A high selenium content nutritional powder and a method for its production

Abstract

This invention discloses a high-selenium nutrient powder and its production method. The seedling raising process involves spreading wheat seeds in a single layer evenly on seedling paper, covering it with seedling cloth, and then performing initial, secondary, and tertiary raising stages to obtain organic selenium-enriched malt. The seedling paper is moistened with selenium-enriched culture solution and replaced every 20-24 hours. The initial raising temperature is 5-10℃, and a selenite solution is sprayed onto the seedling cloth every 4-6 hours, for a total of 3-4 sprays. The secondary raising temperature is 18-20℃, and while spraying the selenite solution at 4-6 hour intervals, an 8-15% aqueous solution of Bacillus cereus is also sprayed. The tertiary raising stage involves alternating temperatures between the initial and secondary raising chambers 2-3 times, maintaining each temperature change for 8-12 hours. A potassium dihydrogen phosphate solution is sprayed onto the seedling cloth; this solution is prepared by adding 2-4 g of potassium dihydrogen phosphate to each liter of Bacillus cereus aqueous solution. The drying hot air temperature of the malt is ≤60℃; the grinding temperature is ≤40℃. The produced nutritional powder contains no less than 190 mg / kg of selenium, and the processing time is more suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention applies to the field of nutritional foods, specifically to selenium-enriched health supplements, and more specifically to a nutritional powder with high organic selenium content and its production method. Background Technology

[0002] Selenium is a trace element in living organisms, but it plays a vital role in various physiological metabolic processes. It not only possesses strong antioxidant capabilities and protects cell membrane structure, but also functions as an anticancer and anti-aging agent, inhibiting cell carcinogenesis, antagonizing the toxicity of heavy metals in the body, and extending lifespan. It plays an important role in enhancing human immunity, cardiovascular disease, and cancer prevention, which is the main reason for the current popularity of selenium-containing nutritional foods. However, only organic selenium (selenopeptides) can be absorbed and utilized by the human body.

[0003] The inventor's previous research, CN202411227068.3, describes a nutrient powder with high activity of selenium peptides and its preparation method. This method utilizes soilless cultivation and seedling raising technology, soaking seeds in pure selenium culture solution and raising seedlings in selenium-enriched culture solution. The nutrient powder contains 110-150 mg / kg of selenium. To maintain the activity of the selenium peptides, the temperature is kept below 60°C. The production method includes: 1) black wheat seed selection; 2) sterilization pretreatment; 3) soaking seeds in sodium selenite pure selenium culture solution; 4) germination in water at 60-65°C; 5) re-soaking in selenium-enriched culture solution; 6) spreading wheat seeds on seedling paper soaked in selenium-enriched culture solution, covering with seedling cloth, and after initial, secondary, and tertiary germination, the black wheat germ grows to 30-40 mm, yielding black wheat germ rich in organic selenium peptides; 7) washing and drying with hot air at 50°C; and 8) grinding at a temperature not exceeding 40°C. This application focuses on process improvements for the industrialization stage of this product. The improvements include: firstly, further increasing the organic selenium content; and secondly, shortening the process time, improving production efficiency, and reducing production costs. Summary of the Invention

[0004] The technical problem solved by this invention is: This invention provides a high-selenium content nutritional powder and its production method, which uses beneficial bacteria to promote the absorption of selenium by malt, and the organic selenium content reaches more than 190mg / kg. The process is improved to shorten the process time or facilitate production arrangement.

