modified composite soybean flour.

[0028] S5. Inoculate Bifidobacterium animalis subsp. lactis and Lactobacillus rhamnosus into Gao's medium for activation culture at 28-32℃ for 2-3 days to obtain activated probiotics.

[0029] S6. Thoroughly mix the modified compound soybean powder obtained in step S4 and the activated probiotics obtained in S5, and ferment them at a temperature of 25-30℃ for 3-4 days. Dry them at a low temperature of 20-30℃ to obtain the compound fermented soybean powder.

[0030] S7. Mix the compound fermented soybean powder obtained in step S6 with compound modified starch, sweet potato leaf extract, oat flour, nut powder, fruit juice powder, calcium carbonate, soybean lecithin, and seasonings. Add warm water at 50-60℃ for hydration. The hydrated liquid is then slurried in nitrogen to obtain a slurry. The slurry is then homogenized, sterilized, vacuum concentrated, and spray-dried to obtain a high-nutrition, high-calcium multi-element soybean powder.

[0031] Preferably, in step S1, the soybean raw material comprises a mixture of black beans, mung beans, soybeans, and red beans in a mass ratio of 1:1-3:1-2:3-5;

[0032] Preferably, in step S2, the amount of papain added is 0.1-0.2% of the mass of the soybean raw material;

[0033] Preferably, in step S3, the amount of transglutaminase added is 0.04-0.06% of the mass of the soybean raw material;

[0034] Preferably, in step S4, the mass ratio of the soybean raw material to β-cyclodextrin is 1:0.1-0.2;

[0035] Preferably, in step S5, the viable count of the *Bifidobacterium animalis* subsp. *lactamase* is 1.2 × 10⁻⁶. 6 CFU / g or higher; the viable count of the *Lactobacillus rhamnosus* is 2.5 × 10⁻⁶. 7 CFU / g or higher;

[0036] Preferably, in step S7, the homogenization conditions are: temperature 50-70℃, pressure 20-30MPa; the sterilization conditions are: water medium ultra-high pressure sterilization at room temperature and pressure 300-500MPa for 5-10 minutes; the vacuum concentration conditions are: vacuum degree 0.09-0.10MPa, temperature 50-60℃; and the spray drying conditions are: inlet air temperature 150-200℃, outlet air temperature 80-100℃, and flow rate 15-20mL / min.

[0037] The beneficial effects achieved by this invention are as follows:

[0038] This invention modifies and ferments compound soybean flour, combines it with modified starch, and adds auxiliary nutrients such as sweet potato leaf extract, nut powder, fruit juice powder, calcium carbonate, soybean lecithin, oat flour, and seasonings. The synergistic effect of these components improves the taste of the soybean flour, enhances its solubility, dispersibility, and expansion, and extends the product's shelf life. It also has antioxidant, anti-inflammatory, and blood sugar-lowering effects, thus achieving the technical effect of increasing the nutrient content of soybean flour and the absorption rate of soybean flour by the human body.

[0039] 1. This invention involves soaking, grinding, and ultrasonically treating soybeans in warm water to obtain soy milk. The soy milk is then modified by papain hydrolysis, transglutaminase hydrolysis, and β-cyclodextrin glycosylation. First, papain hydrolysis breaks down large protein molecules into smaller peptides and amino acids, making the protein easier for the body to absorb and utilize, thus improving protein bioavailability. Furthermore, the small peptides in the hydrolysate promote the growth and reproduction of lactic acid bacteria, significantly increasing the apparent viscosity of the soy milk during storage and extending its shelf life. Then, further... Enzymatic cross-linking of soybean protein hydrolysates with transglutaminase gives the resulting small peptides and amino acids specific functions such as antioxidation, antibacterial, and anti-inflammatory properties, which help promote health and nutrition. The addition of β-cyclodextrin, with its unique hydrophilic exterior and hydrophobic interior structure, allows the hydroxyl groups of the sugar molecules to undergo glycosylation with the carbonyl groups of the amino acids under enzymatic catalysis, resulting in modified composite soybean flour. This improves the solubility, stability, and functionality of the soybean flour, further enhancing its nutritional value, texture, and taste.

[0040] 2. This invention involves fermenting modified compound soybean flour with activated Bifidobacterium animalis subsp. lactis and Lactobacillus rhamnosus. On one hand, Bifidobacterium animalis subsp. lactis and Lactobacillus rhamnosus act as probiotics, and their synergistic effect can regulate the balance of intestinal flora, inhibit the growth of harmful bacteria, promote the increase of beneficial bacteria in the intestine, help improve digestive function, enhance intestinal barrier function, reduce intestinal inflammation, and maintain intestinal health. On the other hand, the enzymes in the fermenting bacteria can help break down some indigestible components in soybean raw materials, making nutrients easier for the human body to absorb. During the fermentation process, vitamins, amino acids, and other nutrients are produced, thereby improving the nutritional value of the multi-nutrient soybean flour and thus helping to enhance the body's immunity.

[0041] 3. The composite modified starch of this invention is obtained by combining corn starch and potato starch, followed by hydrolysis with β-amylase, oxidation with hexose oxidase, and the addition of konjac glucomannan and L-arginine. The corn starch and potato starch complex is modified by using β-amylase and hexose oxidase to oxidize the starch chain. First, β-amylase is used to hydrolyze the starch, producing a large amount of maltose and other low molecular weight sugars. The low molecular weight sugars and the -OH groups of glucose at the end of the starch chain are oxidized by hexose oxidase to form new ester bonds, changing the chemical structure of the starch and giving it higher viscosity, stronger acid resistance and heat resistance. Enzymatic modification is safer and more environmentally friendly than chemical modification. Konjac glucomannan has good water retention properties. Adding konjac glucomannan can reduce the dryness of starch, extend its shelf life, and increase its viscosity. Furthermore, konjac glucomannan can form a stable colloidal structure during freezing and thawing. Adding it to soy flour can improve the stability of soy flour during freezing, thawing, and heating, preventing structural damage. In addition, konjac glucomannan has immune-boosting, antioxidant, anti-inflammatory, anti-cancer, and blood sugar-lowering functions. The addition of L-arginine not only increases the amino acid content of soy flour, enhancing its nutritional value, but also further enhances the bioactivity of konjac glucomannan, increasing its benefits to the human body. Attached Figure Description

[0042] Figure 1 The graph shows the ash content results of the multi-component soybean flour prepared in Examples 1-3 and Comparative Examples 1-4 of this invention.

