Lavender essential oil microcapsule as well as preparation method and application thereof

Abstract

The invention provides a lavender essential oil microcapsule as well as a preparation method and application thereof, and belongs to the technical field of essential oil. The invention provides a lavender essential oil microcapsule, a core material comprises lavender essential oil, and raw materials of a wall material comprise plant-derived pectin and protein. The lavender essential oil microcapsule with good slow release performance and stability is obtained through a complex coacervation method. The lavender essential oil microcapsule disclosed by the invention has a relatively high application value in the fields of food and textile, for example, the food fresh-keeping time limit can be greatly prolonged; the antibacterial agent is used for inhibiting bacteria of cotton fabrics and has a remarkable antibacterial effect on escherichia coli and staphylococcus aureus.

Description

Technical Field

[0001] The present invention belongs to the technical field of essential oils, and particularly relates to a lavender essential oil microcapsule, a preparation method thereof and an application thereof. Background Art

[0002] Lavandula pedunculata belongs to the genus Lavandula of the Lamiaceae family. Its leaf shape and flower color are graceful and elegant, and its blue-purple inflorescence is long and beautiful. It is a new perennial cold-resistant flower in the garden, suitable for planting in clusters or rows in the flower bed, and can also be potted for viewing. Lavender has been widely used in medicine since ancient times. Its stems and leaves can be used as medicine, with the effects of strengthening the stomach, promoting sweating and relieving pain, and it is a good medicine for treating colds, abdominal pains and eczema.

[0003] Essential oil is an aromatic substance, generally an aromatic molecule extracted from plants, which is an important product for industries such as perfumes, seasonings, cosmetics, etc., and the main raw material for aromatherapy. Lavender essential oil has attracted much attention due to its various effects such as sterilization, calming the nerves, skin care, anti-inflammatory and relieving muscle soreness. However, due to the influence of factors such as temperature and light during the storage and use of lavender essential oil, its stability and use effect are reduced, which limits its application fields. Therefore, it is necessary to develop a coating method to encapsulate lavender essential oil in a certain wall material to reduce the contact between the essential oil and the external environment, thereby enhancing its stability and sustained-release performance and broadening its application fields. Summary of the Invention

[0004] The present invention provides a lavender essential oil microcapsule, a preparation method thereof and an application thereof. The lavender essential oil microcapsule has good sustained-release performance and thermal stability, and has high application value in many fields.

[0005] The present invention provides a lavender essential oil microcapsule, which comprises a core material and a wall material. The raw material of the core material includes lavender essential oil, and the raw materials of the wall material include plant-derived pectin and protein.

[0006] In a preferred embodiment of the present invention, the plant-derived pectin includes lavender pectin.

[0007] In a preferred embodiment of the present invention, the protein includes at least one of the following: hydrolyzed milk protein, gelatin, bovine serum albumin and sodium caseinate.

[0008] In a preferred embodiment of the present invention, the mass ratio of the protein to the plant-derived pectin is 3-7:1, and the mass ratio of the core material to the wall material is 1:0.2-2.

[0009] The present invention also provides a method for preparing the above-mentioned lavender essential oil microcapsules, which includes the following steps: (1) Mix an aqueous solution of protein, an aqueous solution of pectin and lavender essential oil to form microcapsules; the mass concentrations of the aqueous solution of protein and the aqueous solution of pectin are both 1.5-3.5%.

[0010] (2) Dry the microcapsules obtained in step (1) to obtain the lavender essential oil microcapsules.

[0011] In a preferred embodiment of the present invention, the mixing in step (1) includes high-speed shearing and stirring in sequence; the rotation speed of the high-speed shearing is 6000-9000 rpm, and the time is 3-6 min; after adjusting the pH value to 4.0-4.5, perform the first stirring, the temperature of the first stirring is 40-60 °C, the rotation speed is 350-550 rpm, and the stirring time is 10-60 min;

[0012] After the first stirring, cool down to 5 °C, and then perform the second stirring, the rotation speed of the second stirring is 350-550 rpm, and the stirring time is 1-2 h.

