Dementholized peppermint oil with good film-forming property and preparation method thereof

Abstract

The invention discloses dementholized peppermint oil with good film-forming property and a preparation method thereof, and belongs to the technical field of dementholized peppermint oil preparation, the dementholized peppermint oil specifically comprises the following components by weight: 40-60 parts of L-menthol, 5-15 parts of D-menthol, 5-15 parts of menthyl acetate, 10-20 parts of menthone, 2-8 parts of pulegone, 3-8 parts of beta-caryophyllene, and 30-50 parts of a film-forming agent compound, the dementholized peppermint oil is enhanced and modified through the modified chitosan, the modified PVA 05-88, the modified PVA 17-88, the modified PVA 124, the octanol-3, the glycerol and the vitamin C, so that not only is the film-forming property of the dementholized peppermint oil effectively improved, but also the antibacterial property and the oxidation resistance of the dementholized peppermint oil are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of peppermint oil preparation, and specifically relates to peppermint oil with good film-forming property and its preparation method. Background Art

[0002] As a volatile terpene compound extracted from natural mint, peppermint oil has a special cool aroma and is widely used in industries such as food, cosmetics, and medicine. The main components of peppermint oil are menthol and menthone, which have antibacterial, anti-inflammatory, analgesic, and cool and soothing effects. However, menthol is volatile, which makes the cool time of peppermint oil shorter and it is not easy to store.

[0003] However, there are certain defects in the film-forming property of peppermint oil in the prior art:

[0004] Firstly, the molecular weight of ordinary chitosan is relatively low and the compatibility of the degree of polymerization of PVA is insufficient, resulting in a decrease in the mechanical strength of the composite film, making it difficult to meet the stability requirements for sustained release and greatly shortening the cool time.

[0005] Secondly, the antibacterial activity is limited by pH conditions and solubility, and the inhibition efficiency against microbial contamination is relatively low. Insufficient hydrophilicity may lead to uneven film layers and easy swelling and degradation in a humid environment, affecting long-term stability.

[0006] In addition, ordinary chitosan lacks charge modification and cannot inhibit oxygen penetration through a charge barrier, accelerating the oxidative rancidity of oils and fats and greatly shortening the cool time. Quaternary ammonium chitosan can significantly improve antibacterial properties and film-forming properties by introducing cationic groups. Moreover, the solubility and charge density of quaternary ammonium chitosan can be optimized by vitamin C, promoting the molecular chain crosslinking with PVA of different degrees of polymerization, enhancing the barrier performance of the composite film, and improving the antioxidant property and cool time of the film. Summary of the Invention

[0007] The purpose of the present invention is to provide peppermint oil with good film-forming property and its preparation method, so as to solve the technical problems that the antibacterial performance, film-forming time, and cool time of peppermint oil in the prior art need to be further improved.

[0008] The peppermint oil with good film-forming property of the present invention includes the following components by weight: 40 - 60 parts of L-menthol, 5 - 15 parts of D-menthol, 5 - 15 parts of methyl acetate, 10 - 20 parts of menthone, 2 - 8 parts of pulegone, 3 - 8 parts of β-caryophyllene, and 30 - 50 parts of a film-forming agent complex;

[0009] The film-forming agent complex includes the following components by weight: 70 - 85 parts of a polyvinyl alcohol complex, 25 - 40 parts of glycerol, and 1 - 5 parts of vitamin C;

[0010] The polyvinyl alcohol composite is composed of modified PVA 05-88 , PVA 17-88 , PVA 124 and octanol-3 in a dosage ratio of 3 g: 1 g: 3 g: 15 mL.

