Preparation method of ganoderma lucidum bitterness suppressing and taste masking microcapsules

Abstract

The present invention belongs to the field of pharmaceutical preparations, and specifically discloses a preparation method of Ganoderma lucidum bitterness-suppressing and taste-masking microcapsules. The Ganoderma lucidum bitterness-suppressing and taste-masking microcapsules are prepared from the following raw and auxiliary materials in parts by weight: 1 part of Ganoderma lucidum water extract, 2.5 - 7.5 parts of chitosan solution, and 2.5 - 7.5 parts of sodium alginate solution. The Ganoderma lucidum bitterness-suppressing and taste-masking microcapsules prepared by simultaneously dropping the Ganoderma lucidum water extract and the sodium alginate solution into the chitosan solution respectively, with the cooperation of this specific process and corresponding process parameters, have an obvious "white-wrapping-black" core-shell structure. The core material, Ganoderma lucidum water extract, is successfully embedded by the gelated chitosan-sodium alginate as the wall material, with a high encapsulation rate, which can effectively mask the bitterness of Ganoderma lucidum, and has a low particle size and dispersion coefficient, stable quality, and has practical popularization and application value.

Description

Technical Field

[0001] The present invention belongs to the field of pharmaceutical preparations, and particularly relates to a preparation method of ganoderma lucidum bitter taste suppressing and taste masking microcapsules. Background Art

[0002] Ganoderma lucidum is a precious medicinal fungus, with a neutral nature, sweet taste, and belongs to the heart, lung, liver, and kidney meridians. Modern pharmacological research shows that ganoderma lucidum is rich in polysaccharides, oligosaccharides, amino acids, proteins, steroids, alkaloids, etc., and has the effects of enhancing immunity, anti-tumor, regulating blood sugar and blood lipids, protecting the liver and detoxifying, improving sleep, delaying aging, etc. It has been used to treat various diseases in traditional Chinese medicine for more than 2,000 years.

[0003] Ganoderma lucidum itself has a slightly bitter taste, which mainly comes from components such as triterpenoid compounds contained in it. These bitter components are also important substances for ganoderma lucidum to exert its medicinal value. However, the bitter taste of ganoderma lucidum will affect the acceptance of the target population, and some consumers will give up using ganoderma lucidum products because of the bitter taste. Therefore, in order to improve the acceptance of ganoderma lucidum, at present, ganoderma lucidum powder is filled into capsules to cover up the bitter taste of ganoderma lucidum. This kind of capsule preparation is not suitable for people such as the elderly with weak bodies, those with difficulty in swallowing, and patients with gastrointestinal diseases. In order to expand the target population of ganoderma lucidum, it is necessary to provide a modern preparation that can not only cover up the bitter taste of ganoderma lucidum but also be convenient for swallowing. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a preparation method of ganoderma lucidum bitter taste suppressing and taste masking microcapsules, including the following steps:

[0005] 1) Weigh the raw and auxiliary materials according to the ratio; the weight parts of the raw and auxiliary materials are: 1 part of ganoderma lucidum water extract, 2.5 - 7.5 parts of chitosan solution, and 2.5 - 7.5 parts of sodium alginate solution;

[0006] 2) Take the chitosan solution and stir, and at the same time, drop the sodium alginate solution and ganoderma lucidum water extract respectively. After dropping, continue to stir, homogenize, and dry to obtain the product;

[0007] The chitosan solution is an acetic acid aqueous solution containing chitosan;

[0008] The sodium alginate solution is an aqueous solution containing sodium alginate.

[0009] Further, the weight parts of the raw and auxiliary materials are:

[0010] 1 part of ganoderma lucidum water extract, 7.5 parts of chitosan solution, and 7.5 parts of sodium alginate solution.

[0011] Furthermore, the concentration of the ganoderma lucidum water extract is 0.1 - 0.8 g of crude drug / mL, preferably 0.1 g of crude drug / mL.

[0012] Furthermore, the chitosan solution is an aqueous acetic acid solution containing chitosan; the concentration of chitosan in the aqueous acetic acid solution is 1-3 mg / mL, preferably 2 mg / mL, and the concentration of acetic acid is 0.5-1.5%, preferably 1%.

[0013] Furthermore, the concentration of the sodium alginate solution is 0.5-1.5 mg / mL, preferably 1 mg / mL.

[0014] Furthermore, the stirring speed of the chitosan solution in step 2) is 400-800 rpm, preferably 600 rpm.

[0015] Furthermore, the temperature for continuous stirring in step 2) is 65-85 °C, the speed is 100-300 rpm, and the time is 20-40 min. Preferably, the temperature is 70 °C, the speed is 200 rpm, and the time is 30 min.

[0016] Furthermore, the temperature for homogenization in step 2) is 50-60 °C, the speed is 3000-5000 rpm, and the time is 3-7 min.

