CN113080464B - Preparation method of selenium-enriched material - Google Patents

Abstract

A preparation method of a granulated and nutritional selenium-rich material is characterized by comprising the following steps: the wheat bran particles are used as carriers, starch particles on the wheat bran are subjected to in-situ titanium calcium oxide replacement by pretreatment, amylase degradation, probiotics microbial fermentation, in-situ hydrolysis synthesis and other methods, and titanium calcium oxide is loaded on the wheat bran, so that the obtained enriched (selenium) material has the advantages of stable property and high enrichment amount, and larger particles can be formed through further embedding steps. The material has rich selenium, and is nutritious. Therefore, the method can realize the supplement of selenium nutrition for people in the selenium-deficient area after enriching selenium in water body containing excessive selenium element in some areas, and has good application prospect.

Description

A kind of preparation method that can enrich selenium material

technical field

The invention relates to a preparation method of a material that can be used to remove high-concentration selenium in drinking water, belongs to the field of water treatment technology and food nutrition technology, and specifically relates to a preparation method of a granulated and nutritious selenium-enriched material.

Background technique

Selenium (Selenium, Se) element has been regarded as a highly toxic substance since it was discovered in 1817. It was not until 1957 that people realized that it was an essential element for animal growth. The safe range between the optimal intake of selenium and the toxic dose is very narrow, too little intake (<10 μg/d) or too much intake (>750 μg/d) will affect human health.

The distribution of selenium in the earth's crust is extremely uneven, the content in most soils is less than 1 μg/g, and the content in some areas is very high (>43 μg/g). In recent years, due to factors such as industrial and agricultural production, selenium-containing substances have been continuously released into water bodies and soils, and the pollution has become increasingly serious, causing serious health hazards to humans and animals.

In view of the dual role of selenium on organisms and the current situation of rich but uneven distribution of selenium resources, if we can use safe organisms with high resistance to selenium toxicity to enrich the excess selenium in the selenium-enriched environment, and apply selenium-enriched organisms In other industries (food, feed or pharmaceutical industries), it is not only beneficial to the prevention and control of selenium pollution, but also can meet the needs of human body or livestock growth for selenium, so as to achieve the role of rational use of resources and environmental protection.

Inorganic metal oxides, such as nanoparticles of iron and manganese metal oxides, have good selenium enrichment performance, but they exist in the form of powder, which cannot be used in the dynamic filtration enrichment process, and have poor biocompatibility and toxicity.

Wheat is one of the important cereal crops. In China, wheat is the staple food of more than half of the population. During the processing of wheat, a large number of by-products will be produced, mainly bran. Wheat bran is mostly used as feed, and the economic value of the product is not high. How to effectively utilize bran and increase its value is the key content in the field of food processing. Therefore, the research on the modification of bran is worthy of researchers' attention and research. Cellulose and lignin in bran are the main substances, which are characterized by resistance to degradation, environmental protection, and no pollution to the environment. The modification of bran into selenium-enriched materials has important application value.

The ability of bran itself to enrich selenium is low, and the high-safety titanium-calcium hydrated oxide commonly used in food is replaced by the binding site of starch granules on bran by in-situ synthesis replacement method, thereby loading on bran On the carrier, the organic-inorganic composite material is prepared, which not only improves the ability of bran to enrich selenium, but also realizes the immobilization and granulation of powdered metal oxides, which facilitates its application in practice.

Wheat bran is rich in nutrients such as fibrous carbohydrates, proteins, minerals, and vitamins, and the titanium-calcium hydrated oxide loaded on it is also a useful element commonly used in food. The prepared organic-inorganic composite material The load of selenium can be precisely controlled. After it is loaded with the nutrient selenium in the environment, it can also be used in animal feed and human food as a nutritional supplement to achieve the nutrition of the toxic element selenium in the environment. The application of agar, sodium alginate and xanthan gum allows the material to form larger particles for the dynamic enrichment process, and it has good food processing properties.

Contents of the invention

The object of the present invention is a preparation method of a granulated and nutritious selenium-enriched material developed based on the above-mentioned prior art status, which is to load titanium-calcium hydrated oxide on the bran and form a granulated selenium-enriched material. The material method combines the advantages of high selenium adsorption capacity and large specific surface area of titanium calcium hydrated oxide with the characteristics of bran granularity and strong mechanical strength. The gel properties of agar, sodium alginate and xanthan gum are closely related to It can be used for the characteristics of food processing, and the advantages of the nutritional properties of bran and calcium. The material can be applied to the accurate and quantitative recovery of useful nutritional metal elements, such as selenium, and has the feasibility of nutritionally processing the enriched selenium.