[0011] Furthermore, the modified PVA 05-88 is prepared by the following steps:

[0012] A1. Add an aqueous solution of 2,3-epoxypropyltrimethylammonium chloride to a flask containing a chitosan acetate solution. Raise the temperature of the flask to 50 - 60 °C, stir for 1 - 2 h, and perform post-treatment to obtain modified chitosan;

[0013] The synthesis mechanism of the modified chitosan is:

[0014] During the reaction, add an aqueous solution of 2,3-epoxypropyltrimethylammonium chloride to the chitosan acetate solution. The epoxy group in 2,3-epoxypropyltrimethylammonium chloride undergoes a nucleophilic ring-opening reaction with the amino group of chitosan, opening the epoxy ring and generating modified chitosan with a cationic quaternary ammonium salt and an ether bond.

[0015] A2. Mix PVA 05-88 , epichlorohydrin, and tetrabutylammonium bromide and stir. Raise the temperature of the flask to 65 - 75 °C, keep the temperature for 40 - 60 min, add sodium hydroxide to the flask, keep the temperature for 160 - 200 min, and perform post-treatment to obtain epoxy PVA 05-88 ;

[0016] The synthesis mechanism of epoxy PVA 05-88 is:

[0017] During the reaction, the epoxy group in epichlorohydrin undergoes a nucleophilic ring-opening reaction with the hydroxyl group in the PVA molecule, introducing the epoxy group into the PVA molecular chain to form epoxy PVA. Tetrabutylammonium bromide acts as a phase transfer catalyst to enhance the electrophilicity of epichlorohydrin and promote the reaction between epichlorohydrin and PVA, ultimately obtaining the modified epoxy PVA 05-88 .

[0018] A3. Add epoxy PVA 05-88 and modified chitosan to a flask. Raise the temperature of the flask to 70 - 80 °C and stir for 3 - 4 h to obtain modified PVA 05-88 .

[0019] The synthesis mechanism of modified PVA 05-88 is:

[0020] During the reaction, epoxy PVA 05-88The epoxy groups therein undergo a nucleophilic ring-opening reaction with the amino groups in the modified chitosan to form new covalent bonds, introducing the chitosan quaternary ammonium salt into PVA 05-88 molecules.

[0021] Furthermore, in step A1, the volume ratio of the aqueous solution of 2,3-epoxypropyltrimethylammonium chloride to the chitosan acetate solution is 1:3, the concentration of the aqueous solution of 2,3-epoxypropyltrimethylammonium chloride is 8-10 wt%, the concentration of the chitosan acetate solution is 2-6 wt%, and the post-treatment includes: after the reaction is completed, adding ethanol to the flask and drying it under vacuum to obtain the modified chitosan.

[0022] Furthermore, in step A2, the dosage ratio of PVA 05-88 , epichlorohydrin, tetrabutylammonium bromide, and sodium hydroxide is 30 g:20 g:0.1 g:0.5 g, and the post-treatment includes: after the reaction is completed, keeping the temperature of the flask at 65-75 °C, reducing the pressure to remove the low-boiling substances, adding ethyl acetate to the flask, reducing the temperature of the flask to room temperature, filtering by suction, transferring the filtrate to a rotary evaporator with a water bath temperature of 55 °C, and reducing the pressure to remove the solvent to obtain epoxy PVA 05-88 .

[0023] Furthermore, in step A3, the mass ratio of epoxy PVA 05-88 to the modified chitosan is 1:3, and the post-treatment includes: after the reaction is completed, standing the complex to defoam and then transferring it to a vacuum drying oven for drying to obtain the modified PVA 05-88 .

[0024] Furthermore, the PVA 05-88 is polyvinyl alcohol with a degree of polymerization of 500-600 and a degree of alcoholysis of 88%; the PVA 17-88 is polyvinyl alcohol with a degree of polymerization of 1700-1800 and a degree of alcoholysis of 88%; the PVA 124 is polyvinyl alcohol with a degree of polymerization of 2400-2500 and a degree of alcoholysis of 98%-99%.

