Nano calcium carbonate for food additive as well as preparation method and application of nano calcium carbonate

Abstract

The invention relates to the field of food additives, in particular to IPC C01F11, and more particularly relates to a preparation method and application of nano calcium carbonate for a food additive. The preparation method of the nano calcium carbonate for the food additive comprises the following steps: filtering, crushing, screening, re-crushing and re-screening the raw materials to finally obtain the nano calcium carbonate for the food additive. The process steps of the calcium carbonate do not involve the addition of chemical substances, so that gases such as SO2, NO, NO2, HCI and the like are not generated in the production process to pollute the environment, excessive chemical impurities are not involved, and the purity of the nano calcium carbonate for the food additive is improved.

Description

[0001] This application is a divisional application of the invention patent with the application number CN202211000954.3, the application date of August 19, 2022, and the title of "Preparation Method and Application of Nano Calcium Carbonate for Food Additives". Technical Field

[0002] The present invention relates to the field of food additives, particularly IPC C01F11, and more specifically, to a preparation method and application of nano calcium carbonate for food additives. Background Art

[0003] Calcium is an important component of the human body, widely distributed in various organs of the human body, and is the most abundant inorganic element in the human body. 99% of calcium is distributed in bones and teeth, and a small part exists in soft tissues and extracellular fluid in the form of calcium ions, playing an important role in maintaining the normal physiological functions of the human body.

[0004] People's usual eating habits can lead to insufficient absorption of calcium elements, causing many adverse problems caused by calcium deficiency, such as infants and young children often crying at night, walking late, teething late, pillow baldness, picky eating, the elderly shrinking in height, osteoporosis and other problems. As a kind of small particle size, nano calcium carbonate is easy to be absorbed by the human body. Therefore, it is very necessary to add nano calcium carbonate to food.

[0005] Currently, the preparation of nano calcium carbonate is as shown in patent CN200910064798.5, which discloses a preparation method of food-grade suspended nano calcium carbonate. Calcium carbonate is calcined at high temperature to calcium oxide, then impurities are removed, carbonized, and the carbonized calcium carbonate is filtered, washed, dried, and rolled to obtain food-grade nano calcium carbonate with excellent suspension performance.

[0006] As shown in patent CN201110050846.2, a preparation method of surface-modified nano calcium carbonate for food is disclosed. A crystal nucleus control agent is added to the calcium hydroxide suspension after impurity removal treatment, carbonized with carbon dioxide into nano calcium carbonate slurry, then sodium salt and stearic acid are added to activate the surface of nano calcium carbonate by stirring, carboxymethyl cellulose sodium is added to improve the suspension stability, and then dried and separated to obtain nano calcium carbonate. These processes all involve a large amount of high-temperature calcination, increasing the cost and having cumbersome steps. After adding various salts and heating and drying, acid anhydrides such as SO2, NO, NO2, HCI, etc. can be volatilized and discharged. This production method not only brings great pollution to the environment, but also inevitably introduces more impurities into the produced nano calcium carbonate, resulting in impure nano calcium carbonate. Summary of the Invention

[0007] In order to solve the above problems, the first aspect of the present invention provides a preparation method of nano calcium carbonate for food additives, which includes the following technological steps:

[0008] S1. Filtration treatment: Filter the raw materials;

[0009] S2. Crushing: Crush the raw materials filtered in step S1 to obtain Substance 1;

[0010] S3. Sieving: Sieve Substance 1 to obtain Substance 2;

[0011] S4. Re-crushing: Crush Substance 2 to obtain Substance 3;

[0012] S5. Re-sieving: Sieve Substance 3 obtained in step S4 to obtain nano-calcium carbonate for food additives.

[0013] Preferably, the raw materials in step S1 are calcium carbonate; more preferably, they are heavy calcium carbonate and / or light calcium carbonate; even more preferably, they are heavy calcium carbonate and light calcium carbonate.

[0014] Preferably, the weight ratio of the heavy calcium carbonate to the light calcium carbonate is (10 - 15):1.