[0017] Furthermore, the drying in step 2) is spray drying, and the temperature is 150-200 °C, preferably 170 °C.

[0018] The "microcapsule" in the present invention is a micro-structure composed of a wall material and a core material.

[0019] By simultaneously dropping the Ganoderma lucidum aqueous extract and the sodium alginate solution into the chitosan solution respectively, the Ganoderma lucidum bitterness-suppressing and taste-masking microcapsules prepared under this specific process and the coordination of corresponding process parameters have an obvious "white wrapping black" core-shell structure. The core material, the Ganoderma lucidum aqueous extract, is successfully embedded by the gelated chitosan-sodium alginate of the wall material, with a high encapsulation rate, which can effectively mask the bitterness of Ganoderma lucidum, and has a low particle size and dispersion coefficient, stable quality, and has practical popularization and application value.

[0020] Obviously, based on the above content of the present invention, according to the common general knowledge and customary means in the art, without departing from the above basic technical idea of the present invention, various other forms of modifications, substitutions or changes can be made.

[0021] The above content of the present invention will be further described in detail through the following specific embodiments in the form of examples. However, it should not be understood that the scope of the above subject matter of the present invention is limited to the following examples. All technologies implemented based on the above content of the present invention belong to the scope of the present invention. Description of the Drawings

[0022] Figure 1 Infrared spectra of different samples;

[0023] Figure 2Scanning electron microscope morphology of microcapsules;

[0024] Figure 3 Transmission electron microscope morphology of microcapsules;

[0025] Figure 4 Atomic force microscope morphology of microcapsules (a: 2D atomic force microscope image of microcapsules, b: 3D atomic force microscope image of microcapsules, c: 2D atomic force microscope image of microcapsules, d: 3D atomic force microscope image of microcapsules). Specific implementation mode

[0026] The raw materials, reagents and equipment used in the specific implementation mode of the present invention are all obtained through commercial purchase. Among them, chitosan is provided by Shanghai Aladdin Biochemical Technology Co., Ltd., with a deacetylation degree of ≥95% and a viscosity of 100-200 mPa·s, and a molecular weight of (C6H 11 NO4) n , and sodium alginate is provided by Shanghai Aladdin Biochemical Technology Co., Ltd., with a molecular weight of (C6H7O6Na) n .

[0027] Example 1 Preparation of Ganoderma lucidum bitterness-suppressing and taste-masking microcapsules

[0028] (I) Solution preparation

[0029] Ganoderma lucidum aqueous extract: Take Ganoderma lucidum fruiting bodies, crush them with a pulverizer, and pass through a 14-mesh sieve to obtain Ganoderma lucidum powder. Add water at a solid-liquid ratio of 1:60 (g / mL), soak for 120 min, heat under reflux for 180 min, extract 4 times, and perform hot filtration immediately after each extraction. The filter residue and filter paper are continued for reflux extraction, and the filtrates are combined and concentrated by heating to obtain a Ganoderma lucidum aqueous extract with a concentration of 0.1 g crude drug / mL;

[0030] Chitosan solution: Take chitosan and dissolve it in ultrapure water containing 1% acetic acid to prepare a 2 mg / mL chitosan solution;

[0031] Sodium alginate solution: Take sodium alginate and dissolve it in ultrapure water to prepare a 1 mg / mL sodium alginate solution;

[0032] (II) Preparation of microcapsules

[0033] Take 7.5 g of chitosan solution and stir it at 600 rpm. At the same time, drop 1 g of Ganoderma lucidum aqueous extract and 7.5 g of sodium alginate solution into it through two closely attached dropping tubes at the same speed (1.6 mL / min). After dropping, stir at 70 °C and 200 rpm for 30 min, then homogenize at 55 °C and 4500 rpm for 5 min, and finally spray-dry at 170 °C to obtain Ganoderma lucidum bitterness-suppressing and taste-masking microcapsules.

[0034] The beneficial effects of the present invention will be specifically described below through experimental examples.

[0035] Experimental Example 1 Research on Ganoderma lucidum bitterness suppression and taste masking microcapsules

[0036] A large number of studies have been conducted on the process of Ganoderma lucidum bitterness suppression and taste masking in the early stage. It has been determined that microcapsules with gelated chitosan and sodium alginate as wall materials and Ganoderma lucidum aqueous extract as the core material can achieve the effect of bitterness suppression and taste masking. The process for achieving good encapsulation of Ganoderma lucidum aqueous extract is as follows: The Ganoderma lucidum aqueous extract and sodium alginate solution are simultaneously dropped into the chitosan solution respectively, and then homogenized and dried. Among them, the process parameters will affect the encapsulation rate and the quality of the microcapsules. Therefore, further research on the process parameters was carried out, as follows:

[0037] 1. Experimental materials

[0038] Wall materials: Chitosan, sodium alginate

[0039] Core material: Ganoderma lucidum aqueous extract (The Ganoderma lucidum fruiting body was crushed using a pulverizer and passed through a 14-mesh sieve to obtain Ganoderma lucidum powder. Water was added at a material-liquid ratio of 1:60 (g / mL), soaked for 120 min, heated under reflux for 180 min, extracted 4 times. After each extraction, hot filtration was carried out while it was hot. The filter residue and filter paper were continued for reflux extraction, the filtrates were combined, heated and concentrated to the required concentration for the experiment, and the solution concentration was calculated based on the crude drug).