[0025] Furthermore, the preparation method of the film-forming agent complex is: adding the polyvinyl alcohol complex, glycerol, and vitamin C into a flask and stirring, heating the temperature of the flask to 60-70 °C, and performing ultrasonic dispersion for 50-80 min to obtain the film-forming agent complex.

[0026] The present invention also proposes a preparation method of menthol oil with good film-forming properties, including the following steps:

[0027] S1. Sequentially adding L-menthol, D-menthol, methyl acetate, and menthone into a flask, raising the temperature of the flask to 50-60 °C, and stirring for 30 min to obtain a spice mixture;

[0028] S2. Add pulegone and β-caryophyllene to the flask containing the spice mixture, and continue stirring for 15 min to form a transparent oil-phase mixture;

[0029] S3. Add the film-forming agent complex to the flask containing the transparent oil-phase mixture, and emulsify and disperse it at 50-55 °C for 20-30 min to obtain peppermint oil with good film-forming properties.

[0030] The present invention has the following beneficial effects:

[0031] 1. In the present invention, by introducing the combination of quaternary ammonium salt of chitosan, epoxy PVA 05-88 , PVA 17-88 , PVA 124 and octanol-3, the synergistic optimization of multi-dimensional properties can be achieved. The quaternary ammonium group of the quaternary ammonium salt of chitosan can significantly enhance the antibacterial activity. Its optimized water-soluble and hydrophobic groups not only improve the film-forming uniformity, but also improve the flexibility and mechanical strength of the film, while retaining the biocompatibility of natural chitosan; epoxy PVA 05-88 , PVA 17-88 and PVA 124 balance the flexibility and rigidity of the film through the molecular weight gradient design and shorten the film-forming time. Among them, low-molecular-weight PVA 05-88 promotes rapid film formation and enhances ductility, while high-molecular-weight PVA 17-88 and PVA 124 greatly improve the tensile strength through molecular chain entanglement, and high-molecular-weight PVA 17-88 and PVA 124 have a slower drug release rate, significantly improving the cooling time of peppermint oil; the introduction of epoxy groups further enhances the interfacial binding force between the quaternary ammonium salt of chitosan and PVA 05-88 through cross-linking reaction, reduces phase separation and improves the denseness and water resistance of the film; octanol-3, as an auxiliary functional agent, reduces the surface tension of the system through its non-ionic surface activity characteristics and promotes the uniform dispersion of peppermint oil and polymer components.

[0032] 2. In the present invention, adding glycerol can significantly improve the comprehensive performance of the membrane material through multi-dimensional synergistic effects. As an efficient plasticizer, glycerol reduces the rigid interaction between polymer chains, chitosan quaternary ammonium salt and PVA with different molecular weights, enhances the ductility and flexibility of the membrane, making the film more easily adhere to the skin or mucosal surface. At the same time, it adjusts the elastic modulus to avoid brittle fracture of the material and maintains the mechanical integrity of the membrane structure. In addition, the strong hydrophilicity of glycerol locks the moisture in the system through hydrogen bonding, effectively alleviating the problem of film drying and cracking caused by the volatilization of menthol oil, and maintaining the softness and ductility of the membrane for a long time. In the composite system, glycerol, as an interfacial lubricant, can promote the uniform dispersion of components such as chitosan quaternary ammonium salt, PVA and octanol-3, reduce the phase separation phenomenon during film formation, improve the smoothness of the film surface, and at the same time cooperate with octanol-3 to reduce the viscosity of the system to improve the film-forming efficiency and inhibit bubble generation. Glycerol, as a non-toxic and biocompatible component, meets the environmental protection requirements of medical dressings and food packaging, and its emulsifying aid characteristics assist in forming a stable emulsion of menthol oil and water-based polymers, enhancing the tensile strength and elongation at break while retaining the cool feeling and antibacterial activity of menthol oil.