[0005] The technical solution adopted in this invention is as follows: The production method of the high-selenium content nutrient powder of this invention includes seed selection, sterilization pretreatment, seed soaking, re-soaking, germination, seedling cultivation, drying, and grinding according to the production process. Seedling cultivation involves spreading germinated wheat seeds in a single layer evenly on seedling paper in a seedling tray, covering it with seedling cloth, and after initial cultivation, secondary cultivation, and tertiary cultivation, organic selenium-enriched wheat germ is obtained. The seedling paper is moistened with selenium-enriched culture solution and replaced regularly every 20-24 hours. The initial incubation room is at a temperature of 5-10℃. A selenite solution is sprayed evenly onto the seedling cloth every 4-6 hours, for a total of 3-4 sprays. The secondary incubation room is at a temperature of 18-20℃. The selenite solution is sprayed onto the seedling cloth every 4-6 hours, along with an aqueous solution of *Bacillus lentigines*, for a total of 3-4 sprays. The weight ratio of *Bacillus lentigines* to water in the aqueous solution is 8-15%. The tertiary incubation involves alternating temperature changes 2-3 times between the initial and secondary incubation rooms, each temperature change lasting 8-12 hours. A potassium dihydrogen phosphate solution is sprayed onto the seedling cloth every 4-6 hours. The potassium dihydrogen phosphate solution is prepared by adding 2-4 g of potassium dihydrogen phosphate (KH2PO4) to each liter of the *Bacillus lentigines* aqueous solution.

[0006] Furthermore, the above-mentioned varieties should preferably be Jizi Black Wheat No. 1, or Jimai U80, or Jimai U87.

[0007] Furthermore, the sterilization pretreatment steps include cleaning and disinfection, re-washing and spin-drying, air-drying and re-selection, etc. Disinfection involves soaking and stirring in a 0.1%–0.2% sodium hypochlorite disinfectant solution for 15–20 minutes.

[0008] Furthermore, the soaking process involves mixing wheat seeds with pure selenium culture medium at a ratio of 1 kg: 6 L and soaking for 8–12 hours at a temperature of 5℃ ± 1℃. The pure selenium culture medium is prepared by mixing sodium selenite and distilled water at a ratio of 61–80 mg / L.

[0009] Furthermore, the re-soaking involves soaking wheat seeds and selenium-enriched culture solution at a ratio of 1 kg: 5 L for 6–10 hours at a temperature of 18°C–20°C. The selenium-enriched culture solution is prepared by adding 31–50 mg of selenate, 80–100 mg of sodium sulfate, 160–200 mg of potassium nitrate, 210–250 mg of potassium dihydrogen phosphate, and 300–400 mg of magnesium sulfate per liter of distilled water, and stirring until homogeneous.

[0010] Furthermore, the germination process involves spreading the soaked wheat seeds in a container lined with damp gauze or burlap sacks to a thickness of 5–15 cm, maintaining an ambient temperature of 24–28°C, covering them with a damp cloth and spraying them with water or a selenium-enriched culture solution to keep them moist, and turning them over every 2–4 hours until 70%–80% of the wheat seeds show signs of sprouting.

[0011] Furthermore, the selenite solution is prepared as follows: 20-60 mg sodium selenite, 3-5 mg boric acid, 2-3 mg manganese sulfate, 5-8 mg zinc sulfate, and 4-5 mg copper sulfate per liter of distilled water.

[0012] Furthermore, the hot air temperature for drying is ≤60℃; the grinding temperature is ≤40℃.

[0013] Another seedling cultivation scheme uses Bacillus subtilis instead of Bacillus mucilaginosus, with the same usage method and ratio as above.

[0014] The organic selenium content in the high-selenium nutritional powder prepared by the above steps is not less than 190 mg / kg.

[0015] The beneficial effects of this invention are: the organic selenium content in the nutrient powder is not less than 190 mg / kg, which is nearly 100% higher than the previous process. This invention increases the selenium content in the culture solution by appropriately increasing the soaking and re-soaking temperatures, thereby shortening the process time and improving efficiency. By lowering the germination temperature and extending the process time, the germination time is matched with the time of the preceding and following processes, facilitating the organization of malt production. In the seedling stage, the use of beneficial bacteria is added, increasing the organic selenium content without shortening the process time. Attached Figure Description

[0016] Figure 1 This is one of the test reports on the selenium content of high-selenium nutritional powder; Figure 2 This is the second test report on the selenium content of high-selenium nutritional powder. Detailed Implementation

[0017] The term "high selenium content" refers to a nutritional product containing no less than 190 mg / kg of organic selenium. The term "preliminary process scheme" refers to the preparation process described in CN202411227068.3, "A nutritional powder with high activity of selenium peptides and its preparation method." The terms "initial incubation room" and "re-incubation room" can refer to either a room or a container.