[0040] 2. Solution preparation

[0041] Chitosan solution: Chitosan was dissolved in ultrapure water containing 1%, v / v acetic acid to prepare a 2 mg / mL chitosan solution.

[0042] Sodium alginate solution: Sodium alginate was dissolved in ultrapure water to prepare a 1 mg / mL sodium alginate solution.

[0043] 3. Preparation of Ganoderma lucidum microcapsules

[0044] A certain amount of 2 mg / mL chitosan solution was placed in a beaker. A 1 mg / mL sodium alginate solution with the same mass as the chitosan solution and a core material with a certain proportion of the wall material mass were simultaneously dropped into the chitosan solution respectively through a peristaltic pump (1.6 mL / min) connected to two closely adjacent dropping tubes, and stirred at 600 rpm simultaneously. After all the sodium alginate solution and core material solution were dropped, it was stirred at 70 °C and 200 rpm for 30 min, and then the stirred solution was homogenized at a certain homogenization temperature and speed. After homogenization, a solid microcapsule product was obtained by spray drying.

[0045] An orthogonal experiment L of seven factors and three levels was designed 18 (3 7), where the last factor is a blank column (similar to the control group in a single-factor experiment). The levels and factors of the orthogonal experiment are shown in Table 1. According to the orthogonal table, a total of 18 groups of experiments were designed in this experiment, and the experimental results were statistically analyzed in sequence. The obtained experimental results were analyzed using software such as Orthogonal Assistant or SPSS. The evaluation indicators were the encapsulation efficiency of Ganoderma lucidum polysaccharide and the bitterness score, and the CRITIC weight method was used to analyze the weights of the encapsulation efficiency of Ganoderma lucidum polysaccharide and the bitterness score.

[0046] Table 1 Orthogonal experiment factor level table

[0047]

[0048] Table 2 Orthogonal table L of seven-factor three-level orthogonal experiment 18 (3 7 )

[0049]

[0050] 4 Analytical test methods

[0051] 4.1 Determination of encapsulation efficiency of Ganoderma lucidum polysaccharide

[0052] Weigh two portions of 0.01 g of Ganoderma lucidum microcapsules. Add 1 mL of ultrapure water to one portion, and then centrifuge at 2000 rpm for 10 min. Retain the supernatant for the determination of surface polysaccharide; add 1 mL of 29 g / L anhydrous citric acid to the other portion and sonicate for 1 h for the determination of total polysaccharide.

[0053] The formula for calculating the encapsulation efficiency is as follows: Encapsulation efficiency (%) , where W1 is the content of polysaccharide on the surface of the microcapsule; W is the total polysaccharide content of the microcapsule.

[0054] The polysaccharide content was determined by the following method

[0055] (1)Solution preparation

[0056] Preparation of polysaccharide reference solution: Prepare an aqueous solution of anhydrous glucose at 0.12 mg / mL. Weigh precisely 12 mg, that is, 0.012 g; make up the volume to 100 mL with ultrapure water. Sulfuric acid anthrone solution: Weigh precisely 0.1 g of anthrone, add 100 ml of sulfuric acid to dissolve it, and shake immediately.

[0057] (2)Preparation of standard curve

[0058] Precisely measure 0.1 mL, 0.2 mL, 0.3 mL, 0.4 mL, 0.5 mL, and 0.6 mL of the reference solution respectively, place them in 10-mL stoppered test tubes, add water to each to make up to 1.0 mL, quickly and precisely add 3 mL of the anthrone sulfate solution, shake immediately, let stand for 15 minutes, then immediately cool in an ice bath for 15 minutes. Take out, using the corresponding reagent as the blank, according to the ultraviolet-visible spectrophotometry method, measure the absorbance at a wavelength of 625 nm. Taking the absorbance as the ordinate and the concentration as the abscissa, plot the standard curve.

[0059] (3)Preparation of the test solution

[0060] While stirring, slowly add 5 mL of 95% ethanol dropwise to the above-prepared sample solution, shake well, let stand at 4°C for 12 hours, centrifuge, discard the supernatant, dissolve the precipitate in hot water and transfer it to a 5-mL volumetric flask, let cool, add water to the scale, and shake well. Take an appropriate amount of the solution, centrifuge, precisely measure 1 mL of the supernatant, place it in a 5-mL volumetric flask, add water to the scale, and shake well to obtain the solution.

