Intestinal release garlic essential oil microcapsules and a method for preparing the same

Abstract

The application provides an intestinal release garlic essential oil microcapsule and a preparation method thereof, and belongs to the technical field of intestinal sustained release. The preparation raw material of the garlic essential oil microcapsule comprises a core material, a wall material and an emulsifier. The core material is garlic essential oil, the wall material is a mixture of malt dextrin and naringin powder, and the emulsifier is Tween-80. The prepared garlic essential oil microcapsule has good stability, and the particle size reaches the nanometer level. The microcapsule has high embedding rate, can well cover the irritating smell of garlic essential oil, and protects the functional components of garlic essential oil. The particle size distribution is uniform, the solubility and dispersibility of the microcapsule are improved, the thermal stability is good, the storage and use time of garlic essential oil can be effectively prolonged, the wall material of malt dextrin and naringin powder can effectively reduce the loss of garlic essential oil in the stomach, and can be rapidly and massively released in the upper small intestine or duodenum, is beneficial to human body absorption, and improves the absorption rate of garlic essential oil.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of intestinal sustained-release technology, and in particular to an intestinal release garlic essential oil microcapsule and a preparation method thereof. BACKGROUND

[0002] Garlic has a strong pungent garlic odor, which can be used as a seasoning and also as a medicine, and is a famous dual-purpose food and medicine plant. Garlic bulbs contain abundant proteins, oligosaccharides and polysaccharides, and also contain fats, minerals, etc. Garlic essential oil is a special substance extracted from garlic, which generally appears as a bright and transparent amber liquid with a strong garlic odor, and is usually extracted by water vapor distillation, solvent extraction, supercritical extraction, ultrasonic and microwave-assisted extraction, etc. The most valuable active sulfide in garlic essential oil has the effects of preventing and treating cardiovascular diseases, reducing blood lipids, resisting hypertension, resisting thrombosis and resisting cancer, etc.

[0003] Garlic essential oil has a pungent odor with a special pungent flavor that is not pleasing to people, and its active compound is unstable, easy to volatilize during processing and transportation, or easy to deteriorate due to environmental influences. At the same time, the solubility of garlic essential oil in water is very low, which greatly limits its application in the food industry.

[0004] China has a long history of planting pears, which dates back more than 3,000 years. Today, the main areas for planting pears are Fujian, Guangdong, Hunan, Jiangxi, Guangxi and other regions. In recent years, with the continuous increase in the planting area and yield of pears, the pear processing industry has developed rapidly, and a large amount of by-products have been formed, among which the pear skin accounting for about 40% of the fresh pear weight is the main by-product. A large amount of pear skin is discarded, which not only wastes resources but also poses a certain threat to the environment. Chemical analysis shows that fresh pear skin is rich in various nutrients and functional compounds, such as dietary fiber, pectin, flavonoids and various polyphenols. The pear skin has a porous structure and natural adsorption properties.

[0005] Microcapsule technology is a technology that uses physical and chemical methods to encapsulate solid, liquid or gaseous substances in semi-transparent or closed microcapsules. Spray drying is one of the microcapsule technologies, which has the advantages of low cost, good retention rate and stability of volatile substances of the core material after encapsulation, and large production scale. By spray drying the garlic essential oil, the pungent odor of the garlic essential oil can be effectively reduced, the influence of the external environment on the active ingredients in the garlic essential oil can be reduced, the garlic essential oil can be converted from a liquid to a solid powder, and the processing and transportation of the garlic essential oil can be effectively improved, thereby reducing the loss.

[0006] The traditional microcapsules either have too much dissolution in the stomach or too slow dissolution, and the dissolution rate in the stomach and the intestinal tract is not high, so the maximum absorption rate of the garlic essential oil cannot be achieved. The high release rate of the garlic essential oil in the intestinal digestion stage is beneficial to absorption and plays various health care effects of the garlic essential oil. SUMMARY

[0007] One of the purposes of the present application is to provide an intestinal release garlic essential oil microcapsule, and the preparation raw materials include a core material, a wall material and an emulsifier. The core material is garlic essential oil, and the garlic essential oil accounts for 1.3%-12.5% according to the mass-volume ratio of the raw materials and water. The wall material is a mixture of malt dextrin and shaddock peel powder, and the malt dextrin accounts for 5%-22% and the shaddock peel powder accounts for 2%-13% according to the mass-volume ratio of the raw materials and water. The emulsifier is Tween-80.