[0018] The preparation steps of the selenium-enriched peptide nutritional powder of the present invention are as follows: 1. Seed Selection: High-protein Jihei Wheat No. 1, Jimai U80, or Jimai U87 yellow wheat varieties are used. These wheat varieties contain high levels of protease, amylase, and various minerals. The polyphenols in wheat have high antioxidant activity and are non-toxic, making them suitable as natural antioxidants added to nutritional supplements. This invention selects wheat seeds grown in local selenium-rich soil, prioritizing seeds with plump grains, no mechanical damage, and free from pests and diseases. These seeds have high germination rates and vigor, which are beneficial for cultivation.

[0019] 2. Sterilization pretreatment: Sterilization pretreatment is to provide clean, sterile wheat seeds for malting. The treatment steps include washing and disinfecting, washing and drying again, and air drying before selection.

[0020] Cleaning and disinfection: Wash the wheat seeds 2-3 times with purified or sterile water to remove impurities or attachments from the surface, which is also the initial selection of wheat seeds. Soak and stir in a 0.1%-0.2% sodium hypochlorite disinfectant solution for 15-20 minutes, stirring continuously or intermittently to ensure full contact and guarantee the disinfection effect.

[0021] Wash and spin dry again: After disinfection, wash repeatedly with purified or sterile water 2 to 4 times to remove the disinfectant from the surface of the wheat seeds, and spin dry with a centrifugal dryer to remove the sterile water from the surface of the wheat seeds.

[0022] Disinfection and re-selection: After drying the wheat seeds with a low-temperature air dryer, microwave disinfection solution is used in conjunction with a color sorter to remove spoiled and unsightly wheat seeds.

[0023] 3. Soaking seeds: Soaking seeds in pure selenium culture solution is intended to allow the wheat seeds to absorb selenium and undergo osmotic regulation, which is beneficial to improving the vitality of the wheat seeds.

[0024] Soaking the seeds uses a pure selenium culture solution, which is a 50mg / L~80mg / L sodium selenite aqueous solution, i.e., 50-80mg of sodium selenite (Na2SeO3) is added to each liter of distilled water and stirred thoroughly. During soaking, the seeds are immersed in a 1kg wheat seed:6L pure selenium culture solution for 8-12 hours, with the temperature of the pure selenium culture solution maintained at 5℃±1℃. The previous process involved soaking the seeds in a 30-60mg / L sodium selenite culture solution at 0℃±1℃ for 15-24 hours. At 0℃, the water nearly solidifies, limiting the diffusion ability of sodium selenite, resulting in a longer processing time. This new process appropriately increases the concentration of the pure selenium culture solution and the soaking temperature, and promotes contact between the wheat seeds and sodium selenite through agitation. This increases the selenium content absorbed into the seeds while shortening the processing time and increasing production efficiency. Low-temperature soaking ensures that the wheat seeds do not germinate and fully absorb selenium.

[0025] 4. Re-soaking: Soak the wheat seeds again in the selenium-enriched culture solution. The purpose is to absorb nutrients and continue to increase the permeation of selenium, thereby increasing the selenium content in the wheat seeds.

[0026] After soaking and drying, the wheat seeds are soaked again in a selenium-enriched culture solution. The solution is prepared as follows: 30-50 mg selenate, 80-100 mg sodium sulfate, 160-200 mg potassium nitrate, 210-250 mg potassium dihydrogen phosphate, and 300-400 mg magnesium sulfate per liter of distilled water. The pH of the selenium-enriched culture solution is neutral, 6.9-7.1. During the second soaking, the solution is prepared at a ratio of 1 kg wheat seeds to 5 L of selenium-enriched culture solution, with slow stirring for 8-12 hours at a temperature of 18℃-20℃. The selenate continues to provide selenium to the wheat seeds, while sodium sulfate, potassium nitrate, potassium dihydrogen phosphate, and magnesium sulfate ions permeate the seeds, providing essential nutrients such as S, N, P, K, Ma, and Mg, thus storing nutrients for the growth of the malt.