[0015] Preferably, the mesh number of the gauze used for filtration in step S1 is 20 - 2000 meshes; more preferably, it is 100 - 1000 meshes.

[0016] In the present invention, filtering calcium carbonate with a gauze of 100 - 1000 meshes can improve the purity of calcium carbonate in the product while also increasing its final yield. The applicant speculates that when filtering with a gauze of less than 100 meshes, there are too many remaining impurities after filtration. When filtering with a gauze of more than 1000 meshes, the output after filtration is too small.

[0017] Preferably, the crushing method in steps S2 and S4 is any one of extrusion crushing, shear crushing, and turbine crushing; more preferably, it is turbine crushing.

[0018] Preferably, the defined wind speed for turbine crushing in steps S2 and S4 is 20 - 80 m / s.

[0019] More preferably, the defined wind speed for turbine crushing in step S2 is 30 - 40 m / s.

[0020] In the present invention, turbo crushing is used to crush calcium carbonate with a particle size of 100 - 1000 meshes, which can reduce the particle size of the obtained product and consume less energy during the process. The turbo crushing method is that in a closed vacuum grinding chamber, the rotation of the turbo blades generates a certain wind speed, creating a pressure difference between the turbo blades and the vacuum grinding chamber. This pressure difference can form a kind of physical vacuum energy, which can quickly process the material into nano-sized particles, thus completing the processing and crushing of the material. The applicant speculates that under the same energy, selecting turbo crushing as the crushing method can make the product obtained in step S1 be crushed more thoroughly. This may be because during the turbo crushing process, the rotation of the turbo blades generates a wind speed of 30 - 40 m / s, creating a pressure difference in the vacuum grinding chamber, thereby forming a kind of physical vacuum energy. The physical vacuum energy has the energy of negative pressure, which can quickly process the material into nano-sized particles, thus completing the processing and crushing of the material. However, if the wind speed is too high during the processing, not only will higher energy consumption be required, but also when crushing, large particles will directly hit the container, causing greater damage to the container and increasing the cost; and when using too high a wind speed to crush the sieved product obtained in step S1, although it will reduce the average particle size of the obtained product, it is very difficult to ensure the uniformity, and there are still many relatively large-sized particles in the product. If the wind speed is too small, the product obtained in step S1 cannot be crushed sufficiently.

[0021] Further preferably, the defined wind speed for turbo crushing in step S4 is 50 - 60 m / s.

[0022] In the present invention, the turbo blades rotate to generate a wind speed of 50 - 60 m / s, and the physical vacuum energy formed in the vacuum grinding chamber performs secondary crushing on calcium carbonate, which can further reduce the average particle size of the obtained product while improving the particle size uniformity of the obtained product. The applicant speculates that the physical vacuum energy generated at a wind speed of 30 - 40 m / s is used to crush the sieved calcium carbonate, and the obtained product has a particle size of micron-sized calcium carbonate particles, which cannot meet the standard of edible-grade calcium carbonate. Therefore, further using the physical vacuum energy generated at a speed of 50 - 60 m / s to perform secondary crushing on calcium carbonate can further reduce the particle size of calcium carbonate while increasing its particle size uniformity; the physical vacuum energy generated at too small a speed cannot crush micron-sized calcium carbonate into nano-sized calcium carbonate; while the physical vacuum energy generated at too large a speed is likely to cause damage to the container, increase the cost, and at the same time, increase the energy consumption.

[0023] Preferably, the screening methods in steps S3 and S5 are any one of vibration separation, gravity separation, and rolling separation; further preferably, it is gravity separation.