[0043] Figure 2 The graph shows the calcium content of the multi-element soybean flour prepared in Examples 1-3 and Comparative Examples 1-4 of this invention.

[0044] Figure 3 The graphs show the solubility results of the multi-component soybean flour prepared in Examples 1-3 and Comparative Examples 1-4 of this invention.

[0045] Figure 4 The graphs show the absorption effect of the multi-element soybean powder prepared in Examples 1-3 and Comparative Examples 1-4 of this invention.

[0046] Figure 5 The graph shows the hypoglycemic performance of the multi-component soybean powder prepared in Examples 1-3 and Comparative Examples 1-4 of this invention.

[0047] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. Detailed Implementation

[0048] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be applied to this invention. The preferred embodiments and materials described herein are for illustrative purposes only and do not limit the scope of this application.

[0050] Unless otherwise specified, the experimental methods used in the following examples are conventional methods; unless otherwise specified, the experimental materials and test strains used in the following examples were purchased from commercial channels.

[0051] The strains involved in this invention originate from the following sources:

[0052] Bifidobacterium animalis subsp. lactis, strain number: CICC21709, purchased from China Industrial Microbial Culture Collection Center;

[0053] Lactaseibacillus rhamnosus, strain number: CICC 20255, was purchased from the China Industrial Microbial Culture Collection Center.

[0054] Example 1

[0055] A high-nutrition, high-calcium multi-element soybean flour, consisting of 60 parts modified compound fermented soybean flour, 20 parts compound modified starch, 5 parts sweet potato leaf extract, 3 parts oat flour, 15 parts white sesame powder, 10 parts strawberry juice powder, 3 parts calcium carbonate, 1 part soybean lecithin, and 2 parts erythritol.

[0056] The preparation method of composite modified starch specifically includes the following steps:

[0057] ① Mix 10g of corn starch and 10g of potato starch to obtain composite starch. Add 0.02g of β-amylase and disperse in 200mL of sodium phosphate buffer solution with a concentration of 1mol / L and a pH of 6.5. React at 50℃ for 12h. Add 0.06g of hexose oxidase, heat to 100℃ and react for 2h. Cool to room temperature, centrifuge and filter at 1000r / min for 10min. Wash the precipitate with deionized water and freeze-dry to obtain pretreated composite modified starch.

[0058] ② Add the pretreated composite modified starch obtained in step ① to 300 mL of deionized water, stir at 300 r / min, add 3 g of konjac glucomannan, heat to 60℃, and swell for 30 min to obtain the pretreated modified starch solution;

[0059] ③ Dissolve 2g of L-arginine in 50mL of deionized water to obtain an L-arginine solution;

[0060] ④ Mix the pretreated modified starch solution obtained in step ② and the L-arginine solution obtained in step ③, heat treat in an 80℃ water bath for 2 hours, cool to room temperature, centrifuge and filter at 500 r / min for 20 minutes, wash the precipitate with deionized water, freeze dry, and obtain the composite modified starch.

[0061] The preparation method of sweet potato leaf extract specifically includes the following steps:

[0062] 5g of sweet potato leaves were washed, dried, and pulverized. Extraction was performed twice with a 50% (v / v) ethanol aqueous solution under a nitrogen atmosphere at 70℃ for 2 hours each time. After cooling to room temperature, the extract was filtered, concentrated under reduced pressure, and allowed to stand for flocculation. Further purification was achieved using a D101 macroporous adsorption resin column and a polyamide resin column with a column diameter-to-height ratio of 1:7. The resin column was washed with water to remove any sugar color. Elution was performed with an 85% (v / v) ethanol aqueous solution at a flow rate of 3 mL / min. The eluent was concentrated under reduced pressure and spray-dried at an inlet air temperature of 160℃, an outlet air temperature of 80℃, and a flow rate of 15 mL / min to obtain the sweet potato leaf extract.

[0063] This invention also provides a method for preparing a high-nutrient, high-calcium, multi-element soybean flour, which specifically includes the following steps:

[0064] S1. Select 60g of clean, insect-free soybean raw material, soak it in 30℃ water for 10 hours, after soaking, take out the soybean and put it into a grinder to grind repeatedly to obtain soy milk, and then treat the soy milk with ultrasound to obtain soy slurry.

[0065] S2. Add 0.06g of papain to the soybean slurry obtained in S1, heat to 45℃, adjust the pH to 6.0, and keep warm for 3 hours to hydrolyze and obtain soybean protein hydrolysate.

[0066] S3. Add 0.024g of transglutaminase to the soybean protein hydrolysate obtained in step S2, heat to 50℃, adjust the pH to 5.0, incubate for 1 hour, place in an 80℃ water bath and incubate for 20 minutes to inactivate the enzyme, and obtain soybean protein hydrolysate.

[0067] S4. Add 6.0g of β-cyclodextrin to the soybean protein hydrolysate obtained in step S3, stir and mix well, adjust the pH to 6.0, react at 60℃ for 2h, cool to room temperature, filter, separate the supernatant, concentrate under reduced pressure, freeze dry, and obtain modified composite soybean flour.

[0068] S5. Bifidobacterium animalis subsp. lactis and Lactobacillus rhamnosus were inoculated into Gao's medium for activation culture at 28℃ for 2 days to obtain activated probiotics.

