Prediction method for roundness of microcapsules prepared by emulsion spray drying

Abstract

The invention relates to the technical field of quality control of microcapsules, in particular to a method for predicting the roundness of microcapsules prepared through emulsion spray drying, and the method comprises the following steps: S1, preparing an emulsion; s2, testing the emulsion viscosity and the emulsion density; s3, the predicted value of the roundness is calculated according to the following formula: phi = 0.88 * ln (Q) + 0.12 * e (-0.002 mu) * (N / 1000) 0.18-0.05 * Te-120 + 0.1 * (epsilon / 2.4) 0.5, all spray drying parameters are substituted into the formula, the predicted value of the roundness of the microcapsules can be calculated, and the method is simple, rapid and high in accuracy. The problem that the roundness is difficult to estimate in the prior art is solved. By accurately predicting the roundness, the spray drying process can be optimized, the investigation workload of the spray drying process is reduced, the time and the cost are greatly saved, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of microcapsule quality control, and in particular to a method for predicting the roundness of microcapsules prepared by emulsion spray drying. Background Art

[0002] Microcapsules, also known as microcapsules, are small capsules that encapsulate solid or liquid drugs using natural or synthetic polymers as their walls (collectively referred to as capsule materials). Spray drying is a commonly used microencapsulation technology. During the spray drying process, an emulsion is dispersed into tiny droplets by an atomizer, which are then rapidly dried by hot air to form microcapsules.

[0003] The roundness of microcapsules is a key indicator of their performance. In the existing technology, microcapsules with insufficient roundness are prone to surface defects (such as depressions or wrinkles), leading to the following problems: (1) Decreased stability: irregular shapes increase the specific surface area, accelerate oxygen penetration, and trigger the oxidative degradation of vitamin A. The monthly degradation rate in the 37°C accelerated test can exceed 5%; (2) Poor mixing uniformity: downstream customers (such as food or feed manufacturers) need to mix microcapsules with other powders. Uneven shapes can easily lead to stratification or agglomeration, affecting the quality of the final product; (3) Deterioration of controlled release performance: low roundness may destroy the integrity of the wall material, leading to premature release in gastric fluid (>10%) and reduced intestinal targeting efficiency. Therefore, improving roundness is crucial for the commercial application of products.

[0004] At present, the roundness of microcapsules mainly depends on the optimization of process parameters (such as inlet air temperature, atomization pressure, emulsion viscosity, etc.). Traditionally, the roundness of microcapsules is obtained through scanning electron microscopy testing, and all require spray drying to prepare microcapsules, which is time-consuming, labor-intensive, and has high experimental costs.

[0005] Therefore, the art expects to develop a method that can quickly and accurately predict the roundness of microcapsules prepared by emulsion spray drying, which has positive significance for the development and promotion of microcapsules. Summary of the Invention

[0006] To this end, the object of the present invention is to provide a method for predicting the roundness of microcapsules prepared by emulsion spray drying, which can quickly and accurately predict the roundness of microcapsules prepared by emulsion spray drying without the need for a spray drying process, greatly saving time and cost.

[0007] The present application provides a method for predicting the circularity of microcapsules prepared by emulsion spray drying, the prediction method comprising the following steps:

[0008] Step S1: prepare emulsion;

[0009] Step S2: testing the emulsion viscosity and emulsion density;

[0010] Step S3: Calculate the predicted value of roundness according to the following formula;

[0011] in,

[0012] is the predicted value of microcapsule roundness;

[0013] μ is the value of the emulsion viscosity, in mPa·s;

[0014] N is the value of the atomizer speed in spray drying, in rpm;

[0015] Te is the value of the inlet air temperature in spray drying, in °C;

[0016] ε is the value of the inlet air velocity in spray drying, in m / s;

[0017] The kinetic coefficient Q is calculated by the emulsion density ρg / mL, the feed rate υmL / min, and the atomizer aperture αmm according to the following formula: Q=ρ×υ / α.

[0018] in, When calculating the formula for Q, all parameters are substituted with the value before the unit.

[0019] Furthermore, N is 18000 to 25000, μ is 50 to 1000, Te is 100 to 140, ε is 1.5 to 3.0, and Q is 1.8 to 3.2.