The mechanism of the present invention is that: the original bran contains many starch granules, after pretreatment, enzyme degradation, fermentation and filtration, the starch is eliminated, the surface of the bran is clean, and exists as a tough wood fiber material. , Titanium calcium oxide replaces starch and forms between the bran lignocellulosic medium, forming a firm composite material of bran and titanium calcium oxide. If it is used for high-quality food, the pre-treated bran can be treated with H ₂ O ₂ to improve the quality.

The purpose of the present invention is achieved through the following technical solutions:

Using bran as raw material, pass the bran through a 30-mesh sieve, take the sieve, add 5-50 times the quality of water, and freeze at -15--20°C for 6-12 hours to partially destroy the bran tissue and starch structure. After melting, heat at 55-80°C for 10-30 minutes to destroy the bran tissue and gelatinize the starch.

Then add 0.1-1% mass ratio of amylase or glucoamylase, act for 10-30 minutes, then inoculate a single-cell microbial culture with an _OD600 of 0.5-1.0 at a volume ratio of 1-10%, and cultivate for 3-36 Hours (microorganisms completely act on starch, and partially remove minerals and water-soluble non-starch polymers, such as fat, pectin, etc.). The unicellular microorganisms here are Lactobacillus crustorum , Lactobacillus brevis , Lactobacillus plantarum , Weissella cibaria , Lactobacillus paralimentarius , Probiotic lactic acid bacteria such as Latococcus qarvieae and Leuconostoc fallax , as well as Saccharomyces cerevisiae , Wickerhamomyces anomalus , Saccharomycopsis fibuligera A mixed culture of one or more yeasts such as Torulaspora delbrueckii , Saccharomyces boulardii and other yeasts. ;

Pass the above-mentioned pretreated bran through a 30-mesh sieve, take the sieve, wash it with water for 1-3 times, take a certain amount and add it to the reaction container, and then add 5-40 times the volume of titanium salt, calcium salt and Aqueous solution of phosphate (concentrations of titanium salt, calcium salt and phosphate salt are 0.1-100g, 0.01-4.5g and 0-3.94g per 100ml, respectively), after sealing, stir at 70-100℃, 0-50 rpm Heating and mixing reaction at high speed for 2-5h, after the reaction, add dropwise a strong base (sodium hydroxide or potassium hydroxide) with a mass percentage concentration of 8-50% under the stirring condition of 50-150 rpm to neutralize the precipitation, to reach pH4.0-6.0. Finally, the prepared material is rinsed with distilled water until it is neutral, and dried at 50-80° C. to obtain the target product of the present invention—a granulated and nutritious selenium-enriched material.

The bran after the single-cell microbial pretreatment step can be added 2-15 times the volume of H ₂ O ₂ with a mass percentage concentration of 1-5%, and it is incubated at 50-70°C for 1-5 hours for advanced treatment to remove reducing group, change the color and bran structure, improve the quality and then carry out the subsequent improvement process.

In the present invention, the bran after the single-cell microbial pretreatment step can be washed with tap water, dried at 50-80°C, passed through a 30-mesh sieve, and stored after taking the sieved material, and then used for subsequent improved process processing when necessary .

The titanium salt is titanium oxysulfate, titanium sulfate or titanium tetrachloride, the calcium salt is calcium chloride, calcium sulfate, calcium nitrate or calcium carbonate, and the phosphate is disodium hydrogen phosphate, hydrogen phosphate Sodium, Sodium Phosphate, Dipotassium Phosphate, Potassium Phosphate, Potassium Phosphate.

Disperse and suspend the selenium-enriched material (i.e., the bran sample loaded with titanium calcium) prepared in the present invention in a concentration of 0.3-50% at 50-100°C in agar containing 0.1-2.0%, In the solution of 2-10% sodium alginate and 0-2.0% xanthan gum, after mixing evenly, keep warm at 0-10°C, and slowly drop to 1-10 under the condition of stirring at 50-150 rpm % calcium chloride ice-water mixture, polymerize for 30-60 minutes, wash with water 1-2 times, and dry at 50-80°C, so as to prepare larger particles of selenium-enriched material samples.

The selenium-enriching material prepared by the invention can be applied to the adsorption of excess selenium element, and can also be used to supplement selenium nutrient elements for humans or animals in selenium-deficient regions after selenium enrichment.