[0027] Compared to the previous process, the nutrient content in the selenium-enriched culture medium remains unchanged, only the selenate content increases from 20–30 mg / L to 30–50 mg / L, and the temperature is adjusted from 15℃±1℃ to 18℃–20℃. The process time is shortened from 12–20 hours to 8–12 hours, significantly improving efficiency. This process time is consistent with the seed soaking process, facilitating production planning and organization. Furthermore, the process temperature is the same as the re-incubation temperature, allowing it to be carried out in a seedling nursery.

[0028] This invention emphasizes the importance of ensuring a balanced intake of nutrients while wheat seeds absorb selenium. The selenium-enriched culture solution provides a large number of essential elements for wheat seed growth, laying the material foundation for malt growth, stable selenium accumulation, and the conversion into organic selenium. In summary, soaking and re-soaking are key steps in achieving soilless cultivation and are also core steps in achieving high selenium content.

[0029] 5. Germination: Germinate in an environment with a temperature of 24℃~28℃ and a humidity of not less than 95%.

[0030] After soaking, drain the wheat seeds and spread them out in a container lined with damp gauze or burlap sacks, 5-15 cm thick. Place them in a warm environment (such as a greenhouse or hothouse) at 24-28℃, covered with a damp cloth. Spray water or selenium-enriched culture solution onto the cloth periodically to maintain humidity at no less than 95%. Turn the seeds every 2-4 hours to ensure even heat dissipation and prevent overheating and "scalding" of the sprouts. The sign of successful germination is "white sprouting," meaning the radicle has just broken through the seed coat. Ideally, the sprout should be no more than half the length of the seed, and about 70-80% of the seed should be white sprouting, which usually takes 48-72 hours.

[0031] The previous process involved germinating the seeds in water at 60-65℃ for 2-5 minutes after soaking. This application changes the germination temperature to 24-28℃ and extends the germination time to 48-72 hours. The advantages are: 1) This temperature environment provides a comfortable working environment; 2) Longer germination time helps ensure malt quality; 3) The extended germination time of 48-72 hours can be matched with the time of preceding and following processes, facilitating production organization; 4) It saves energy, eliminating the need to change the heated water for each germination cycle. This process uses semi-mechanical assisted turning, without increasing workload.

[0032] 6. Seedling raising: Spread the germinated wheat seeds evenly in a single layer on the seedling paper in the seedling tray, cover with seedling cloth, and after initial, secondary, and tertiary seedling raising, the wheat germ will grow to 30-40mm, yielding wheat germ rich in organic selenium peptides. Seedling raising is the process of converting the selenium element in the wheat seeds into organic selenium, which is the core step in cultivating high organic selenium content wheat germ.

[0033] The seedling paper is soaked in selenium-enriched culture solution and replaced regularly every 20-24 hours during the seedling stage. The purpose is to remove the metabolites produced during wheat growth in a timely manner. The selenate in the selenium-enriched culture solution that soaks the seedling paper continues to provide selenium, while other solutes provide the main nutrients.

[0034] During the initial cultivation, the seedling cloth is periodically sprayed with a selenite solution containing trace elements to keep it moist. The initial cultivation temperature is controlled at 5–10℃, and the relative humidity is above 95%. The selenite solution is sprayed evenly onto the seedling cloth every 4–6 hours, for a total of 3–4 times. Each time, the cloth is sprayed until it is moist but not dripping. The selenite solution is prepared as follows: per liter of distilled water, add 20–60 mg of sodium selenite, 3–5 mg of boric acid, 2–3 mg of manganese sulfate, 5–8 mg of zinc sulfate, and 4–5 mg of copper sulfate. Alternatively, 2 mg / L–3 mg / L of ammonium molybdate and 9%–12% (by weight) of plant protein can be added to the above selenite solution. The selenite solution preparation used in this application is the same as the previous process scheme.

