Color developing microsphere as well as preparation method and application thereof

Abstract

The invention provides a color developing microsphere and a preparation method and application thereof, materials for preparing the color developing microsphere comprise sodium alginate, polyacrylic resin II, an ascorbic acid solution, a molybdate solution and inorganic salt, and the inorganic salt comprises CaCL2 or ZnSO4. According to the color developing microspheres, the content of phosphate in food can be detected according to the color change of the microspheres, the lower detection limit of phosphate is 0.5 mg / L, the detection range is 0.5-20 mg / L, and detection is convenient and rapid.

Description

Technical Field

[0001] The invention belongs to the technical field of food detection, and specifically relates to a color developing microsphere and a preparation method and application thereof. Background Art

[0002] There are many methods for detecting phosphate in food, such as colorimetry, ion chromatography, and electrochemical methods. Most of them are designed based on changes in pH. Color-developing substances are divided into two categories: natural pigments and synthetic pigments. Natural pigments such as betaine, alizarin, anthocyanin, shikonin, curcumin, etc., and synthetic pigments such as methyl red, bromocresol green, and bromothymol blue, etc., can all develop color under different pH conditions. However, the method of detecting phosphate by changes in pH value cannot quickly detect the phosphate content in meat products, that is, this method is not convenient and fast enough. Summary of the invention

[0003] In view of this, the present invention provides a color-developing microsphere and a preparation method and application thereof, which are used to detect the phosphate content in food quickly and conveniently.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides a color-developing microsphere, and the materials used to prepare the color-developing microsphere include: sodium alginate, polyacrylic acid resin II, ascorbic acid solution, molybdate solution, and inorganic salt, and the inorganic salt includes CaCL2 or ZnSO4.

[0006] Preferably, the concentration of the ascorbic acid solution is 100 g / L; and / or the concentration of the molybdate solution is 0.02104 mol / L.

[0007] Preferably, the mass of the sodium alginate is 1-1.5 g; and / or,

[0008] The mass of the polyacrylic acid resin II is 0.5-1g; and / or,

[0009] The volume of the ascorbic acid solution is 1-2 mL; and / or,

[0010] The volume of the molybdate solution is 2-3 mL; and / or,

[0011] The inorganic salt comprises CaCL2, and the weight of the CaCL2 is 0.5-1g; or,

[0012] The inorganic salt includes ZnSO4, and the weight of the ZnSO4 is 0.5-1g.

[0013] In a second aspect, the present invention provides a method for preparing the chromogenic microspheres, comprising the following steps:

[0014] S1, mixing water, sodium alginate, polyacrylic acid resin II, ascorbic acid solution and molybdate solution to obtain a precursor solution;

[0015] S2, mixing water and inorganic salt to obtain a contact liquid;

[0016] S3, mixing the precursor solution and the contact solution, filtering and washing, and obtaining colored spheres.

[0017] Preferably, in step S1, water and sodium alginate are first stirred and mixed to obtain an SA solution, polyacrylic acid resin II is added to the SA solution and stirred and mixed, and then ascorbic acid solution and molybdate solution are added in sequence and mixed to obtain a precursor solution.

[0018] Preferably, when mixing water and sodium alginate, the stirring condition is 700r / min; and / or,

[0019] When adding polyacrylic acid resin II to the SA solution, the stirring time is 12-20 hours and the stirring temperature is 70-80° C.; and / or,

[0020] Add ascorbic acid solution and molybdate solution in sequence to the mixture. Add ascorbic acid solution first, and then add molybdate solution after an interval of 30 seconds.

[0021] Preferably, in step S3, in mixing the precursor solution and the contact liquid, a microfluidic injection method is used to mix the precursor solution and the contact liquid.

[0022] Preferably, in step S3, the precursor solution and the contact liquid are mixed, filtered and washed, and the number of washing times is three times.

[0023] In a third aspect, the present invention provides a use of the color-developing microspheres described above, or the color-developing microspheres prepared according to the preparation method described above, in detecting the phosphate content in food.

[0024] In a fourth aspect, the present invention provides a method for detecting the color-developing microspheres described above, or the color-developing microspheres prepared by the preparation method described above, firstly preparing a microsphere color-developing color card, then adding the color-developing microspheres to the solution to be detected, standing at room temperature for adsorption and color development; after 0.5 hours, taking out, washing, and drying. The chromaticity of the color-developing microspheres is compared with the microsphere color-developing color card to determine the concentration of phosphate in the food.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The present invention provides a color developing microsphere which can detect the content of phosphate in food according to the color change of the microsphere. The detection lower limit of phosphate is 0.5 mg / L, the detection range is 0.5-20 mg / L, and the detection is convenient and fast. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The corresponding color images of the microspheres provided in Examples 2 and 4 of the present invention and Comparative Examples 1-2;

[0028] Figure 2 This is a graph showing the test results of the microspheres provided in Examples 2 and 4 of the present invention on minced meat. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below in conjunction with specific embodiments so that those skilled in the art can understand the present invention more clearly.