[0008] The Tween-80 accounts for 0.1%-0.5% according to the mass-volume ratio of the raw materials and water.

[0009] Meanwhile, the present application also provides a preparation method of the intestinal release garlic essential oil microcapsule, which includes the following steps:

[0010] (1) 5%-22% of malt dextrin and 2%-13% of shaddock peel powder are taken according to the mass-volume ratio, and are added into distilled water. After complete dissolution, 1.3%-12.5% of garlic essential oil and 0.1%-0.5% of Tween-80 are added;

[0011] (2) an initial emulsion is formed by shearing and emulsifying 5-10 min at 10000-12000 r / min of a high-speed dispersion machine, and the initial emulsion is high-pressure homogenized to obtain a uniform garlic essential oil emulsion;

[0012] (3) the garlic essential oil emulsion is spray dried to obtain the intestinal release garlic essential oil microcapsule.

[0013] The flow rate of the spray drying is 500-800 mL / h, the inlet air temperature is 120-180 ℃, and the outlet air temperature is 70-90 ℃.

[0014] The pressure of the high-pressure homogenization is 20-50 MPa.

[0015] The preparation method of the shaddock peel powder is as follows: a fresh shaddock is peeled and the pulp is taken out, crushed into coarse powder, and sieved through a 40-80 mesh screen to obtain coarse shaddock peel powder. The coarse shaddock peel powder is ultra-micro pulverized by a ball mill for 1-2 h to obtain the shaddock peel powder. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a particle size diagram of the garlic essential oil emulsion;

[0017] Figure 2ζ-potential and PDI graph of garlic essential oil emulsion;

[0018] Figure 3 Scanning electron micrograph of garlic essential oil microcapsules; wherein, a is 500 times scanning electron micrograph; b is 2000 times scanning electron micrograph; c is 6000 times scanning electron micrograph;

[0019] Figure 4 Particle size graph of garlic essential oil microcapsules;

[0020] Figure 5 Thermogravimetric graph of garlic essential oil microcapsules; wherein, A is TGA curve; B is DTG curve;

[0021] Figure 6 Release curve graph of garlic essential oil microcapsules in simulated gastrointestinal fluid in Example 1.

[0022] Figure 7 Release curve graph of garlic essential oil microcapsules in simulated gastrointestinal fluid in Example 2.

[0023] Figure 8 Release curve graph of garlic essential oil microcapsules in simulated gastrointestinal fluid in Example 3.

[0024] Figure 9 Release curve graph of garlic essential oil microcapsules in simulated gastrointestinal fluid in Example 4.

[0025] Figure 10 Release curve graph of garlic essential oil microcapsules in simulated gastrointestinal fluid in Comparative Example 1.

[0026] Figure 11 Release curve graph of garlic essential oil microcapsules in simulated gastrointestinal fluid in Comparative Example 2.

[0027] Beneficial effects

[0028] Garlic essential oil has strong bacteriostatic effect, especially strong bacteriostatic effect on Aspergillus niger and Candida albicans, and has broad development space in food and medicine. The mucosal surface of human intestinal tract has a folded structure and small intestinal villi, which makes it have a large surface area, and there are rich capillaries and capillary lymphatic vessels in the intestinal villi, so it is the main site of drug absorption and the specific site of drug transport. Therefore, the high release rate of garlic essential oil in the intestinal digestion stage is more conducive to absorption and play a role.

[0029] The traditional microcapsule sustained-release releases uniformly in the oral cavity, stomach and intestinal tract, or releases after a period of time, but the release rate is generally linear, or too much is lost in the stomach, or too little is released in the small intestine, and it cannot be completely released in the large intestine.