[0033] 3. In the present invention, vitamin C significantly improves the comprehensive performance of the membrane material through multiple synergistic mechanisms. Its strong antioxidant property can inhibit the oxidative degradation of components such as menthol and menthone in menthol oil, maintain the film-forming time and cool time, and at the same time ensure the stability of the drug effect and the uniform transparency of the membrane. Vitamin C and the antibacterial components of menthol oil cooperate to damage the bacterial cell membrane, inhibit the proliferation of pathogenic bacteria and the formation of biofilms. Its water solubility and ability to promote collagen synthesis can enhance the hydrophilicity of the membrane material and its affinity with biological tissues, optimize the surface wettability and accelerate skin repair. In addition, vitamin C cooperates with glycerol through hydrogen bonding to regulate the flexibility of polymer chains and the crosslinking degree of PVA, balance the mechanical strength and ductility, and avoid the problem of membrane softening. Its non-toxic and metabolizable characteristics are compatible with the cool feeling and antibacterial function of menthol oil, prolonging the cool time of menthol oil. Detailed implementation manners

[0034] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0035] In this application, L-menthol is selected from Wuhan Kemi Biopharmaceutical Technology Co., Ltd., with a CAS number of 2216-51-5, a purity of 99%, and an active ingredient content of 99%.

[0036] In this application, D-menthol is selected from Wuhan Chengtian Fine Chemical Co., Ltd., with a CAS number of 15356-60-2, a model number of 15356-60-2, and an active ingredient content of 99%;

[0037] In this application, menthyl acetate is selected from Hubei Xingheng Technology Co., Ltd., with a CAS number of 89-48-5 and an active ingredient content of 99%;

[0038] In this application, menthone is selected from Wuhan Kemi Biomedical Technology Co., Ltd., with a CAS number of 10458-14-7 and an active ingredient content of 99%;

[0039] In this application, pulegone is selected from Wuhan Huaxiang Kejie Biotechnology Co., Ltd., with a CAS number of 89-80-5 and a purity of 99%;

[0040] In this application, β-caryophyllene is selected from Wuhan Smart Bio-Technology Co., Ltd., with a CAS number of 87-44-5 and an active ingredient content of 98%;

[0041] In this application, PVA 05-88 and PVA 17-88 are selected from Xi'an Tianzheng Pharmaceutical Excipients Co., Ltd., with a CAS number of 9002-89-5, a model number of CP2020, and an active ingredient content of 99%;

[0042] In this application, PVA 124 is selected from Guangzhou Qihua Chemical Co., Ltd., with a CAS number of 990-89-5, a brand number of PVA124, a viscosity of 54.0 - 66.0 cps, and a purity of 99%;

[0043] In this application, octanol-3 is selected from Hubei Xingyan New Materials Technology Co., Ltd., with a CAS number of 20296-29-1 and a density of 0.821 g / cm 3 and an active ingredient content of 99%;

[0044] In this application, glycerol is selected from Shandong Xinbaiwei Chemical Co., Ltd., with a CAS number of 56-81-5 and a density of 1.25 g / cm 3 and an active ingredient content of 99%;

[0045] In this application, vitamin C is selected from Sichuan Chengzhu Biotechnology Co., Ltd., with a CAS number of 50-81-7 and an EINECS number of 200-066-2;

[0046] In this application, 2,3-epoxypropyltrimethylammonium chloride is selected from Hubei Yamai Biomedical Co., Ltd., with a CAS number of 3033-77-0 and an active ingredient content of 99%;

[0047] In this application, chitosan is selected from Shaanxi Changji Auxiliary Biotechnology Co., Ltd., with a CAS number of 9012-76-4 and an active ingredient content of 99%.

[0048] In this application, tetrabutylammonium bromide is selected from Shandong Xinghai Chemical Industry Co., Ltd., with a CAS number of 1643-19-2, a model of XH-96, and an active ingredient content of 99%.