[0020] Furthermore, N is 18000-25000, μ is 50-200, Te is 120-130, ε is 1.8-2.5, and Q is 1.8-2.6.

[0021] Furthermore, υ is 1 to 15, α is 0.4 to 2.0, and ρ is 0.5 to 1.2.

[0022] Furthermore, υ is 1 to 1.2, α is 0.44 to 0.5, and ρ is 0.88 to 1.0.

[0023] Furthermore, the emulsion includes vitamin A emulsion.

[0024] Furthermore, the preparation method of the emulsion comprises the following steps:

[0025] Step S1: dissolving the wall material in water to obtain an aqueous phase; heating vitamin A to obtain an oil phase;

[0026] Step S2: Mixing the water phase and the oil phase to form an emulsion containing vitamin A;

[0027] Preferably, the aqueous phase is prepared by dissolving the antioxidant enzyme and the wall material in water simultaneously or successively to prepare the aqueous phase;

[0028] Preferably, the method further comprises mixing an oil-soluble antioxidant with vitamin A before the vitamin A is heated.

[0029] Furthermore, during the spray drying process, the temperature of the emulsion is controlled to be 50°C-80°C, preferably 62°C.

[0030] Furthermore, the wall material includes protein. Optionally, the wall material includes one or more of zein, prolamin, rice gluten, gliadin, hordein, kafirin, and vicilin.

[0031] Furthermore, the vitamin A is selected from one or more of retinol, retinoic acid, retinyl esters or retinal; optionally, the retinyl esters include vitamin A acetate.

[0032] Furthermore, the antioxidant enzyme includes one or more of superoxide dismutase, catalase, and glutathione peroxidase.

[0033] Furthermore, the mass ratio of antioxidant enzyme to vitamin A is 0.2-0.8:20-65.5.

[0034] Furthermore, the oil-soluble antioxidant includes one or more of purple sweet potato proanthocyanidins, phycocyanin, and carnosic acid;

[0035] Furthermore, the mass ratio of the oil-soluble antioxidant to vitamin A is 10-40:20-65.5.

[0036] Furthermore, in the vitamin A microcapsule, the mass ratio of the wall material to vitamin A is 20-50:20-65.5.

[0037] Furthermore, in step S1, the step of dissolving the antioxidant enzyme and the wall material in water simultaneously or successively to prepare the aqueous phase also includes the step of mixing the oil-soluble antioxidant with the vitamin A before the vitamin A is heated.

[0038] Furthermore, in step S1, the mass ratio of water to vitamin A is 1200-1500:20-65.5.

[0039] Furthermore, the wall material is zein, the antioxidant enzyme is superoxide dismutase, and the oil-soluble antioxidant is phycocyanin.

[0040] Furthermore, the preparation method of the vitamin A-containing emulsion comprises:

[0041] Step S1: dissolving zein and superoxide dismutase in water to obtain an aqueous phase; mixing vitamin A and phycocyanin, and heating to obtain an oil phase;

[0042] Step S2: Mix the water phase and the oil phase to form an emulsion containing vitamin A.

[0043] Furthermore, the vitamin A microcapsules include, by weight, 30-40 parts of zein, 20-30 parts of vitamin A acetate, 0.3-0.5 parts of superoxide dismutase and 30-40 parts of phycocyanin.

[0044] Furthermore, the dissolution temperature during the preparation of the aqueous phase is 20°C-75°C; and / or, the heating treatment temperature during the preparation of the oil phase is 50°C-80°C; and / or, in step S2, the mixing temperature of the aqueous phase and the oil phase is 50°C-80°C, and the stirring rate is 800-1500 rpm.

[0045] Furthermore, the preparation method of the emulsion comprises the following steps:

[0046] (1) Aqueous phase preparation step: Zein and superoxide dismutase are dissolved in water;

[0047] (2) Oil phase preparation step: heating and dissolving vitamin A acetate and phycocyanin;

[0048] (3) Emulsion preparation step: mixing the water phase and the oil phase; preparing the emulsion.

[0049] Furthermore, in step S2, the step of mixing the emulsion with water is also included before testing the viscosity and density of the emulsion.

[0050] In the present application, the viscosity of the emulsion can be adjusted to different levels by adding different amounts of water, for example, the viscosity of the emulsion is 50 mPa·s, 150 mPa·s, and 200 mPa·s.