[0030] The present application selects malt dextrin and pomelo peel powder to mix to serve as the wall material. Due to the addition of the pomelo peel powder, the release amount of the whole microcapsule in the stomach is reduced, and the embedding rate is basically maintained at 90%. However, when entering the intestinal tract, the mixed wall material of the pomelo peel powder and the malt dextrin is unstable in the simulated intestinal fluid, so that the microcapsule is rapidly destabilized, and the garlic essential oil is rapidly released, so that the garlic essential oil can be rapidly released and absorbed in the duodenum and the small intestine, and the utilization rate of the garlic essential oil is improved. According to the description Figures 6-9 It can be seen that the garlic essential oil microcapsule prepared by the present application exhibits good sustained-release performance in the simulated in-vitro digestion. In the simulated gastric juice stage, the garlic essential oil microcapsules in Examples 1-4 all exhibit similar rules in the digestion stage, and are slowly released in the simulated gastric juice stage. The cumulative release rate of the garlic essential oil microcapsule in Example 1 in the simulated gastric juice reaches 26.48%. When transferred from the gastric juice digestion stage to the intestinal juice digestion stage, it is observed that the rapid release in the first 90 min (120-210 min) of the simulated intestinal juice digestion stage, and then the sustained release to 360 min. The rapid release of the core material in the intestinal juice is beneficial to the absorption of the human body. The best absorption site of the drug is the upper part of the small intestine or the duodenum, and the rectal blood vessels are rich, which is the absorption site of the suppository. The sustained slow release of the core material in the gastrointestinal tract can effectively improve the bioavailability thereof. The rapid release result may be due to the aggregation of the bile acid, bile salt and phospholipid in the simulated intestinal juice to form mixed micelles or complexes, which destroys the microcapsule structure, so that the pore size is increased and the permeability is increased. The partial destabilization of the garlic essential oil microcapsule in the intestinal juice can make the garlic essential oil in the garlic essential oil microcapsule be released in the intestinal tract, so as to be more effectively absorbed and utilized. DETAILED DESCRIPTION

[0031] The present application will be further illustrated below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present application, and are not used to limit the scope of the present application. After reading the present application, those skilled in the art can make various modifications to the present application, and all modifications fall within the scope defined by the claims attached hereto.

[0032] In the examples, the preparation method of the pomelo peel powder is as follows: the fresh pomelo is peeled and the pulp is crushed into coarse powder by a high-speed crusher, and then the coarse pomelo peel powder is sieved by a 40-80 mesh sieve to obtain the coarse pomelo peel powder. The coarse pomelo peel powder is ultra-micro pulverized by a ball mill for 1-2 h, and the obtained pomelo peel powder is sealed and stored for use.

[0033] The determination method of the embedding rate of the garlic essential oil is as follows:

[0034] ①Drawing of the standard curve of the garlic essential oil:

[0035] The garlic essential oil was scanned by UV at 190nm-400nm with anhydrous ethanol as solvent, and the maximum absorption peak was at 203nm. 0.1g of garlic essential oil was dissolved in 10mL of anhydrous ethanol to prepare a solution of 10mg / mL, and then the solution was diluted to prepare solutions with concentrations of 0.002mg / mL, 0.005mg / mL, 0.008mg / mL, 0.01mg / mL, 0.014mg / mL, 0.017mg / mL and 0.02mg / mL, respectively. The absorbance was measured at the maximum absorption peak of 203nm, and the standard curve of garlic essential oil was drawn by linear regression of the absorbance y value and the concentration x value of garlic essential oil.

[0036] 2. Determination of embedding rate:

[0037] 0.1g of garlic essential oil microcapsules were dissolved in 10mL of anhydrous ethanol, washed by shaking, centrifuged at 4000r / min for 8min, and 0.1mL of the washing solution was taken and diluted to 10mL. The absorbance was measured by UV spectrophotometer, and the mass M1 of garlic essential oil was calculated by substituting the standard curve of garlic essential oil.

[0038]

[0039] In the formula, M represents the mass of garlic essential oil in spray drying, and the unit is mg.

[0040] Method for testing particle size distribution and stability of garlic essential oil emulsion.