[0049] Example 1

[0050] This example provides a preparation method of peppermint oil with good film-forming properties, including the following steps:

[0051] S1. Prepare modified chitosan

[0052] Mix chitosan and 1 wt% acetic acid and stir until the system becomes clear to obtain a 2 wt% chitosan acetate solution.

[0053] Weigh: 10 mL of 8 wt% aqueous solution of 2,3-epoxypropyltrimethylammonium chloride and 30 mL of 2 wt% chitosan acetate solution and add them to a flask. Raise the temperature of the flask to 50 °C, stir for 1 h, and perform post-treatment to obtain modified chitosan.

[0054] S2. Prepare modified PVA 05-88

[0055] Weigh: PVA 05-88 20 g of PVA, 20 g of epichlorohydrin, and 0.1 g of tetrabutylammonium bromide are added to a flask and mixed and stirred. Raise the temperature of the flask to 65 °C, keep the temperature for reaction for 40 min, add 0.5 g of sodium hydroxide to the flask, keep the temperature for reaction for 160 min, and perform post-treatment to obtain epoxy PVA 05-88 ;

[0056] Weigh: epoxy PVA 05-88 5 g of epoxy PVA and 15 g of modified chitosan are added to a flask. Raise the temperature of the flask to 70 °C and stir for 3 h to obtain modified PVA 05-88 。

[0057] S3. Prepare a film-forming agent complex

[0058] Weigh: modified PVA 05-88 6 g of modified PVA, PVA 17-88 2 g of PVA, PVA 124 6 g of PVA and 330 mL of octanol are added to a flask and mixed to obtain a polyvinyl alcohol complex;

[0059] Weigh: 70 g of polyvinyl alcohol complex, 25 g of glycerol, and 1 g of vitamin C and add them to a flask and stir. Heat the temperature of the flask to 60 °C and perform ultrasonic dispersion for 50 min to obtain a film-forming agent complex.

[0060] S4. Preparation of Mentha arvensis oil

[0061] Weigh: 40 g of L-menthol, 5 g of D-menthol, 5 g of menthyl acetate and 10 g of menthone and add them to a flask. Raise the temperature of the flask to 50 °C and stir for 30 min to obtain a spice mixture;

[0062] Weigh: 2 g of pulegone and 3 g of β-caryophyllene and add them to the flask containing the spice mixture, and stir for 15 min to form a transparent oil-phase mixture;

[0063] Weigh: 30 g of film-forming agent complex and add it to the oil-phase mixture, and emulsify and disperse it at 50 °C for 20 min to obtain Mentha arvensis oil with good film-forming property.

[0064] Example 2

[0065] This example provides a preparation method of Mentha arvensis oil with good film-forming property, including the following steps:

[0066] S1. Preparation of modified chitosan

[0067] Mix chitosan and 1 wt% acetic acid and stir until the system becomes clear to obtain a 2 wt% chitosan acetate solution;

[0068] Weigh: 10 mL of 8 wt% aqueous solution of 2,3-epoxypropyltrimethylammonium chloride and 30 mL of 2 wt% chitosan acetate solution and add them to a flask. Raise the temperature of the flask to 55 °C and stir for 1.5 h, and then perform post-treatment to obtain modified chitosan.

[0069] S2. Preparation of modified PVA 05-88

[0070] Weigh: PVA 05-88 20 g, 20 g of epichlorohydrin and 0.1 g of tetrabutylammonium bromide are added to a flask and mixed and stirred. Raise the temperature of the flask to 70 °C, keep the temperature for reaction for 50 min, add 0.5 g of sodium hydroxide to the flask, keep the temperature for reaction for 180 min, and perform post-treatment to obtain epoxy PVA 05-88 ;

[0071] Weigh: epoxy PVA 05-88 5 g and 15 g of modified chitosan are added to a flask. Raise the temperature of the flask to 75 °C and stir for 3.5 h to obtain modified PVA 05-88 .