[0035] After 12-24 hours of initial cultivation, spraying is stopped, and the malt is moved to a rearing room at a temperature of 18-20℃, consistent with the re-soaking temperature, facilitating temperature control during production. Re-soaking can also be carried out in the rearing room. Selenite solution is sprayed onto the seedling cloth every 4-6 hours, for a total of 3-4 times, keeping the upper layer of seedling cloth moist throughout the spraying process. The selenite solution in the seedling cloth also provides selenium, as well as trace elements such as boron, manganese, zinc, copper, and molybdenum. Under the influence of these nutrients and trace elements, soilless malt can accumulate more nutrients, resulting in malt with high selenium content. Simultaneously or shortly after spraying the selenite solution, an aqueous solution of Bacillus mucilaginosus is sprayed, with a weight ratio of Bacillus mucilaginosus to water of 8-15%.

[0036] Bacillus mucilaginosus has a smooth, moist surface and a gelatinous texture due to the secretion of large amounts of viscous substances. Its color is mostly milky white or pale yellow, and it forms a viscous bacterial solution in liquid culture media. It can form highly resistant spores and exhibits excellent tolerance to harsh environments such as high temperatures, dryness, and acidity / alkalinity, facilitating formulation preservation and transportation. The fermentation process is relatively simple, resulting in low production costs, making it suitable for large-scale industrial production. The formulation has a long shelf life, lasting for several months or even longer at room temperature, and is convenient to use. As an important microbial fertilizer strain, its use does not cause soil pollution or residues, aligning with the concepts of green agriculture and sustainable development. Bacillus mucilaginosus thrives at temperatures between 24 and 28°C and a pH range of 6.0 to 7.5. While an aerobic bacterium, it can also survive in micro-anaerobic environments. It has low nutritional requirements and can utilize various carbon and nitrogen sources for growth. It can secrete organic acids such as citric acid and oxalic acid, lowering the pH value of wheat roots and enhancing the solubility of insoluble metal salts. Simultaneously, it produces hormones such as gibberellin and indoleacetic acid, promoting root development and enhancing the absorption of selenium, nutrients, and trace elements, thus promoting malt growth and development. Intermittent spraying is to replenish the activity of beneficial bacteria to prevent their death. Furthermore, *Bacillus mucilaginosus* also enhances immunity, preventing malt diseases and ensuring successful malt growth. *Bacillus mucilaginosus* has excellent phosphorus and potassium solubilizing abilities, making it a typical phosphorus and potassium solubilizing bacterium. It can secrete organic acids and enzymes, enhancing the plant's absorption and utilization of phosphorus and potassium, which is a major reason for its use in malt cultivation.

[0037] After 12-24 hours of secondary incubation, the seedling trays are moved to the primary incubation room at 5-10℃. Spraying with selenite solution is stopped, and potassium dihydrogen phosphate solution is sprayed onto the seedling cloth every 4-6 hours. The potassium dihydrogen phosphate solution is prepared by adding 2-4g of potassium dihydrogen phosphate (KH2PO4) to each liter of the aforementioned 8-15% Bacillus lentigines aqueous solution. After 8-12 hours, the trays are moved back to the secondary incubation room at 18-20℃, and potassium dihydrogen phosphate solution is sprayed onto the seedling cloth every 4-6 hours. This alternation between the primary and secondary incubation rooms is repeated 2-3 times. The third incubation uses variable temperature treatment. At low temperatures, malt growth is slow, and Bacillus lentigines activity is low. At this time, the primary focus is on the osmosis of selenium, nutrients, and trace elements (the seedling paper is soaked in selenium-enriched culture solution, the seedling cloth is not replaced, selenite solution is retained, and freshly sprayed potassium dihydrogen phosphate solution is applied), similar to energy accumulation. At high temperatures, malt growth is promoted. This variable temperature treatment is similar to the natural phenomenon of higher temperatures during the day and lower temperatures at night. Once the malt has grown to 30-40mm, the seedlings are removed from the seedling trays to obtain malt rich in organic selenium.