[0041] The sample solution was diluted 100 times with deionized water to avoid multiple scattering. 1mL of the sample was taken into a sample cell, and the particle size distribution, ζ-potential and PDI of the sample were measured by Zetasizer Nano ZS particle size potential instrument. The measurement temperature was 25℃, the fixed angle was 173°, the particle refractive index was 1.53, and the average value was taken by measuring three times.

[0042] Method for determining basic indicators of garlic essential oil microcapsules.

[0043] 1. Determination of moisture content and water activity

[0044] 0.5g of different samples were taken into a drying dish, respectively, and the moisture content of the powder was measured by using a rapid moisture meter. The water activity of the powder was measured by using an HD-3A intelligent water activity meter, and the temperature was 25℃. Each sample was measured three times.

[0045] 2. Determination of repose angle and sliding angle

[0046] A glass plate is placed horizontally on a table, a funnel is fixed on the table so that the funnel is perpendicular to the glass plate, the tail end of the funnel is 3 cm away from the glass plate vertically, 3 g of sample is dropped through the funnel to accumulate, the diameter D and the height H of the cone formed by the powder on the glass plate are measured, the experiment is repeated 3 times, and the angle of repose θ of the microcapsule product can be calculated according to the formula:

[0047]

[0048] 3 g of sample is taken on a horizontal glass plate, then the glass plate is slowly inclined, 90% of the powder is moved, and the angle between the plate and the horizontal plane is measured, which is the sliding angle of the powder, and the experiment is repeated 3 times.

[0049] 3. Determination of bulk density

[0050] A weighing cylinder with a constant weight is taken and weighed, the microcapsule powder is slowly filled into the cylinder and leveled, the volume of the powder after filling is measured, and the bulk density of the microcapsule product can be calculated according to the formula:

[0051]

[0052] In the formula, M1 is the initial mass of the cylinder (g), M2 is the mass of the cylinder after adding the sample (g), and V is the final volume of the sample (mL).

[0053] Determination method of garlic essential oil microcapsule characterization

[0054] 1. Determination method of garlic essential oil microcapsule SEM

[0055] The appearance and morphology of the microcapsule are observed by scanning electron microscope, a layer of conductive glue is pasted on the electron microscope sample stage, a small amount of powder sample is scattered on the glue surface, the excess powder on the surface is blown away, and the gold plating film is observed and photographed.

[0056] 2. Determination method of garlic essential oil microcapsule particle size distribution

[0057] The particle size distribution of different microcapsule samples is determined by laser particle size analyzer. The microcapsule sample is dispersed in deionized water, the temperature is 25℃, the pump speed is 2000 r / min, and the determination is started after the sample is added.

[0058] Thermal stability of garlic essential oil microcapsule

[0059] Thermogravimetry is one of the important indicators for evaluating the thermal stability of microcapsules. The thermal stability of maltodextrin, naringin powder, garlic essential oil and garlic essential oil microcapsule is determined by TGAQ5000IR thermogravimetric analyzer. The nitrogen flow rate is set to 30 mL / min, the temperature range is 50-600℃, and the temperature rising rate is 10℃ / min.

[0060] Method for determining in vitro digestion release rate of garlic essential oil microcapsules

[0061] Simulated human gastric fluid (containing 2.0 g / mL NaCl and 3.2 mg / mL pepsin, pH 2.0) and intestinal fluid (containing 8.8 mg / mL NaCl, 6.8 mg / mL KH2PO4, 2 mg / mL trypsin and 5 mg / mL cholic acid, pH 7.0) under the state of eating. The in vitro release characteristics of garlic essential oil microcapsules were analyzed by dialysis bag method. The simulated intestinal fluid and gastric fluid were mixed with equal amount of anhydrous ethanol as release medium. 0.5 g of garlic essential oil microcapsules and 2.5 mL of ethanol solution were sealed in dialysis bags (8-14 kDa molecular weight) containing 3 mL of simulated gastric fluid, and soaked in 60 mL of simulated gastric fluid release medium for 2 h and shaken in a constant temperature water bath shaker at 37℃. Then 6 mL of simulated intestinal fluid was added to the dialysis bag, and then the dialysis bag was transferred to 120 mL of simulated intestinal fluid release medium, and continued to shake at 37℃ in a constant temperature water bath shaker for 4 h. 1 mL of release medium was collected every 30 min, and 1 mL of release medium was supplemented to ensure the constant total volume. Then the absorbance at each time stage was measured by ultraviolet spectrophotometer, and the concentration of garlic essential oil was calculated.