[0072] S3. Preparation of film-forming agent complex

[0073] Weigh: modified PVA 05-88 6 g, PVA 17-88 2 g, PVA 1246g and octanol - 330 mL were added to a flask and mixed to obtain a polyvinyl alcohol complex;

[0074] Weigh: 77 g of polyvinyl alcohol complex, 32 g of glycerol and 2 g of vitamin C were added to a flask and stirred. The temperature of the flask was heated to 65 °C and ultrasonic dispersion was carried out for 65 min to obtain a film - forming agent complex.

[0075] S4. Preparation of peppermint oil

[0076] Weigh: 50 g of L - menthol, 10 g of D - menthol, 10 g of methyl acetate and 15 g of menthone were added to a flask. The temperature of the flask was raised to 55 °C and stirred for 30 min to obtain a spice mixture;

[0077] Weigh: 5 g of pulegone and 5 g of β - caryophyllene were added to the flask containing the spice mixture and stirred for 15 min to form a transparent oil - phase mixture;

[0078] Weigh: 40 g of the film - forming agent complex was added to the oil - phase mixture and emulsified and dispersed at 50 °C for 25 min to obtain peppermint oil with good film - forming property.

[0079] Example 3

[0080] Chitosan and 1 wt% acetic acid were mixed and stirred until the system became clear to obtain a 2 wt% chitosan acetate solution;

[0081] This example provides a preparation method of peppermint oil with good film - forming property, including the following steps:

[0082] S1. Preparation of modified chitosan

[0083] Chitosan and 1 wt% acetic acid were mixed and stirred until the system became clear to obtain a 2 wt% chitosan acetate solution;

[0084] Weigh: 10 mL of 8 wt% aqueous solution of 2,3 - epoxypropyltrimethylammonium chloride and 30 mL of 2 wt% chitosan acetate solution were added to a flask. The temperature of the flask was raised to 60 °C and stirred for 2 h, and then post - treatment was carried out to obtain modified chitosan.

[0085] S2. Preparation of modified PVA 05-88

[0086] Weigh: 05-88 20 g of PVA, 20 g of epichlorohydrin and 0.1 g of tetrabutylammonium bromide were added to a flask and mixed and stirred. The temperature of the flask was raised to 75 °C and kept warm for reaction for 60 min. 0.5 g of sodium hydroxide was added to the flask and kept warm for reaction for 200 min, and then post - treatment was carried out to obtain epoxy PVA 05-88 ;

[0087] Weigh: epoxy PVA05-88 5 g of 5G and 15 g of modified chitosan were added to a flask. The temperature of the flask was raised to 80 °C and stirred for 4 h to obtain modified PVA. 05-88 。

[0088] S3. Preparation of film-forming agent complex

[0089] Weigh: Modified PVA 05-88 6 g, PVA 17-88 2 g, PVA 124 6 g and 330 mL of octanol were added to a flask and mixed to obtain a polyvinyl alcohol complex.

[0090] Weigh: 85 g of polyvinyl alcohol complex, 40 g of glycerol and 5 g of vitamin C were added to a flask and stirred. The temperature of the flask was heated to 70 °C and ultrasonically dispersed for 80 min to obtain a film-forming agent complex.

[0091] S4. Preparation of peppermint oil

[0092] Weigh: 60 g of L-menthol, 15 g of D-menthol, 15 g of menthyl acetate and 20 g of menthone were added to a flask. The temperature of the flask was raised to 60 °C and stirred for 30 min to obtain a spice mixture.

[0093] Weigh: 8 g of pulegone and 8 g of β-caryophyllene were added to the flask containing the spice mixture and stirred for 15 min to form a transparent oil-phase mixture.

[0094] Weigh: 50 g of the film-forming agent complex was added to the oil-phase mixture and emulsified and dispersed at 55 °C for 30 min to obtain peppermint oil with good film-forming properties.

[0095] Comparative Example 1

[0096] The difference between this comparative example and Example 3 is that step S1 was cancelled and the chitosan in step S1 was used to replace the modified chitosan in step S2.