[0051] The technical solution of the present invention has the following advantages:

[0052] The present invention provides a method for predicting the roundness of microcapsules prepared by emulsion spray drying, the method comprising the following steps: step S1: preparing an emulsion; step S2: testing the viscosity and density of the emulsion; step S3: calculating the predicted value of the roundness according to the following formula; The kinetic coefficient Q is calculated using the emulsion density ρg / mL, the feed rate υmL / min, and the atomizer aperture αmm according to the following formula: Q = ρ × υ / α. Substituting the spray drying parameters into this formula, the predicted value of microcapsule roundness can be calculated. This simple, rapid, and highly accurate method addresses the difficulty in estimating roundness in existing technologies. Accurately predicting roundness not only optimizes the spray drying process, but also reduces the workload of spray drying process inspections, significantly saving time and costs and improving production efficiency. DETAILED DESCRIPTION

[0053] The following examples are provided for a better understanding of the present invention and are not intended to limit the best mode of implementation. They do not limit the content and scope of protection of the present invention. Any product identical or similar to the present invention obtained by anyone under the guidance of the present invention or by combining the features of the present invention with other prior arts shall fall within the scope of protection of the present invention.

[0054] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments is not specified, they are all commercially available conventional reagents.

[0055] Example 1

[0056] This embodiment provides a method for predicting the roundness of microcapsules prepared by emulsion spray drying, comprising:

[0057] 1. Preparation of emulsion

[0058] (1) Aqueous phase preparation step: Weigh 356 g of zein and 5 g of superoxide dismutase, dissolve them in 1200 g of water, keep the water in a water bath at 28 ± 2 °C, and dissolve the solids by stirring for 50 min;

[0059] (2) Oil phase preparation step: Place 265 g of vitamin A acetate crystals and 374 g of phycocyanin in a three-well plate and heat to dissolve in a 62°C oil bath for 50 min.

[0060] (3) Emulsion preparation step: The aqueous phase and the oil phase were stirred and mixed using a stirrer at a temperature of 62° C., a stirring speed of 1200 rpm, and a mixing time of 50 min to obtain an emulsion.

[0061] 2. Emulsion viscosity and emulsion density testing

[0062] The emulsion was kept at 62° C., water was added to the emulsion to adjust the viscosity of the emulsion at 62° C. to 50 mPa·s, and the density of the emulsion was measured to be 0.91 g / mL.

[0063] 3. Calculate the predicted value of roundness

[0064] According to the spray drying parameters in Table 1, the atomization speed is 18,000 rpm, the feed flow rate is 1 mL / min, the inlet air velocity is 1.8 m / s, an atomizer with an aperture of 0.5 mm is selected, and the inlet air temperature is 120°C. Substituting into the following formula, φ = 0.88 × ln(Re) + 0.12 × e^(-0.002μ) × (N / 1000)^0.18 - 0.05 × |Te-120| + 0.1 × (ε / 2.4)^0.5, the predicted value of the microcapsule roundness is calculated, and the results are shown in Table 1.

[0065] Examples 2 to 18

[0066] The results are basically the same as those in Example 1, except that different spray drying parameters including emulsion viscosity and density lead to different predicted values of microcapsule roundness, as shown in Table 1.

[0067] Table 1 Spray drying parameters and roundness prediction values

[0068]

[0069] The above formula is based on 18 sets of experimental data obtained from Examples 1 to 18. Based on multiple nonlinear regression, a mathematical relationship between φ and Q, N, μ, Te, and ε is preliminarily established: φ = a × ln (Q) + b × e^(cμ) × (N / d)^e + f × |Te-g| + h × (ε / i)^j, and an interaction term (e^(cμ) × (N / d)^e) is introduced to describe the coupling effect of N and μ. Then, the least squares method is used to fit the result, where R 2 ≥0.95.

[0070] Comparative Example 1

[0071] This comparative example provides a method for testing the roundness of microcapsules prepared by spray drying an emulsion. The test is performed after the microcapsules are prepared by spray drying using the conventional method, including the following steps:

[0072] Sample preparation: Take the spray-dried microcapsule sample and disperse it on a glass slide to avoid particle overlap. Use a scanning electron microscope (SEM) to take clear images of at least 100 microcapsules.