[0061] (4)Determination of the sample

[0062] Precisely measure 1 mL of the test solution, place it in a 10-mL stoppered test tube, according to the method under the preparation of the standard curve, starting from "quickly and precisely add 3 mL of the anthrone sulfate solution", operate in the same way, measure the absorbance, read the content of anhydrous glucose in the test solution from the standard curve, and calculate to obtain the result.

[0063] 4.2 Bitter taste evaluation

[0064] Weigh 0.0125 g of Ganoderma lucidum microcapsules, add 5 mL of ultrapure water, and then centrifuge at 2000 rpm for 15 min. Retain the supernatant as the sample for sensory bitter taste evaluation. Evaluation method: The sensory evaluation is based on the national standard (GB / T 15038-2006) and ISO4121. The sensory evaluation uses a 9-point system: 0 points: no bitter taste; (0 - 2) points: slightly bitter taste; [2 - 4) points: weak bitter taste; [4 - 6) points: obvious bitter taste; [6 - 8] points: extremely bitter taste; 9 points: unbearable bitter taste. Before each tasting, the evaluators rinse their mouths with pure water, with the dorsal surface and the edge of the tongue as the main perception parts. Absorb 0.5 mL of each sample, taste each sample for 10 s, and then score the perceived intensity of the bitter taste of each sample. After evaluating each sample, wait for 5 min before evaluating the next sample.

[0065] 4.3 Determination of Zeta potential and average particle size

[0066] Weigh 0.010 g of Ganoderma lucidum microcapsules, add 10 mL of ultrapure water to obtain the test sample, and use a Zeta potential analyzer and a nanoparticle size analyzer to measure the Zeta potential and the average particle size. Ultrasonic the sample for 5 min before testing to make it evenly dispersed.

[0067] 4.4 Determination of moisture content and solubility

[0068] Weigh 0.020 g of microcapsules in a crucible, place it in an oven and dry it to a constant weight at 105 ºC, and calculate the moisture content (%) of the microcapsules according to the percentage of weight loss.

[0069] Weigh 0.050 (W) of microcapsules and dissolve them in 10 mL of ultrapure water. First, stir at a low speed (200 rpm) on a magnetic stirrer for 15 s, then increase the speed of the magnetic stirrer to 1500 rmp and stir for another 3 min. Add the stirred sample solution to a 15 ml centrifuge tube, centrifuge at 4000 rmp for 20 min, transfer all the precipitate at the bottom of the centrifuge tube to a weighing dish (the weighing dish has a constant weight of W1), dry it to a constant weight in an oven at 105 ºC, and record it as W2. Solubility (%) 。

[0070] 4.5 Fourier transform infrared spectroscopy

[0071] Using the KBr tablet method, use a Fourier transform infrared spectrometer to test chitosan, sodium alginate, Ganoderma lucidum aqueous extract, and Ganoderma lucidum microcapsules.

[0072] 4.6 Morphology characterization

[0073] Take a certain amount of Ganoderma lucidum microcapsule samples and use a scanning electron microscope (SEM), a transmission electron microscope (TEM), and an atomic force microscope (AFM) to observe the morphological characteristics of the microcapsules.

[0074] 5 Results

[0075] 5.1 Results of orthogonal experiments

[0076] Use the CRITIC weight method to conduct a weight analysis on the encapsulation rate of Ganoderma lucidum polysaccharide and the bitterness score, and determine that the weight ratio of each index is: encapsulation rate 54.14%, bitterness score 45.86%. The results are shown in Table 4. Conduct a comprehensive score on the results of the orthogonal experiment, and the results are shown in Table 3.

[0077] As can be seen from Table 3, the order of influence of each factor on the comprehensive score of Ganoderma lucidum microcapsules is A > B > D > F > E > C. That is, the core material concentration has the greatest influence, followed by the mass ratio of the core material to the wall material, while the homogenization time and homogenization speed have the least influence. Therefore, the optimal process for preparing Ganoderma lucidum microcapsules is A1B3C2D1E2F2, namely, the core material concentration is 0.1 g / mL, the mass ratio of the core material to the wall material is 1:15, the homogenization speed is 4500 rpm, the homogenization temperature is 55 °C, the homogenization time is 5 min, and the inlet air temperature for spray drying is 170 °C.

[0078] Table 3 Results of orthogonal experiment

[0079]

[0080] Table 4 Results of CRITIC weight calculation

[0081]

[0082] 5.2 Process verification

[0083] Three batches of microcapsules were prepared according to the optimal process conditions determined by the orthogonal experiment (the core material concentration is 0.1 g / mL, the mass ratio of the core material to the wall material is 1:15, the homogenization speed is 4500 rpm, the homogenization temperature is 55 °C, the homogenization time is 5 min, and the inlet air temperature for spray drying is 170 °C). The encapsulation efficiency of Ganoderma lucidum polysaccharide and the bitterness score were measured to verify the stability of this process. The results are shown in Table 5. The results show that the encapsulation efficiency of Ganoderma lucidum polysaccharide and the bitterness score are closest to those of the optimized process, indicating that the optimal process has good stability and the method is feasible.