[0062] Example 1

[0063] A preparation method of naringin powder garlic essential oil microcapsules for intestinal release, specifically comprising the following steps:

[0064] (1) 15 g of malt dextrin and 5 g of naringin powder were taken according to the mass-volume ratio, 100 mL of distilled water was added, stirred in a 60℃ water bath, and after complete dissolution, 5 g of garlic essential oil and 0.5 g of Tween-80 were added;

[0065] (2) The primary emulsion was formed by shearing emulsification with a high-speed dispersion machine at 12000 r / min for 6 min, and the uniform garlic essential oil emulsion was obtained by homogenizing the primary emulsion once with a high-pressure homogenizer at 20 MPa;

[0066] (3) The emulsion was spray dried, the inlet air temperature of spray drying was 160℃, the inlet liquid flow rate was 600 mL / h, and the outlet air temperature was 80℃, to obtain garlic essential oil microcapsules for intestinal release.

[0067] Example 2

[0068] A preparation method of naringin powder garlic essential oil microcapsules for intestinal release, specifically comprising the following steps:

[0069] (1) 22 g of malt dextrin and 11 g of naringin powder were taken according to the mass-volume ratio, 100 mL of distilled water was added, stirred in a 65℃ water bath, and after complete dissolution, 11 g of garlic essential oil and 0.1 g of Tween-80 were added;

[0070] (2) The primary emulsion is formed by shearing and emulsifying with a high-speed dispersion machine at 10000 r / min for 5 min, and the uniform garlic essential oil emulsion is obtained by homogenizing the primary emulsion once with a high-pressure homogenizer at 30 MPa;

[0071] (3) The emulsion is spray dried, the inlet air temperature of spray drying is 170℃, the inlet liquid flow rate is 500 mL / h, the outlet air temperature is 70℃, and the intestinal release garlic essential oil microcapsule is obtained.

[0072] Example 3

[0073] A preparation method of a pomelo peel powder garlic essential oil microcapsule, specifically comprising the following steps:

[0074] (1) 13 g of malt dextrin and 13 g of pomelo peel powder are taken according to the mass-volume ratio, 100 mL of distilled water is added, stirring in a 55℃ water bath, and after complete dissolution, 12.5 g of garlic essential oil and 0.3 g of Tween-80 are added;

[0075] (2) The primary emulsion is formed by shearing and emulsifying with a high-speed dispersion machine at 11000 r / min for 10 min, and the uniform garlic essential oil emulsion is obtained by homogenizing the primary emulsion once with a high-pressure homogenizer at 50 MPa;

[0076] (3) The emulsion is spray dried, the inlet air temperature of spray drying is 180℃, the inlet liquid flow rate is 800 mL / h, the outlet air temperature is 90℃, and the intestinal release garlic essential oil microcapsule is obtained.

[0077] Example 4

[0078] A preparation method of a pomelo peel powder garlic essential oil microcapsule, specifically comprising the following steps:

[0079] (1) 5 g of malt dextrin and 2 g of pomelo peel powder are taken according to the mass-volume ratio, 100 mL of distilled water is added, stirring in a 60℃ water bath, and after complete dissolution, 2 g of garlic essential oil and 0.2 g of Tween-80 are added;

[0080] (2) The primary emulsion is formed by shearing and emulsifying with a high-speed dispersion machine at 11000 r / min for 8 min, and the uniform garlic essential oil emulsion is obtained by homogenizing the primary emulsion once with a high-pressure homogenizer at 40 MPa;

[0081] (3) The emulsion is spray dried, the inlet air temperature of spray drying is 175℃, the inlet liquid flow rate is 600 mL / h, the outlet air temperature is 75℃, and the intestinal release garlic essential oil microcapsule is obtained.