[0038] The table below compares the process temperatures during malt cultivation. It can be seen that re-soaking, re-cultivation, and high-temperature cultivation can all be carried out in one seedling room, which can improve the space utilization of the seedling room and reduce production costs.

[0039]

[0040] 7. Washing and drying: The hot air temperature for drying malt should be ≤60℃; The selenium-enriched malt is washed 2-4 times with deionized water to remove root and husk residues. Deionized water contains virtually no ionic impurities, providing a purer cleaning environment and improving cleaning effectiveness and quality by reducing surface tension. After washing, it is dried in a drying oven with hot air at a temperature not exceeding 60℃, ideally maintained at 50℃±5℃.

[0041] Organic selenium loses its biological activity at temperatures above 80°C. High temperatures can inactivate proteins, leading to the destruction of protein structure, promoting protein oxidation, and accelerating protein degradation, ultimately causing proteins to lose their normal structure and function. Therefore, active selenium is more easily absorbed and acts on the human body, while inert selenium is not absorbed by the body.

[0042] 8. Grinding: Use a low-temperature protective sleeve grinder for grinding, with a temperature ≤40℃.

[0043] The dried selenium-enriched malt was ground into a fine powder using a grinder. Because grinding fine powder involves temperature increases, existing grinders cannot maintain a low temperature of no more than 40°C for extended periods. Two colloid mill technologies applied for by the applicant in September 2025 were used: a low-temperature grinding colloid mill (application number 2025220812458) and a rotor-cooled water-cooled colloid mill (application number 2025221771703). The former cools the stator of the colloid mill, and the latter cools the rotor, ensuring the grinding temperature does not exceed 40°C.

[0044] 9. Packaging the finished product.

[0045] After being ground, the fine powder is sieved through a 150μm sieve at a speed of 200-300r / min for 5 minutes to obtain a high-selenium content nutritional powder. The high-selenium content nutritional powder is then packaged into small bags using a packaging machine.

[0046] The examples in the table below are typical experimental data. The high-selenium nutritional powders in Examples 1 and 2 were tested by a testing company in Shanghai, and the results are shown in the appendix. Figure 1 and attached Figure 2 Examples 3-5 are to be self-inspected by the applicant.

[0047]

[0048] Example 5 uses Bacillus subtilis instead of Bacillus colloidis, with the same usage method and ratio as before, and the organic selenium content can also reach ≥190mg / kg.

[0049] As can be seen from the table, the organic selenium content in the nutritional powder is not less than 190 mg / kg, which is nearly 100% higher than the previous process. Since this application is a continuation of CN202411227068.3, it represents a process improvement based on that application to meet production adjustments, while simultaneously modifying process parameters to increase the selenium content in the nutritional product. Therefore, the roles of trace elements and nutritional elements in this invention, as well as the principle of temperature-controlled processing, are the same as in CN202411227068.3.

[0050] Compared to previous processes, this invention increases the selenium content in the culture medium by appropriately raising the soaking and re-soaking temperatures, thereby shortening the processing time and improving efficiency. By lowering the germination temperature and extending the processing time, the germination time is matched with the previous steps, facilitating the organization of soilless malt cultivation. In the seedling stage, the use of beneficial microorganisms is added, increasing the selenium content without shortening the processing time. The next step is to conduct research on processes with even higher organic selenium content, aiming for medicinal applications.