[0024] In the present invention, after the calcium carbonate is crushed by the physical vacuum energy generated at different speeds each time and then subjected to gravity separation, not only can the yield of the final product be improved, but also the purity of calcium carbonate in the product and the particle uniformity of calcium carbonate can be increased. The applicant speculates that first, the physical vacuum energy generated by the wind speed of 30 - 40 m / s is used, and then the physical vacuum energy generated by the wind speed of 50 - 60 m / s is used to crush the sieved calcium carbonate of 100 - 1000 meshes twice and perform two gravity separations for collection. The gravity separation is to collect the calcium carbonate with the required particle size according to the different suspension conditions of nanoscale calcium carbonate in the air. Only after two crushings and two sievings can a product with a higher purity and the required particle size be obtained with less energy consumption, and it has a high yield (the yield reaches 98%).

[0025] The second aspect of the present invention provides an application of the nano calcium carbonate obtained by the described preparation method in baby and maternal foods.

[0026] Preferably, the baby and maternal foods are milk powder, rice flour, protein powder, pasta, and calcium tablet foods.

[0027] Beneficial effects

[0028] 1. In the processing of the present invention, no chemical substances are added, and no harmful substances such as waste gas and waste water are generated during the production process, which can better ensure the purity of nano calcium carbonate.

[0029] 2. The present invention adopts the method of two - stage turbine crushing for processing, performs in - depth treatment on calcium carbonate, and obtains nanoscale calcium carbonate.

[0030] 3. The present invention adopts the method of gravity separation for screening and then crushing, and can obtain nanoscale calcium carbonate with better particle size uniformity.

[0031] 4. The present invention adopts the method of two - stage turbine crushing and two - stage gravity separation for screening. The process steps used are reduced, the energy consumption is reduced, and the cost is further reduced.

[0032] 5. Through two crushings with a certain energy, the yield of nanoscale calcium carbonate obtained by the present invention is higher than that of nanoscale calcium carbonate prepared by chemical methods. Description of the drawings

[0033] Figure 1 It is the SEM image of the nano calcium carbonate prepared in Example 1 of the present application, with a magnification of 35,000 times;

[0034] Figure 2 It is the SEM image of the nano calcium carbonate prepared in Example 3 of the present application, with a magnification of 37,000 times;

[0035] Figure 3SEM image of the nano calcium carbonate prepared in Comparative Example 3 described in this application, with a magnification of 30,000 times. Detailed implementation mode

[0036] Example 1

[0037] Example 1 provides a preparation method of nano calcium carbonate for food additives in the first aspect, which comprises the following technological steps:

[0038] S1. Filtration treatment: Filter the raw materials.

[0039] S2. Crushing: Crush the raw materials filtered in step S1 to obtain substance 1.

[0040] S3. Sieving: Sieve substance 1 to obtain substance 2.

[0041] S4. Re-crushing: Crush substance 2 to obtain substance 3.

[0042] S5. Re-sieving: Sieve substance 3 obtained in step S4 to obtain nano calcium carbonate for food additives.

[0043] The raw material in step S1 is calcium carbonate.

[0044] The calcium carbonate is heavy calcium carbonate and light calcium carbonate, and their weight ratio is 10:1.

[0045] The mesh number of the gauze used for filtration in step S1 is 300 meshes.

[0046] The crushing methods in steps S2 and S4 are turbo crushing.

[0047] The limited wind speed of turbo crushing in step S2 is 30 m / s.

[0048] The limited wind speed of turbo crushing in step S4 is 50 m / s.

[0049] The sieving methods in steps S3 and S5 are gravity separation.

[0050] The second aspect of the present invention provides an application of the nano calcium carbonate obtained by the above-mentioned preparation method in baby and maternal foods.

[0051] The baby and maternal foods are milk powder.

[0052] Example 2

[0053] The specific implementation mode of Example 2 is the same as that of Example 1; the difference is that in Example 2, the limited wind speed of turbo crushing in step S2 is 35 m / s, and the limited wind speed of turbo crushing in step S4 is 45 m / s.

[0054] Example 3

[0055] The specific implementation manner of Example 3 is the same as that of Example 1; the difference is that in Example 3, the defined wind speed for turbine grinding in step S2 is 40 m / s. The defined wind speed for turbine grinding in step S4 is 60 m / s.

