Compound essential oil as well as preparation method and application thereof

Abstract

The invention discloses a preparation method of compound essential oil, and relates to the technical field of fine chemical engineering, the preparation method comprises the following steps: uniformly mixing base oil, a plant extract and an antioxidant to obtain a core material, the antioxidant being a composite system of resveratrol and vitamin E; preparing a composite wall material from chitosan and beta cyclodextrin, mixing the composite wall material with the core material, carrying out high-pressure microjet treatment, and adding sodium tripolyphosphate to crosslink and solidify the microcapsule wall, so as to obtain a microcapsule suspension; mixing the microcapsule suspension with EDTA-disodium and hyaluronic acid, and then cooling to 20-30 DEG C by adopting a gradient cooling method to obtain a microcapsule concentrated solution; and compounding the micro-capsule concentrated solution, grape seed oil and a preservative, filtering through a 0.20-0.25 mu m microporous membrane, and then filling nitrogen and packaging.

Description

Technical Field

[0001] The invention relates to the technical field of fine chemical industry, and in particular to a method for preparing compound essential oil based on nano-microcapsule sustained-release technology and natural antioxidant formula. Background Art

[0002] In modern life, essential oils are widely used in massage, aromatherapy and skin care due to their unique aroma and multiple benefits, such as relieving stress, improving sleep, and nourishing the skin. However, traditional essential oils have exposed many defects in actual application, which seriously limit their performance and usage experience.

[0003] First, the volatilization rate of traditional essential oils is too fast, and their efficacy usually declines significantly within 1-2 hours. This means that users need to reapply frequently during use, which not only increases the cost of use, but also brings a lot of inconvenience to users. For example, when using traditional essential oils for aromatherapy, essential oils need to be added continuously to maintain the ideal aroma concentration, which not only wastes resources, but also destroys the continuity and comfort of the aromatherapy. In the application of massage oil, frequent reapplication will affect the smoothness and comfort of the massage, reducing user satisfaction.

[0004] Secondly, traditional essential oils are prone to oxidation and deterioration, and have a short shelf life of only 1-2 years. They are also extremely unstable in high temperature environments. Oxidative deterioration not only causes the loss of the aroma and efficacy of essential oils, but may also produce substances that are harmful to the human body. During storage and transportation, traditional essential oils need to strictly control temperature and light conditions, otherwise they are prone to deterioration. This not only increases the storage and transportation costs of the company, but also poses potential safety hazards to consumers. For example, in high temperature environments in summer, traditional essential oils are prone to oxidation reactions, resulting in darker colors, changes in odor, and may even cause adverse reactions such as skin allergies.

[0005] Furthermore, there are obvious deficiencies in the microencapsulation technology in the prior art. Microencapsulation technology is an important means to improve the stability of essential oils and prolong their efficacy, but the current microencapsulation technology has a low encapsulation rate, usually less than 85%, and the particle size is uneven, greater than 200nm. The low encapsulation rate means that a large amount of essential oils have not been effectively encapsulated, and are easily volatilized or oxidized in the external environment, and the advantages of microencapsulation cannot be fully utilized. Uneven particle size will affect the stability and release performance of the microcapsules, resulting in an unstable release rate of the essential oils and the inability to achieve precise control. For example, using microencapsulated essential oils with uneven particle size in skin care products may cause the essential oils to be unevenly distributed on the skin surface, affecting the absorption effect and skin care efficacy.

[0006] In the prior art, chitosan or β-cyclodextrin is used alone as a wall material, and the coating effect is limited. Although chitosan has good biocompatibility and certain film-forming properties, its coating ability is relatively weak and cannot effectively prevent the volatilization and oxidation of essential oils. β-cyclodextrin has a hydrophobic cavity and can coat essential oil molecules, but its coating amount is limited and it is easy to leak when the external environment changes. In addition, it is difficult to achieve synergistic effect by using a single antioxidant in the prior art. A single antioxidant can often only play a role against a specific type of free radical and cannot fully inhibit the oxidation reaction of essential oils. For example, using vitamin E alone as an antioxidant, although it can effectively remove lipid free radicals, it is not effective for other types of free radicals such as hydroxyl radicals, and cannot achieve comprehensive protection of essential oils. Summary of the invention

[0007] The present invention provides a method for preparing a compound essential oil based on nano-microcapsule sustained-release technology and a natural antioxidant formula. The method significantly improves the sustained-release performance, antioxidant capacity and shelf life of the essential oil by optimizing the nano-microcapsule preparation process, the antioxidant compounding system and the stability control technology. The essential oil is suitable for massage oil, aromatherapy liquid and skin care products.