[0013] In a preferred embodiment of the present invention, before drying in step (2), it further includes mixing the microcapsules with an acetic acid solution of chitosan, the mass concentration of chitosan in the acetic acid solution of chitosan is 1%, and the addition amount of chitosan is 20%-40% of the total mass of the protein and pectin.

[0014] In a preferred embodiment of the present invention, before the mixing, it further includes adjusting the pH to 4.3-4.8, and then performing stirring, the rotation speed of the stirring is 350-550 rpm, and the stirring time is 10-60 min.

[0015] The present invention also provides the application of the above-mentioned lavender essential oil microcapsules as a preservative.

[0016] The present invention also provides the application of the above-mentioned lavender essential oil microcapsules in textiles.

[0017] Beneficial effects: The present invention uses lavender essential oil as the core material, and plant-derived pectin, protein and chitosan as the wall materials, and obtains a lavender essential oil microcapsule with good slow-release performance and stability through the complex coacervation method. The release rates of the lavender essential oil microcapsules of the present invention are 15.40% and 26.53% respectively after being stored at 4 °C and 25 °C for 14 days, and the slow-release property is good; after being heated at 100 °C for 60 min, the retention rate can reach 69.24%, and the thermal stability is good. The lavender essential oil microcapsules of the present invention have high application value in the food and textile fields. For example, in the examples, the lavender essential oil microcapsules are used for the postharvest preservation of flat peaches, which can greatly improve the preservation time limit; for the antibacterial of cotton fabrics, it has a significant antibacterial effect on Escherichia coli and Staphylococcus aureus. Brief Description of the Drawings

[0018] Figure 1 is a comparison chart of the embedding rates of lavender essential oil microcapsules in Examples 1-5 and Comparative Example 1 of the present invention;

[0019] Figure 2 is a sustained-release performance chart of the lavender essential oil microcapsules in Example 5 of the present invention at different temperatures;

[0020] Figure 3 is a comparison chart of the high-temperature sustained-release performances of the lavender essential oil microcapsules and lavender essential oil in Example 5 of the present invention;

[0021] Figure 4 is an appearance chart of the preservation of flat peaches by the lavender essential oil microcapsule group and the control group in Example 5 of the present invention at different temperatures;

[0022] Figure 5 is the hardness of flat peaches by the lavender essential oil microcapsule group and the control group in Example 5 of the present invention at different temperatures;

[0023] Figure 6 is the malondialdehyde content of flat peaches by the lavender essential oil microcapsule group and the control group in Example 5 of the present invention at different temperatures;

[0024] Figure 7 is an antibacterial effect chart of the lavender essential oil microcapsule cotton fabric and the control group on Escherichia coli in Example 5 of the present invention;

[0025] Figure 8 is an antibacterial effect chart of the lavender essential oil microcapsule cotton fabric and the control group on Staphylococcus aureus in Example 5 of the present invention;

[0026] Figure 9 is a scanning electron microscope image of the lavender essential oil microcapsules prepared in Example 5 of the present invention. Detailed Embodiments

[0027] The present invention provides a lavender essential oil microcapsule, comprising a core material and a wall material, wherein the raw materials of the core material include lavender essential oil, and the raw materials of the wall material include plant-derived pectin and protein.

[0028] The present invention does not particularly limit the source of the lavender essential oil, which can be prepared by itself or directly prepared from commercially available products. For example, in an embodiment of the present invention, lavender essential oil purchased from the Lavender Base of the 65th Regiment of Yili, Xinjiang is selected. The main components of the essential oil are linalool and linalyl acetate, with contents of 29.07% and 17.71% respectively.

[0029] The plant-derived pectin described in the present invention includes lavender pectin. The lavender pectin uses the lavender residue after essential oil extraction as the raw material, and the lavender pectin is extracted by an ultrasonic-assisted method. Lavender essential oil microcapsules are prepared using the lavender pectin as the wall material. In the examples of the present invention, a comparative example is also set. In the comparative example, citrus pectin (galacturonic acid ≥ 58.0%, methoxy ≥ 6%) purchased from Beijing Solarbio Science & Technology Co., Ltd. is used as the wall material to prepare lavender essential oil microcapsules.