[0082] Comparative Example 1

[0083] A preparation method of a pomelo peel powder garlic essential oil microcapsule, specifically comprising the following steps:

[0084] (1) Take 20 g of malt dextrin according to the mass-volume ratio, add 100 mL of distilled water, stir in a 60°C water bath, and after complete dissolution, add 5 g of garlic essential oil and 0.5 g of Tween-80;

[0085] (2) Use a high-speed dispersion machine to shear emulsify for 6 min at 12000 r / min to form a primary emulsion, and then use a high-pressure homogenizer to homogenize the primary emulsion once at 20 MPa to obtain a uniform garlic essential oil emulsion;

[0086] (3) Spray dry the emulsion (the spray drying feed liquid flow rate is 600 mL / h, and the air outlet temperature is 80°C) to obtain garlic essential oil microcapsules.

[0087] Comparative Example 2

[0088] A method for preparing pummelo peel powder garlic essential oil microcapsules, specifically comprising the following steps:

[0089] (1) Take 20 g of pummelo peel powder according to the mass-volume ratio, add 100 mL of distilled water, stir in a 60°C water bath, and after complete dissolution, add 5 g of garlic essential oil and 0.5 g of Tween-80;

[0090] (2) Use a high-speed dispersion machine to shear emulsify for 6 min at 12000 r / min to form a primary emulsion, and then use a high-pressure homogenizer to homogenize the primary emulsion once at 20 MPa to obtain a uniform garlic essential oil emulsion;

[0091] (3) Spray dry the emulsion (the spray drying feed liquid flow rate is 600 mL / h, and the air outlet temperature is 80°C) to obtain garlic essential oil microcapsules.

[0092] Experimental results

[0093] Garlic essential oil microcapsule embedding rate

[0094] In Examples 1-4, the measured garlic essential oil microcapsule embedding rates were 91.68±0.50%, 84.94±2.88%, 83.75±3.02%, and 81.73±3.83%, respectively.

[0095] Garlic essential oil emulsion particle size distribution and stability

[0096] By the description attached Figure 1It can be seen that the particle size distribution of garlic essential oil emulsion prepared by single wall material is uneven, showing a bimodal state. Compared with the emulsion prepared by traditional malt dextrin embedding garlic essential oil, the particle size of the garlic essential oil emulsion prepared by adding naringin powder in the malt dextrin water phase is normally distributed, the width of the peak is small, indicating that the particle size distribution of garlic essential oil emulsion is narrow and uniform, and the average particle size is 55.04 nm, which is a nano-particle (<200 nm). Generally speaking, the size of the particle has an important influence on the formation and stability of the emulsion, and the size of the emulsion droplet is positively correlated with the particle size, and the stability of the emulsion is negatively correlated with the particle size. The smaller the particle size, the larger the surface area of the particle, the stronger the adsorption force, and the smaller the emulsion droplet. Small droplets are more conducive to maintaining the stability of the emulsion. Combined with the particle size distribution of the emulsion prepared by the malt dextrin embedding garlic essential oil in the specification attached Figure 2 It can be seen that the particle size distribution of garlic essential oil emulsion prepared by single wall material is uneven, showing a bimodal state. Compared with the emulsion prepared by traditional malt dextrin embedding garlic essential oil, the particle size of the garlic essential oil emulsion prepared by adding naringin powder in the malt dextrin water phase is normally distributed, the width of the peak is small, indicating that the particle size distribution of garlic essential oil emulsion is narrow and uniform, and the average particle size is 55.04 nm, which is a nano-particle (<200 nm). Generally speaking, the size of the particle has an important influence on the formation and stability of the emulsion, and the size of the emulsion droplet is positively correlated with the particle size, and the stability of the emulsion is negatively correlated with the particle size. The smaller the particle size, the larger the surface area of the particle, the stronger the adsorption force, and the smaller the emulsion droplet. Small droplets are more conducive to maintaining the stability of the emulsion. Combined with the particle size distribution of the emulsion prepared by the malt dextrin embedding garlic essential oil in the specification attached