[0069] S6. The modified composite soybean powder obtained in step S4 and the activated probiotics obtained in step S5 are thoroughly mixed and fermented at a temperature of 25°C for 3 days. The mixture is then dried at a low temperature of 20°C to obtain the composite fermented soybean powder.

[0070] S7. The compound fermented soybean powder obtained in step S6 is mixed with compound modified starch, sweet potato leaf extract, oat flour, white sesame powder, strawberry juice powder, calcium carbonate, soybean lecithin, and erythritol. 50°C warm water is added for hydration. The hydrated liquid is slurried in nitrogen to obtain a slurry. The slurry is homogenized at 50°C and 20MPa, sterilized by ultra-high pressure sterilization in water medium at 300MPa for 5 minutes, vacuum concentrated at 0.09MPa and 50°C, and spray-dried at an inlet air temperature of 150°C, an outlet air temperature of 80°C, and a flow rate of 15mL / min to obtain a high-nutrition, high-calcium multi-element soybean powder.

[0071] Example 2

[0072] A high-nutrition, high-calcium multi-element soybean flour, consisting of 70 parts modified compound fermented soybean flour, 30 parts compound modified starch, 7.5 parts sweet potato leaf extract, 4 parts oat flour, 17.5 parts almond flour, 12.5 parts lemon juice powder, 4 parts calcium carbonate, 1.5 parts soybean lecithin, and 2.5 parts steviol glycosides.

[0073] The preparation method of composite modified starch specifically includes the following steps:

[0074] ① Mix 10g of corn starch and 20g of potato starch to obtain composite starch. Add 0.075g of β-amylase and disperse in 200mL of sodium phosphate buffer solution with a concentration of 1mol / L and a pH of 6.5. React at 55℃ for 15h. Add 0.12g of hexose oxidase, heat to 100℃ and react for 3h. Cool to room temperature, centrifuge and filter at 1000r / min for 13min. Wash the precipitate with deionized water and freeze-dry to obtain pretreated composite modified starch.

[0075] ② Add the pretreated composite modified starch obtained in step ① to 300 mL of deionized water, stir at 400 r / min, add 6 g of konjac glucomannan, heat to 62℃, and swell for 45 min to obtain the pretreated modified starch solution;

[0076] ③ Dissolve 2.5g of L-arginine in 50mL of deionized water to obtain an L-arginine solution;

[0077] ④ Mix the pretreated modified starch solution obtained in step ② and the L-arginine solution obtained in step ③, heat treat in an 85℃ water bath for 2.5h, cool to room temperature, centrifuge and filter at 500r / min for 25min, wash the precipitate with deionized water, freeze dry, and obtain the composite modified starch.

[0078] The preparation method of sweet potato leaf extract is the same as in Example 1.

[0079] This invention also provides a method for preparing a high-nutrient, high-calcium, multi-element soybean flour, which specifically includes the following steps:

[0080] S1. Select 70g of clean, insect-free soybean raw material, soak it in 35℃ water for 11 hours, after soaking, take out the soybean and put it into a grinder to grind repeatedly to obtain soy milk, and then treat the soy milk with ultrasound to obtain soy slurry.

[0081] S2. Add 0.105g of papain to the soybean slurry obtained in S1, heat to 50℃, adjust the pH to 6.5, and keep warm for 4 hours to hydrolyze and obtain soybean protein hydrolysate.

[0082] S3. Add 0.035g of transglutaminase to the soybean protein hydrolysate obtained in step S2, heat to 55℃, adjust the pH to 6.0, incubate for 1.5h for enzymatic hydrolysis, place in a 90℃ water bath and incubate for 25min to inactivate the enzyme, and obtain soybean protein hydrolysate.

[0083] S4. Add 10.5g of β-cyclodextrin to the soybean protein hydrolysate obtained in step S3, stir and mix well, adjust the pH to 6.5, react at 70℃ for 2.5h, cool to room temperature, filter, separate the supernatant, concentrate under reduced pressure, freeze dry, and obtain modified composite soybean flour.

[0084] S5. Bifidobacterium animalis subsp. lactis and Lactobacillus rhamnosus were inoculated into Gao's medium for activation culture at 30℃ for 2.5 days to obtain activated probiotics.

[0085] S6. The modified composite soybean powder obtained in step S4 and the activated probiotics obtained in step S5 are thoroughly mixed and fermented at a temperature of 28°C for 3.5 days. The mixture is then dried at a low temperature of 25°C to obtain the composite fermented soybean powder.

[0086] S7. The compound fermented soybean powder obtained in step S6 is mixed with compound modified starch, sweet potato leaf extract, oat flour, almond flour, lemon juice powder, calcium carbonate, soybean lecithin, and steviol glycosides. 55°C warm water is added for hydration. The hydrated liquid is slurried in nitrogen to obtain a slurry. The slurry is homogenized at 60°C and 25MPa, sterilized by ultra-high pressure sterilization in water medium at 400MPa for 8 minutes, vacuum concentrated at 0.095MPa and 55°C, and spray-dried at an inlet air temperature of 175°C, an outlet air temperature of 90°C, and a flow rate of 18mL / min to obtain a high-nutrition, high-calcium multi-element soybean powder.

[0087] Example 3

[0088] A high-nutrition, high-calcium multi-element soybean flour, consisting of 80 parts modified compound fermented soybean flour, 40 parts compound modified starch, 10 parts sweet potato leaf extract, 5 parts oat flour, 20 parts cashew powder, 15 parts grape juice powder, 5 parts calcium carbonate, 2 parts soybean lecithin, and 3 parts white sugar.

[0089] The preparation method of composite modified starch specifically includes the following steps:

[0090] ① Mix 10g of corn starch and 30g of potato starch to obtain composite starch. Add 0.2g of β-amylase and disperse in 200mL of 1mol / L sodium phosphate buffer solution with pH 6.5. React at 60℃ for 18h. Add 0.2g of hexose oxidase, heat to 100℃ and react for 4h. Cool to room temperature, centrifuge and filter at 1000r / min for 15min. Wash the precipitate with deionized water and freeze-dry to obtain pretreated composite modified starch.