[0056] Comparative Example 1

[0057] The specific implementation manner of Comparative Example 1 is the same as that of Example 1; the difference is that in Comparative Example 1, the mesh number of the gauze used for filtration in step S1 is 100 meshes.

[0058] Comparative Example 2

[0059] The specific implementation manner of Comparative Example 2 is the same as that of Example 1; the difference is that in Comparative Example 2, the mesh number of the gauze used for filtration in step S1 is 2000 meshes.

[0060] Comparative Example 3

[0061] The specific implementation manner of Comparative Example 3 is the same as that of Example 1; the difference is that in Comparative Example 3, the separation method in steps S3 and S5 is rolling separation.

[0062] Comparative Example 4

[0063] The specific implementation manner of Comparative Example 4 is the same as that of Example 1; the difference is that in Comparative Example 4, the defined wind speed for turbine grinding in step S2 is 25 m / s.

[0064] Comparative Example 5

[0065] The specific implementation manner of Comparative Example 5 is the same as that of Example 1; the difference is that in Comparative Example 5, the defined wind speed for turbine grinding in step S4 is 45 m / s.

[0066] Performance test:

[0067] 1. Color and state

[0068] For the products prepared in Examples 1 - 3 and Comparative Examples 1 - 5, observe their color and state.

[0069] 2. Particle size range

[0070] Referring to the test method of JY / T 010 - 1996, use an analytical scanning electron microscope to observe the size of the nano - calcium carbonate for food additives in Examples 1 - 3 and Comparative Examples 1 - 5. The results of Example 1, Example 3 and Comparative Example 3 are respectively as Figures 1-3 shown.

[0071] 3. Purity

[0072] According to the test method of GB 1886.214-2016, titration was carried out using a standard titration solution of disodium ethylenediaminetetraacetate (EDTA) to determine the purity of nano-calcium carbonate for food additives.

[0073] 4. Yield

[0074] To determine the yield of nano-calcium carbonate in this application document, when preparing nano-calcium carbonate for a food additive, each example and comparative example started with 1 kg of raw materials, weighed the mass of the finally obtained nano-calcium carbonate, and calculated the yield.

[0075] The color and luster state, particle size range, purity, and yield of the examples and comparative examples are recorded in Table 1.

[0076] Table 1:

[0077]

[0078]

Claims

1. A nano calcium carbonate, characterized in that, Prepared by the following method: S1. Filtration treatment: Filter the raw materials; S2. Crushing: Crush the raw materials filtered in step S1 to obtain Substance 1; S3. Sieving: Sieve Substance 1 to obtain Substance 2; S4. Re-crushing: Crush Substance 2 to obtain Substance 3; S5. Re-sieving: Sieve Substance 3 obtained in step S4 to obtain nano-calcium carbonate.

2. The nano calcium carbonate according to claim 1, characterized in that, The raw material in step S1 is calcium carbonate.

3. The nano calcium carbonate according to claim 1, characterized in that, The mesh number of the gauze used for filtration in step S1 is 20 - 2000 meshes.

4. The nano calcium carbonate according to claim 1, wherein The crushing methods in steps S2 and S4 are any one of extrusion crushing, shear crushing, and turbo crushing.

5. The nano calcium carbonate according to claim 4, characterized in that, The defined air velocity for turbo crushing in steps S2 and S4 is 20 - 80 m / s.

6. The nano calcium carbonate according to claim 5, wherein The defined air velocity for turbo crushing in step S2 is 30 - 40 m / s.

7. The nano calcium carbonate according to claim 5, wherein The defined air velocity for turbo crushing in step S4 is 50 - 60 m / s.

8. The nano calcium carbonate according to claim 1, characterized in that, The sieving methods in steps S3 and S5 are any one of vibration separation, gravity separation, and rolling separation.

9. Application of the nano-calcium carbonate as claimed in claim 1 in terms of being used as a food additive.

10. A high-calcium food, characterized in that, Including the nano-calcium carbonate as claimed in claim 1.

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