[0097] Basic index determination results of garlic essential oil microcapsules

[0098] Basic physicochemical index of microcapsules

[0099]

[0100] The moisture content of the microcapsule powders prepared in Examples 1-4 was mainly affected by the inlet air temperature and the solids content of the emulsion. In the food industry, the moisture content of powders is generally required to be 2%–5% to ensure good product stability. The optimized garlic oil microcapsule powder had a moisture content of 2.64±0.48%, and there was no significant difference in moisture content among the three wall material microcapsules (P<0.05), meeting the requirements for food powder moisture content. Water activity reflects the degree of binding between water and non-aqueous components in the powder. Microorganisms basically do not grow in powders with a water activity below 0.6, mainly because garlic oil has strong antioxidant and antibacterial properties, resulting in minimal microbial growth and low water activity in the microcapsule powder. The water activity of the composite wall material microcapsules was 0.13±0.01, which was not significantly different from that of the maltodextrin garlic oil microcapsules (P<0.05), but slightly higher than that of the grapefruit peel powder garlic oil microcapsules. The angle of repose and the angle of slip are important visual standards for measuring the flowability of powders. An angle of repose and an angle of slip of 30° to 45° are considered to indicate good flowability. The bulk density of maltodextrin garlic oil microcapsule powder is 0.37±0.02, and the bulk density of composite wall material microcapsule powder is 0.31±0.01, which is higher than that of grapefruit peel powder garlic oil microcapsule powder. Higher bulk density can reduce the packaging volume of microcapsule powder, which is beneficial for the storage and transportation of microcapsule powder.

[0101] Garlic essential oil microcapsule characterization

[0102] Included in the instruction manual Figure 3 It can be seen that the garlic essential oil microcapsule product has a relatively uniform particle size distribution, a relatively complete surface structure, and is dense and free of cracks, resulting in a good encapsulation effect on garlic essential oil. (See attached instruction manual.) Figure 4 The measured particle size results were consistent; the garlic essential oil microcapsules exhibited a uniform, normally distributed particle size, primarily ranging from 1 to 100 μm, with an average particle size of 18.353 μm. This indicates that the garlic essential oil microcapsule product prepared under the optimal process has good dispersibility. The uneven surface and depressions of the microcapsules may be due to the instantaneous high temperature during spray drying. After the surface moisture evaporates, internal moisture moves to the outer layer, causing unevenness on the microcapsule surface and internal collapse. The interaction force between the wall material maltodextrin and grapefruit peel powder is strengthened after combination, allowing it to withstand greater spray drying airflow pressure. Therefore, the garlic essential oil microcapsule product has high efficiency and good storage stability.

[0103] Thermal stability analysis of garlic essential oil microcapsules

[0104] From the instruction manual Figure 5It can be seen that the garlic essential oil is very sensitive to heat, and the mass of the garlic essential oil decreases rapidly between 25°C and 205°C, which reflects the strong volatility of the garlic essential oil, mainly due to the volatile degradation of the organic sulfides in the garlic essential oil, and the weight loss rate reaches a maximum at 151°C, at which time the garlic essential oil microcapsule only loses about 3.8%, mainly due to the loss of water in the microcapsule and the volatilization of a small amount of surface essential oil, indicating that the thermal stability of the garlic essential oil is significantly improved by embedding with maltodextrin and pomelo peel powder, and the garlic essential oil has been basically volatilized completely at about 310°C, and the thermal decomposition residual mass is 1.76%. Maltodextrin and pomelo peel powder have a stage of weight loss below 80°C, mainly due to the volatilization of some small organic molecules and water. The second stage of the garlic essential oil microcapsule is mainly the thermal degradation stage, and the degradation rate starts to gradually accelerate from 125°C, and tends to be flat at about 500°C, this process first damages the structure of the microcapsule sample, and the wall material starts to thermally decompose, and the core material is released and volatilized from the microcapsule, and the second step is the thermal decomposition of each substance in the microcapsule, and the degradation rate reaches a maximum at 308°C, the maximum thermal degradation rate temperature values of the garlic essential oil microcapsule, maltodextrin and pomelo peel powder in this stage are similar, but the mass loss rate of the garlic essential oil microcapsule is significantly lower than that of the maltodextrin at this time, which may be due to the interaction between maltodextrin and pomelo peel powder, causing the thermal properties of the microcapsule to change. During the entire thermal degradation process, the weight loss rate of the microcapsule is about 82%, indicating that the thermal stability of the garlic essential oil microcapsule is good, and it is suitable for food industry production.