[0084] Table 5 Determination results of the encapsulation efficiency of Ganoderma lucidum polysaccharide and the bitterness score in the process verification experiment

[0085]

[0086] 5.3 Zeta potential and average particle size

[0087] Zeta potential, also known as surface potential, is a characterization of the amount of charge carried on the surface of particles and is related to the stability of the particle system. Zeta potential can be positive or negative. The larger the absolute value of the Zeta potential, the better the stability. The Zeta potential of this aqueous solution of Ganoderma lucidum microcapsules is 19.9 ± 2.17 mV, the average particle size is 3579.1 ± 148.2 d.nm, and the PDI is 0.252 ± 0.092, indicating that the microcapsules are relatively stable, can be redispersed in aqueous solution, and are not easily flocculated or precipitated due to electrostatic repulsion.

[0088] Table 6 Zeta potential and average particle size

[0089]

[0090] 5.4 Moisture content and solubility

[0091] The water content of the microcapsules is an important evaluation index for the storage of microcapsule products. Generally speaking, the less the water content, the longer the shelf life of the microcapsules. As can be seen from the following table, the Ganoderma lucidum microcapsules have a low water content and good storage stability. The solubility of the microcapsules is low, presenting a suspension state.

[0092] Table 7 Moisture content and solubility

[0093]

[0094] 5.5 Fourier transform infrared spectroscopy

[0095] As shown in the infrared spectrum diagram, first of all, the infrared absorption peaks of chitosan and sodium alginate are roughly the same. The differences are that the stretching vibration peak of the amino N—H of chitosan is around 3433 cm Figure 1 , the stretching vibration peak of C—N of chitosan is at 1153 cm －1 , the stretching vibration peaks of sodium alginate —C=O—O are around 1416 cm －1 and 1615 cm －1 . Secondly, the Ganoderma lucidum aqueous extract has obvious absorption peaks at around 3417 cm －1 , 2925 cm -1 , 1645 cm -1 , 1376 cm -1 , 1075 cm -1 . These peak absorptions belong to carbohydrates and can provide important information about the polysaccharide structure. The strong broad band at 3417 cm -1 belongs to the stretching vibration absorption peak of -OH in carbohydrates. The absorption peak at 2925 cm -1 belongs to the C-H stretching vibration peak of methyl or methylene in the carbohydrate structure. The absorption peaks around 1075 - 1376 cm -1 belong to the bending vibration peak of C-H, which constitutes the characteristic absorption of the sugar ring together with the stretching vibration of C-H. The absorption peak around 1645 cm -1 is the stretching vibration peak of C=O. The infrared spectrum of the Ganoderma lucidum microcapsules simultaneously has the absorption characteristics of chitosan, sodium alginate and the Ganoderma lucidum aqueous extract, indicating that the Ganoderma lucidum aqueous extract has been encapsulated in the microcapsules. -1

[0096] 5.6 Morphology

[0097] (1) Scanning electron microscope. The appearance morphology of the Ganoderma lucidum microcapsules was measured by a scanning electron microscope (SEM), as shown in Figure 2 ​As shown in the figure. It can be seen from the figure that the Ganoderma lucidum microcapsules are irregular spherical in shape, with a relatively rough surface and no cracks, indicating that the microcapsule structure is good and can effectively protect the substances in the microcapsules. There is a certain degree of depression and shrinkage in the microcapsules, which may be caused by water loss during the spray drying process. The particle size distribution of the Ganoderma lucidum microcapsules is relatively uniform, and most of the particle sizes are distributed in the range of 0.5 - 5 μm. The average particle size measured by the nano particle size analyzer is basically consistent with the particle size measured by the scanning electron microscope.

[0098] (2) Transmission electron microscope. The morphology of the Ganoderma lucidum microcapsules was tested using a transmission electron microscope (TEM), as Figure 3 shown. The surface of the microcapsules is relatively rough, with an obvious "white wrapping black" core-shell structure. The capsule wall tightly wraps the core, and the diameter of the core is about 0.5 - 2 μm, and the shell thickness is about 0.1 μm. This is consistent with the results of the scanning electron microscope images.

[0099] (3) Atomic force microscope. The morphology of the Ganoderma lucidum microcapsules was tested using an atomic force microscope (AFM), as Figure 4 shown. It can be seen from Figure 4 that the surface of the microcapsules is relatively rough, irregular in shape, with an obvious core-shell structure, and the core material is successfully embedded in the wall material, which is basically consistent with the results of the scanning electron microscope and the transmission electron microscope.