[0091] ② Add the pretreated composite modified starch obtained in step ① to 300 mL of deionized water, stir at 500 r / min, add 9 g of konjac glucomannan, heat to 65℃, and swell for 60 min to obtain the pretreated modified starch solution;

[0092] ③ Dissolve 3g of L-arginine in 50mL of deionized water to obtain an L-arginine solution;

[0093] ④ Mix the pretreated modified starch solution obtained in step ② and the L-arginine solution obtained in step ③, heat treat in a 90℃ water bath for 3 hours, cool to room temperature, centrifuge and filter at 500 r / min for 30 minutes, wash the precipitate with deionized water, freeze dry, and obtain the composite modified starch.

[0094] The preparation method of sweet potato leaf extract is the same as in Example 1.

[0095] This invention also provides a method for preparing a high-nutrient, high-calcium, multi-element soybean flour, which specifically includes the following steps:

[0096] S1. Select 80g of clean, insect-free soybean raw material, soak it in 40℃ water for 12 hours, after soaking, take out the soybean and put it into a grinder to grind repeatedly to obtain soy milk, and then treat the soy milk with ultrasound to obtain soy slurry.

[0097] S2. Add 0.16g of papain to the soybean slurry obtained in S1, heat to 55℃, adjust the pH to 7.0, and keep warm for 5 hours to hydrolyze and obtain soybean protein hydrolysate.

[0098] S3. Add 0.048g of transglutaminase to the soybean protein hydrolysate obtained in step S2, heat to 60℃, adjust the pH to 7.0, incubate for 2 hours for enzymatic hydrolysis, place in a 100℃ water bath and incubate for 30 minutes to inactivate the enzyme, and obtain soybean protein hydrolysate.

[0099] S4. Add 9.0g of β-cyclodextrin to the soybean protein hydrolysate obtained in step S3, stir and mix well, adjust the pH to 7.0, react at 80℃ for 3h, cool to room temperature, filter, separate the supernatant, concentrate under reduced pressure, freeze dry, and obtain modified composite soybean flour.

[0100] S5. Bifidobacterium animalis subsp. lactis and Lactobacillus rhamnosus were inoculated into Gao's medium for activation culture at 32℃ for 3 days to obtain activated probiotics.

[0101] S6. The modified composite soybean powder obtained in step S4 and the activated probiotics obtained in step S5 are thoroughly mixed and fermented at a temperature of 30°C for 4 days. The mixture is then dried at a low temperature of 30°C to obtain the composite fermented soybean powder.

[0102] S7. The compound fermented soybean powder obtained in step S6 is mixed with compound modified starch, sweet potato leaf extract, oat flour, cashew powder, grape juice powder, calcium carbonate, soybean lecithin, and white sugar. Hydration is carried out in 60°C warm water. The hydrated liquid is then slurried under nitrogen to obtain a slurry. The slurry is homogenized at 70°C and 30MPa, sterilized by ultra-high pressure sterilization in a water medium at 500MPa for 10 minutes, vacuum concentrated at 0.10MPa and 60°C, and spray-dried at an inlet air temperature of 200°C, an outlet air temperature of 100°C, and a flow rate of 20mL / min to obtain a high-nutrient, high-calcium, multi-element soybean powder.

[0103] Comparative Example 1

[0104] This comparative example provides a high-nutrition, high-calcium multi-element soybean powder and its preparation method. The only difference between this example and Example 1 is that the modified compound fermented soybean powder is not fermented, that is, the preparation method does not include steps S5 and S6. The remaining components, component contents, and preparation methods are the same as in Example 1.

[0105] Comparative Example 2

[0106] This comparative example provides a high-nutrition, high-calcium multi-element soybean powder and its preparation method. The only difference between this example and Example 1 is that the modified compound fermented soybean powder has not undergone hydrolysis, enzymatic hydrolysis, or glycosylation modification treatment. That is, the preparation method does not include steps S2, S3, and S4. The remaining components, component contents, and preparation methods are the same as in Example 1.

[0107] Comparative Example 3

[0108] This comparative example provides a high-nutrition, high-calcium multi-element soybean flour and its preparation method. The only difference between this example and Example 1 is that the composite starch is not modified, while the other components, component contents, and preparation methods are the same as in Example 1.

[0109] Comparative Example 4

[0110] This comparative example provides a high-nutrition, high-calcium multi-element soybean powder and its preparation method. The only difference between this example and Example 1 is that sweet potato leaf extract and oat flour are not added. The other components, component contents, and preparation methods are the same as in Example 1.

[0111] Experimental Example 1

[0112] This experimental example measures the ash and calcium content of the multi-component soybean flour prepared in Examples 1-3 and Comparative Examples 1-4 of this invention. The specific method is as follows:

[0113] (1) Determination of ash content:

[0114] The ash content in food was determined according to the method in GB5009.4 "Determination of Ash Content in Food". A suitable-sized porcelain crucible was placed in a high-temperature furnace and ignited at 550°C for 30 minutes. After cooling to approximately 200°C, it was removed and placed in a desiccator for 30 minutes. The crucible was accurately weighed, and the process was repeated until the difference between two consecutive weighings did not exceed 0.5 mg, at which point it was considered constant weight and marked as M1. 2.0 g (accurate to 0.01 g) of the multi-component soybean flour prepared in Examples 1-3 and Comparative Examples 1-4, and ordinary commercially available soybean flour were weighed and placed in constant-weight porcelain crucibles. These crucibles were ignited in a muffle furnace at 700°C for 1 hour, cooled to 200°C, and then placed in a desiccator to cool to room temperature and weighed. This process was repeated until constant weight was achieved. When the difference between two consecutive weighings did not exceed 0.5 mg, it was considered constant weight and marked as M2. The ash content in the multi-component soybean flour was calculated using the following formula:

[0115] ;

[0116] Where M is the mass of the sample (g); M1 is the mass of the empty porcelain crucible (g); M2 is the mass of the residual ash plus the mass of the empty porcelain crucible (g);

[0117] (2) Determination of calcium content:

[0118] The ash content was determined according to the method in GB5009.92-2016 "Determination of Calcium in Food". After the above ash content measurement was completed, the ashed sample in the porcelain crucible was removed, and then diluted to 50 mL with (1:4) hydrochloric acid. 10 mL of the sample solution was transferred to a 50 mL centrifuge tube, and then 1 drop of methyl red indicator, 4 mL of 5% ammonium oxalate solution, and 1 mL of 1:4 acetic acid solution were added and mixed thoroughly. The solution was then diluted with 1:4 ammonia water and further diluted with acetic acid solution until a slightly red color was achieved. After standing for one hour until the precipitate was completely formed, the sample was centrifuged for 15 minutes at 500 rpm. Centrifuge at 0 r / min, then aspirate the supernatant, blot the water from the precipitate in the test tube with filter paper, add a small amount of 3% ammonium hydroxide to the centrifuge tube, then shake the centrifuge tube to loosen the precipitate, add another 10 mL of 3% ammonium hydroxide, centrifuge for another 15 minutes, collect the supernatant, add 4 mL of 2 mol / L sulfuric acid to the precipitate, shake well, and heat in a 70℃ water bath until the precipitate is completely dissolved. Titrate with 0.0067 mol / L potassium permanganate standard solution until a faint red color persists for 30 seconds, and record the volume of the potassium permanganate standard solution. Calculate the calcium content in the multi-element soybean flour according to the following formula:

[0119] ;

[0120] Where C is the concentration of potassium permanganate solution (mol / L); V0 is the volume of potassium permanganate solution consumed (mL); V1 is the total volume of sample solution after dilution (mL); V2 is the volume of sample solution used for measurement (mL); and m is the sample weight (g).

[0121] Figure 1 The figures show the ash content results of the multi-component soybean flour prepared in Examples 1-3 and Comparative Examples 1-4 of this invention. As shown in the figures, the ash content of the soybean flour prepared in Examples 1-3 is significantly lower than that of commercially available soybean flour. The ash content of the soybean flour prepared in Comparative Examples 1-4 is significantly lower than that of commercially available soybean flour. The ash content of the soybean flour prepared in Examples 1-3 is also significantly lower than that of commercially available soybean flour. Compared with commercially available soybean flour, the ash content of the soybean flour prepared in Examples 1-3 of this invention decreased by an average of 10.82%.

[0122] Figure 2The figure shows the calcium content results of the multi-element soybean flour prepared in Examples 1-3 and Comparative Examples 1-4 of the present invention. As shown in the figure, the calcium content of the soybean flour prepared in Examples 1-3 and Comparative Example 3 is significantly higher than that of commercially available soybean flour. Compared with commercially available soybean flour, the calcium content of the soybean flour prepared in Examples 1-3 increased by an average of 16.91%, and the calcium content of the soybean flour prepared in Comparative Example 3 increased by an average of 13.20%. The calcium content of the soybean flour prepared in Comparative Examples 1, 2, and 4 is significantly higher than that of commercially available soybean flour. Among them, there is a significant difference between Comparative Example 1 and Examples 1-3, while there is no significant difference between Comparative Examples 2 and 4 and Examples 1-3.

[0123] This invention describes a multi-element soybean flour with low ash content and high calcium content obtained by modifying and fermenting compound soybean flour, compounding modified starch, and adding auxiliary nutrients. This is because the soybeans are soaked in warm water, ground, and ultrasonically treated to obtain soy milk, which improves the dispersibility of the soybean flour. The soy milk is then hydrolyzed with papain and transglutaminase, making the protein easier for the human body to absorb and utilize, thus improving the bioavailability of the protein. The addition of β-cyclodextrin, which has a unique hydrophilic exterior and hydrophobic interior structure, allows the hydroxyl portion of the sugar molecule to undergo a glycosylation reaction with the carbonyl portion of the amino acid under enzymatic catalysis, resulting in modified compound soybean flour with better solubility, stability, and functionality, thereby improving the nutritional value of the soybean flour.

[0124] Example 2

[0125] This experimental example tests the solubility of the multi-component soybean powder prepared in Examples 1-3 and Comparative Examples 1-4 of this invention. The specific method is as follows: Following the method in GB5413.29-2016, 5.0 g (accurate to 0.01 g) of the multi-component soybean powder prepared in Examples 1-3 and Comparative Examples 1-4 were weighed into 50 mL centrifuge tubes. 40 mL of distilled water at 30°C was added, and the mixture was magnetically stirred at 30°C for 15 min to ensure complete dissolution. The mixture was then centrifuged at 4000 rpm for 10 min. The supernatant was discarded, the tube walls were wiped clean, and another 40 mL of distilled water at 30°C was added. After mixing, the mixture was centrifuged at 4000 rpm for 10 min. The supernatant was discarded, the tube walls were wiped clean, and the precipitate was transferred to a weighing dish with a small amount of distilled water. The water was evaporated in a boiling water bath and then dried at 105°C until equilibrium was reached. The solubility of the multi-component soybean powder was calculated using the following formula:

[0126] ;

[0127] Where X is the solubility (g / 100g); m is the sample mass (g); m0 is the mass of the weighing dish (g); m1 is the mass of the weighing dish and precipitate after drying (g); and B is the sample moisture content (g / 100g).