[0030] The preparation method of the lavender pectin described in the present invention includes crushing and sieving the air-dried lavender residue, and extracting the lavender pectin by an ultrasonic-assisted method. The extraction parameters used can be as follows: using a citric acid aqueous solution with a pH of 1.5 - 3.5, a solid-liquid ratio of 1 g:25 - 50 mL, an ultrasonic power of 80 - 120 W, a temperature of 40 - 60 °C, an ultrasonic time of 30 - 90 min. After the extraction, centrifuge at 8000 rpm for 5 min to collect the supernatant. Use a rotary evaporator to concentrate the supernatant to 15% of the original volume, then add anhydrous ethanol with a volume 1.5 times that of the concentrated solution for precipitation. After precipitation for 2 - 4 h, centrifuge at 4800 rpm for 10 min, pour off the supernatant, then wash the precipitate with 75% ethanol. Repeat the above steps of centrifuging and pouring off the supernatant, and then freeze-dry at -45 - 50 °C for 20 - 36 h to obtain lavender pectin.

[0031] In the present invention, the pectin is a natural polysaccharide with good water solubility, which is easy to mix evenly with the essential oil to form a stable embedding system; at the same time, the pectin has excellent film-forming properties and can form a dense protective film on the surface of the essential oil, effectively preventing the direct contact between the essential oil and the external environment. In an embodiment of the present invention, lavender essential oil microcapsules are prepared using lavender pectin as the wall material, embedding its active ingredients based on the raw material components of the plant itself, which can not only maintain the activity of the essential oil to the greatest extent, but also realize the high-value utilization of the raw materials.

[0032] The protein described in the present invention includes at least one of the following: hydrolyzed milk protein, gelatin, bovine serum albumin, and sodium caseinate. In a preferred manner, it is one of hydrolyzed milk protein, gelatin, bovine serum albumin, and sodium caseinate, and the mass ratio of the protein to the plant-derived pectin is 3 - 7:1, such as 3:1, 4:1, 5:1, 6:1, or 7:1; and the mass ratio of the core material to the wall material is 1:0.2 - 2, such as 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, or 1:2. The protein described in the present invention has excellent emulsifying properties and film-forming properties as the wall material, and can effectively improve the encapsulation efficiency and stability through electrostatic interaction with pectin.

[0033] The present invention also provides a method for preparing the above-mentioned lavender essential oil microcapsules, which includes the following steps: (1) Mix an aqueous solution of protein, an aqueous solution of pectin and lavender essential oil to form microcapsules; the mass concentration of both the aqueous solution of protein and the aqueous solution of pectin is 1.5-3.5%.

[0034] (2) Dry the microcapsules obtained in step (1) to obtain the lavender essential oil microcapsules.

[0035] Before preparing the lavender essential oil microcapsules of the present invention, the protein and pectin in the raw materials need to be dissolved separately. The solvents for the protein and pectin can be distilled water; and chitosan can also be coated on the surface of the complex coacervation microcapsules, which can effectively reduce the sensitivity of the microcapsules to the external environment, thereby improving their stability. The solvent for the chitosan can be an acetic acid solution. In one embodiment, 1% acetic acid solution is used to dissolve chitosan. The chitosan used in the present invention is purchased from the market. For example, in one embodiment, it is purchased from Macklin Biochemical Technology Co., Ltd. Coating chitosan on the surface of the complex coacervation microcapsules can effectively reduce the sensitivity of the microcapsules to the external environment, thereby improving their stability. The addition amount of chitosan is 20%-40% of the total mass of the wall materials (protein and pectin).

[0036] In one embodiment of the method for preparing the lavender essential oil microcapsules of the present invention, an aqueous solution of pectin and lavender essential oil is added to the dissolved aqueous protein solution. After high-speed shearing at a certain rotation speed and time, the pH of the system is adjusted, and then stirred at a certain temperature and rotation speed for a certain time; then cooled to 5°C using an ice-water bath and stirred for a certain time to shape the microcapsules; then a chitosan solution is added, the pH of the system is adjusted, and stirred at a certain temperature for a certain time, and then freeze-dried to obtain the lavender essential oil microcapsules.