[0100] The above results show that when the core material concentration is 0.1 g / mL, the mass ratio of the core material to the wall material is 1:15, the homogenization speed is 4500 rpm, the homogenization temperature is 55 °C, the homogenization time is 5 min, and the inlet air temperature of spray drying is 170 °C, the encapsulation rate of Ganoderma lucidum polysaccharide in the microcapsules can reach 66.79%, the bitterness score is 0.54 points, indicating that the bitterness of the Ganoderma lucidum aqueous extract decreases after being made into microcapsules. The average particle size is 3579.1 d.nm, and the results of PDI and Zeta potential show that the prepared microcapsules are relatively stable. The moisture content is 5.67%, indicating that the microcapsules have good storage stability. Infrared spectrum analysis confirms that the Ganoderma lucidum aqueous extract is successfully coated by the wall material. SEM, TEM, and AFM analyses show that the microcapsules are irregular spherical in shape, with a relatively rough surface, an obvious "white wrapping black" core-shell structure, and the core material is successfully embedded in the wall material. The microencapsulation of the Ganoderma lucidum aqueous extract reduces the bitterness of the Ganoderma lucidum aqueous extract.

[0101] II. Comparison of the Ganoderma lucidum bitterness suppression and taste masking microcapsule processes

[0102] Currently, when loading drugs through the chitosan-sodium alginate gelation process, appropriate concentrations of salt ions must be added to enable chitosan and sodium alginate to form a gel and successfully load the drugs. However, during the research on loading Ganoderma lucidum aqueous extract as the core material, it was found that the addition of salt ions could not result in a chitosan-sodium alginate gel that could completely encapsulate the Ganoderma lucidum aqueous extract and mask its bitter taste for an oral preparation. On this basis, various processes for Ganoderma lucidum bitter taste suppression and taste masking microcapsules were attempted, but none of them could obtain Ganoderma lucidum bitter taste suppression and taste masking microcapsules with good taste and stable quality. The following lists some of the processes tried during the research. The salt used in the processes refers to sodium chloride disclosed in <Research on the Synergistic Interaction and Gelation of Chitosan-Sodium Alginate> by He Dongbao, etc.:

[0103] 1. Experimental materials

[0104] Wall materials: Chitosan, sodium alginate, sodium chloride

[0105] Core material: Ganoderma lucidum aqueous extract (0.1 g / mL, prepared in the same way as in Test Example 1)

[0106] 2. Solution preparation

[0107] Chitosan solution: Chitosan solution ①: Chitosan was dissolved in ultrapure water containing 1% acetic acid to prepare a 2 mg / mL chitosan solution.

[0108] Chitosan solution ②: Chitosan was dissolved in 0.15 mol / L sodium chloride solution containing 1% acetic acid to prepare a 2 mg / mL chitosan solution.

[0109] Chitosan solution ③: Chitosan was dissolved in 1.2 mol / L sodium chloride solution containing 1% acetic acid to prepare a 2 mg / mL chitosan solution.

[0110] Sodium alginate solution: Sodium alginate was dissolved in ultrapure water to prepare a 1 mg / mL sodium alginate solution.

[0111] 3. Preparation of Ganoderma lucidum microcapsules

[0112] Process ①: A certain amount of chitosan solution ① was placed in a beaker. The sodium alginate solution with the same mass as the chitosan solution and the core material with a mass ratio of 1:15 to the wall material were mixed evenly, and then dropped into the chitosan solution while stirring at 600 rpm. After dropping, it was stirred at 70 °C and 200 rpm for 30 min, and then the stirred solution was homogenized at 55 °C and 4500 rpm for 5 min. After homogenization, a solid microcapsule product (numbered A) was obtained by spray drying at 170 °C.

[0113] Process ②: Pour a certain amount of chitosan solution ② into a beaker. Drop the sodium alginate solution with the same mass as the chitosan solution and the core material with a mass ratio of 1:15 to the wall material into the chitosan solution simultaneously, and stir at 600 rpm. After dropping, stir at 70 °C and 200 rpm for 30 min. Then, homogenize the stirred solution at 55 °C and 4500 rpm for 5 min. After homogenization, spray-dry at 170 °C to obtain a solid Ganoderma lucidum microcapsule product (numbered B).

[0114] Process ③: Pour a certain amount of chitosan solution ③ into a beaker. Drop the sodium alginate solution with the same mass as the chitosan solution and the core material with a mass ratio of 1:15 to the wall material into the chitosan solution simultaneously, and stir at 600 rpm. After dropping, stir at 70 °C and 200 rpm for 30 min. Then, homogenize the stirred solution at 55 °C and 4500 rpm for 5 min. After homogenization, spray-dry at 170 °C to obtain a solid Ganoderma lucidum microcapsule product (numbered C).

[0115] 4 Analysis and Testing

[0116] 4.1 Determination of Encapsulation Efficiency of Ganoderma lucidum Polysaccharide

[0117] Weigh two portions of 0.01 g of Ganoderma lucidum microcapsules. Add 1 mL of ultrapure water to one portion, and centrifuge at 2000 rpm for 10 min. Retain the supernatant for the determination of surface polysaccharides; add 1 mL of 29 g / L anhydrous citric acid to the other portion and sonicate for 1 h for the determination of total polysaccharides.