[0128] Figure 3The figures show the solubility results of the multi-component soybean flour prepared in Examples 1-3 and Comparative Examples 1-4 of this invention. As shown, the solubility of the soybean flour prepared in Examples 1-3 reached 96.8-97.2 (g / 100g), the solubility of the soybean flour prepared in Comparative Example 1 was 86.3 (g / 100g), the solubility of the soybean flour prepared in Comparative Example 2 was 83.6 (g / 100g), and the solubility of the soybean flour prepared in Comparative Examples 3 and 4 were 90.2 (g / 100g) and 93.5 (g / 100g), respectively. In Comparative Example 1, the modified compound fermented soybean flour was not fermented, resulting in a significant decrease in solubility. This indicates that the modified compound soybean flour, fermented with *Bifidobacterium animalis* subsp. *lactotrichum* and *Lactobacillus rhamnosus*, allows the enzymes in the fermenting cells to help break down the indigestible components in the soybean raw material, thus improving solubility. Nutrients are more easily absorbed by the human body, which helps improve the solubility of soybean flour. In Comparative Example 2, the modified compound fermented soybean flour was not hydrolyzed, enzymatically hydrolyzed, or glycosylated, which prevented the breakdown of large protein molecules into smaller peptides and amino acids, making the proteins easier for the human body to absorb and utilize, thus reducing the solubility of soybean flour. This indicates that adding β-cyclodextrin after hydrolyzing and enzymatically hydrolyzing soybean milk allows the hydroxyl groups of sugar molecules to undergo glycosylation with the carbonyl groups of amino acids under enzymatic catalysis, resulting in better solubility of soybean flour. In Comparative Example 3, the modified starch in the soybean flour was not hydrolyzed by β-amylase or oxidized by hexose oxidase, and no konjac glucomannan or L-arginine was added. In Comparative Example 4, the soybean flour did not contain sweet potato leaf extract, reducing the synergistic effect between the components and lowering the solubility of soybean flour.

[0129] Experimental Example 3

[0130] This experiment tested the dispersibility of the multi-component soybean powder prepared in Examples 1-3 and Comparative Examples 1-4 of this invention. The specific method was as follows: 5.0 g (accurate to 0.01 g) of the multi-component soybean powder prepared in Examples 1-3 and Comparative Examples 1-4 were weighed into 100 mL beakers and magnetically stirred at a constant temperature of 25°C. The time (s) from the start of stirring until the soybean powder was completely dispersed and dissolved was recorded. The dispersibility of the multi-component soybean powder was evaluated using the dispersion time as an indicator. The results are recorded in Table 1.

[0131] Table 1. Dispersion time of soybean flour

[0132]

[0133] As can be seen from the table above, the soybean flour prepared in Examples 1-3 of this invention has a short dissolution and dispersion time in water, high solubility, good edibility, and a significant market advantage.

[0134] Experiment Example 4

[0135] This experiment tested the swelling power of the multi-component soybean flour prepared in Examples 1-3 and Comparative Examples 1-4 of this invention. The specific method was as follows: 2.5 g (accurate to 0.01 g) of the multi-component soybean flour prepared in Examples 1-3 and Comparative Examples 1-4 were weighed and dissolved in 30 mL of distilled water. The mixture was heated in a 70°C water bath for 30 min. The heated paste was cooled to room temperature and placed in a pre-weighed centrifuge tube. The mixture was centrifuged at 3000 rpm for 20 min. The supernatant was poured into a pre-weighed evaporating dish and dried in a 105°C oven. The solid content was measured, and the sediment was weighed. Each experiment was repeated three times. The swelling power of the multi-component soybean flour was calculated using the following formula, and the results are recorded in Table 2.

[0136] ;

[0137] Table 2. Soy flour swelling power

[0138]

[0139] As can be seen from the table above, the soybean flour prepared in Examples 1-3 of this invention has a large swelling power, indicating that the soybean flour has a large water absorption and swelling capacity, which helps with digestion and absorption.

[0140] Experimental Example 5

[0141] This experiment tested the absorption performance of the multi-element soybean powder prepared in Examples 1-3 and Comparative Examples 1-4 of this invention. The multi-element soybean powder prepared in Examples 1-3 and Comparative Examples 1-4 was packaged into 20g / bags. For consumption, it was prepared by mixing with hot water at a ratio of 1:5. Test conditions: Twenty people from a community were selected, 10 men and 10 women, divided into two groups with an equal number of men and women in each group. The average age was 53.60 ± 0.5 years. Test method: The participants in both groups consumed the multi-element soybean powder prepared in this invention, once in the morning and once in the evening, one bag each time. Bone mineral density (BMD) values ​​were measured using a bone mineral density analyzer (OSTEOPRO, Korea) after 15 and 30 days. The test data were statistically analyzed. The BMD value before consumption was -2.45 ± 0.34. A normal BMD value greater than -1.00 is considered normal; a normal BMD value between -1.00 and -2.50 indicates bone loss; and a normal BMD value less than -2.50 indicates osteoporosis.

[0142] Figure 4The figure shows the absorption effect of the multi-element soybean powder prepared in Examples 1-3 and Comparative Examples 1-4 of this invention. As shown, after 15 days of consumption, the bone mineral density (BMD) of the Example 1-3 group increased to -1.56 to -1.53; after 30 days of consumption, the BMD of the Example 1-3 group increased to -0.92 to -0.91, greater than -1.0, and the BMD was within the normal range. After 30 days of consumption, the BMD of the Comparative Examples 1-4 group was -1.21 to -1.02, close to the normal range. The soybean powder prepared in Examples 1-3... The main raw material, soybeans, is soaked in warm water, ground, and ultrasonically treated to improve the dispersibility of the soybean flour. It then undergoes papain hydrolysis, transglutaminase hydrolysis, and β-cyclodextrin glycosylation modification. This process not only breaks down large protein molecules into smaller peptides and amino acids, making them easier for the body to absorb and utilize, but also provides the small peptides and amino acids with specific functions such as antioxidation, antibacterial, and anti-inflammatory properties, contributing to health and nutrition. Furthermore, these small peptides and amino acids undergo glycosylation under enzymatic catalysis, resulting in improved solubility, stability, and functionality. The modified compound soybean powder is fermented with activated probiotics to regulate the balance of intestinal flora, inhibit the growth of harmful bacteria, help reduce intestinal inflammation, and maintain intestinal health. During fermentation, vitamins, amino acids, and other nutrients are produced, thereby increasing the nutritional value of the multi-element soybean powder and helping to enhance the body's immunity. The corn starch and potato starch complex is modified by using β-amylase and hexose oxidase in combination to oxidize the starch chain, changing the chemical structure of the starch to give it higher viscosity, stronger acid resistance, and heat resistance. Adding konjac glucomannan to the starch can improve the stability of the soybean powder during freezing, thawing, and heating, preventing damage to the soybean powder structure and thus maintaining high biological activity and nutritional components. This indicates that the soybean powder prepared in Examples 1-3 of this invention has high stability and biological activity, and high nutritional value. Experimental data shows that the bone density of people consuming the soybean powder prepared in Examples 1-3 of this invention is significantly improved, indicating that the multi-element soybean powder prepared in this invention can significantly improve osteoporosis.