[0037] The rotation speed of the high-speed shearing in the present invention is 6000-9000 rpm, and the time is 3-6 min; after adjusting the pH value to 4.0-4.5, the first stirring is carried out. The temperature of the first stirring is 40-60°C, the rotation speed is 350-550 rpm, and the stirring time is 10-60 min; after the first stirring, it is cooled to 5°C using an ice-water bath, and then the second stirring is carried out. The rotation speed of the second stirring is 350-550 rpm, and the stirring time is 1-2 h. After the microcapsules are shaped, a chitosan solution is added thereto in the present invention, the pH is adjusted to 4.3-4.8, and then stirred. The rotation speed of the stirring is 350-550 rpm, and the stirring time is 10-60 min.

[0038] The present invention also provides the application of the above-mentioned lavender essential oil microcapsules as a preservative.

[0039] The preservative described in the present invention can be a food preservative, such as a fruit preservative. In Example 5, the lavender essential oil microcapsules are used as a preservative for flat peaches. The lavender essential oil microcapsules are placed in a breathable non-woven cloth bag and hung in the container for holding flat peaches, without direct contact with the flat peach fruits, for example, hung on the side wall of a polypropylene plastic box.

[0040] The present invention also provides the application of the above-mentioned lavender essential oil microcapsules in textiles.

[0041] The present invention does not particularly limit the type of the textiles, which can be cotton fabrics. The impregnation method can be used to finish the lavender essential oil microcapsules on the cotton fabric, which can play a bacteriostatic role, such as inhibiting Escherichia coli and Staphylococcus aureus.

[0042] To further illustrate the present invention, the following examples are used to describe in detail a kind of lavender essential oil microcapsules provided by the present invention, its preparation method and application, but they cannot be understood as limiting the protection scope of the present invention.

[0043] Example 1

[0044] Lavender pectin was extracted by ultrasonic-assisted method. The extraction conditions were as follows: using a citric acid aqueous solution with a pH of 2.5, a solid-to-liquid ratio of 1:35, an ultrasonic power of 100 W, a temperature of 50 °C, ultrasonic treatment for 60 min. After extraction, the supernatant was collected by centrifugation at 8000 rpm for 5 min, and the supernatant was concentrated by a rotary evaporator to 15% of the original volume. Then, 1.5 times the volume of anhydrous ethanol of the concentrated solution was added for precipitation. After precipitation for 3 h, centrifugation was carried out at 4800 rpm for 10 min, the supernatant was decanted, and the precipitate was washed with 75% ethanol. The above steps of centrifugation and decanting the supernatant were repeated, and the precipitate was freeze-dried to obtain lavender pectin.

[0045] Hydrolyzed milk protein was dissolved in distilled water to prepare a hydrolyzed milk protein solution with a mass concentration of 2.5%; lavender pectin with a mass concentration of 2.5% was prepared by dissolving it in distilled water; then the lavender pectin solution was slowly added dropwise to the hydrolyzed milk protein solution, where the mass ratio of protein to pectin was 5:1; then lavender essential oil with a core-wall ratio of 1:1 was added and sheared at a high speed of 8000 rpm for 5 min, and then the pH was adjusted to 4.4, and stirred at 45 °C and a rotation speed of 450 rpm for 30 min; subsequently, the temperature of the system was rapidly lowered to 5 °C using an ice-water bath, and stirred at a rotation speed of 450 rpm for 1 h to shape the microcapsules. Finally, the lavender essential oil microcapsules were obtained by freeze-drying.

[0046] Example 2

[0047] The difference from Example 1 was that hydrolyzed milk protein was replaced with gelatin, and the others were the same as Example 1.

[0048] Example 3

[0049] The difference from Example 1 is that the hydrolyzed milk protein is replaced by bovine serum albumin, and the others are the same as Example 1.