[0118] The formula for calculating the encapsulation efficiency is as follows: Encapsulation efficiency (%) , where W1 is the content of surface polysaccharides in the microcapsules; W is the total polysaccharide content in the microcapsules.

[0119] Among them, the polysaccharide content is determined by the following method:

[0120] (1)Solution preparation

[0121] Preparation of polysaccharide reference solution: Prepare an aqueous solution of anhydrous glucose at 0.12 mg / mL. Weigh accurately 12 mg, that is, 0.012 g; make up the volume to 100 mL with ultrapure water. Sulfuric acid anthrone solution: Weigh accurately 0.1 g of anthrone, add 100 ml of sulfuric acid to dissolve it, and shake well immediately.

[0122] (2)Preparation of standard curve

[0123] Precisely measure 0.1 mL, 0.2 mL, 0.3 mL, 0.4 mL, 0.5 mL, and 0.6 mL of the reference solution respectively, place them in 10-mL stoppered test tubes, add water to each to make 1.0 mL, quickly and precisely add 3 mL of the anthrone sulfate solution, shake immediately, let stand for 15 minutes, then immediately cool in an ice bath for 15 minutes. Take out, use the corresponding reagent as the blank, and according to the ultraviolet-visible spectrophotometry, measure the absorbance at a wavelength of 625 nm. Use the absorbance as the ordinate and the concentration as the abscissa to plot the standard curve.

[0124] (3)Preparation of the test solution

[0125] Take the sample solution prepared under "4.1 Determination of the encapsulation efficiency of ganoderma polysaccharide", slowly add 5 mL of 95% ethanol dropwise while stirring, shake well, place at 4°C for 12 hours, centrifuge, discard the supernatant, dissolve the precipitate in hot water and transfer it to a 5-mL volumetric flask, let it cool, add water to the scale, and shake well. Take an appropriate amount of the solution, centrifuge, precisely measure 1 mL of the supernatant, place it in a 5-mL volumetric flask, add water to the scale, and shake well to obtain the solution.

[0126] (4)Sample determination

[0127] Precisely measure 1 mL of the test solution, place it in a 10-mL stoppered test tube, and according to the method under the preparation of the standard curve, starting from "quickly and precisely add 3 mL of the anthrone sulfate solution", operate in the same way to measure the absorbance, read the content of anhydrous glucose in the test solution from the standard curve, and calculate to obtain the result.

[0128] 4.2 Evaluation of bitterness and saltiness

[0129] Weigh 0.0125 g of ganoderma microcapsules, add 5 mL of ultrapure water, and then centrifuge at 2000 rpm for 15 minutes. Retain the supernatant as the sample for the sensory bitterness evaluation. Evaluation method: The sensory evaluation is based on the national standard (GB / T 15038-2006) and ISO4121. The sensory evaluation uses a 9-point system: 0 point: no bitterness; (0-2) points: slightly bitter; [2-4) points: weakly bitter; [4-6) points: obviously bitter; [6-8] points: extremely bitter; 9 points: intolerable bitterness. Before each tasting, the evaluators rinse their mouths with pure water, use the dorsal surface and the edge of the tongue as the main sensing parts, suck 0.5 mL of each sample, taste each sample for 10 s, and then score the bitterness perception intensity of each sample. After the evaluation of each sample, wait for 5 minutes before evaluating the next sample.

[0130] Since salt is added to chitosan, the sensory evaluation adds the saltiness evaluation, and the score levels are the same as those of the bitterness evaluation.

[0131] 4.3 Determination of the average particle size

[0132] Weigh 0.010 g of Ganoderma lucidum microcapsules, add 10 mL of ultrapure water to obtain the test sample, and use a nanoparticle size analyzer to measure the average particle size. The sample is ultrasonically treated for 5 min before testing to make it evenly dispersed.

[0133] 5 Results

[0134] Prepare 3 batches of samples A, B, and C according to the corresponding process, and conduct encapsulation efficiency, bitterness and saltiness scoring, and particle size measurement. The results are as follows:

[0135] 5.1 Encapsulation efficiency, bitterness and saltiness scoring of Ganoderma lucidum polysaccharide

[0136] The encapsulation efficiency of sample A is 59.57 ± 2.89, and the bitterness score is 0.94 ± 1.12. The encapsulation efficiency of sample B is 44.05 ± 1.91, the bitterness score is 0.63 ± 0.69, and the saltiness score is 4.44 ± 1.45. The encapsulation efficiency of sample C is 0.00, the bitterness score is 0.50 ± 0.60, and the saltiness score is 6.31 ± 1.22. The encapsulation efficiencies of Ganoderma lucidum polysaccharide in samples A, B, and C are all lower than those of the samples prepared under the optimal process in Test Example 1 (66.5266.79 ± 1.96). In addition, the bitterness score of sample A is higher than that of the sample prepared under the optimal process in Test Example 1 (0.750.54 ± 0.27). Samples B and C can obviously taste saltiness in addition to bitterness. Although the saltiness weakens the perception of bitterness, it results in an overall poor taste and low acceptance during the test.