[0073] Image processing: Import the image into image analysis software (such as ImageJ), extract the microcapsule outline by grayscale threshold segmentation, and calculate the projected area (A) and perimeter (P) of each particle.

[0074] Sphericity calculation: The sphericity index is calculated according to the formula SI = 4πA / P2. The closer the SI value is to 1, the closer the particle is to an ideal sphere.

[0075] Data verification: Each group of samples was tested three times and the average value was taken as the final result to ensure that the test error was ≤1%.

[0076] Calculation of the measured value of roundness ω: Calculate the measured value of roundness according to the formula ω = sphericity × 100%.

[0077] Experimental Example 1

[0078] The emulsions prepared in Examples 1 to 18 were spray dried under their respective spray drying parameters to prepare microcapsule samples. The measured values ω of the roundness of each group of microcapsule samples were tested using the method of Comparative Example 1, and compared with the predicted values to calculate the relative deviation. The results are shown in Table 2.

[0079] Table 2 Relative deviation results

[0080]

[0081] The results are shown in Table 2. The roundness of the actual test is basically consistent with the result calculated by the method of the present invention, with a relative deviation of <5%, indicating that the prediction method of the present invention is accurate and reliable.

[0082] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for predicting the roundness of microcapsules prepared by emulsion spray drying, characterized in that: The prediction method comprises the following steps: Step S1: prepare emulsion; Step S2: testing the emulsion viscosity and emulsion density; Step S3: Calculate the predicted value of roundness according to the following formula; φ=0.88×ln(Q)+0.12×e^(-0.002μ)×(N / 1000)^0.18-0.05×|Te-120|+0.1×(ε / 2.4)^0.5; where, φ is the predicted value of microcapsule circularity; μ is the value of the emulsion viscosity, in mPa·s; N is the value of the atomizer speed in spray drying, in rpm; Te is the value of the inlet air temperature in spray drying, in °C; ε is the value of the inlet air velocity in spray drying, in m / s; The kinetic coefficient Q is calculated by the emulsion density ρg / mL, the feed rate υmL / min, and the atomizer aperture αmm according to the following formula: Q=ρ×υ / α.

2. The prediction method according to claim 1, characterized in that N is 18000~25000, μ is 50~1000, Te is 100~140, ε is 1.5~3.0, and Q is 1.8~3.

2.

3. The prediction method according to claim 2, characterized in that N is 18000~25000, μ is 50~200, Te is 120~130, ε is 1.8~2.5, and Q is 1.8~2.

6.

4. The prediction method according to claim 1, wherein: υ is 1~15, α is 0.4~2.0, and ρ is 0.5~1.

2.

5. The prediction method according to claim 4, characterized in that υ is 1~1.2, α is 0.44~0.5, and ρ is 0.88~1.

0.

6. The prediction method according to any one of claims 1 to 5, characterized in that: The lotion includes a vitamin A lotion.

7. The prediction method according to claim 6, characterized in that The preparation method of the emulsion comprises the following steps: Step S1: dissolving the wall material in water to obtain an aqueous phase; heating vitamin A to obtain an oil phase; Step S2: Mixing the water phase and the oil phase to form an emulsion containing vitamin A; Preferably, the aqueous phase is prepared by dissolving the antioxidant enzyme and the wall material in water simultaneously or successively to prepare the aqueous phase; Preferably, the method further comprises mixing an oil-soluble antioxidant with vitamin A before the vitamin A is heated.

8. The prediction method according to claim 7, characterized in that During the spray drying process, the wall material includes protein; and / or the antioxidant enzyme includes one or more of superoxide dismutase, catalase, and glutathione peroxidase; and / or the oil-soluble antioxidant includes one or more of purple sweet potato proanthocyanidins, phycocyanin, and carnosic acid.

9. The prediction method according to any one of claims 1 to 8, characterized in that: During the spray drying process, the temperature of the emulsion is controlled at 50°C-80°C, preferably 62°C.

10. The prediction method according to any one of claims 1 to 9, characterized in that: In step S2, the step of mixing the emulsion with water is also included before testing the viscosity and density of the emulsion.

Images