[0008] The technical solution adopted by the present invention is as follows:

[0009] A method for preparing a compound essential oil comprises the following steps:

[0010] Step 1, pre-treatment of raw materials, uniformly mixing base oil, plant extract and antioxidant to obtain core material, wherein the antioxidant is a composite system of resveratrol and vitamin E;

[0011] Step 2, nano-microcapsule preparation, using chitosan and β-cyclodextrin to form a composite wall material, mixing it with the core material, and after high-pressure microfluidization treatment, adding sodium tripolyphosphate to cross-link and solidify the microcapsule wall to obtain a microcapsule suspension;

[0012] Step 3, stabilization treatment, mixing the microcapsule suspension with EDTA-disodium and hyaluronic acid, and then cooling to 20-30° C. using a gradient cooling method to obtain a microcapsule concentrate;

[0013] Step 4, finished product preparation, the microcapsule concentrate, grape seed oil and preservatives are compounded, filtered through a 0.20-0.25 μm microporous membrane, and then filled with nitrogen and packaged to obtain a finished compound essential oil.

[0014] Specifically, in step 1, the mass ratio of the base oil, the plant extract and the antioxidant is (2.5-3.5):(0.8-1.2):(0.6-1.0), and the mixing method is stirring at 35-45°C and 250-350rpm for 20-40 minutes.

[0015] Specifically, in step 1, the base oil is lavender oil or tea tree oil; and the plant extract is asiatica glycoside or glycyrrhizic acid.

[0016] Specifically, in step 1, the antioxidant consists of 0.4-0.6% resveratrol and 0.2-0.4% vitamin E, and the mass ratio of resveratrol to vitamin E is 1.2-1.8:1.

[0017] Specifically, in step 2, the mass ratio of chitosan to β-cyclodextrin is 1.5-2.5:1; the mass ratio of the composite wall material to the core material is 1:4-6; the number of high-pressure microfluidization treatments is 2-4, and the pressure is 140-160 MPa; after the high-pressure microfluidization treatment, 0.08-0.12% sodium tripolyphosphate is added to cross-link and solidify under pH 5.0-6.0.

[0018] Specifically, in step 3, the microcapsule suspension is mixed with 0.03-0.07% EDTA-disodium and 0.8-1.2% hyaluronic acid, and the gradient cooling rate is 5-8° C. / h.

[0019] Specifically, in step 4, the mass ratio of the microcapsule concentrate, grape seed oil and preservative is (5-7):(2-4):(0.8-1.2), and the preservative is 0.8-1.2% sodium benzoate.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1) It has a synergistic coating system. The cationic properties of chitosan and the hydrophobic cavity of β-cyclodextrin form a double coating structure. The essential oil release curve conforms to the Higuchi kinetic model (R 2 >0.98).

[0022] 2) It has an antioxidant synergistic mechanism. Resveratrol (phenolic hydroxyl donor) and vitamin E (free radical quencher) produce a redox potential difference, inhibiting the degradation of active ingredients, and the ORAC value is increased to 12000μmol TE / g.

[0023] 3) The present invention realizes controlled release of microcapsules, that is, the porosity of the wall material is precisely controlled by adjusting the concentration of the crosslinking agent to achieve 0.8-1.2 mg / cm 2 h, and the gradient cooling combined with hyaluronic acid and EDTA-disodium inhibited the aggregation of microcapsules (PDI≤0.25).

[0024] 4) The compound essential oil prepared by the present invention has significantly better microcapsule performance (encapsulation rate reaches 93.7%, particle size is more uniform, average particle size is 52.3±3.8nm, sustained release time is 6.8 hours), antioxidant stability (DPPH clearance rate after accelerated test (40°C / 75%RH, 6 months) is ≥95%, peroxide value is ≤5meq / kg) and shelf life (up to 36 months under 25°C dark conditions), which are significantly better than conventional essential oils (12-24 months) and are greatly improved.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the embodiments of the present invention are specifically cited below and described in detail as follows. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0027] Example 1

[0028] The embodiment of the present invention provides a method for preparing a compound essential oil, comprising the following steps:

[0029] Step 1: Raw material pretreatment

[0030] Base oil (lavender oil), plant extract (asiaticoside) and antioxidant (resveratrol (0.5%) and vitamin E (0.3%) compounded in a mass ratio of 1.5:1) were weighed in a mass ratio of 3:1:1, and stirred at 300 rpm for 30 minutes at a constant temperature of 40°C to form a homogeneous mixed phase to obtain a core material.