[0097] Comparative Example 2

[0098] The difference between this comparative example and Example 3 is that in the process of preparing modified PVA in step S2 05-88 PVA was used to replace epoxy PVA 05-88 。 05-88 。

[0099] Comparative Example 3

[0100] The difference between this comparative example and Example 3 is that in step S3, PVA 17-88 and PVA 124 were not added.

[0101] Comparative Example 4

[0102] The difference between this comparative example and Example 3 is that in step S3, glycerol was not added.

[0103] Comparative Example 5

[0104] The difference between this comparative example and Example 3 is that in step S3, vitamin C was not added.

[0105] Performance test:

[0106] Referring to the standard SN / T 2162-2008 "Inspection Regulations for Chitosan Antibacterial Cotton Textiles", the antibacterial rates of the menthol oils with good film-forming properties prepared in Examples 1-3 and Comparative Examples 1-5 were determined;

[0107] Take 1 mL of the menthol oils prepared in Examples 1-3 and Comparative Examples 1-5 respectively, apply them to the skin of 4 cm × 4 cm, observe once every half minute, and record the film-forming time and the cooling time. The specific test results are shown in Table 1 below:

[0108] Table 1 - Data Sheet of Performance Detection of Samples

[0109]

[0110]

[0111] Data analysis:

[0112] By comparing and analyzing the data in Table 1 above, the antibacterial rate of the menthol oil with good film-forming properties prepared by the present invention is 99%, the film-forming time is 1.2 min, and the cooling time is 30 min;

[0113] Compared with the example, the antibacterial rate of the menthol oil in Comparative Example 1 was significantly improved, but the optimization of the film-forming time and the cooling time of the menthol oil was small, indicating that the modified chitosan can effectively improve the antibacterial property of the menthol oil;

[0114] Compared with the example, the cooling time of the menthol oil in Comparative Example 2 was significantly reduced, the film-forming time increased slightly, but the improvement of the antibacterial property was not significant, indicating that epoxy PVA 05-88 can significantly prolong the cooling time of the menthol oil;

[0115] Compared with the example, the film-forming time and the cooling time of the menthol oil in Comparative Example 3 were significantly optimized, but the improvement of the antibacterial rate was not significant, indicating that adding PVA 17-88 and PVA 124 to the polyvinyl alcohol composite can significantly shorten the film-forming time of the menthol oil and prolong the cooling time of the menthol oil;

[0116] Compared with the example, Comparative Example 4 optimizes the overall performance of peppermint oil. Glycerol mainly functions as a humectant and co-emulsifier, regulating the viscosity of peppermint oil while maintaining its evaporation rate, and extending its cooling time to a certain extent.

[0117] Compared with the example, Comparative Example 5 significantly shortens the cooling time of peppermint oil and also affects its antibacterial property, indicating that vitamin C can significantly enhance the antioxidant property of peppermint oil and extend its cooling duration.

[0118] The above are only examples and explanations of the structure of the present invention. Those skilled in the art of the present technology can make various modifications, supplements, or use similar methods to replace the specific embodiments described. As long as they do not deviate from the structure of the invention or exceed the scope defined by this claim book, they shall fall within the protection scope of the present invention.

Claims

1. A peppermint oil having good film-forming properties, characterized in that: The invention comprises the following components by weight: 40-60 parts of L-menthol, 5-15 parts of D-menthol, 5-15 parts of menthyl acetate, 10-20 parts of menthone, 2-8 parts of pulegone, 3-8 parts of β-caryophyllene and 30-50 parts of a film-forming agent complex; The film-forming agent complex comprises the following components by weight: 70-85 parts of polyvinyl alcohol complex, 25-40 parts of glycerol and 1-5 parts of vitamin C; The polyvinyl alcohol composite is composed of modified PVA 05-88 、PVA 17-88 、PVA 124 and octanol-3 in a dosage ratio of 3g:1g:3g:15mL.