[0137] Table 8 Measurement results of encapsulation efficiency of Ganoderma lucidum polysaccharide and taste score

[0138]

[0139] 5.2 Average particle size

[0140] The encapsulation efficiency of sample C is 0, so the average particle size is not measured.

[0141] The polydispersity index (PDI) represents the degree of uniformity of the particle size distribution. The higher the PDI value, the greater the difference in particle size. The average particle size of sample A is 4178 ± 650.1 d.nm, and the PDI is 0.321 ± 0.275. The average particle size of sample B is 6445 ± 1054 d.nm, and the PDI is 0.252 ± 0.092. The average particle sizes and PDI of samples A and B are both higher than those of the samples prepared under the optimal process in Test Example 1 (average particle size 3579.1 ± 148.2 d.nm, PDI 0.252 ± 0.092), indicating that the particles of samples A and B are relatively large, the particle size distribution is wide, and the difference is relatively large.

[0142] Table 9 Average particle size

[0143]

[0144] The above results show that when preparing microcapsules, after the sodium alginate solution and the water extract of Ganoderma lucidum are mixed and then dropped into the chitosan solution, the water extract of Ganoderma lucidum cannot be well encapsulated within the wall material. The prepared microcapsules have a stronger bitter taste, larger particle size and dispersion coefficient compared with the process of separately and simultaneously dropping the sodium alginate solution and the water extract of Ganoderma lucidum into the chitosan solution. When the sodium alginate solution and the water extract of Ganoderma lucidum are separately and simultaneously dropped into the chitosan solution containing salt ions, the obtained microcapsules not only have a bitter taste but also a salty taste, with an overall poor taste, an increased particle size, and the encapsulation effect of the water extract of Ganoderma lucidum deteriorates with the increase of the salt ion concentration, ultimately resulting in the failure of chitosan-sodium alginate to form a gel. It shows that for the core material of the water extract of Ganoderma lucidum with complex components, only by separately and simultaneously dropping the sodium alginate solution and the water extract of Ganoderma lucidum into the chitosan solution prepared with water can the water extract of Ganoderma lucidum as the main drug also play an auxiliary role in forming the shape, enabling the sodium alginate-chitosan to form a gel and thus well encapsulating the Ganoderma lucidum extract within the colloid. At the same time, through the coordination of specific process parameters, the microcapsules have a high encapsulation rate, small particle size and dispersion coefficient, stable quality, and obvious effect of suppressing bitterness and masking taste.

[0145] In summary, the bitter taste suppressing and taste masking Ganoderma lucidum microcapsules prepared by the present invention through separately and simultaneously dropping the water extract of Ganoderma lucidum and the sodium alginate solution into the chitosan solution under this specific process and the coordination of corresponding process parameters have an obvious "white wrapping black" core-shell structure. The core material of the water extract of Ganoderma lucidum is successfully embedded in the gelated chitosan-sodium alginate of the wall material, with a high encapsulation rate, can effectively mask the bitter taste of Ganoderma lucidum, and has a low particle size and dispersion coefficient, stable quality, and has practical popularization and application value.

Claims

1. A method for preparing Ganoderma lucidum bitterness-inhibiting and taste-masking microcapsules, characterized in that: The steps include: 1) Weigh the raw materials and auxiliary materials according to the proportion; the weight parts of the raw materials and auxiliary materials are: 1 part of Ganoderma lucidum water extract, 2.5-7.5 parts of chitosan solution, and 2.5-7.5 parts of sodium alginate solution; 2) Take chitosan solution and stir at 400-800 rpm, and simultaneously drop sodium alginate solution and Ganoderma lucidum water extract into the solution, continue stirring at 65-85°C and 100-300 rpm for 20-40 min, then homogenize at 50-60°C and 3000-5000 rpm for 3-7 min, and finally spray dry at 150-200°C to obtain; The chitosan solution is an acetic acid aqueous solution containing chitosan; the chitosan concentration in the acetic acid aqueous solution is 1-3 mg / mL, and the concentration of acetic acid is 0.5-1.5%; The sodium alginate solution is an aqueous solution containing sodium alginate; the concentration of the sodium alginate solution is 0.5-1.5 mg / mL; The concentration of the Ganoderma lucidum water extract is 0.1 g of crude drug / mL.

2. The preparation method according to claim 1, characterized in that: The weight parts of the raw materials are: 1 part of Ganoderma lucidum water extract, 7.5 parts of chitosan solution, and 7.5 parts of sodium alginate solution.

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