[0143] Experimental Example 6

[0144] This experiment tested the hypoglycemic properties of the multi-component soybean powder prepared in Examples 1-3 and Comparative Examples 1-4 of this invention. A 1 wt% solution of the soybean powder prepared in Examples 1-3 and Comparative Examples 1-4 was prepared, placed at 37°C for 30 min, centrifuged, and the supernatant was mixed with buffer to prepare a 5% (v / v) test sample. The inhibition rate of the test sample prepared in Examples 1-3 and Comparative Examples 1-4 against α-glucosidase (0.2 U) was detected. The test method was as follows: 100 μL of the 5% test sample solution was taken, and 500 μL of α-glucosidase was added. Glucosidase solution (0.2 U / mL, prepared with 0.05 mol / L phosphate buffer, pH 6.8) was reacted in a 37°C water bath for 15 min; p-nitro-D-glucopyranoside substrate solution (3 mmol / L) was added, and the mixture was shaken well and reacted in a 37°C water bath for 30 min; the reaction was terminated by adding Na2CO3 stop solution (0.3 mol / L); the absorbance of the solution was measured using a 405 nm double-beam UV-Vis spectrophotometer, and the inhibition rate was calculated according to the following formula:

[0145] α-glucosidase inhibition rate (%) = [1 - (cd) ÷ (ab)] × 100%;

[0146] Where a is the absorbance of the control group (buffer solution + enzyme solution + substrate); b is the absorbance of the blank control group (buffer solution); c is the absorbance of the sample assay group (sample + enzyme solution + substrate); and d is the absorbance of the sample control group (sample).

[0147] Figure 5 The graph shows the hypoglycemic performance of the multi-component soybean flour prepared in Examples 1-3 and Comparative Examples 1-4 of this invention. As shown in the figure, the soybean flour prepared in Examples 1-3 showed an inhibition rate of 62.3-62.8% against α-glucosidase, while the soybean flour prepared in Comparative Examples 1 and 2 showed inhibition rates of 53.2% and 55.7% against α-glucosidase, respectively. The soybean flour prepared in Comparative Examples 3 and 4 showed inhibition rates of 48.6% and 42.1% against α-glucosidase, respectively. The high inhibition rate of α-glucosidase in the soybean flour prepared in the examples of this invention indicates that the modified compound fermented soybean flour combined with modified compound starch, sweet potato leaf extract, and oat flour, with the synergistic effect among the components, helps to scavenge free radicals in the body, reduce the damage of oxidative stress to the body, and achieve a strong hypoglycemic effect.

[0148] In summary, the multi-element soybean flour prepared in this embodiment of the invention uses modified compound fermented soybean flour as the main raw material, making the nutrients in soybean flour easier for the human body to absorb and utilize. It also produces various nutrients such as vitamins and amino acids, improving its nutritional value and bioavailability, thereby enhancing immune function. The compound modified starch, through safe and green enzymatic modification, alters the chemical structure of the starch, giving it stronger acid and heat resistance. The addition of konjac glucomannan reduces the dryness of the soybean flour, extends its shelf life, and improves its stability during freezing, thawing, and heating. Furthermore, the addition of nut powder, calcium carbonate, and soybean lecithin further increases the calcium content of the soybean flour. Sweet potato leaf extract and konjac glucomannan have immune-boosting, antioxidant, anti-inflammatory, anti-cancer, and blood sugar-lowering functions; their addition to the soybean flour enhances its benefits to the human body.

[0149] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

[0150] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention. The actual application is not limited to this. In conclusion, if those skilled in the art are inspired by this description and design similar methods and embodiments without departing from the spirit of the present invention, they should all fall within the protection scope of the present invention.

Claims

1. A high-nutrient, high-calcium, multi-element soybean powder, characterized in that: The multi-component soybean flour consists of the following components in parts by weight: 60-80 parts modified compound fermented soybean flour, 20-40 parts compound modified starch, 5-10 parts sweet potato leaf extract, 3-5 parts oat flour, 15-20 parts nut flour, 10-15 parts fruit juice powder, 3-5 parts calcium carbonate, 1-2 parts soybean lecithin, and 2-3 parts seasoning. The modified compound fermented soybean powder is obtained by inoculating compound probiotics into soybean slurry after hydrolysis by papain, enzymatic hydrolysis by transglutaminase, β-cyclodextrin saccharification modification. The composite modified starch is obtained by combining corn starch and potato starch in a mass ratio of 1:1-3, followed by hydrolysis with β-amylase, oxidation with hexose oxidase, and the addition of konjac glucomannan and L-arginine.

2. The high-nutrition, high-calcium multi-element soy flour according to claim 1, characterized in that: The nut powder includes at least one of white sesame powder, black sesame powder, almond powder, walnut powder, cashew powder, peanut powder, and pine nut powder; the fruit juice powder includes at least one of strawberry juice powder, lemon juice powder, blueberry juice powder, blackcurrant juice powder, grape juice powder, and orange juice powder; the seasoning includes at least one of erythritol, steviol glycosides, white sugar, and salt.