[0105] Simulated human release performance of garlic essential oil

[0106] By the description attached Figures 6-9 It can be seen that the garlic essential oil microcapsules of Examples 1-4 exhibit good sustained-release performance in simulated in vitro digestion. In the simulated gastric juice stage, the garlic essential oil microcapsules in Examples 1-4 all exhibit similar rules, and slowly release in the simulated gastric juice stage, among which the cumulative release rate of the garlic essential oil microcapsule in Example 1 in the simulated gastric juice reaches 26.48%. When transferred from the gastric juice digestion stage to the intestinal juice digestion stage, it is observed that the rapid release in the first 90 min (120-210 min) of the simulated intestinal juice digestion stage, and then continues to release until 360 min. The rapid release of the core material in the intestinal juice is beneficial to the absorption of the human body, and the best absorption site of the drug is the upper small intestine or the duodenum, and the rectum is rich in blood vessels, which is the absorption site of the suppository. The sustained slow release of the core material in the gastrointestinal tract can effectively improve its bioavailability, and the rapid release result may be due to the aggregation of bile acids, bile salts and phospholipids in the simulated intestinal juice to form mixed micelles or complexes, which destroys the microcapsule structure, resulting in larger pore size and increased permeability. The partial destabilization of the garlic essential oil microcapsule in the intestinal juice can release the garlic essential oil in the garlic essential oil microcapsule in the intestinal tract, so as to be more effectively absorbed and utilized. From the attached Figure 10 and 11It is apparent that the release process in the early stage is substantially linear, and the release rate in the intestinal tract is lower than that in Examples 1 to 4 for the first two hours.

Claims

1. An enteric release garlic essential oil microcapsule, the preparation raw material comprising a core material, a wall material and an emulsifier, characterized in that, The core material is garlic essential oil, and the mass / volume ratio of garlic essential oil to water is 1.3%-12.5%. The wall material is a mixture of malt dextrin and pomelo peel powder, and the mass / volume ratio of malt dextrin to water is 5%-22%, and the mass / volume ratio of pomelo peel powder to water is 2%-13%. The emulsifier is Tween-80, and the mass / volume ratio of Tween-80 to water is 0.1%-0.5%. The preparation method of the intestinal release garlic essential oil microcapsule is as follows: (1) 5%-22% malt dextrin and 2%-13% pomelo peel powder are taken according to the mass / volume ratio, and distilled water is added. Stirring is carried out at 55-65 DEG C, and after complete dissolution, 1.3%-12.5% garlic essential oil and 0.1%-0.5% Tween-80 are added; (2) an initial emulsion is formed by shearing emulsification at 10000-12000 r / min for 5-10 min using a high-speed dispersion machine, and the initial emulsion is high-pressure homogenized, wherein the pressure of the high-pressure homogenization is 20-50 MPa, and a uniform garlic essential oil emulsion is obtained; (3) the garlic essential oil emulsion is spray dried to obtain the intestinal release garlic essential oil microcapsule; The preparation method of the pomelo peel powder is as follows: after the outer skin of a fresh pomelo is removed, the pulp is crushed into coarse powder, and the coarse pomelo peel powder is obtained by sieving through a 40-80 mesh screen. The coarse pomelo peel powder is ultra-micro pulverized by a ball mill for 1-2 h to obtain the pomelo peel powder.

2. The enteric garlic essential oil microcapsules according to claim 1, characterized by: The flow rate of the spray drying is 500-800 mL / h, the inlet air temperature is 120 DEG C-180 DEG C, and the outlet air temperature is 70-90 DEG C.

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