[0030] Example 1

[0031] Provided is a color-developing microsphere, and the specific preparation method is as follows: add 1g of sodium alginate to 100mL of deionized water, and stir the solution magnetically at a speed of 700r / min to fully dissolve SA; take 0.5g of polyacrylic acid resin II and add it to the sodium alginate solution, stir it magnetically for 12h at about 80°C to make it evenly dispersed in the sodium alginate solution, add 0.5mL of ascorbic acid solution under stirring conditions, add 1mL of molybdate solution after 30s, and remove bubbles in the solution by ultrasonication for 5min, and use it as a precursor solution for standby; take 0.5g of calcium chloride (CaCL2) and add it to 100mL of deionized water, fully dissolve it to form a CaCL2 and ZnSO4 solution, and use it as a contact solution for standby; use a microfluidic injection method to drop the precursor solution into the contact solution, let it stand for 6h, filter it, and wash it three times with pure water to obtain the color-developing microsphere.

[0032] Example 2

[0033] Provided is a color-developing microsphere, the specific preparation method is the same as that of Example 1, except that the sodium alginate is 1.25 g, the polyacrylic acid resin II is 0.75 g, the ascorbic acid solution is 1 mL, the molybdate solution is 2 mL, and the CaCL2 is 0.8 g.

[0034] Example 3

[0035] Provided is a color-developing microsphere, the specific preparation method is the same as that of Example 1, except that the sodium alginate is 1.5 g, the polyacrylic acid resin II is 1 g, the ascorbic acid solution is 1.5 mL, the molybdate solution is 3 mL, and the CaCL2 is 1 g.

[0036] Example 4

[0037] Provided is a color-developing microsphere, the specific preparation method is the same as that of Example 1, except that the sodium alginate is 1.5 g, the polyacrylic acid resin II is 1 g, the ascorbic acid solution is 1.5 mL, the molybdate solution is 3 mL, and the ZnSO4 is 0.8 g.

[0038] Comparative Example 1

[0039] Provided is a color-developing microsphere, the specific preparation method of which is the same as that of Example 2, except that polyacrylic acid resin II and ZnSO4 are removed.

[0040] Comparative Example 2

[0041] Provided is a color-developing microsphere, the specific preparation method of which is the same as that of Example 2, except that polyacrylic acid resin II and CaCL2 are removed.

[0042] Performance testing and results

[0043] 1. Prepare corresponding microsphere color cards for the color-developing microspheres obtained in Example 2, Example 4 and Comparative Example 1-2. Figure 1 .

[0044] 2. The color-developing microspheres obtained in Example 2 and Example 4 were used to detect minced meat food, and the color of each color-developing microsphere was compared with the corresponding microsphere color-developing card. Figure 2 As shown, the conclusion is that the concentrations of phosphate in minced meat food are 0 mg / L, 2 mg / L and 20 mg / L respectively.

[0045] The specific raw materials not described in the present invention are all existing materials and can be directly purchased from the market.

[0046] The above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A color-developing microsphere, characterized in that: The materials used to prepare the chromogenic microspheres include: Sodium alginate; Polyacrylic acid resin II; Ascorbic acid solution; Molybdate solution; Inorganic salts: including CaCL2 or ZnSO4.

2. The chromogenic microsphere according to claim 1, characterized in that: The concentration of the ascorbic acid solution is 100 g / L; and / or, The concentration of the molybdate solution is 0.02104 mol / L.

3. The chromogenic microsphere according to claim 1, characterized in that: The mass of the sodium alginate is 1-1.5 g; and / or, The mass of the polyacrylic acid resin II is 0.5-1g; and / or, The volume of the ascorbic acid solution is 0.5-1.5 mL; and / or, The volume of the molybdate solution is 1-3 mL; and / or, The inorganic salt comprises CaCL2, and the weight of the CaCL2 is 0.5-1g; or, The inorganic salt includes ZnSO4, and the weight of the ZnSO4 is 0.5-1g.

4. The method for preparing the chromogenic microspheres according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1, mixing water, sodium alginate, polyacrylic acid resin II, ascorbic acid solution and molybdate solution to obtain a precursor solution; S2, mixing water and inorganic salt to obtain a contact liquid; S3, mixing the precursor solution and the contact solution, filtering and washing, and obtaining colored spheres.

5. The method according to claim 4, characterized in that In step S1, water and sodium alginate are first stirred and mixed to obtain an SA solution, polyacrylic acid resin II is added to the SA solution and stirred and mixed, and then ascorbic acid solution and molybdate solution are added in sequence and mixed to obtain a precursor solution.

6. The method according to claim 5, characterized in that When mixing water and sodium alginate, the stirring condition is 700r / min; and / or, When adding polyacrylic acid resin II to the SA solution, the stirring time is 12-20 hours and the stirring temperature is 70-80° C.; and / or, Add ascorbic acid solution and molybdate solution in sequence to the mixture. Add ascorbic acid solution first, and then add molybdate solution after an interval of 30 seconds.

7. The method according to claim 4, characterized in that In step S3, the precursor solution and the contact liquid are mixed by using a microfluidic injection method.

8. The method according to claim 4, characterized in that In step S3, the precursor solution and the contact solution are mixed, filtered and washed three times.

9. Use of the chromogenic microspheres according to any one of claims 1 to 3, or the chromogenic microspheres prepared according to the preparation method according to any one of claims 4 to 8, in detecting the phosphate content in food.

10. A method for detecting the chromogenic microspheres according to any one of claims 1 to 3, or the chromogenic microspheres prepared by the preparation method according to any one of claims 4 to 8, characterized in that: First, prepare a microsphere color development color card, then add the color development microspheres to the solution to be tested, let stand at room temperature for adsorption and color development; take out, wash and dry after 0.5 hours. Compare the chromaticity of the color development microspheres with the microsphere color development color card to determine the concentration of phosphate in the food.

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