[0031] Step 2, nanocapsule preparation

[0032] Chitosan and β-cyclodextrin were mixed in a mass ratio of 2:1 to form a composite wall material, and the composite wall material and the core material were mixed in a mass ratio of 1:5. Nanoemulsion droplets were prepared by high-pressure microfluidization technology (160MPa, 3 cycles), and sodium tripolyphosphate with a concentration of 0.1% was added thereto. The microcapsule wall was cross-linked and solidified at pH 5.5 to obtain a microcapsule suspension.

[0033] Step 3: Stabilization

[0034] The microcapsule suspension was mixed with 0.5% EDTA-disodium and 1% hyaluronic acid, and then a phase transition stabilization was achieved by gradient cooling (60°C→25°C, cooling rate 5°C / h) to obtain a microcapsule concentrate.

[0035] Step 4: Finished product preparation

[0036] The microcapsule concentrate, grape seed oil and preservative (sodium benzoate with a concentration of 1%) are compounded in a mass ratio of 6:3:1, filtered through a 0.22 μm microporous membrane, and then filled with nitrogen (oxygen content <0.5%) to obtain a compound essential oil.

[0037] Example 2

[0038] The embodiment of the present invention provides a method for preparing a compound essential oil, comprising the following steps:

[0039] Step 1: Raw material pretreatment

[0040] Base oil (tea tree oil), plant extract (glycyrrhizic acid) and antioxidant (resveratrol (0.4%) and vitamin E (0.2%) compounded in a mass ratio of 1.2:1) were weighed in a mass ratio of 2.5:0.8:0.6, and stirred at 250 rpm for 20 minutes at a constant temperature of 35°C to form a homogeneous mixed phase to obtain a core material.

[0041] Step 2, nanocapsule preparation

[0042] Chitosan and β-cyclodextrin were mixed in a mass ratio of 1.5:1 to form a composite wall material, and the composite wall material and the core material were mixed in a mass ratio of 1:4. Nanoemulsion droplets were prepared by high-pressure microfluidization technology (150MPa, 2 cycles), and sodium tripolyphosphate with a concentration of 0.08% was added thereto. The microcapsule wall was cross-linked and solidified at pH 5.0 to obtain a microcapsule suspension.

[0043] Step 3: Stabilization

[0044] The microcapsule suspension was mixed with 0.03% EDTA-disodium and 0.8% hyaluronic acid, and then a gradient cooling (60°C→20°C, cooling rate 8°C / h) was used to achieve phase transition stabilization to obtain a microcapsule concentrate.

[0045] Step 4: Finished product preparation

[0046] The microcapsule concentrate, grape seed oil and preservative (1.2% sodium benzoate) are compounded in a mass ratio of 5:4:0.8, filtered through a 0.20 μm microporous membrane and then nitrogen-filled and packaged (oxygen content <0.5%) to obtain a compound essential oil.

[0047] Example 3

[0048] The embodiment of the present invention provides a method for preparing a compound essential oil, comprising the following steps:

[0049] Step 1: Raw material pretreatment

[0050] Base oil (a mixture of lavender oil and tea tree oil), plant extract (a mixture of Centella asiatica and glycyrrhizic acid) and antioxidant (resveratrol (0.6%) and vitamin E (0.4%) compounded in a mass ratio of 1.8:1) were weighed in a mass ratio of 3.5:1.2:1, and stirred at 350 rpm for 40 minutes at a constant temperature of 45°C to form a homogeneous mixed phase to obtain a core material.

[0051] Step 2, nanocapsule preparation

[0052] Chitosan and β-cyclodextrin were mixed in a mass ratio of 2.5:1 to form a composite wall material, and the composite wall material and the core material were mixed in a mass ratio of 1:6. Nanoemulsion droplets were prepared using high-pressure microfluidization technology (140MPa, 4 cycles), and sodium tripolyphosphate with a concentration of 0.12% was added thereto. The microcapsule wall was cross-linked and solidified at pH 6.0 to obtain a microcapsule suspension.

[0053] Step 3: Stabilization

[0054] The microcapsule suspension was mixed with 0.07% EDTA-disodium and 1.2% hyaluronic acid, and then phase transition stabilization was achieved by gradient cooling (60°C → 30°C, cooling rate 6.5°C / h) to obtain a microcapsule concentrate.