3. The high-nutrition, high-calcium multi-element soy flour according to claim 2, characterized in that: The preparation method of the composite modified starch specifically includes the following steps: ① Mix corn starch and potato starch to obtain composite starch, add β-amylase, disperse in 200 mL of 1 mol / L sodium phosphate buffer solution with pH 6.5, react at 50-60℃ for 12-18 h, add hexose oxidase, heat to 100℃, react for 2-4 h, cool to room temperature, centrifuge and filter at 1000 r / min for 10-15 min, wash the precipitate with deionized water, freeze dry to obtain pretreated composite modified starch; ② Add the pretreated composite modified starch obtained in step ① to 300 mL of deionized water, stir at 300-500 r / min, add konjac glucomannan, heat to 60-65℃, and swell for 30-60 min to obtain the pretreated modified starch solution. ③ Dissolve L-arginine in 50 mL of deionized water to obtain an L-arginine solution; ④ Mix the pretreated modified starch solution obtained in step ② and the L-arginine solution obtained in step ③, heat treat in a water bath at 80-90℃ for 2-3 hours, cool to room temperature, centrifuge and filter at 500r / min for 20-30 minutes, wash the precipitate with deionized water, freeze dry to obtain composite modified starch.

4. The high-nutrition, high-calcium multi-element soy flour according to claim 3, characterized in that: In step ①, based on the total starch content in the compound starch, the amount of β-amylase added is 0.1-0.5%, and the amount of hexose oxidase added is 0.3-0.5%. The mass ratio of the composite starch, konjac glucomannan, and L-arginine is 20-40:3-9:2-3.

5. The high-nutrition, high-calcium multi-element soy flour according to claim 4, characterized in that: The preparation method of the sweet potato leaf extract specifically includes the following steps: Sweet potato leaves were washed, dried, and pulverized. They were then extracted 2-3 times with a 50-70% (v / v) ethanol aqueous solution under a nitrogen atmosphere at 70-80℃ for 2-3 hours each time. After cooling to room temperature, the extract was filtered, concentrated under reduced pressure, and allowed to stand for flocculation. The extract was further purified by adsorption using a D101 macroporous adsorption resin column and a polyamide resin column, with a column diameter-to-height ratio of 1:(7-8). The resin column was washed with water until no sugar color was observed. The extract was then eluted with an 85% (v / v) ethanol aqueous solution at a flow rate of 3-5 mL / min. The eluent was concentrated under reduced pressure and spray-dried at an inlet air temperature of 160-180℃, an outlet air temperature of 80-90℃, and a flow rate of 15-20 mL / min to obtain the sweet potato leaf extract.

6. A method for preparing a high-nutrient, high-calcium, multi-element soybean flour according to any one of claims 1-5, characterized in that: Specifically, the following steps are included: S1. Select clean, insect-free soybean raw materials, soak them in water at 30-40℃ for 10-12 hours, after soaking, take out the soybeans and put them into a grinder to grind them repeatedly to obtain soy milk, and then treat the soy milk with ultrasound to obtain soy slurry. S2. Add papain to the soybean slurry obtained in S1, heat to 45-55℃, adjust the pH to 6.0-7.0, and keep warm for 3-5 hours to hydrolyze and obtain soybean protein hydrolysate. S3. Add transglutaminase to the soybean protein hydrolysate obtained in step S2, heat to 50-60℃, adjust the pH to 5.0-7.0, incubate for 1-2 hours, place in a water bath at 80-100℃ and incubate for 20-30 minutes to inactivate the enzyme, and obtain soybean protein hydrolysate. S4. Add β-cyclodextrin to the soybean protein hydrolysate obtained in step S3, stir and mix well, adjust the pH to 6.0-7.0, react at 60-80℃ for 2-3 hours, cool to room temperature, filter, separate the supernatant, concentrate under reduced pressure, and freeze dry to obtain modified composite soybean flour. S5. Inoculate Bifidobacterium animalis subsp. lactis and Lactobacillus rhamnosus into Gao's medium for activation culture at 28-32℃ for 2-3 days to obtain activated probiotics. S6. Thoroughly mix the modified compound soybean powder obtained in step S4 and the activated probiotics obtained in S5, and ferment them at a temperature of 25-30℃ for 3-4 days. Dry them at a low temperature of 20-30℃ to obtain the compound fermented soybean powder. S7. Mix the compound fermented soybean powder obtained in step S6 with compound modified starch, sweet potato leaf extract, nut powder, fruit juice powder, calcium carbonate, soybean lecithin, seasoning, and oat flour. Add warm water at 50-60℃ for hydration. The hydrated liquid is then slurried in nitrogen to obtain a slurry. The slurry is homogenized, sterilized, vacuum concentrated, and spray-dried to obtain a high-nutrition, high-calcium multi-element soybean powder.

7. The method for preparing a high-nutrition, high-calcium, multi-element soybean flour according to claim 6, characterized in that: In step S2, the amount of papain added is 0.1-0.2% of the mass of the soybean raw material; In step S3, the amount of transglutaminase added is 0.04-0.06% of the mass of the soybean raw material; In step S4, the mass ratio of the soybean raw material to β-cyclodextrin is 1:0.1-0.

2.

8. The method for preparing a high-nutrition, high-calcium, multi-element soybean flour according to claim 7, characterized in that: In step S7, the homogenization conditions are: temperature 50-70℃, pressure 20-30MPa; the sterilization conditions are: water medium ultra-high pressure sterilization at room temperature and pressure 300-500MPa for 5-10 minutes; the vacuum concentration conditions are: vacuum degree 0.09-0.10MPa, temperature 50-60℃; and the spray drying conditions are: inlet air temperature 150-200℃, outlet air temperature 80-100℃, and flow rate 15-20mL / min.

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