[0050] Example 4

[0051] The difference from Example 1 is that the hydrolyzed milk protein is replaced by sodium caseinate, and the others are the same as Example 1.

[0052] Example 5

[0053] The differences from Example 1 and Example 4 are as follows: Before the step of cooling and shaping the microcapsules, dissolve sodium caseinate with distilled water to prepare a sodium caseinate solution with a mass concentration of 2.5%; dissolve lavender pectin with distilled water to prepare a lavender pectin solution with a mass concentration of 2.5%; then slowly drip the lavender pectin solution into the sodium caseinate solution, where the mass ratio of protein to pectin is 5:1; then add lavender essential oil with a core-wall ratio of 1:1 and perform high-speed shearing at 8000 rpm for 5 min, and then adjust the pH to 4.4 and stir at 45°C and a rotation speed of 450 rpm for 30 min; before the step of cooling and shaping the microcapsules, add a chitosan solution, the mass of which is 30% of the total mass of sodium caseinate-lavender pectin, adjust the pH to 4.5, stir at 50°C and a rotation speed of 450 rpm for 30 min, and finally obtain lavender essential oil microcapsules by freeze-drying.

[0054] Perform electron microscopy scanning on the lavender essential oil microcapsules prepared in Example 5. The scanning electron micrograph is as Figure 9 shown. The particle size of the prepared lavender essential oil microcapsules is about 10 μm. The surface of the microcapsules is smooth and the size is relatively uniform, which can be better dispersed evenly, and play a stable, long-lasting and excellent antibacterial and fresh-keeping effect.

[0055] Comparative Example 1

[0056] The difference from Example 4 is that the lavender pectin is replaced by citrus pectin, and the others are the same as Example 4.

[0057] 1. Compare the encapsulation rates of the lavender essential oil microcapsules prepared in Examples 1 to 5 and Comparative Example 1 respectively. The encapsulation rate of Example 5 reaches 76.7%, and the encapsulation rate of Comparative Example 1 is 57.8% ( Figure 1 ).

[0058] Specific method for measuring the encapsulation efficiency: Take 0.1 g of the lavender essential oil microcapsules prepared in Examples 1 to 5 and Comparative Example 1 respectively, mix them with 5 mL of absolute ethanol, take the filtrate to measure its absorbance, obtain the surface oil content of the microcapsules, and calculate the surface oil content in the microcapsules according to the standard curve; then take 0.1 g of the lavender essential oil microcapsules prepared in Examples 1 to 5 and Comparative Example 1 respectively, add 5 mL of absolute ethanol for ultrasonic treatment, the ultrasonic temperature is 25 °C, the ultrasonic power is 100 W, after ultrasonic treatment for 30 min, take the filtrate to measure its absorbance, obtain the total oil content of the microcapsules, and calculate the content of the total essential oil in the microcapsules according to the standard curve. Calculate the encapsulation efficiency of the lavender essential oil according to the following formula:

[0059] Encapsulation efficiency % = (total oil content of microcapsules - surface oil content of microcapsules) / total oil content of microcapsules × 100%.

[0060] 2. Compare the sustained-release properties of the lavender essential oil microcapsules prepared in Examples 1 to 5 and Comparative Example 1. It is found that after storing the lavender essential oil microcapsules described in Example 5 for 14 days at 4 °C, the release rate of the lavender essential oil is 15.40%; at 25 °C, it is 26.53%( Figure 2 ).

[0061] Method for measuring the sustained-release property: Accurately weigh a certain mass of the lavender essential oil microcapsules into a reagent bottle and seal it. Place it at 4 °C and 25 °C respectively, and sample on the 1st, 2nd, 4th, 6th, 8th, 10th, 12th, and 14th days respectively. Use a UV spectrophotometer to measure the content of the lavender essential oil in the microcapsules. Thus, the relative cumulative release rate of the lavender essential oil in a certain time period can be obtained. Calculate the relative cumulative release rate according to the following formula:

[0062] Relative cumulative release rate % = (1 - total oil content of microcapsules at time t / initial total oil content of microcapsules) × 100%.