[0055] Step 4: Finished product preparation

[0056] The microcapsule concentrate, grape seed oil and preservative (0.8% sodium benzoate) are compounded in a mass ratio of 7:2:1.2, filtered through a 0.25 μm microporous membrane, and then filled with nitrogen (oxygen content <0.5%) to obtain a compound essential oil.

[0057] The compound essential oils prepared in Examples 1, 2 and 3 were tested, and the technical parameters were shown in Tables 1, 2 and 3 respectively:

[0058] Table 1

[0059]

[0060] Table 2

[0061]

[0062] Table 3

[0063]

[0064] The compound essential oils prepared in Examples 1, 2 and 3 are all well applicable to the fields of SPA massage, aromatherapy diffusion and skin care products.

[0065] The compound essential oil prepared in Example 1 was blended into the jojoba oil matrix in an addition amount of 10% to obtain No. 1 SPA massage oil.

[0066] The compound essential oil prepared in Example 2 was blended into the jojoba oil matrix in an addition amount of 10% to obtain No. 2 SPA massage oil.

[0067] The compound essential oil prepared in Example 3 was blended into the jojoba oil matrix in an addition amount of 10% to obtain No. 3 SPA massage oil.

[0068] In clinical tests, SPA massage oils No. 1, 2, and 3 all showed an increase in skin moisture content by more than 32%, and the muscle relaxation effect lasted for ≥ 7.2 hours (EMG electromyography monitoring).

[0069] The compound essential oils prepared in Examples 1, 2 and 3 were used as aromatherapy liquids. Their aroma intensity half-lives in an ultrasonic diffuser were all ≥ 6.5 hours (GC-MS dynamic monitoring), and the residual amounts of benzene volatiles were all < 0.1 ppm (in compliance with IFRA standards).

[0070] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a compound essential oil, characterized in that: include: Step 1, pre-treatment of raw materials, uniformly mixing base oil, plant extract and antioxidant to obtain core material, wherein the antioxidant is a composite system of resveratrol and vitamin E; Step 2, nano-microcapsule preparation, using chitosan and β-cyclodextrin to form a composite wall material, mixing it with the core material, and after high-pressure microfluidization treatment, adding sodium tripolyphosphate to cross-link and solidify the microcapsule wall to obtain a microcapsule suspension; Step 3, stabilization treatment, mixing the microcapsule suspension with EDTA-disodium and hyaluronic acid, and then cooling to 20-30° C. using a gradient cooling method to obtain a microcapsule concentrate; Step 4, finished product preparation, the microcapsule concentrate, grape seed oil and preservatives are compounded, filtered through a 0.20-0.25 μm microporous membrane and then nitrogen-filled and packaged.

2. The preparation method according to claim 1, characterized in that: In step 1, the mass ratio of the base oil, the plant extract and the antioxidant is (2.5-3.5):(0.8-1.2):(0.6-1.0), and the mixing method is stirring at 35-45° C. and 250-350 rpm for 20-40 minutes.

3. The preparation method according to claim 1, characterized in that: In step 1, the base oil is lavender oil or tea tree oil; and the plant extract is asiatica glycoside or glycyrrhizic acid.

4. The preparation method according to claim 1, characterized in that: In step 1, the antioxidant consists of 0.4-0.6% resveratrol and 0.2-0.4% vitamin E, and the mass ratio of resveratrol to vitamin E is 1.2-1.8:

1.

5. The preparation method according to claim 1, characterized in that: In step 2, the mass ratio of chitosan to β-cyclodextrin is 1.5-2.5:1; the mass ratio of the composite wall material to the core material is 1:4-6; the number of high-pressure microfluidization treatments is 2-4, and the pressure is 140-160 MPa; after the high-pressure microfluidization treatment, 0.08-0.12% sodium tripolyphosphate is added to cross-link and solidify under pH 5.0-6.

0.

6. The preparation method according to claim 1, characterized in that: In step 3, the microcapsule suspension is mixed with 0.03-0.07% EDTA-disodium and 0.8-1.2% hyaluronic acid, and the gradient cooling rate is 5-8° C. / h.

7. The preparation method according to claim 1, characterized in that: In step 4, the mass ratio of the microcapsule concentrate, grape seed oil and preservative is (5-7):(2-4):(0.8-1.2), and the preservative is 0.8-1.2% sodium benzoate.

8. A compound essential oil, characterized in that: It is prepared based on the preparation method according to any one of claims 1 to 7.

9. The compound essential oil according to claim 8 is used to prepare SPA massage oil, or as a skin care product matrix, or as an aromatherapy liquid.

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