The outstanding advantages of the present invention are: the prepared material can be applied to the precise and quantitative recovery of useful nutritional metal elements such as selenium, and has the feasibility of carrying out nutritional processing of the enriched selenium.

Description of drawings

Figure 1 is a microscopic enlarged view of the characteristics of bran raw materials,

Figure 2 is a microscopic enlarged view of bran features after enzyme treatment, fermentation and filtration,

Figure 3 is a microscopic enlarged view of the bran features loaded with titanium calcium,

Figure 4 is an energy spectrum diagram of the elemental composition after enrichment of selenium.

Detailed ways

The present invention is described in further detail below in conjunction with specific embodiment:

Example 1

10g of bran passed through a 30-mesh sieve, washed with 20 times the volume of water, frozen at -15°C for 12 hours, heated at 70°C for 10 minutes; then added with 0.1% amylase for 15 minutes; inoculated at a volume ratio of 5% Weissella cibaria with OD ₆₀₀ =0.8 was cultured for 24 hours; then passed through a 30-mesh sieve, and the sieved material was washed once with water; 5 times the volume of 1% H ₂ O ₂ was added, 60 Treat at ℃ for 2 hours, wash, dry at 70℃ and sieve through 30 meshes; put 1.4g of sieved material into 100mL distilled water dissolved with 0.8g TiOSO ₄ , 0.01g calcium chloride and 0.009g disodium hydrogen phosphate, seal, Treat at 80°C for 3 hours at 50 rpm, neutralize the precipitate with 10% NaOH to pH 4.0 after the reaction, rinse with distilled water to neutral after filtration, and dry at 50°C to constant weight; then take 1g of calcium titanium as a load The bran was soaked in 5 ml of a solution containing 0.1% agar, 2% sodium alginate and 0.01% xanthan gum at 50 °C, mixed evenly, cooled to 10 °C, and slowly added dropwise to 2% calcium chloride ice In the water mixture, polymerize for 30 minutes, wash with water twice, and dry at 50-80°C. According to the test, the enrichment amount of the prepared selenium-enriched material to 10mg/L sodium selenite is 1.1mg/g, and the sample has relatively stable selenium-enrichment characteristics under a wide pH condition. Bran raw materials, bran after enzyme treatment, fermentation and filtration, bran loaded with titanium calcium, and selenium-enriched element composition are shown in Figure 1-4.

Example 2

10g of bran passed through a 30-mesh sieve, washed with 40 times the volume of water, frozen at -20°C for 8 hours, heated at 60°C for 30 minutes; then added 0.6% glucoamylase for 25 minutes; the ratio is 8% by volume Inoculate Torulaspora delbrueckii with OD ₆₀₀ =0.8 and culture for 24 hours; then pass through a 30-mesh sieve, take the sieve, and rinse with water once; dry at 70°C and pass through a 30-mesh sieve; 4g of the sieve Put it into 100mL distilled water dissolved with 48gTi(SO ₄ ) ₂ , 4.5g calcium sulfate and 3.94g dipotassium hydrogen phosphate, seal it, treat it at 80°C at 50 rpm for 2h, and after the reaction, wash it with 40% NaOH and precipitated to pH 5.0, filtered, rinsed with distilled water to neutral, and dried to constant weight at 70°C; then soaked 0.1g of titanium-calcium-loaded bran at 50°C in 5 ml of 0.1% agar, 2% seaweed Sodium chloride and 0.01% xanthan gum solution, mix evenly, cool to 10°C, slowly add dropwise to 2% calcium chloride ice-water mixture, polymerize for 30 minutes, wash twice with water, and cool at 50-80°C Set aside to dry. According to the test, the enrichment amount of the prepared selenium-enriched material to 5 mg/L sodium selenite is 2.15 mg/g, and the sample has relatively stable selenium-enrichment characteristics under a wide pH condition.