2. The peppermint oil with good film-forming property according to claim 1, characterized in that Modified PVA 05-88 Prepared by the following steps: A1. Add 2,3-epoxypropyltrimethylammonium chloride aqueous solution into a flask containing chitosan acetic acid solution, raise the temperature of the flask to 50-60°C, stir for 1-2h, and post-treat to obtain modified chitosan; A2. PVA 05-88 , epichlorohydrin and tetrabutylammonium bromide are mixed and stirred, the temperature of the flask is raised to 65-75°C, and the reaction is kept warm for 40-60 minutes. Sodium hydroxide is added to the flask, and the reaction is kept warm for 160-200 minutes. After post-treatment, epoxy PVA is obtained. 05-88 ; A3, epoxy PVA 05-88 and modified chitosan were added into the flask, the flask temperature was raised to 70-80°C, and stirred for 3-4h to obtain modified PVA 05-88 .

3. The peppermint oil with good film-forming property according to claim 2, characterized in that In step A1, the volume ratio of the 2,3-epoxypropyltrimethylammonium chloride aqueous solution to the chitosan acetic acid solution is 1:3, the concentration of the 2,3-epoxypropyltrimethylammonium chloride aqueous solution is 8-10wt%, and the concentration of the chitosan acetic acid solution is 2-6wt%. The post-treatment includes: after the reaction is completed, adding ethanol to the flask, vacuum drying, and obtaining modified chitosan.

4. The peppermint oil with good film-forming property according to claim 2, characterized in that In step A2, PVA 05-88 , epichlorohydrin, tetrabutylammonium bromide and sodium hydroxide in an amount ratio of 30g:20g:0.1g:0.5g, and the post-treatment includes: after the reaction is completed, the flask temperature is kept at 65-75°C, the low-boiling substances are removed under reduced pressure, ethyl acetate is added to the flask, the flask temperature is lowered to room temperature, suction filtered, the filtrate is transferred to a rotary evaporator with a water bath temperature of 55°C, and the solvent is removed under reduced pressure to obtain epoxy PVA 05-88 .

5. The peppermint oil with good film-forming property according to claim 2, characterized in that: In step A3, epoxy PVA 05-88 The mass ratio of the modified chitosan to the modified chitosan is 1:

3. The post-treatment includes: after the reaction is completed, the composite is placed in a vacuum drying oven for drying after being allowed to stand for degassing to obtain the modified PVA. 05-88 .

6. The peppermint oil with good film-forming property according to claim 1, characterized in that The PVA 05-88 It is polyvinyl alcohol with a polymerization degree of 500-600 and an alcoholysis degree of 88%; PVA 17-88 It is polyvinyl alcohol with a degree of polymerization of 1700-1800 and a degree of alcoholysis of 88%; PVA 124 It is polyvinyl alcohol with a polymerization degree of 2400-2500 and an alcoholysis degree of 98%-99%.

7. The peppermint oil with good film-forming property according to claim 1, characterized in that The preparation method of the film-forming agent complex is as follows: polyvinyl alcohol complex, glycerol and vitamin C are added into a flask and stirred, the flask temperature is heated to 60-70° C., and ultrasonically dispersed for 50-80 minutes to obtain the film-forming agent complex.

8. The method for preparing the peppermint oil with good film-forming property according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Add L-menthol, D-menthol, menthyl acetate and menthone into a flask in sequence, raise the temperature of the flask to 50-60° C., and stir for 30 min to obtain a flavor mixture; S2. Add pulegone and β-caryophyllene to the flask containing the spice mixture, and continue stirring for 15 minutes to form a transparent oil phase mixture; S3. Add the film-forming agent complex into the flask containing the transparent oil phase mixture, emulsify and disperse it at 50-55° C. for 20-30 minutes to obtain peppermint oil with good film-forming properties.

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