[0063] 3. Detect the high-temperature sustained-release property. After heating at 100 °C for 60 min, the lavender essential oil has completely volatilized, while the retention rate of the microcapsules prepared by the present invention can reach 69.24%, showing high stability( Figure 3 ).

[0064] Method for measuring the high-temperature sustained-release property: Put the microcapsules and the lavender essential oil into a constant temperature incubator. Adjust the temperature to 100 °C. Sample every 10 min, measure the total oil content of the lavender essential oil in the microcapsules at this time through a UV-visible spectrophotometer, and weigh the mass of the lavender essential oil at the same time. Calculate the high-temperature retention rate according to the following formula:

[0065] High-temperature retention rate % = (1 - content of initial lavender essential oil / total oil content of microcapsules at time t) × 100%.

[0066] Experimental Example 1

[0067] The specific content of flat peach preservation includes the following steps:

[0068] Fresh flat peaches purchased locally with similar maturity and size were randomly divided into two groups, namely the control group and the experimental group, and placed in polypropylene plastic boxes respectively. The flat peaches in the control group were directly packed into the polypropylene plastic boxes, while in the experimental group, the lavender essential oil microcapsules described in Example 5 were placed in a breathable non-woven fabric bag and put into the polypropylene plastic box without directly touching the flat peaches.

[0069] At different temperatures, the preservation effect of flat peaches is as Figure 4 shown. After storing for 6 days and 24 days at 25°C and 4°C, all the flat peaches in the control group became moldy and spoiled, while the flat peaches in the microcapsule group did not become moldy and some of them maintained a good appearance. This proves that the lavender essential oil microcapsules can effectively preserve flat peaches.

[0070] The change in the hardness of flat peaches is as Figure 5 shown. During the storage period, the hardness of flat peaches generally showed a continuous downward trend. At 25°C, on the 6th day, the hardness of the flat peaches in the control group dropped to 0.65 N, with a decrease rate as high as 77.59%, showing a significant loss of hardness; in contrast, the hardness of the flat peaches in the microcapsule group only dropped to 2.35 N, with a decrease rate of 18.97%, and the change in hardness was relatively small. Under the same storage conditions, at 4°C, the hardness of the flat peaches in the control group and the microcapsule group was 2.3 N and 2.7 N respectively. Compared with that at 25°C, the rate of hardness decrease of flat peaches at 4°C was significantly slower. This indicates that the microcapsule treatment can effectively delay the process of hardness decrease of flat peaches, and this delaying effect is better under lower temperature storage.

[0071] The change in the content of malondialdehyde is as Figure 6 shown. With the extension of the storage time, the content of malondialdehyde in flat peaches showed an increasing trend. On the 6th day, the content of malondialdehyde in the flat peaches in the control group at 25°C and 4°C reached 2.35% and 0.50% respectively, while the content of malondialdehyde in the flat peaches in the microcapsule group was 0.98% and 0.47% respectively, which was significantly lower than that in the control group. The growth rate of the content of malondialdehyde in the control group was relatively fast, while the upward trend in the microcapsule treatment group was relatively gentle and the increase amplitude was smaller. This shows that the microcapsule treatment can slow down the increase in the content of malondialdehyde in flat peaches.

[0072] Experimental Example 2

[0073] The specific content of the preparation of antibacterial cotton fabric and the antibacterial experiment includes the following steps:

[0074] Soak the cotton fabric in deionized water for 30 min to wash away the impurities on the cotton fabric, then wash it under running water and air dry for later use. Uniformly mix 15 g / L of the lavender essential oil microcapsules described in Example 5, 3% (by mass) of aqueous polyurethane, and a certain amount of distilled water at room temperature for 30 min to evenly distribute the microcapsules in the system. Immerse the pretreated pure cotton hydroentangled nonwoven fabric into the above finishing solution, with a liquor ratio of 1:30, an impregnation time of 1 h, and an impregnation temperature of 40 °C. Subsequently, bake the finished cotton fabric at a high temperature of 80 °C for 3 min, and finally air dry at room temperature. Among them, the main difference between the control group and the microcapsule group is that the control group does not add microcapsules, and the remaining steps are the same.