Claims

1. A method of producing a high selenium content nutritional powder, characterized by: This method, according to the production process, includes seed selection, sterilization pretreatment, soaking, re-soaking, germination, seedling cultivation, drying, and grinding; The seedling raising process involves spreading germinated wheat seeds in a single layer evenly on seedling paper in a seedling tray, covering it with seedling cloth, and then raising the seeds through initial, secondary, and tertiary stages to obtain organic selenium-enriched wheat germ. The seedling paper is soaked in selenium-enriched culture solution and replaced regularly every 20–24 hours. The initial incubation room temperature is 5-10℃. Selenite solution is sprayed evenly on the seedling cloth at 4-6 hour intervals, 3-4 times. The temperature of the regrowth room is 18-20℃. The selenite solution is sprayed on the seedling cloth every 4-6 hours, and at the same time, an aqueous solution of Bacillus jellyii is sprayed, 3-4 times. The weight ratio of Bacillus jellyii to water in the aqueous solution of Bacillus jellyii is 8-15%. The three stages of cultivation involve alternating temperature changes 2-3 times between the primary cultivation room and the secondary cultivation room, with each temperature change lasting 8-12 hours; potassium dihydrogen phosphate solution is sprayed onto the seedling cloth every 4-6 hours; the potassium dihydrogen phosphate solution is prepared by adding 2-4g of potassium dihydrogen phosphate to each liter of the gelatinous Bacillus aqueous solution.

2. A process for the production of a high selenium content nutritional powder as claimed in claim 1, characterized in that: The selected varieties are Jizi Black Wheat No. 1, or Jimai U80, or Jimai U87.

3. The method for producing a high-selenium content nutritional powder according to claim 1, characterized in that: The sterilization pretreatment includes cleaning and disinfection, washing and spin-drying, air-drying and re-selection; the disinfection is to soak and stir in 0.1% to 0.2% sodium hypochlorite disinfectant solution for 15 to 20 minutes.

4. A process for the production of a high selenium content nutritional powder as claimed in claim 1, characterized in that: The soaking process involves mixing wheat seeds with pure selenium culture solution at a ratio of 1 kg: 6 L and soaking for 8–12 hours at a temperature of 5℃±1℃. The pure selenium culture solution is prepared by mixing sodium selenite with distilled water at a ratio of 61–80 mg / L.

5. A process for the production of a high selenium content nutritional powder as claimed in claim 1, characterized in that: The re-soaking involves soaking wheat seeds and selenium-enriched culture solution at a ratio of 1 kg: 5 L for 6–10 hours at a temperature of 18°C–20°C. The selenium-enriched culture solution is prepared by adding 31–50 mg of selenate, 80–100 mg of sodium sulfate, 160–200 mg of potassium nitrate, 210–250 mg of potassium dihydrogen phosphate, and 300–400 mg of magnesium sulfate to each liter of distilled water and stirring until homogeneous.

6. A process for the production of a high selenium content nutritional powder as claimed in claim 1, characterized in that: The germination process involves spreading the soaked wheat seeds in a container lined with damp gauze or burlap sacks to a thickness of 5–15 cm, maintaining an ambient temperature of 24℃–28℃, covering them with a damp cloth and spraying them with water or a selenium-enriched culture solution to keep them moist, and turning them over every 2–4 hours until 70%–80% of the wheat seeds show signs of sprouting.

7. A process for the production of a high selenium content nutritional powder as claimed in claim 1, wherein: The selenite solution is prepared as follows: 20-60 mg sodium selenite, 3-5 mg boric acid, 2-3 mg manganese sulfate, 5-8 mg zinc sulfate, and 4-5 mg copper sulfate per liter of distilled water.

8. A process for the production of a high selenium content nutritional powder as claimed in claim 1, characterized in that: The temperature of the hot air used for drying is ≤60℃; the temperature of the grinding process is ≤40℃.

9. The method for producing a high-selenium content nutritional powder according to claim 1, characterized in that: The gelatinous Bacillus was replaced with Bacillus subtilis.

10. A high selenium content nutritional powder produced by the method of any one of claims 1 to 9, characterized by: The organic selenium content is not less than 190 mg / kg.

Images