Example 3

1000g of bran passed through a 30-mesh sieve, washed with 10 times the volume of water, frozen at -15°C for 12 hours, heated at 80°C for 10 minutes; then added 0.1% amylase for 15 minutes; inoculated at a volume ratio of 5% Lactobacillus brevis , Saccharomycopsis fibuligera , and Torulaspora delbrueckii with OD ₆₀₀ =0.6 were cultured for 24 hours; then passed through a 30-mesh sieve, and the supernatant was taken, Rinse once with water; add 5 times the volume of 1% H ₂ O ₂ , treat at 60°C for 2 hours, wash, dry at 70°C and pass through a 30-mesh sieve; put 14g of the sieved material into the dissolved 90gTi(SO ₄ ) _{2 (} Titanium tetrachloride can also be used instead), 4.41g of calcium nitrate in 100mL of distilled water, sealed, treated at 90°C at 80 rpm for 3 hours, after the reaction, use 8% NaOH to neutralize the precipitate to pH 6.0, After filtration, rinse with distilled water until neutral, and dry to constant weight at 50°C. After testing, the enrichment amount of the prepared selenium-rich material to 10mg/L sodium selenite is 3.1mg/g, and the sample is in a wide range of pH It has a relatively stable selenium-enriching characteristic under certain conditions.

Claims (6)

1. A preparation method of a selenium-rich material is characterized by comprising the following steps:

pretreatment: taking bran as a raw material, sieving the bran with a 30-mesh sieve, taking a oversize product, adding 5-50 times of water, freezing for 6-12 hours at the temperature of minus 20 ℃ to minus 15 ℃, and heating for 10-30 minutes at the temperature of 55-80 ℃ after melting;

then adding amylase with the mass ratio of 0.1-1% for 10-30 minutes, and inoculating OD with the mass ratio of 1-10% ₆₀₀ Culturing in 0.5-1.0 single cell microorganism culture for 3-36 hr;

the single-cell microorganism is Weissella foodWeissella cibaria) Circular yeast of DebuhaerTorulaspora delbrueckii) Or Lactobacillus brevisLactobacillus brevis) Circular yeast of De Bu ZhiTorulaspora delbrueckii) Saccharomycetes glabra tectorial membrane spore yeastSaccharomycopsis fibuligera) Is a mixture of (a) and (b);

the improvement process comprises the following steps: sieving pretreated bran with a 30-mesh sieve, taking a oversize product, washing with water for 1-3 times, taking a certain amount, adding into a reaction container, adding 5-40 times of volume of aqueous solution containing titanium salt, calcium salt and phosphate, sealing, heating and mixing at 70-100 ℃ and stirring speed of 0-50 r/min for reacting for 2-5h, dripping 8-50% of alkali with mass percent concentration under stirring condition of 50-150 r/min for neutralizing precipitation, reaching pH4.0-6.0, washing with distilled water to neutrality, and drying at 50-80 ℃ to obtain selenium-enriched material;

the titanium salt is titanyl sulfate, titanium sulfate or titanium tetrachloride, the calcium salt is calcium chloride, calcium sulfate, calcium nitrate or calcium carbonate, the phosphate is disodium hydrogen phosphate, sodium phosphate, dipotassium hydrogen phosphate, potassium hydrogen phosphate or potassium phosphate, and the strong base is sodium hydroxide or potassium hydroxide;

the concentration of the titanium salt, the calcium salt and the phosphate in the aqueous solution containing the titanium salt, the calcium salt and the phosphate is respectively 0.1-100g, 0.01-4.5g and 0-3.94g per hundred milliliters.

2. The method for preparing selenium-enriched material according to claim 1, wherein the wheat bran after the single-cell microorganism pretreatment step is added with 2-15 times of H with a mass percentage concentration of 1-5% by volume ₂ O ₂ The temperature is kept at 50-70 ℃ for 1-5 hours for advanced treatment, and the subsequent improvement process is carried out after the quality is improved.

3. The method for preparing selenium-enriched material according to claim 1, wherein the bran after the step of pretreatment by single-cell microorganism is washed with tap water, dried at 50-80 ℃, sieved by a 30-mesh sieve, and the oversize is stored and used for subsequent improvement process processing when needed.

4. The method for preparing selenium-enriched material according to claim 1, wherein the prepared selenium-enriched material is dispersed and suspended in a solution containing 0.1-2.0% of agar, 2-10% of sodium alginate and 0-2.0% of xanthan gum according to the mass percentage concentration of 0.3-50% at 50-100 ℃, the mixture is uniformly mixed, then the mixture is kept at 0-10 ℃, and is slowly dripped into a 1-10% calcium chloride ice water mixed solution under the condition of 50-150 revolutions per minute stirring, and polymerized for 30-60 minutes, washed for 1-2 times, and dried at 50-80 ℃ to prepare the selenium-enriched material with larger particles.

5. The method of preparing a selenium-enriched material of claim 1, wherein the amylase is a glucoamylase.

6. Use of a selenium-enriched material prepared by the method of any of claims 1-5 for the adsorption of excess selenium.

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