[0075] The antibacterial performance of the cotton fabric was detected by the inhibition zone method, and the tested bacteria were the Gram-negative bacterium Escherichia coli and the Gram-positive bacterium Staphylococcus aureus.

[0076] The antibacterial effect of the lavender essential oil microcapsule cotton fabric described in Example 5 of the present invention against Escherichia coli is as Figure 7 shown. An obvious inhibition zone appeared around the fabric sample finished in Example 5, and the diameter of the inhibition zone reached 29.1 ± 0.9 mm. Compared with the untreated control group, the antibacterial effect of the microcapsule group against Escherichia coli was obvious, and this finding verified the effectiveness of the microcapsule technology in enhancing the antibacterial performance of cotton fabric.

[0077] The antibacterial effect against Staphylococcus aureus is as Figure 8 shown. The control group fabric sample was completely covered with Staphylococcus aureus and no inhibition zone was formed, while the fabric sample finished in Example 5 had an obvious inhibition zone, and the diameter of the inhibition zone reached 29.3 ± 0.3 mm. This indicates that the fabric sample finished in the microcapsule group has better antibacterial performance against Staphylococcus aureus, and the complex coacervation microcapsule technology can effectively retain the antibacterial active ingredients in the essential oil.

[0078] Although the above embodiments have made a detailed description of the present invention, they are only a part of the embodiments of the present invention, rather than all embodiments. People can also obtain other embodiments according to this embodiment without creative efforts, and these embodiments all belong to the protection scope of the present invention.

Claims

1. A lavender essential oil microcapsule, characterized in that: It comprises a core material and a wall material, wherein the raw material of the core material comprises lavender essential oil, and the raw material of the wall material comprises plant-derived pectin and protein.

2. The lavender essential oil microcapsule according to claim 1, characterized in that: The plant-derived pectin includes lavender pectin.

3. The lavender essential oil microcapsule according to claim 1, characterized in that: The protein comprises at least one of the following: hydrolyzed milk protein, gelatin, bovine serum albumin and sodium caseinate.

4. The lavender essential oil microcapsule according to claim 1, characterized in that: The mass ratio of the protein to the plant-derived pectin is 3-7:1, and the mass ratio of the core material to the wall material is 1:0.2-2.

5. The method for preparing the lavender essential oil microcapsules according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: (1) mixing a protein aqueous solution, a pectin aqueous solution and lavender essential oil to form microcapsules; the mass concentrations of the protein aqueous solution and the pectin aqueous solution are both 1.5-3.5%; (2) Drying the microcapsules in step (1) to obtain the lavender essential oil microcapsules.

6. The preparation method according to claim 5, characterized in that: The mixing in step (1) includes sequentially performing high-speed shearing and stirring; the speed of the high-speed shearing is 6000-9000 rpm, and the time is 3-6 min; after adjusting the pH value to 4.0-4.5, a first stirring is performed, and the temperature of the first stirring is 40-60° C., the speed is 350-550 rpm, and the stirring time is 10-60 min; After the first stirring, the temperature is lowered to 5° C., and then a second stirring is performed. The second stirring has a rotation speed of 350 to 550 rpm and a stirring time of 1 to 2 hours.

7. The preparation method according to claim 5, characterized in that: Before the drying in step (2), the microcapsules are mixed with an acetic acid solution of chitosan, wherein the mass concentration of chitosan in the acetic acid solution of chitosan is 1%, and the amount of chitosan added is 20% to 40% of the total mass of the protein and pectin.

8. The preparation method according to claim 7, characterized in that: The method further comprises adjusting the pH value to 4.3-4.8 before mixing, and then stirring the mixture. The stirring speed is 350-550 rpm, and the stirring time is 10-60 min.

9. Use of the lavender essential oil microcapsules according to any one of claims 1 to 8 as a preservative.

10. Use of the lavender essential oil microcapsules according to any one of claims 1 to 8 in textiles.

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